[pgpool-hackers: 383] Re: Exception Manager for pgpool

Tatsuo Ishii ishii at postgresql.org
Sat Oct 26 10:30:05 JST 2013


> Hi Tatsuo
> 
> 
> On Wed, Oct 23, 2013 at 2:46 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
> 
>> Usama,
>>
>> I still don't know why my gcc complains but I found a solution.
>> I have made changes to src/include/parser/pool_parser.h.
>>
>> I added #include "postgres_ext.h".
>>
>> Then remove this because PoolOid seems not to be used anywhere in
>> pgpool-II.
>>
>> typedef unsigned int PoolOid;
>>
>> So I removed this too.
>>
>> #define Oid PoolOid
>>
>> Then running the regression test, I found two tests failed.
>>
>> testing 056.bug63...failed.
>> testing 058.bug68...failed.
>>
>> Theses tests are passed in master branch head. I will look into this
>> more.
>>
>> Anyway I think your patch goes to the right direction.
>>
> 
> Thanks for looking into this issue and the patch. I am working on the next
> todo for this task, and will also look into the regression failures you are
> getting. Can you please create a separate branch for this work so that bugs
> and new todos for this task can become granule and easier to manage and
> review, and once we will get this thing stable we will merge it to the
> master branch.

I have made a patch for this. Please take a look at.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp

>> Maybe now is the time to add Usama to one of pgpool-II committers?
>>
> 
> Thanks
> Muhammad Usama
> 
> 
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese: http://www.sraoss.co.jp
>>
>> >> Hi Tatsuo
>> >>
>> >> I have been trying to reproduce this compilation issue but unable to do
>> so.
>> >> I have compiled the patched code with GCC 4.6.3 and also with
>> >> LLVM 5.0 and in both case I am able to successfully compile the code.
>> >> Can you please guide me to reproduce the issue at my end as the Oid
>> >> definition which is conflicting at your end is not changed by the patch.
>> >
>> > No idea. I just type "make" and got the error.
>> >
>> >> here is the gcc log of files compilation,
>> >>
>> >> gcc -DHAVE_CONFIG_H
>> >>
>> -DDEFAULT_CONFIGDIR=\"/home/usama/EDB/pgpool/elog_work/mypgpool/test/comanddel/installed/etc\"
>> >> -I. -I../src/include  -D_GNU_SOURCE -I
>> /home/usama/EDB/PG/installed/include
>> >>   -O0 -g3 -Wall -Wmissing-prototypes -Wmissing-declarations -MT
>> main/main.o
>> >> -MD -MP -MF $depbase.Tpo -c -o main/main.o main/main.c &&\
>> >> mv -f $depbase.Tpo $depbase.Po
>> >> main/main.c: In function ‘daemonize’:
>> >> main/main.c:384:17: warning: variable ‘rc_chdir’ set but not used
>> >> [-Wunused-but-set-variable]
>> >> depbase=`echo main/pgpool_main.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
>> >> gcc -DHAVE_CONFIG_H
>> >>
>> -DDEFAULT_CONFIGDIR=\"/home/usama/EDB/pgpool/elog_work/mypgpool/test/comanddel/installed/etc\"
>> >> -I. -I../src/include  -D_GNU_SOURCE -I
>> /home/usama/EDB/PG/installed/include
>> >>   -O0 -g3 -Wall -Wmissing-prototypes -Wmissing-declarations -MT
>> >> main/pgpool_main.o -MD -MP -MF $depbase.Tpo -c -o main/pgpool_main.o
>> >> main/pgpool_main.c &&\
>> >> mv -f $depbase.Tpo $depbase.Po
>> >> main/pgpool_main.c: In function ‘find_primary_node’:
>> >> main/pgpool_main.c:1981:14: warning: variable ‘status’ set but not used
>> >> [-Wunused-but-set-variable]
>> >> ..
>> >>
>> >> pgpool2$ gcc --version
>> >> gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
>> >> Copyright (C) 2011 Free Software Foundation, Inc.
>> >>
>> >> And on OS/X the compilation is also successfull.
>> >> gcc --version
>> >> Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr
>> >> --with-gxx-include-dir=/usr/include/c++/4.2.1
>> >> Apple LLVM version 5.0 (clang-500.2.76) (based on LLVM 3.3svn)
>> >> Target: x86_64-apple-darwin12.5.0
>> >>
>> >> Thanks
>> >> Usama
>> >>
>> >>
>> >>
>> >> On Sat, Oct 12, 2013 at 5:41 AM, Tatsuo Ishii <ishii at postgresql.org>
>> wrote:
>> >>
>> >>> I have freshly checkout git master and applied your patch.
>> >>> I got this:
>> >>>
>> >>>         gcc -DHAVE_CONFIG_H -DDEFAULT_CONFIGDIR=\"/home/t-ishii/work/
>> >>>
>> git.postgresql.org/exception/pgpool2/src/test/regression/temp/installed/etc\
>> "
>> >>> -I. -I../src/include  -D_GNU_SOURCE -I /usr/local/pgsql/include   -g
>> -O2
>> >>> -Wall -Wmissing-prototypes -Wmissing-declarations -MT
>> main/pgpool_main.o
>> >>> -MD -MP -MF $depbase.Tpo -c -o main/pgpool_main.o main/pgpool_main.c
>> &&\
>> >>>         mv -f $depbase.Tpo $depbase.Po
>> >>> In file included from /usr/local/pgsql/include/libpq-fe.h:29,
>> >>>                  from ../src/include/pool.h:34,
>> >>>                  from main/pgpool_main.c:51:
>> >>> /usr/local/pgsql/include/postgres_ext.h:31: error: redefinition of
>> typedef
>> >>> ‘PoolOid’
>> >>> ../src/include/parser/pool_parser.h:43: note: previous declaration of
>> >>> ‘PoolOid’ was here
>> >>>
>> >>> This is caused by the conflict in postgres_ext.h:
>> >>> typedef unsigned int Oid;
>> >>>
>> >>> and
>> >>>
>> >>> ./include/parser/pool_parser.h:typedef unsigned int PoolOid;
>> >>> ./include/parser/pool_parser.h:#define Oid PoolOid
>> >>>
>> >>> This is gcc 4.4.5.
>> >>> --
>> >>> Tatsuo Ishii
>> >>> SRA OSS, Inc. Japan
>> >>> English: http://www.sraoss.co.jp/index_en.php
>> >>> Japanese: http://www.sraoss.co.jp
>> >>>
>> >>> > Hi
>> >>> >
>> >>> > Seems like the repository was changed after I had generated the
>> patch.
>> >>> > Please find the updated patch rebased with the current state of git.
>> >>> >
>> >>> >
>> >>> > Thanks
>> >>> > Usama
>> >>> >
>> >>> >
>> >>> >
>> >>> > On Fri, Oct 11, 2013 at 9:47 AM, Ahsan Hadi <
>> ahsan.hadi at enterprisedb.com
>> >>> >wrote:
>> >>> >
>> >>> >> Usama,
>> >>> >> Please take a look.
>> >>> >>
>> >>> >> Tatsuo,
>> >>> >> I was apply to apply this patch cleanly on pgpool master and test
>> before
>> >>> >> Usama sent the patch. It is likely that we have done some changes
>> to the
>> >>> >> master branch since then..
>> >>> >>
>> >>> >>
>> >>> >> On Fri, Oct 11, 2013 at 4:03 AM, Tatsuo Ishii <ishii at postgresql.org
>> >>> >wrote:
>> >>> >>
>> >>> >>> Usama,
>> >>> >>>
>> >>> >>> I have applied your patch and got following error:
>> >>> >>>
>> >>> >>> Hunk #12 FAILED at 499.
>> >>> >>> 1 out of 12 hunks FAILED -- saving rejects to file
>> src/main/main.c.rej
>> >>> >>>
>> >>> >>> I also attached main.c.rej.
>> >>> >>> --
>> >>> >>> Tatsuo Ishii
>> >>> >>> SRA OSS, Inc. Japan
>> >>> >>> English: http://www.sraoss.co.jp/index_en.php
>> >>> >>> Japanese: http://www.sraoss.co.jp
>> >>> >>>
>> >>> >>> > Muhammad,
>> >>> >>> >
>> >>> >>> > Thank you for your great work! I'll look into this.
>> >>> >>> > --
>> >>> >>> > Tatsuo Ishii
>> >>> >>> > SRA OSS, Inc. Japan
>> >>> >>> > English: http://www.sraoss.co.jp/index_en.php
>> >>> >>> > Japanese: http://www.sraoss.co.jp
>> >>> >>> >
>> >>> >>> >> Hi
>> >>> >>> >>
>> >>> >>> >> I am working on adding the exception manager in pgpool and my
>> plan
>> >>> of
>> >>> >>> >> action for this is to use the Postgres exception manager API
>> (elog
>> >>> and
>> >>> >>> >> friends). Since the exception manager in Postgres uses the long
>> >>> jump,
>> >>> >>> so
>> >>> >>> >> importing this API in pgpool will effect all existing pgpool
>> code
>> >>> flows
>> >>> >>> >> especially in case of an error. and lot of care will be
>> required for
>> >>> >>> this
>> >>> >>> >> integration, and secondly the elog API along with its friends
>> will
>> >>> >>> touch
>> >>> >>> >> almost all parts of pgpool source code which will add up to a
>> very
>> >>> huge
>> >>> >>> >> patch.
>> >>> >>> >> So instead throwing a very huge patch to the community my plan
>> is to
>> >>> >>> divide
>> >>> >>> >> this task into multiple smaller sub tasks so that it would be
>> easier
>> >>> >>> >> maintain and review the patch.
>> >>> >>> >>
>> >>> >>> >> Cut to the chase, attached is the  first of the series of
>> related
>> >>> >>> patches
>> >>> >>> >> to come.This is the first cut patch for implementing the
>> exception
>> >>> >>> manager
>> >>> >>> >> in pgpool. As described above the exception manager and related
>> >>> code is
>> >>> >>> >> borrowed from PostgreSQL source code.
>> >>> >>> >> and the exception manager (elog API) is very closely tied with
>> >>> memory
>> >>> >>> >> manager in PostgreSQL (palloc API) so the patch also borrows the
>> >>> PG's
>> >>> >>> >> memory manager.
>> >>> >>> >>
>> >>> >>> >> Below is the little description of things part of this patch.
>> >>> >>> >>
>> >>> >>> >> -- Exception manager API of Postgres is added to pgpool, The API
>> >>> >>> consists
>> >>> >>> >> of elog.c and elog.h files. Since this API is very extensive
>> and is
>> >>> >>> >> designed for PostgreSQL so to fit it properly into pgpool I have
>> >>> >>> modified
>> >>> >>> >> it a little bit, and most of the modifications are related to
>> >>> removal
>> >>> >>> of
>> >>> >>> >> code which is not required for pgpool.
>> >>> >>> >>
>> >>> >>> >> -- Added on_proc_exit callback mechanism of Postgres. To
>> facilitate
>> >>> the
>> >>> >>> >> cleanup at exit time.
>> >>> >>> >>
>> >>> >>> >> -- Added PostgreSQL's memory manager (palloc API). This
>> includes the
>> >>> >>> client
>> >>> >>> >> side palloc functions placed in 'src/tools' directory
>> (fe_memutils)
>> >>> >>> >>
>> >>> >>> >> -- Removed the existing memory manager which was very
>> minimalistic
>> >>> and
>> >>> >>> was
>> >>> >>> >> not integrated in all parts of the code.
>> >>> >>> >>
>> >>> >>> >> -- I have also tried to reflector some portions of code to make
>> the
>> >>> >>> code
>> >>> >>> >> more readable at first glance. This includes
>> >>> >>> >>
>> >>> >>> >> - dividing the main.c file into two files main.c and
>> pgpool_main.c,
>> >>> >>> Now the
>> >>> >>> >> main.c file only contains the code related to early
>> initialisations
>> >>> of
>> >>> >>> >> pgpool and parsing the command line options and related code.
>> The
>> >>> >>> actual
>> >>> >>> >> logic of the pgpool main process is moved to new pgpool_main.c
>> file.
>> >>> >>> >> - breaking up some large functions in child.c into smaller
>> >>> functions.
>> >>> >>> >> - rewrite the pgpool's main loop logic to make the code more
>> >>> readable.
>> >>> >>> >>
>> >>> >>> >>
>> >>> >>> >> Remaining TODOs on this front.
>> >>> >>> >>
>> >>> >>> >> -- The current patch only integrates the memory and exception
>> >>> manager
>> >>> >>> in
>> >>> >>> >> main process and connection creation segment of pgpool child
>> >>> process.
>> >>> >>> >> integration of newly added APIs in pcp and worker child process
>> >>> codes
>> >>> >>> will
>> >>> >>> >> be done be next patch.
>> >>> >>> >>
>> >>> >>> >> -- Integration of newly added API into query processor logic in
>> >>> child
>> >>> >>> >> process. ( this will be the toughest part)
>> >>> >>> >>
>> >>> >>> >> -- elog.c and elog.h files needs some cleanups and changes ( to
>> >>> remove
>> >>> >>> >> unwanted functions and data members of ErrorData structure) but
>> this
>> >>> >>> will
>> >>> >>> >> be done at the end when we will have 100% surety if something in
>> >>> there
>> >>> >>> is
>> >>> >>> >> required or not.
>> >>> >>> >>
>> >>> >>> >>
>> >>> >>> >> Thanks
>> >>> >>> >> Muhammad Usama
>> >>> >>> > _______________________________________________
>> >>> >>> > pgpool-hackers mailing list
>> >>> >>> > pgpool-hackers at pgpool.net
>> >>> >>> > http://www.pgpool.net/mailman/listinfo/pgpool-hackers
>> >>> >>>
>> >>> >>> --- src/main/main.c
>> >>> >>> +++ src/main/main.c
>> >>> >>> @@ -499,1915 +-23,60 @@
>> >>> >>>         fd = open(pool_config->pid_file_name, O_CREAT|O_WRONLY,
>> >>> >>> S_IRUSR|S_IWUSR);
>> >>> >>>         if (fd == -1)
>> >>> >>>         {
>> >>> >>> -               pool_error("could not open pid file as %s. reason:
>> %s",
>> >>> >>> -                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno));
>> >>> >>> -               pool_shmem_exit(1);
>> >>> >>> -               exit(1);
>> >>> >>> +               ereport(FATAL,
>> >>> >>> +                       (errmsg("could not open pid file as %s.
>> reason:
>> >>> >>> %s",
>> >>> >>> +                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno))));
>> >>> >>>         }
>> >>> >>>         snprintf(pidbuf, sizeof(pidbuf), "%d", (int)getpid());
>> >>> >>>         if (write(fd, pidbuf, strlen(pidbuf)+1) == -1)
>> >>> >>>         {
>> >>> >>> -               pool_error("could not write pid file as %s. reason:
>> >>> %s",
>> >>> >>> -                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno));
>> >>> >>>                 close(fd);
>> >>> >>> -               pool_shmem_exit(1);
>> >>> >>> -               exit(1);
>> >>> >>> +               ereport(FATAL,
>> >>> >>> +                       (errmsg("could not write pid file as %s.
>> >>> reason:
>> >>> >>> %s",
>> >>> >>> +                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno))));
>> >>> >>>         }
>> >>> >>>         if (fsync(fd) == -1)
>> >>> >>>         {
>> >>> >>> -               pool_error("could not fsync pid file as %s. reason:
>> >>> %s",
>> >>> >>> -                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno));
>> >>> >>>                 close(fd);
>> >>> >>> -               pool_shmem_exit(1);
>> >>> >>> -               exit(1);
>> >>> >>> +               ereport(FATAL,
>> >>> >>> +                       (errmsg("could not fsync pid file as %s.
>> >>> reason:
>> >>> >>> %s",
>> >>> >>> +                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno))));
>> >>> >>>         }
>> >>> >>>         if (close(fd) == -1)
>> >>> >>>         {
>> >>> >>> -               pool_error("could not close pid file as %s. reason:
>> >>> %s",
>> >>> >>> -                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno));
>> >>> >>> -               pool_shmem_exit(1);
>> >>> >>> -               exit(1);
>> >>> >>> +               ereport(FATAL,
>> >>> >>> +                       (errmsg("could not close pid file as %s.
>> >>> reason:
>> >>> >>> %s",
>> >>> >>> +                                  pool_config->pid_file_name,
>> >>> >>> strerror(errno))));
>> >>> >>>         }
>> >>> >>> +       /* register the call back to delete the pid file at system
>> >>> exit */
>> >>> >>> +       on_proc_exit(FileUnlink, (Datum)
>> pool_config->pid_file_name);
>> >>> >>>  }
>> >>> >>>
>> >>> >>>  /*
>> >>> >>> -* Read the status file
>> >>> >>> -*/
>> >>> >>> -static int read_status_file(bool discard_status)
>> >>> >>> + * get_config_file_name: return full path of pgpool.conf.
>> >>> >>> + */
>> >>> >>> +char *get_config_file_name(void)
>> >>> >>>  {
>> >>> >>> -       FILE *fd;
>> >>> >>> -       char fnamebuf[POOLMAXPATHLEN];
>> >>> >>> -       int i;
>> >>> >>> -       bool someone_wakeup = false;
>> >>> >>> -
>> >>> >>> -       snprintf(fnamebuf, sizeof(fnamebuf), "%s/%s",
>> >>> >>> pool_config->logdir, STATUS_FILE_NAME);
>> >>> >>> -       fd = fopen(fnamebuf, "r");
>> >>> >>> -       if (!fd)
>> >>> >>> -       {
>> >>> >>> -               pool_log("Backend status file %s does not exist",
>> >>> >>> fnamebuf);
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * If discard_status is true, unlink pgpool_status and
>> >>> >>> -        * do not restore previous status.
>> >>> >>> -        */
>> >>> >>> -       if (discard_status)
>> >>> >>> -       {
>> >>> >>> -               fclose(fd);
>> >>> >>> -               if (unlink(fnamebuf) == 0)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("Backend status file %s
>> discarded",
>> >>> >>> fnamebuf);
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       pool_error("Failed to discard backend
>> status
>> >>> file
>> >>> >>> %s reason:%s", fnamebuf, strerror(errno));
>> >>> >>> -               }
>> >>> >>> -               return 0;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (fread(&backend_rec, 1, sizeof(backend_rec), fd) !=
>> >>> >>> sizeof(backend_rec))
>> >>> >>> -       {
>> >>> >>> -               pool_error("Could not read backend status file as
>> %s.
>> >>> >>> reason: %s",
>> >>> >>> -                                  fnamebuf, strerror(errno));
>> >>> >>> -               fclose(fd);
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -       fclose(fd);
>> >>> >>> -
>> >>> >>> -       for (i=0;i< pool_config->backend_desc->num_backends;i++)
>> >>> >>> -       {
>> >>> >>> -               if (backend_rec.status[i] == CON_DOWN)
>> >>> >>> -               {
>> >>> >>> -                       BACKEND_INFO(i).backend_status = CON_DOWN;
>> >>> >>> -                       pool_log("read_status_file: %d th backend
>> is
>> >>> set
>> >>> >>> to down status", i);
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       BACKEND_INFO(i).backend_status =
>> >>> CON_CONNECT_WAIT;
>> >>> >>> -                       someone_wakeup = true;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * If no one woke up, we regard the status file bogus
>> >>> >>> -        */
>> >>> >>> -       if (someone_wakeup == false)
>> >>> >>> -       {
>> >>> >>> -               for (i=0;i<
>> >>> pool_config->backend_desc->num_backends;i++)
>> >>> >>> -               {
>> >>> >>> -                       BACKEND_INFO(i).backend_status =
>> >>> CON_CONNECT_WAIT;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       return 0;
>> >>> >>> +       return conf_file;
>> >>> >>>  }
>> >>> >>>
>> >>> >>>  /*
>> >>> >>> -* Write the pid file
>> >>> >>> -*/
>> >>> >>> -static int write_status_file(void)
>> >>> >>> -{
>> >>> >>> -       FILE *fd;
>> >>> >>> -       char fnamebuf[POOLMAXPATHLEN];
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       snprintf(fnamebuf, sizeof(fnamebuf), "%s/%s",
>> >>> >>> pool_config->logdir, STATUS_FILE_NAME);
>> >>> >>> -       fd = fopen(fnamebuf, "w");
>> >>> >>> -       if (!fd)
>> >>> >>> -       {
>> >>> >>> -               pool_error("Could not open status file %s",
>> fnamebuf);
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       memset(&backend_rec, 0, sizeof(backend_rec));
>> >>> >>> -
>> >>> >>> -       for (i=0;i< pool_config->backend_desc->num_backends;i++)
>> >>> >>> -       {
>> >>> >>> -               backend_rec.status[i] =
>> BACKEND_INFO(i).backend_status;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (fwrite(&backend_rec, 1, sizeof(backend_rec), fd) !=
>> >>> >>> sizeof(backend_rec))
>> >>> >>> -       {
>> >>> >>> -               pool_error("Could not write backend status file as
>> %s.
>> >>> >>> reason: %s",
>> >>> >>> -                                  fnamebuf, strerror(errno));
>> >>> >>> -               fclose(fd);
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -       fclose(fd);
>> >>> >>> -       return 0;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * fork a child for PCP
>> >>> >>> - */
>> >>> >>> -pid_t pcp_fork_a_child(int unix_fd, int inet_fd, char
>> *pcp_conf_file)
>> >>> >>> -{
>> >>> >>> -       pid_t pid;
>> >>> >>> -
>> >>> >>> -       pid = fork();
>> >>> >>> -
>> >>> >>> -       if (pid == 0)
>> >>> >>> -       {
>> >>> >>> -               close(pipe_fds[0]);
>> >>> >>> -               close(pipe_fds[1]);
>> >>> >>> -
>> >>> >>> -               myargv = save_ps_display_args(myargc, myargv);
>> >>> >>> -
>> >>> >>> -               /* call PCP child main */
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -               health_check_timer_expired = 0;
>> >>> >>> -               reload_config_request = 0;
>> >>> >>> -               run_as_pcp_child = true;
>> >>> >>> -               pcp_do_child(unix_fd, inet_fd, pcp_conf_file);
>> >>> >>> -       }
>> >>> >>> -       else if (pid == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("fork() failed. reason: %s",
>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       return pid;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> -* fork a child
>> >>> >>> -*/
>> >>> >>> -pid_t fork_a_child(int unix_fd, int inet_fd, int id)
>> >>> >>> -{
>> >>> >>> -       pid_t pid;
>> >>> >>> -
>> >>> >>> -       pid = fork();
>> >>> >>> -
>> >>> >>> -       if (pid == 0)
>> >>> >>> -       {
>> >>> >>> -               /* Before we unconditionally closed pipe_fds[0] and
>> >>> >>> pipe_fds[1]
>> >>> >>> -                * here, which is apparently wrong since in the
>> start
>> >>> up
>> >>> >>> of
>> >>> >>> -                * pgpool, pipe(2) is not called yet and it
>> mistakenly
>> >>> >>> closes
>> >>> >>> -                * fd 0. Now we check the fd > 0 before close(),
>> >>> expecting
>> >>> >>> -                * pipe returns fds greater than 0.  Note that we
>> >>> cannot
>> >>> >>> -                * unconditionally remove close(2) calls since
>> >>> >>> fork_a_child()
>> >>> >>> -                * may be called *after* pgpool starting up.
>> >>> >>> -                */
>> >>> >>> -               if (pipe_fds[0] > 0)
>> >>> >>> -               {
>> >>> >>> -                       close(pipe_fds[0]);
>> >>> >>> -                       close(pipe_fds[1]);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               myargv = save_ps_display_args(myargc, myargv);
>> >>> >>> -
>> >>> >>> -               /* call child main */
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -               health_check_timer_expired = 0;
>> >>> >>> -               reload_config_request = 0;
>> >>> >>> -               my_proc_id = id;
>> >>> >>> -               run_as_pcp_child = false;
>> >>> >>> -               do_child(unix_fd, inet_fd);
>> >>> >>> -       }
>> >>> >>> -       else if (pid == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("fork() failed. reason: %s",
>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       return pid;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> -* fork worker child process
>> >>> >>> -*/
>> >>> >>> -pid_t worker_fork_a_child()
>> >>> >>> -{
>> >>> >>> -       pid_t pid;
>> >>> >>> -
>> >>> >>> -       pid = fork();
>> >>> >>> -
>> >>> >>> -       if (pid == 0)
>> >>> >>> -       {
>> >>> >>> -               /* Before we unconditionally closed pipe_fds[0] and
>> >>> >>> pipe_fds[1]
>> >>> >>> -                * here, which is apparently wrong since in the
>> start
>> >>> up
>> >>> >>> of
>> >>> >>> -                * pgpool, pipe(2) is not called yet and it
>> mistakenly
>> >>> >>> closes
>> >>> >>> -                * fd 0. Now we check the fd > 0 before close(),
>> >>> expecting
>> >>> >>> -                * pipe returns fds greater than 0.  Note that we
>> >>> cannot
>> >>> >>> -                * unconditionally remove close(2) calls since
>> >>> >>> fork_a_child()
>> >>> >>> -                * may be called *after* pgpool starting up.
>> >>> >>> -                */
>> >>> >>> -               if (pipe_fds[0] > 0)
>> >>> >>> -               {
>> >>> >>> -                       close(pipe_fds[0]);
>> >>> >>> -                       close(pipe_fds[1]);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               myargv = save_ps_display_args(myargc, myargv);
>> >>> >>> -
>> >>> >>> -               /* call child main */
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -               health_check_timer_expired = 0;
>> >>> >>> -               reload_config_request = 0;
>> >>> >>> -               do_worker_child();
>> >>> >>> -       }
>> >>> >>> -       else if (pid == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("fork() failed. reason: %s",
>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       return pid;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> -* create inet domain socket
>> >>> >>> -*/
>> >>> >>> -static int create_inet_domain_socket(const char *hostname, const
>> int
>> >>> >>> port)
>> >>> >>> -{
>> >>> >>> -       struct sockaddr_in addr;
>> >>> >>> -       int fd;
>> >>> >>> -       int status;
>> >>> >>> -       int one = 1;
>> >>> >>> -       int len;
>> >>> >>> -       int backlog;
>> >>> >>> -
>> >>> >>> -       fd = socket(AF_INET, SOCK_STREAM, 0);
>> >>> >>> -       if (fd == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("Failed to create INET domain socket.
>> >>> reason:
>> >>> >>> %s", strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       if ((setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)
>> &one,
>> >>> >>> -                                       sizeof(one))) == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("setsockopt() failed. reason: %s",
>> >>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       memset((char *) &addr, 0, sizeof(addr));
>> >>> >>> -       addr.sin_family = AF_INET;
>> >>> >>> -
>> >>> >>> -       if (strcmp(hostname, "*")==0)
>> >>> >>> -       {
>> >>> >>> -               addr.sin_addr.s_addr = htonl(INADDR_ANY);
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               struct hostent *hostinfo;
>> >>> >>> -
>> >>> >>> -               hostinfo = gethostbyname(hostname);
>> >>> >>> -               if (!hostinfo)
>> >>> >>> -               {
>> >>> >>> -                       pool_error("could not resolve host name
>> \"%s\":
>> >>> >>> %s", hostname, hstrerror(h_errno));
>> >>> >>> -                       myexit(1);
>> >>> >>> -               }
>> >>> >>> -               addr.sin_addr = *(struct in_addr *)
>> hostinfo->h_addr;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       addr.sin_port = htons(port);
>> >>> >>> -       len = sizeof(struct sockaddr_in);
>> >>> >>> -       status = bind(fd, (struct sockaddr *)&addr, len);
>> >>> >>> -       if (status == -1)
>> >>> >>> -       {
>> >>> >>> -               char *host = "", *serv = "";
>> >>> >>> -               char hostname[NI_MAXHOST], servname[NI_MAXSERV];
>> >>> >>> -               if (getnameinfo((struct sockaddr *) &addr, len,
>> >>> hostname,
>> >>> >>> sizeof(hostname), servname, sizeof(servname), 0) == 0) {
>> >>> >>> -                       host = hostname;
>> >>> >>> -                       serv = servname;
>> >>> >>> -               }
>> >>> >>> -               pool_error("bind(%s:%s) failed. reason: %s", host,
>> >>> serv,
>> >>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       backlog = pool_config->num_init_children * 2;
>> >>> >>> -       if (backlog > PGPOOLMAXLITSENQUEUELENGTH)
>> >>> >>> -               backlog = PGPOOLMAXLITSENQUEUELENGTH;
>> >>> >>> -
>> >>> >>> -       status = listen(fd, backlog);
>> >>> >>> -       if (status < 0)
>> >>> >>> -       {
>> >>> >>> -               pool_error("listen() failed. reason: %s",
>> >>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       return fd;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> -* create UNIX domain socket
>> >>> >>> -*/
>> >>> >>> -static int create_unix_domain_socket(struct sockaddr_un
>> un_addr_tmp)
>> >>> >>> -{
>> >>> >>> -       struct sockaddr_un addr;
>> >>> >>> -       int fd;
>> >>> >>> -       int status;
>> >>> >>> -       int len;
>> >>> >>> -
>> >>> >>> -       fd = socket(AF_UNIX, SOCK_STREAM, 0);
>> >>> >>> -       if (fd == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("Failed to create UNIX domain socket.
>> >>> reason:
>> >>> >>> %s", strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       memset((char *) &addr, 0, sizeof(addr));
>> >>> >>> -       addr.sun_family = AF_UNIX;
>> >>> >>> -       snprintf(addr.sun_path, sizeof(addr.sun_path), "%s",
>> >>> >>> un_addr_tmp.sun_path);
>> >>> >>> -       len = sizeof(struct sockaddr_un);
>> >>> >>> -       status = bind(fd, (struct sockaddr *)&addr, len);
>> >>> >>> -       if (status == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("bind(%s) failed. reason: %s",
>> >>> addr.sun_path,
>> >>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (chmod(un_addr_tmp.sun_path, 0777) == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("chmod() failed. reason: %s",
>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       status = listen(fd, PGPOOLMAXLITSENQUEUELENGTH);
>> >>> >>> -       if (status < 0)
>> >>> >>> -       {
>> >>> >>> -               pool_error("listen() failed. reason: %s",
>> >>> >>> strerror(errno));
>> >>> >>> -               myexit(1);
>> >>> >>> -       }
>> >>> >>> -       return fd;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -static void myunlink(const char* path)
>> >>> >>> -{
>> >>> >>> -       if (unlink(path) == 0) return;
>> >>> >>> -       pool_error("unlink(%s) failed: %s", path, strerror(errno));
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -static void myexit(int code)
>> >>> >>> -{
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       if (getpid() != mypid)
>> >>> >>> -               return;
>> >>> >>> -
>> >>> >>> -       if (process_info != NULL) {
>> >>> >>> -               POOL_SETMASK(&AuthBlockSig);
>> >>> >>> -               exiting = 1;
>> >>> >>> -               for (i = 0; i < pool_config->num_init_children;
>> i++)
>> >>> >>> -               {
>> >>> >>> -                       pid_t pid = process_info[i].pid;
>> >>> >>> -                       if (pid)
>> >>> >>> -                       {
>> >>> >>> -                               kill(pid, SIGTERM);
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               /* wait for all children to exit */
>> >>> >>> -               while (wait(NULL) > 0)
>> >>> >>> -                       ;
>> >>> >>> -               if (errno != ECHILD)
>> >>> >>> -                       pool_error("wait() failed. reason:%s",
>> >>> >>> strerror(errno));
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       myunlink(un_addr.sun_path);
>> >>> >>> -       myunlink(pcp_un_addr.sun_path);
>> >>> >>> -       myunlink(pool_config->pid_file_name);
>> >>> >>> -
>> >>> >>> -       write_status_file();
>> >>> >>> -
>> >>> >>> -       pool_shmem_exit(code);
>> >>> >>> -       exit(code);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -void notice_backend_error(int node_id)
>> >>> >>> -{
>> >>> >>> -       int n = node_id;
>> >>> >>> -
>> >>> >>> -       if (getpid() == mypid)
>> >>> >>> -       {
>> >>> >>> -               pool_log("notice_backend_error: called from pgpool
>> >>> main.
>> >>> >>> ignored.");
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               degenerate_backend_set(&n, 1);
>> >>> >>> -       }
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/* notice backend connection error using SIGUSR1 */
>> >>> >>> -void degenerate_backend_set(int *node_id_set, int count)
>> >>> >>> -{
>> >>> >>> -       pid_t parent = getppid();
>> >>> >>> -       int i;
>> >>> >>> -       bool need_signal = false;
>> >>> >>> -#ifdef HAVE_SIGPROCMASK
>> >>> >>> -       sigset_t oldmask;
>> >>> >>> -#else
>> >>> >>> -       int     oldmask;
>> >>> >>> -#endif
>> >>> >>> -
>> >>> >>> -       if (pool_config->parallel_mode)
>> >>> >>> -       {
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       POOL_SETMASK2(&BlockSig, &oldmask);
>> >>> >>> -       pool_semaphore_lock(REQUEST_INFO_SEM);
>> >>> >>> -       Req_info->kind = NODE_DOWN_REQUEST;
>> >>> >>> -       for (i = 0; i < count; i++)
>> >>> >>> -       {
>> >>> >>> -               if (node_id_set[i] < 0 || node_id_set[i] >=
>> >>> >>> MAX_NUM_BACKENDS ||
>> >>> >>> -                       !VALID_BACKEND(node_id_set[i]))
>> >>> >>> -               {
>> >>> >>> -                       pool_log("degenerate_backend_set: node %d
>> is
>> >>> not
>> >>> >>> valid backend.", i);
>> >>> >>> -                       continue;
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               if
>> >>> >>> (POOL_DISALLOW_TO_FAILOVER(BACKEND_INFO(node_id_set[i]).flag))
>> >>> >>> -               {
>> >>> >>> -                       pool_log("degenerate_backend_set: %d
>> failover
>> >>> >>> request from pid %d is canceled because failover is disallowed",
>> >>> >>> node_id_set[i], getpid());
>> >>> >>> -                       continue;
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               pool_log("degenerate_backend_set: %d fail over
>> request
>> >>> >>> from pid %d", node_id_set[i], getpid());
>> >>> >>> -               Req_info->node_id[i] = node_id_set[i];
>> >>> >>> -               need_signal = true;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (need_signal)
>> >>> >>> -       {
>> >>> >>> -               if (!pool_config->use_watchdog || WD_OK ==
>> >>> >>> wd_degenerate_backend_set(node_id_set, count))
>> >>> >>> -               {
>> >>> >>> -                       kill(parent, SIGUSR1);
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       pool_log("degenerate_backend_set: failover
>> >>> >>> request from pid %d is canceled by other pgpool", getpid());
>> >>> >>> -                       memset(Req_info->node_id, -1, sizeof(int) *
>> >>> >>> MAX_NUM_BACKENDS);
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -       POOL_SETMASK(&oldmask);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/* send promote node request using SIGUSR1 */
>> >>> >>> -void promote_backend(int node_id)
>> >>> >>> -{
>> >>> >>> -       pid_t parent = getppid();
>> >>> >>> -
>> >>> >>> -       if (!MASTER_SLAVE ||
>> strcmp(pool_config->master_slave_sub_mode,
>> >>> >>> MODE_STREAMREP))
>> >>> >>> -       {
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (node_id < 0 || node_id >= MAX_NUM_BACKENDS ||
>> >>> >>> !VALID_BACKEND(node_id))
>> >>> >>> -       {
>> >>> >>> -               pool_error("promote_backend: node %d is not valid
>> >>> >>> backend.", node_id);
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       pool_semaphore_lock(REQUEST_INFO_SEM);
>> >>> >>> -       Req_info->kind = PROMOTE_NODE_REQUEST;
>> >>> >>> -       Req_info->node_id[0] = node_id;
>> >>> >>> -       pool_log("promote_backend: %d promote node request from pid
>> >>> %d",
>> >>> >>> node_id, getpid());
>> >>> >>> -
>> >>> >>> -       if (!pool_config->use_watchdog || WD_OK ==
>> >>> >>> wd_promote_backend(node_id))
>> >>> >>> -       {
>> >>> >>> -               kill(parent, SIGUSR1);
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               pool_log("promote_backend: promote request from
>> pid %d
>> >>> is
>> >>> >>> canceled by other pgpool", getpid());
>> >>> >>> -               Req_info->node_id[0] = -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/* send failback request using SIGUSR1 */
>> >>> >>> -void send_failback_request(int node_id)
>> >>> >>> -{
>> >>> >>> -       pid_t parent = getppid();
>> >>> >>> -
>> >>> >>> -       pool_log("send_failback_request: fail back %d th node
>> request
>> >>> >>> from pid %d", node_id, getpid());
>> >>> >>> -       Req_info->kind = NODE_UP_REQUEST;
>> >>> >>> -       Req_info->node_id[0] = node_id;
>> >>> >>> -
>> >>> >>> -    if (node_id < 0 || node_id >= MAX_NUM_BACKENDS ||
>> >>> >>> -               (RAW_MODE && BACKEND_INFO(node_id).backend_status
>> !=
>> >>> >>> CON_DOWN && VALID_BACKEND(node_id)))
>> >>> >>> -       {
>> >>> >>> -               pool_error("send_failback_request: node %d is
>> alive.",
>> >>> >>> node_id);
>> >>> >>> -               Req_info->node_id[0] = -1;
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (pool_config->use_watchdog && WD_OK !=
>> >>> >>> wd_send_failback_request(node_id))
>> >>> >>> -       {
>> >>> >>> -               pool_log("send_failback_request: failback request
>> from
>> >>> >>> pid %d is canceled by other pgpool", getpid());
>> >>> >>> -               Req_info->node_id[0] = -1;
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -       kill(parent, SIGUSR1);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -static RETSIGTYPE exit_handler(int sig)
>> >>> >>> -{
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       POOL_SETMASK(&AuthBlockSig);
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * this could happen in a child process if a signal has
>> been
>> >>> sent
>> >>> >>> -        * before resetting signal handler
>> >>> >>> -        */
>> >>> >>> -       if (getpid() != mypid)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("exit_handler: I am not parent");
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -               pool_shmem_exit(0);
>> >>> >>> -               exit(0);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (sig == SIGTERM)
>> >>> >>> -               pool_log("received smart shutdown request");
>> >>> >>> -       else if (sig == SIGINT)
>> >>> >>> -               pool_log("received fast shutdown request");
>> >>> >>> -       else if (sig == SIGQUIT)
>> >>> >>> -               pool_log("received immediate shutdown request");
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               pool_error("exit_handler: unknown signal received
>> %d",
>> >>> >>> sig);
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       exiting = 1;
>> >>> >>> -
>> >>> >>> -       for (i = 0; i < pool_config->num_init_children; i++)
>> >>> >>> -       {
>> >>> >>> -               pid_t pid = process_info[i].pid;
>> >>> >>> -               if (pid)
>> >>> >>> -               {
>> >>> >>> -                       kill(pid, sig);
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       kill(pcp_pid, sig);
>> >>> >>> -       kill(worker_pid, sig);
>> >>> >>> -
>> >>> >>> -       if (pool_config->use_watchdog)
>> >>> >>> -       {
>> >>> >>> -               wd_kill_watchdog(sig);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -
>> >>> >>> -       while (wait(NULL) > 0)
>> >>> >>> -               ;
>> >>> >>> -
>> >>> >>> -       if (errno != ECHILD)
>> >>> >>> -               pool_error("wait() failed. reason:%s",
>> >>> strerror(errno));
>> >>> >>> -
>> >>> >>> -       process_info = NULL;
>> >>> >>> -       myexit(0);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * Calculate next valid master node id.
>> >>> >>> - * If no valid node found, returns -1.
>> >>> >>> - */
>> >>> >>> -static int get_next_master_node(void)
>> >>> >>> -{
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       for (i=0;i<pool_config->backend_desc->num_backends;i++)
>> >>> >>> -       {
>> >>> >>> -               /*
>> >>> >>> -                * Do not use VALID_BACKEND macro in raw mode.
>> >>> >>> -                * VALID_BACKEND return true only if the argument
>> is
>> >>> >>> master
>> >>> >>> -                * node id. In other words, standby nodes are
>> false. So
>> >>> >>> need
>> >>> >>> -                * to check backend status with VALID_BACKEND_RAW.
>> >>> >>> -                */
>> >>> >>> -               if (RAW_MODE)
>> >>> >>> -               {
>> >>> >>> -                       if (VALID_BACKEND_RAW(i))
>> >>> >>> -                               break;
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       if (VALID_BACKEND(i))
>> >>> >>> -                               break;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (i == pool_config->backend_desc->num_backends)
>> >>> >>> -               i = -1;
>> >>> >>> -
>> >>> >>> -       return i;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * handle SIGUSR1
>> >>> >>> - *
>> >>> >>> - */
>> >>> >>> -static RETSIGTYPE failover_handler(int sig)
>> >>> >>> -{
>> >>> >>> -       POOL_SETMASK(&BlockSig);
>> >>> >>> -       failover_request = 1;
>> >>> >>> -       write(pipe_fds[1], "\0", 1);
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * backend connection error, failover/failback request, if
>> possible
>> >>> >>> - * failover() must be called under protecting signals.
>> >>> >>> - */
>> >>> >>> -static void failover(void)
>> >>> >>> -{
>> >>> >>> -       int i;
>> >>> >>> -       int node_id;
>> >>> >>> -       bool by_health_check;
>> >>> >>> -       int new_master;
>> >>> >>> -       int new_primary;
>> >>> >>> -       int nodes[MAX_NUM_BACKENDS];
>> >>> >>> -       bool need_to_restart_children;
>> >>> >>> -       int status;
>> >>> >>> -       int sts;
>> >>> >>> -
>> >>> >>> -       pool_debug("failover_handler called");
>> >>> >>> -
>> >>> >>> -       memset(nodes, 0, sizeof(int) * MAX_NUM_BACKENDS);
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * this could happen in a child process if a signal has
>> been
>> >>> sent
>> >>> >>> -        * before resetting signal handler
>> >>> >>> -        */
>> >>> >>> -       if (getpid() != mypid)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("failover_handler: I am not parent");
>> >>> >>> -               kill(pcp_pid, SIGUSR2);
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * processing SIGTERM, SIGINT or SIGQUIT
>> >>> >>> -        */
>> >>> >>> -       if (exiting)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("failover_handler called while
>> exiting");
>> >>> >>> -               kill(pcp_pid, SIGUSR2);
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * processing fail over or switch over
>> >>> >>> -        */
>> >>> >>> -       if (switching)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("failover_handler called while
>> switching");
>> >>> >>> -               kill(pcp_pid, SIGUSR2);
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       pool_semaphore_lock(REQUEST_INFO_SEM);
>> >>> >>> -
>> >>> >>> -       if (Req_info->kind == CLOSE_IDLE_REQUEST)
>> >>> >>> -       {
>> >>> >>> -               pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -               kill_all_children(SIGUSR1);
>> >>> >>> -               kill(pcp_pid, SIGUSR2);
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * if not in replication mode/master slave mode, we treat
>> this
>> >>> a
>> >>> >>> restart request.
>> >>> >>> -        * otherwise we need to check if we have already
>> failovered.
>> >>> >>> -        */
>> >>> >>> -       pool_debug("failover_handler: starting to select new master
>> >>> >>> node");
>> >>> >>> -       switching = 1;
>> >>> >>> -       Req_info->switching = true;
>> >>> >>> -       node_id = Req_info->node_id[0];
>> >>> >>> -
>> >>> >>> -       /* start of command inter-lock with watchdog */
>> >>> >>> -       if (pool_config->use_watchdog)
>> >>> >>> -       {
>> >>> >>> -               by_health_check = (!failover_request &&
>> >>> >>> Req_info->kind==NODE_DOWN_REQUEST);
>> >>> >>> -               wd_start_interlock(by_health_check);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* failback request? */
>> >>> >>> -       if (Req_info->kind == NODE_UP_REQUEST)
>> >>> >>> -       {
>> >>> >>> -               if (node_id >= MAX_NUM_BACKENDS ||
>> >>> >>> -                       (Req_info->kind == NODE_UP_REQUEST &&
>> >>> !(RAW_MODE
>> >>> >>> &&
>> >>> >>> -            BACKEND_INFO(node_id).backend_status == CON_DOWN) &&
>> >>> >>> VALID_BACKEND(node_id)) ||
>> >>> >>> -                       (Req_info->kind == NODE_DOWN_REQUEST &&
>> >>> >>> !VALID_BACKEND(node_id)))
>> >>> >>> -               {
>> >>> >>> -                       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -                       pool_error("failover_handler: invalid
>> node_id
>> >>> %d
>> >>> >>> status:%d MAX_NUM_BACKENDS: %d", node_id,
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_status, MAX_NUM_BACKENDS);
>> >>> >>> -                       kill(pcp_pid, SIGUSR2);
>> >>> >>> -                       switching = 0;
>> >>> >>> -                       Req_info->switching = false;
>> >>> >>> -
>> >>> >>> -                       /* end of command inter-lock */
>> >>> >>> -                       if (pool_config->use_watchdog)
>> >>> >>> -                               wd_leave_interlock();
>> >>> >>> -
>> >>> >>> -                       return;
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               pool_log("starting fail back. reconnect host
>> %s(%d)",
>> >>> >>> -
>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -               BACKEND_INFO(node_id).backend_status =
>> >>> CON_CONNECT_WAIT;
>> >>> >>>        /* unset down status */
>> >>> >>> -
>> >>> >>> -               /* wait for failback command lock or to be lock
>> holder
>> >>> */
>> >>> >>> -               if (pool_config->use_watchdog &&
>> >>> !wd_am_I_lock_holder())
>> >>> >>> -               {
>> >>> >>> -                       wd_wait_for_lock(WD_FAILBACK_COMMAND_LOCK);
>> >>> >>> -               }
>> >>> >>> -               /* execute failback command if lock holder */
>> >>> >>> -               if (!pool_config->use_watchdog ||
>> >>> wd_am_I_lock_holder())
>> >>> >>> -               {
>> >>> >>> -                       trigger_failover_command(node_id,
>> >>> >>> pool_config->failback_command,
>> >>> >>> -
>> >>> >>> MASTER_NODE_ID, get_next_master_node(), PRIMARY_NODE_ID);
>> >>> >>> -
>> >>> >>> -                       /* unlock failback command */
>> >>> >>> -                       if (pool_config->use_watchdog)
>> >>> >>> -
>> wd_unlock(WD_FAILBACK_COMMAND_LOCK);
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -       else if (Req_info->kind == PROMOTE_NODE_REQUEST)
>> >>> >>> -       {
>> >>> >>> -               if (node_id != -1 && VALID_BACKEND(node_id))
>> >>> >>> -               {
>> >>> >>> -                       pool_log("starting promotion. promote host
>> >>> >>> %s(%d)",
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       pool_log("failover: no backends are
>> promoted");
>> >>> >>> -                       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -                       kill(pcp_pid, SIGUSR2);
>> >>> >>> -                       switching = 0;
>> >>> >>> -                       Req_info->switching = false;
>> >>> >>> -
>> >>> >>> -                       /* end of command inter-lock */
>> >>> >>> -                       if (pool_config->use_watchdog)
>> >>> >>> -                               wd_leave_interlock();
>> >>> >>> -
>> >>> >>> -                       return;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               int cnt = 0;
>> >>> >>> -
>> >>> >>> -               for (i = 0; i < MAX_NUM_BACKENDS; i++)
>> >>> >>> -               {
>> >>> >>> -                       if (Req_info->node_id[i] != -1 &&
>> >>> >>> -                               ((RAW_MODE &&
>> >>> >>> VALID_BACKEND_RAW(Req_info->node_id[i])) ||
>> >>> >>> -
>>  VALID_BACKEND(Req_info->node_id[i])))
>> >>> >>> -                       {
>> >>> >>> -                               pool_log("starting degeneration.
>> >>> shutdown
>> >>> >>> host %s(%d)",
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(Req_info->node_id[i]).backend_hostname,
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(Req_info->node_id[i]).backend_port);
>> >>> >>> -
>> >>> >>> -
>> >>> >>> BACKEND_INFO(Req_info->node_id[i]).backend_status = CON_DOWN;   /*
>> set
>> >>> down
>> >>> >>> status */
>> >>> >>> -                               /* save down node */
>> >>> >>> -                               nodes[Req_info->node_id[i]] = 1;
>> >>> >>> -                               cnt++;
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               if (cnt == 0)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("failover: no backends are
>> >>> degenerated");
>> >>> >>> -                       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -                       kill(pcp_pid, SIGUSR2);
>> >>> >>> -                       switching = 0;
>> >>> >>> -                       Req_info->switching = false;
>> >>> >>> -
>> >>> >>> -                       /* end of command inter-lock */
>> >>> >>> -                       if (pool_config->use_watchdog)
>> >>> >>> -                               wd_leave_interlock();
>> >>> >>> -
>> >>> >>> -                       return;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       new_master = get_next_master_node();
>> >>> >>> -
>> >>> >>> -       if (new_master < 0)
>> >>> >>> -       {
>> >>> >>> -               pool_error("failover_handler: no valid DB node
>> found");
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * Before we tried to minimize restarting pgpool to protect
>> existing
>> >>> >>> - * connections from clients to pgpool children. What we did here
>> was,
>> >>> >>> - * if children other than master went down, we did not fail over.
>> >>> >>> - * This is wrong. Think about following scenario. If someone
>> >>> >>> - * accidentally plugs out the network cable, the TCP/IP stack
>> keeps
>> >>> >>> - * retrying for long time (typically 2 hours). The only way to
>> stop
>> >>> >>> - * the retry is restarting the process.  Bottom line is, we need
>> to
>> >>> >>> - * restart all children in any case.  See pgpool-general list
>> posting
>> >>> >>> - * "TCP connections are *not* closed when a backend timeout" on
>> Jul 13
>> >>> >>> - * 2008 for more details.
>> >>> >>> - */
>> >>> >>> -#ifdef NOT_USED
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               if (Req_info->master_node_id == new_master &&
>> >>> *InRecovery
>> >>> >>> == RECOVERY_INIT)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("failover_handler: do not restart
>> >>> >>> pgpool. same master node %d was selected", new_master);
>> >>> >>> -                       if (Req_info->kind == NODE_UP_REQUEST)
>> >>> >>> -                       {
>> >>> >>> -                               pool_log("failback done. reconnect
>> host
>> >>> >>> %s(%d)",
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -                       }
>> >>> >>> -                       else
>> >>> >>> -                       {
>> >>> >>> -                               pool_log("failover done. shutdown
>> host
>> >>> >>> %s(%d)",
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>> >>> >>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -                       }
>> >>> >>> -
>> >>> >>> -                       /* exec failover_command */
>> >>> >>> -                       for (i = 0; i <
>> >>> >>> pool_config->backend_desc->num_backends; i++)
>> >>> >>> -                       {
>> >>> >>> -                               if (nodes[i])
>> >>> >>> -                                       trigger_failover_command(i,
>> >>> >>> pool_config->failover_command);
>> >>> >>> -                       }
>> >>> >>> -
>> >>> >>> -                       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -                       switching = 0;
>> >>> >>> -                       Req_info->switching = false;
>> >>> >>> -                       kill(pcp_pid, SIGUSR2);
>> >>> >>> -                       switching = 0;
>> >>> >>> -                       Req_info->switching = false;
>> >>> >>> -                       return;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -#endif
>> >>> >>> -
>> >>> >>> -
>> >>> >>> -   /* On 2011/5/2 Tatsuo Ishii says: if mode is streaming
>> replication
>> >>> >>> -       * and request is NODE_UP_REQUEST(failback case) we don't
>> need
>> >>> to
>> >>> >>> -       * restart all children. Existing session will not use newly
>> >>> >>> -       * attached node, but load balanced node is not changed
>> until
>> >>> this
>> >>> >>> -       * session ends, so it's harmless anyway.
>> >>> >>> -       */
>> >>> >>> -       if (MASTER_SLAVE &&
>> !strcmp(pool_config->master_slave_sub_mode,
>> >>> >>> MODE_STREAMREP) &&
>> >>> >>> -               Req_info->kind == NODE_UP_REQUEST)
>> >>> >>> -       {
>> >>> >>> -               pool_log("Do not restart children because we are
>> >>> >>> failbacking node id %d host%s port:%d and we are in streaming
>> >>> replication
>> >>> >>> mode", node_id,
>> >>> >>> -
>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -
>> >>> >>> -               need_to_restart_children = false;
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               pool_log("Restart all children");
>> >>> >>> -
>> >>> >>> -               /* kill all children */
>> >>> >>> -               for (i = 0; i < pool_config->num_init_children;
>> i++)
>> >>> >>> -               {
>> >>> >>> -                       pid_t pid = process_info[i].pid;
>> >>> >>> -                       if (pid)
>> >>> >>> -                       {
>> >>> >>> -                               kill(pid, SIGQUIT);
>> >>> >>> -                               pool_debug("failover_handler: kill
>> %d",
>> >>> >>> pid);
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               need_to_restart_children = true;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* wait for failover command lock or to be lock holder*/
>> >>> >>> -       if (pool_config->use_watchdog && !wd_am_I_lock_holder())
>> >>> >>> -       {
>> >>> >>> -               wd_wait_for_lock(WD_FAILOVER_COMMAND_LOCK);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* execute failover command if lock holder */
>> >>> >>> -       if (!pool_config->use_watchdog || wd_am_I_lock_holder())
>> >>> >>> -       {
>> >>> >>> -               /* Exec failover_command if needed */
>> >>> >>> -               for (i = 0; i <
>> >>> pool_config->backend_desc->num_backends;
>> >>> >>> i++)
>> >>> >>> -               {
>> >>> >>> -                       if (nodes[i])
>> >>> >>> -                               trigger_failover_command(i,
>> >>> >>> pool_config->failover_command,
>> >>> >>> -
>> >>> >>>               MASTER_NODE_ID, new_master, PRIMARY_NODE_ID);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               /* unlock failover command */
>> >>> >>> -               if (pool_config->use_watchdog)
>> >>> >>> -                       wd_unlock(WD_FAILOVER_COMMAND_LOCK);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -
>> >>> >>> -/* no need to wait since it will be done in reap_handler */
>> >>> >>> -#ifdef NOT_USED
>> >>> >>> -       while (wait(NULL) > 0)
>> >>> >>> -               ;
>> >>> >>> -
>> >>> >>> -       if (errno != ECHILD)
>> >>> >>> -               pool_error("failover_handler: wait() failed.
>> >>> reason:%s",
>> >>> >>> strerror(errno));
>> >>> >>> -#endif
>> >>> >>> -
>> >>> >>> -       if (Req_info->kind == PROMOTE_NODE_REQUEST &&
>> >>> >>> VALID_BACKEND(node_id))
>> >>> >>> -               new_primary = node_id;
>> >>> >>> -       else
>> >>> >>> -               new_primary =  find_primary_node_repeatedly();
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * If follow_master_command is provided and in master/slave
>> >>> >>> -        * streaming replication mode, we start degenerating all
>> >>> backends
>> >>> >>> -        * as they are not replicated anymore.
>> >>> >>> -        */
>> >>> >>> -       int follow_cnt = 0;
>> >>> >>> -       if (MASTER_SLAVE &&
>> !strcmp(pool_config->master_slave_sub_mode,
>> >>> >>> MODE_STREAMREP))
>> >>> >>> -       {
>> >>> >>> -               if (*pool_config->follow_master_command != '\0' ||
>> >>> >>> -                       Req_info->kind == PROMOTE_NODE_REQUEST)
>> >>> >>> -               {
>> >>> >>> -                       /* only if the failover is against the
>> current
>> >>> >>> primary */
>> >>> >>> -                       if (((Req_info->kind == NODE_DOWN_REQUEST)
>> &&
>> >>> >>> -
>>  (nodes[Req_info->primary_node_id])) ||
>> >>> >>> -                               ((Req_info->kind ==
>> >>> PROMOTE_NODE_REQUEST)
>> >>> >>> &&
>> >>> >>> -                                (VALID_BACKEND(node_id)))) {
>> >>> >>> -
>> >>> >>> -                               for (i = 0; i <
>> >>> >>> pool_config->backend_desc->num_backends; i++)
>> >>> >>> -                               {
>> >>> >>> -                                       /* do not degenerate the
>> new
>> >>> >>> primary */
>> >>> >>> -                                       if ((new_primary >= 0) &&
>> (i !=
>> >>> >>> new_primary)) {
>> >>> >>> -                                               BackendInfo
>> *bkinfo;
>> >>> >>> -                                               bkinfo =
>> >>> >>> pool_get_node_info(i);
>> >>> >>> -                                               pool_log("starting
>> >>> follow
>> >>> >>> degeneration. shutdown host %s(%d)",
>> >>> >>> -
>> >>> >>>  bkinfo->backend_hostname,
>> >>> >>> -
>> >>> >>>  bkinfo->backend_port);
>> >>> >>> -
>> bkinfo->backend_status
>> >>> =
>> >>> >>> CON_DOWN;      /* set down status */
>> >>> >>> -                                               follow_cnt++;
>> >>> >>> -                                       }
>> >>> >>> -                               }
>> >>> >>> -
>> >>> >>> -                               if (follow_cnt == 0)
>> >>> >>> -                               {
>> >>> >>> -                                       pool_log("failover: no
>> follow
>> >>> >>> backends are degenerated");
>> >>> >>> -                               }
>> >>> >>> -                               else
>> >>> >>> -                               {
>> >>> >>> -                                       /* update new master node
>> */
>> >>> >>> -                                       new_master =
>> >>> >>> get_next_master_node();
>> >>> >>> -                                       pool_log("failover: %d
>> follow
>> >>> >>> backends have been degenerated", follow_cnt);
>> >>> >>> -                               }
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       memset(Req_info->node_id, -1, sizeof(int) *
>> MAX_NUM_BACKENDS);
>> >>> >>> -       pool_semaphore_unlock(REQUEST_INFO_SEM);
>> >>> >>> -
>> >>> >>> -       /* wait for follow_master_command lock or to be lock
>> holder */
>> >>> >>> -       if (pool_config->use_watchdog && !wd_am_I_lock_holder())
>> >>> >>> -       {
>> >>> >>> -               wd_wait_for_lock(WD_FOLLOW_MASTER_COMMAND_LOCK);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* execute follow_master_command */
>> >>> >>> -       if (!pool_config->use_watchdog || wd_am_I_lock_holder())
>> >>> >>> -       {
>> >>> >>> -               if ((follow_cnt > 0) &&
>> >>> >>> (*pool_config->follow_master_command != '\0'))
>> >>> >>> -               {
>> >>> >>> -                       follow_pid =
>> >>> >>> fork_follow_child(Req_info->master_node_id, new_primary,
>> >>> >>> -
>> >>> >>>       Req_info->primary_node_id);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               /* unlock follow_master_command  */
>> >>> >>> -               if (pool_config->use_watchdog)
>> >>> >>> -                       wd_unlock(WD_FOLLOW_MASTER_COMMAND_LOCK);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* end of command inter-lock */
>> >>> >>> -       if (pool_config->use_watchdog)
>> >>> >>> -               wd_end_interlock();
>> >>> >>> -
>> >>> >>> -       /* Save primary node id */
>> >>> >>> -       Req_info->primary_node_id = new_primary;
>> >>> >>> -       pool_log("failover: set new primary node: %d",
>> >>> >>> Req_info->primary_node_id);
>> >>> >>> -
>> >>> >>> -       if (new_master >= 0)
>> >>> >>> -       {
>> >>> >>> -               Req_info->master_node_id = new_master;
>> >>> >>> -               pool_log("failover: set new master node: %d",
>> >>> >>> Req_info->master_node_id);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -
>> >>> >>> -       /* Fork the children if needed */
>> >>> >>> -       if (need_to_restart_children)
>> >>> >>> -       {
>> >>> >>> -               for (i=0;i<pool_config->num_init_children;i++)
>> >>> >>> -               {
>> >>> >>> -
>> >>> >>> -                       /*
>> >>> >>> -                        * Try to kill pgpool child because
>> previous
>> >>> kill
>> >>> >>> signal
>> >>> >>> -                        * may not be received by pgpool child.
>> This
>> >>> >>> could happen
>> >>> >>> -                        * if multiple PostgreSQL are going down
>> (or
>> >>> even
>> >>> >>> starting
>> >>> >>> -                        * pgpool, without starting PostgreSQL can
>> >>> >>> trigger this).
>> >>> >>> -                        * Child calls degenerate_backend() and it
>> >>> tries
>> >>> >>> to aquire
>> >>> >>> -                        * semaphore to write a failover request.
>> In
>> >>> this
>> >>> >>> case the
>> >>> >>> -                        * signal mask is set as well, thus
>> signals are
>> >>> >>> never
>> >>> >>> -                        * received.
>> >>> >>> -                        */
>> >>> >>> -                       kill(process_info[i].pid, SIGQUIT);
>> >>> >>> -
>> >>> >>> -                       process_info[i].pid = fork_a_child(unix_fd,
>> >>> >>> inet_fd, i);
>> >>> >>> -                       process_info[i].start_time = time(NULL);
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               /* Set restart request to each child. Children will
>> >>> >>> exit(1)
>> >>> >>> -                * whenever they are idle to restart.
>> >>> >>> -                */
>> >>> >>> -               for (i=0;i<pool_config->num_init_children;i++)
>> >>> >>> -               {
>> >>> >>> -                       process_info[i].need_to_restart = 1;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * Send restart request to worker child.
>> >>> >>> -        */
>> >>> >>> -       kill(worker_pid, SIGUSR1);
>> >>> >>> -
>> >>> >>> -       if (Req_info->kind == NODE_UP_REQUEST)
>> >>> >>> -       {
>> >>> >>> -               pool_log("failback done. reconnect host %s(%d)",
>> >>> >>> -
>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -       }
>> >>> >>> -       else if (Req_info->kind == PROMOTE_NODE_REQUEST)
>> >>> >>> -       {
>> >>> >>> -               pool_log("promotion done. promoted host %s(%d)",
>> >>> >>> -
>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -       }
>> >>> >>> -       else
>> >>> >>> -       {
>> >>> >>> -               pool_log("failover done. shutdown host %s(%d)",
>> >>> >>> -
>> >>>  BACKEND_INFO(node_id).backend_hostname,
>> >>> >>> -
>>  BACKEND_INFO(node_id).backend_port);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       switching = 0;
>> >>> >>> -       Req_info->switching = false;
>> >>> >>> -
>> >>> >>> -       /* kick wakeup_handler in pcp_child to notice that
>> >>> >>> -        * failover/failback done
>> >>> >>> -        */
>> >>> >>> -       kill(pcp_pid, SIGUSR2);
>> >>> >>> -
>> >>> >>> -       sleep(1);
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * Send restart request to pcp child.
>> >>> >>> -        */
>> >>> >>> -       kill(pcp_pid, SIGUSR1);
>> >>> >>> -       for (;;)
>> >>> >>> -       {
>> >>> >>> -               sts = waitpid(pcp_pid, &status, 0);
>> >>> >>> -               if (sts != -1)
>> >>> >>> -                       break;
>> >>> >>> -               if (sts == -1)
>> >>> >>> -               {
>> >>> >>> -                       if (errno == EINTR)
>> >>> >>> -                               continue;
>> >>> >>> -                       else
>> >>> >>> -                       {
>> >>> >>> -                               pool_error("failover: waitpid
>> failed.
>> >>> >>> reason: %s", strerror(errno));
>> >>> >>> -                               return;
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -       if (WIFSIGNALED(status))
>> >>> >>> -               pool_log("PCP child %d exits with status %d by
>> signal
>> >>> %d
>> >>> >>> in failover()", pcp_pid, status, WTERMSIG(status));
>> >>> >>> -       else
>> >>> >>> -               pool_log("PCP child %d exits with status %d in
>> >>> >>> failover()", pcp_pid, status);
>> >>> >>> -
>> >>> >>> -       pcp_pid = pcp_fork_a_child(pcp_unix_fd, pcp_inet_fd,
>> >>> >>> pcp_conf_file);
>> >>> >>> -       pool_log("fork a new PCP child pid %d in failover()",
>> pcp_pid);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * health check timer handler
>> >>> >>> - */
>> >>> >>> -static RETSIGTYPE health_check_timer_handler(int sig)
>> >>> >>> -{
>> >>> >>> -       POOL_SETMASK(&BlockSig);
>> >>> >>> -       health_check_timer_expired = 1;
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * Check if we can connect to the backend
>> >>> >>> - * returns 0 for OK. otherwise returns backend id + 1
>> >>> >>> - */
>> >>> >>> -static int health_check(void)
>> >>> >>> -{
>> >>> >>> -       POOL_CONNECTION_POOL_SLOT *slot;
>> >>> >>> -       BackendInfo *bkinfo;
>> >>> >>> -       static bool is_first = true;
>> >>> >>> -       static char *dbname;
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       /* Do not execute health check during recovery */
>> >>> >>> -       if (*InRecovery)
>> >>> >>> -               return 0;
>> >>> >>> -
>> >>> >>> - Retry:
>> >>> >>> -       /*
>> >>> >>> -        * First we try with "postgres" database.
>> >>> >>> -        */
>> >>> >>> -       if (is_first)
>> >>> >>> -               dbname = "postgres";
>> >>> >>> -
>> >>> >>> -       for (i=0;i<pool_config->backend_desc->num_backends;i++)
>> >>> >>> -       {
>> >>> >>> -               /*
>> >>> >>> -                * Make sure that health check timer has not been
>> >>> expired.
>> >>> >>> -                * Before called health_check(),
>> >>> >>> health_check_timer_expired is
>> >>> >>> -                * set to 0.  However it is possible that while
>> >>> >>> processing DB
>> >>> >>> -                * nodes health check timer expired.
>> >>> >>> -                */
>> >>> >>> -               if (health_check_timer_expired)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("health_check: health check timer
>> has
>> >>> >>> been already expired before attempting to connect to %d th
>> backend",
>> >>> i);
>> >>> >>> -                       return i+1;
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               bkinfo = pool_get_node_info(i);
>> >>> >>> -
>> >>> >>> -               pool_debug("health_check: %d th DB node status:
>> %d", i,
>> >>> >>> bkinfo->backend_status);
>> >>> >>> -
>> >>> >>> -               if (bkinfo->backend_status == CON_UNUSED ||
>> >>> >>> -                       bkinfo->backend_status == CON_DOWN)
>> >>> >>> -                       continue;
>> >>> >>> -
>> >>> >>> -               slot =
>> >>> >>> make_persistent_db_connection(bkinfo->backend_hostname,
>> >>> >>> -
>> >>> >>>                bkinfo->backend_port,
>> >>> >>> -
>> >>> >>>                dbname,
>> >>> >>> -
>> >>> >>>                pool_config->health_check_user,
>> >>> >>> -
>> >>> >>>                pool_config->health_check_password, false);
>> >>> >>> -
>> >>> >>> -               if (is_first)
>> >>> >>> -                       is_first = false;
>> >>> >>> -
>> >>> >>> -               if (!slot)
>> >>> >>> -               {
>> >>> >>> -                       /*
>> >>> >>> -                        * Retry with template1 unless health check
>> >>> timer
>> >>> >>> is expired.
>> >>> >>> -                        */
>> >>> >>> -                       if (!strcmp(dbname, "postgres") &&
>> >>> >>> health_check_timer_expired == 0)
>> >>> >>> -                       {
>> >>> >>> -                               dbname = "template1";
>> >>> >>> -                               goto Retry;
>> >>> >>> -                       }
>> >>> >>> -                       else
>> >>> >>> -                       {
>> >>> >>> -                               pool_error("health check failed.
>> %d th
>> >>> >>> host %s at port %d is down",
>> >>> >>> -                                                  i,
>> >>> >>> -
>> >>> >>>  bkinfo->backend_hostname,
>> >>> >>> -
>> >>>  bkinfo->backend_port);
>> >>> >>> -                               return i+1;
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       discard_persistent_db_connection(slot);
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       return 0;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * check if we can connect to the SystemDB
>> >>> >>> - * returns 0 for OK. otherwise returns -1
>> >>> >>> - */
>> >>> >>> -static int
>> >>> >>> -system_db_health_check(void)
>> >>> >>> -{
>> >>> >>> -       int fd;
>> >>> >>> -
>> >>> >>> -       /* V2 startup packet */
>> >>> >>> -       typedef struct {
>> >>> >>> -               int len;                /* startup packet length */
>> >>> >>> -               StartupPacket_v2 sp;
>> >>> >>> -       } MySp;
>> >>> >>> -       MySp mysp;
>> >>> >>> -       char kind;
>> >>> >>> -
>> >>> >>> -       memset(&mysp, 0, sizeof(mysp));
>> >>> >>> -       mysp.len = htonl(296);
>> >>> >>> -       mysp.sp.protoVersion = htonl(PROTO_MAJOR_V2 << 16);
>> >>> >>> -       strcpy(mysp.sp.database, "template1");
>> >>> >>> -       strncpy(mysp.sp.user, SYSDB_INFO->user,
>> sizeof(mysp.sp.user) -
>> >>> 1);
>> >>> >>> -       *mysp.sp.options = '\0';
>> >>> >>> -       *mysp.sp.unused = '\0';
>> >>> >>> -       *mysp.sp.tty = '\0';
>> >>> >>> -
>> >>> >>> -       pool_debug("health_check: SystemDB status: %d",
>> SYSDB_STATUS);
>> >>> >>> -
>> >>> >>> -       /* if SystemDB is already down, ignore */
>> >>> >>> -       if (SYSDB_STATUS == CON_UNUSED || SYSDB_STATUS == CON_DOWN)
>> >>> >>> -               return 0;
>> >>> >>> -
>> >>> >>> -       if (*SYSDB_INFO->hostname == '/')
>> >>> >>> -               fd =
>> >>> connect_unix_domain_socket_by_port(SYSDB_INFO->port,
>> >>> >>> SYSDB_INFO->hostname, FALSE);
>> >>> >>> -       else
>> >>> >>> -               fd =
>> >>> >>> connect_inet_domain_socket_by_port(SYSDB_INFO->hostname,
>> >>> SYSDB_INFO->port,
>> >>> >>> FALSE);
>> >>> >>> -
>> >>> >>> -       if (fd < 0)
>> >>> >>> -       {
>> >>> >>> -               pool_error("health check failed. SystemDB host %s
>> at
>> >>> port
>> >>> >>> %d is down",
>> >>> >>> -                                  SYSDB_INFO->hostname,
>> >>> >>> -                                  SYSDB_INFO->port);
>> >>> >>> -
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (write(fd, &mysp, sizeof(mysp)) < 0)
>> >>> >>> -       {
>> >>> >>> -               pool_error("health check failed during write.
>> SystemDB
>> >>> >>> host %s at port %d is down",
>> >>> >>> -                                  SYSDB_INFO->hostname,
>> >>> >>> -                                  SYSDB_INFO->port);
>> >>> >>> -               close(fd);
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       read(fd, &kind, 1);
>> >>> >>> -
>> >>> >>> -       if (write(fd, "X", 1) < 0)
>> >>> >>> -       {
>> >>> >>> -               pool_error("health check failed during write.
>> SystemDB
>> >>> >>> host %s at port %d is down",
>> >>> >>> -                                  SYSDB_INFO->hostname,
>> >>> >>> -                                  SYSDB_INFO->port);
>> >>> >>> -               close(fd);
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       close(fd);
>> >>> >>> -       return 0;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * handle SIGCHLD
>> >>> >>> - */
>> >>> >>> -static RETSIGTYPE reap_handler(int sig)
>> >>> >>> -{
>> >>> >>> -       POOL_SETMASK(&BlockSig);
>> >>> >>> -       sigchld_request = 1;
>> >>> >>> -       write(pipe_fds[1], "\0", 1);
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * Attach zombie processes and restart child processes.
>> >>> >>> - * reaper() must be called protected from signals.
>> >>> >>> - */
>> >>> >>> -static void reaper(void)
>> >>> >>> -{
>> >>> >>> -       pid_t pid;
>> >>> >>> -       int status;
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       pool_debug("reap_handler called");
>> >>> >>> -
>> >>> >>> -       if (exiting)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("reap_handler: exited due to exiting");
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (switching)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("reap_handler: exited due to
>> switching");
>> >>> >>> -               return;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* clear SIGCHLD request */
>> >>> >>> -       sigchld_request = 0;
>> >>> >>> -
>> >>> >>> -#ifdef HAVE_WAITPID
>> >>> >>> -       pool_debug("reap_handler: call waitpid");
>> >>> >>> -       while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
>> >>> >>> -#else
>> >>> >>> -       pool_debug("reap_handler: call wait3");
>> >>> >>> -       while ((pid = wait3(&status, WNOHANG, NULL)) > 0)
>> >>> >>> -#endif
>> >>> >>> -       {
>> >>> >>> -               if (WIFSIGNALED(status) && WTERMSIG(status) ==
>> SIGSEGV)
>> >>> >>> -               {
>> >>> >>> -                       /* Child terminated by segmentation fault.
>> >>> Report
>> >>> >>> it */
>> >>> >>> -                       pool_error("Child process %d was
>> terminated by
>> >>> >>> segmentation fault", pid);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               /* if exiting child process was PCP handler */
>> >>> >>> -               if (pid == pcp_pid)
>> >>> >>> -               {
>> >>> >>> -                       if (WIFSIGNALED(status))
>> >>> >>> -                               pool_log("PCP child %d exits with
>> >>> status
>> >>> >>> %d by signal %d", pid, status, WTERMSIG(status));
>> >>> >>> -                       else
>> >>> >>> -                               pool_log("PCP child %d exits with
>> >>> status
>> >>> >>> %d", pid, status);
>> >>> >>> -
>> >>> >>> -                       pcp_pid = pcp_fork_a_child(pcp_unix_fd,
>> >>> >>> pcp_inet_fd, pcp_conf_file);
>> >>> >>> -                       pool_log("fork a new PCP child pid %d",
>> >>> pcp_pid);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               /* exiting process was worker process */
>> >>> >>> -               else if (pid == worker_pid)
>> >>> >>> -               {
>> >>> >>> -                       if (WIFSIGNALED(status))
>> >>> >>> -                               pool_log("worker child %d exits
>> with
>> >>> >>> status %d by signal %d", pid, status, WTERMSIG(status));
>> >>> >>> -                       else
>> >>> >>> -                               pool_log("worker child %d exits
>> with
>> >>> >>> status %d", pid, status);
>> >>> >>> -
>> >>> >>> -                       if (status)
>> >>> >>> -                               worker_pid = worker_fork_a_child();
>> >>> >>> -
>> >>> >>> -                       pool_log("fork a new worker child pid %d",
>> >>> >>> worker_pid);
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               /* exiting process was watchdog process */
>> >>> >>> -               else if (pool_config->use_watchdog &&
>> >>> >>> wd_is_watchdog_pid(pid))
>> >>> >>> -               {
>> >>> >>> -                       if (!wd_reaper_watchdog(pid, status))
>> >>> >>> -                       {
>> >>> >>> -                               pool_error("wd_reaper failed");
>> >>> >>> -                               myexit(1);
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       if (WIFSIGNALED(status))
>> >>> >>> -                               pool_debug("child %d exits with
>> status
>> >>> %d
>> >>> >>> by signal %d", pid, status, WTERMSIG(status));
>> >>> >>> -                       else
>> >>> >>> -                               pool_debug("child %d exits with
>> status
>> >>> >>> %d", pid, status);
>> >>> >>> -
>> >>> >>> -                       /* look for exiting child's pid */
>> >>> >>> -                       for
>> (i=0;i<pool_config->num_init_children;i++)
>> >>> >>> -                       {
>> >>> >>> -                               if (pid == process_info[i].pid)
>> >>> >>> -                               {
>> >>> >>> -                                       /* if found, fork a new
>> child
>> >>> */
>> >>> >>> -                                       if (!switching && !exiting
>> &&
>> >>> >>> status)
>> >>> >>> -                                       {
>> >>> >>> -
>> process_info[i].pid =
>> >>> >>> fork_a_child(unix_fd, inet_fd, i);
>> >>> >>> -
>> >>> >>> process_info[i].start_time = time(NULL);
>> >>> >>> -                                               pool_debug("fork a
>> new
>> >>> >>> child pid %d", process_info[i].pid);
>> >>> >>> -                                               break;
>> >>> >>> -                                       }
>> >>> >>> -                               }
>> >>> >>> -                       }
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -       pool_debug("reap_handler: normally exited");
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get node information specified by node_number
>> >>> >>> - */
>> >>> >>> -BackendInfo *
>> >>> >>> -pool_get_node_info(int node_number)
>> >>> >>> -{
>> >>> >>> -       if (node_number < 0 || node_number >= NUM_BACKENDS)
>> >>> >>> -               return NULL;
>> >>> >>> -
>> >>> >>> -       return &BACKEND_INFO(node_number);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get number of nodes
>> >>> >>> - */
>> >>> >>> -int
>> >>> >>> -pool_get_node_count(void)
>> >>> >>> -{
>> >>> >>> -       return NUM_BACKENDS;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get process ids
>> >>> >>> - */
>> >>> >>> -int *
>> >>> >>> -pool_get_process_list(int *array_size)
>> >>> >>> -{
>> >>> >>> -       int        *array;
>> >>> >>> -       int             i;
>> >>> >>> -
>> >>> >>> -       *array_size = pool_config->num_init_children;
>> >>> >>> -       array = calloc(*array_size, sizeof(int));
>> >>> >>> -       for (i = 0; i < *array_size; i++)
>> >>> >>> -               array[i] = process_info[i].pid;
>> >>> >>> -
>> >>> >>> -       return array;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get process information specified by pid
>> >>> >>> - */
>> >>> >>> -ProcessInfo *
>> >>> >>> -pool_get_process_info(pid_t pid)
>> >>> >>> -{
>> >>> >>> -       int             i;
>> >>> >>> -
>> >>> >>> -       for (i = 0; i < pool_config->num_init_children; i++)
>> >>> >>> -               if (process_info[i].pid == pid)
>> >>> >>> -                       return &process_info[i];
>> >>> >>> -
>> >>> >>> -       return NULL;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get System DB information
>> >>> >>> - */
>> >>> >>> -SystemDBInfo *
>> >>> >>> -pool_get_system_db_info(void)
>> >>> >>> -{
>> >>> >>> -       if (system_db_info == NULL)
>> >>> >>> -               return NULL;
>> >>> >>> -
>> >>> >>> -       return system_db_info->info;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * handle SIGUSR2
>> >>> >>> - * Wakeup all processes
>> >>> >>> - */
>> >>> >>> -static void wakeup_children(void)
>> >>> >>> -{
>> >>> >>> -       kill_all_children(SIGUSR2);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -
>> >>> >>> -static RETSIGTYPE wakeup_handler(int sig)
>> >>> >>> -{
>> >>> >>> -       POOL_SETMASK(&BlockSig);
>> >>> >>> -       wakeup_request = 1;
>> >>> >>> -       write(pipe_fds[1], "\0", 1);
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * handle SIGHUP
>> >>> >>> - *
>> >>> >>> - */
>> >>> >>> -static RETSIGTYPE reload_config_handler(int sig)
>> >>> >>> -{
>> >>> >>> -       POOL_SETMASK(&BlockSig);
>> >>> >>> -       reload_config_request = 1;
>> >>> >>> -       write(pipe_fds[1], "\0", 1);
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -static void reload_config(void)
>> >>> >>> -{
>> >>> >>> -       pool_log("reload config files.");
>> >>> >>> -       pool_get_config(conf_file, RELOAD_CONFIG);
>> >>> >>> -       if (pool_config->enable_pool_hba)
>> >>> >>> -               load_hba(hba_file);
>> >>> >>> -       if (pool_config->parallel_mode)
>> >>> >>> -               pool_memset_system_db_info(system_db_info->info);
>> >>> >>> -       kill_all_children(SIGHUP);
>> >>> >>> -
>> >>> >>> -       if (worker_pid)
>> >>> >>> -               kill(worker_pid, SIGHUP);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -static void kill_all_children(int sig)
>> >>> >>> -{
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       /* kill all children */
>> >>> >>> -       for (i = 0; i < pool_config->num_init_children; i++)
>> >>> >>> -       {
>> >>> >>> -               pid_t pid = process_info[i].pid;
>> >>> >>> -               if (pid)
>> >>> >>> -               {
>> >>> >>> -                       kill(pid, sig);
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /* make PCP process reload as well */
>> >>> >>> -       if (sig == SIGHUP)
>> >>> >>> -               kill(pcp_pid, sig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * pause in a period specified by timeout. If any data is coming
>> >>> >>> - * through pipe_fds[0], that means one of: failover
>> request(SIGUSR1),
>> >>> >>> - * SIGCHLD received, children wake up request(SIGUSR2 used in on
>> line
>> >>> >>> - * recovery processing) or config file reload request(SIGHUP) has
>> been
>> >>> >>> - * occurred.  In this case this function returns 1.
>> >>> >>> - * otherwise 0: (no signal event occurred), -1: (error)
>> >>> >>> - * XXX: is it OK that select(2) error is ignored here?
>> >>> >>> - */
>> >>> >>> -static int pool_pause(struct timeval *timeout)
>> >>> >>> -{
>> >>> >>> -       fd_set rfds;
>> >>> >>> -       int n;
>> >>> >>> -       char dummy;
>> >>> >>> -
>> >>> >>> -       FD_ZERO(&rfds);
>> >>> >>> -       FD_SET(pipe_fds[0], &rfds);
>> >>> >>> -       n = select(pipe_fds[0]+1, &rfds, NULL, NULL, timeout);
>> >>> >>> -       if (n == 1)
>> >>> >>> -               read(pipe_fds[0], &dummy, 1);
>> >>> >>> -       return n;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * sleep for seconds specified by "second".  Unlike pool_pause(),
>> this
>> >>> >>> - * function guarantees that it will sleep for specified seconds.
>>  This
>> >>> >>> - * function uses pool_pause() internally. If it informs that
>> there is
>> >>> >>> - * a pending signal event, they are processed using CHECK_REQUEST
>> >>> >>> - * macro. Note that most of these processes are done while all
>> signals
>> >>> >>> - * are blocked.
>> >>> >>> - */
>> >>> >>> -void pool_sleep(unsigned int second)
>> >>> >>> -{
>> >>> >>> -       struct timeval current_time, sleep_time;
>> >>> >>> -
>> >>> >>> -       gettimeofday(&current_time, NULL);
>> >>> >>> -       sleep_time.tv_sec = second + current_time.tv_sec;
>> >>> >>> -       sleep_time.tv_usec = current_time.tv_usec;
>> >>> >>> -
>> >>> >>> -       POOL_SETMASK(&UnBlockSig);
>> >>> >>> -       while (sleep_time.tv_sec > current_time.tv_sec)
>> >>> >>> -       {
>> >>> >>> -               struct timeval timeout;
>> >>> >>> -               int r;
>> >>> >>> -
>> >>> >>> -               timeout.tv_sec = sleep_time.tv_sec -
>> >>> current_time.tv_sec;
>> >>> >>> -               timeout.tv_usec = sleep_time.tv_usec -
>> >>> >>> current_time.tv_usec;
>> >>> >>> -               if (timeout.tv_usec < 0)
>> >>> >>> -               {
>> >>> >>> -                       timeout.tv_sec--;
>> >>> >>> -                       timeout.tv_usec += 1000000;
>> >>> >>> -               }
>> >>> >>> -
>> >>> >>> -               r = pool_pause(&timeout);
>> >>> >>> -               POOL_SETMASK(&BlockSig);
>> >>> >>> -               if (r > 0)
>> >>> >>> -                       CHECK_REQUEST;
>> >>> >>> -               POOL_SETMASK(&UnBlockSig);
>> >>> >>> -               gettimeofday(&current_time, NULL);
>> >>> >>> -       }
>> >>> >>> -       POOL_SETMASK(&BlockSig);
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get_config_file_name: return full path of pgpool.conf.
>> >>> >>> - */
>> >>> >>> -char *get_config_file_name(void)
>> >>> >>> -{
>> >>> >>> -       return conf_file;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * get_config_file_name: return full path of pool_hba.conf.
>> >>> >>> - */
>> >>> >>> -char *get_hba_file_name(void)
>> >>> >>> + * get_config_file_name: return full path of pool_hba.conf.
>> >>> >>> + */
>> >>> >>> +char *get_hba_file_name(void)
>> >>> >>>  {
>> >>> >>>         return hba_file;
>> >>> >>>  }
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * trigger_failover_command: execute specified command at
>> failover.
>> >>> >>> - *                           command_line is null-terminated
>> string.
>> >>> >>> - */
>> >>> >>> -static int trigger_failover_command(int node, const char
>> >>> *command_line,
>> >>> >>> -
>> >>> >>> int old_master, int new_master, int old_primary)
>> >>> >>> -{
>> >>> >>> -       int r = 0;
>> >>> >>> -       String *exec_cmd;
>> >>> >>> -       char port_buf[6];
>> >>> >>> -       char buf[2];
>> >>> >>> -       BackendInfo *info;
>> >>> >>> -       BackendInfo *newmaster;
>> >>> >>> -
>> >>> >>> -       if (command_line == NULL || (strlen(command_line) == 0))
>> >>> >>> -               return 0;
>> >>> >>> -
>> >>> >>> -       /* check failed nodeID */
>> >>> >>> -       if (node < 0 || node > NUM_BACKENDS)
>> >>> >>> -               return -1;
>> >>> >>> -
>> >>> >>> -       info = pool_get_node_info(node);
>> >>> >>> -       if (!info)
>> >>> >>> -               return -1;
>> >>> >>> -
>> >>> >>> -       buf[1] = '\0';
>> >>> >>> -       pool_memory = pool_memory_create(PREPARE_BLOCK_SIZE);
>> >>> >>> -       if (!pool_memory)
>> >>> >>> -       {
>> >>> >>> -               pool_error("trigger_failover_command:
>> >>> >>> pool_memory_create() failed");
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -       exec_cmd = init_string("");
>> >>> >>> -
>> >>> >>> -       while (*command_line)
>> >>> >>> -       {
>> >>> >>> -               if (*command_line == '%')
>> >>> >>> -               {
>> >>> >>> -                       if (*(command_line + 1))
>> >>> >>> -                       {
>> >>> >>> -                               char val = *(command_line + 1);
>> >>> >>> -                               switch (val)
>> >>> >>> -                               {
>> >>> >>> -                                       case 'p': /* failed node
>> port
>> >>> */
>> >>> >>> -                                               snprintf(port_buf,
>> >>> >>> sizeof(port_buf), "%d", info->backend_port);
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, port_buf);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'D': /* failed node
>> >>> database
>> >>> >>> directory */
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, info->backend_data_directory);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'd': /* failed node
>> id */
>> >>> >>> -                                               snprintf(port_buf,
>> >>> >>> sizeof(port_buf), "%d", node);
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, port_buf);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'h': /* failed host
>> name
>> >>> */
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, info->backend_hostname);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'H': /* new master
>> host
>> >>> name
>> >>> >>> */
>> >>> >>> -                                               newmaster =
>> >>> >>> pool_get_node_info(new_master);
>> >>> >>> -                                               if (newmaster)
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, newmaster->backend_hostname);
>> >>> >>> -                                               else
>> >>> >>> -                                                       /* no
>> valid new
>> >>> >>> master */
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, "");
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'm': /* new master
>> node
>> >>> id */
>> >>> >>> -                                               snprintf(port_buf,
>> >>> >>> sizeof(port_buf), "%d", new_master);
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, port_buf);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'r': /* new master
>> port */
>> >>> >>> -                                               newmaster =
>> >>> >>> pool_get_node_info(get_next_master_node());
>> >>> >>> -                                               if (newmaster)
>> >>> >>> -                                               {
>> >>> >>> -
>> >>> >>> snprintf(port_buf, sizeof(port_buf), "%d",
>> newmaster->backend_port);
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, port_buf);
>> >>> >>> -                                               }
>> >>> >>> -                                               else
>> >>> >>> -                                                       /* no
>> valid new
>> >>> >>> master */
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, "");
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'R': /* new master
>> >>> database
>> >>> >>> directory */
>> >>> >>> -                                               newmaster =
>> >>> >>> pool_get_node_info(get_next_master_node());
>> >>> >>> -                                               if (newmaster)
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, newmaster->backend_data_directory);
>> >>> >>> -                                               else
>> >>> >>> -                                                       /* no
>> valid new
>> >>> >>> master */
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, "");
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'M': /* old master
>> node
>> >>> id */
>> >>> >>> -                                               snprintf(port_buf,
>> >>> >>> sizeof(port_buf), "%d", old_master);
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, port_buf);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case 'P': /* old primary
>> node
>> >>> id
>> >>> >>> */
>> >>> >>> -                                               snprintf(port_buf,
>> >>> >>> sizeof(port_buf), "%d", old_primary);
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, port_buf);
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       case '%': /* escape */
>> >>> >>> -
>> >>> >>> string_append_char(exec_cmd, "%");
>> >>> >>> -                                               break;
>> >>> >>> -
>> >>> >>> -                                       default: /* ignore */
>> >>> >>> -                                               break;
>> >>> >>> -                               }
>> >>> >>> -                               command_line++;
>> >>> >>> -                       }
>> >>> >>> -               } else {
>> >>> >>> -                       buf[0] = *command_line;
>> >>> >>> -                       string_append_char(exec_cmd, buf);
>> >>> >>> -               }
>> >>> >>> -               command_line++;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (strlen(exec_cmd->data) != 0)
>> >>> >>> -       {
>> >>> >>> -               pool_log("execute command: %s", exec_cmd->data);
>> >>> >>> -               r = system(exec_cmd->data);
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       pool_memory_delete(pool_memory, 0);
>> >>> >>> -       pool_memory = NULL;
>> >>> >>> -
>> >>> >>> -       return r;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> - * Find the primary node (i.e. not standby node) and returns its
>> node
>> >>> >>> - * id. If no primary node is found, returns -1.
>> >>> >>> - */
>> >>> >>> -static int find_primary_node(void)
>> >>> >>> -{
>> >>> >>> -       BackendInfo *bkinfo;
>> >>> >>> -       POOL_CONNECTION_POOL_SLOT *s;
>> >>> >>> -       POOL_CONNECTION *con;
>> >>> >>> -       POOL_STATUS status;
>> >>> >>> -       POOL_SELECT_RESULT *res;
>> >>> >>> -       bool is_standby;
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       /* Streaming replication mode? */
>> >>> >>> -       if (pool_config->master_slave_mode == 0 ||
>> >>> >>> -               strcmp(pool_config->master_slave_sub_mode,
>> >>> >>> MODE_STREAMREP))
>> >>> >>> -       {
>> >>> >>> -               /* No point to look for primary node if not in
>> >>> streaming
>> >>> >>> -                * replication mode.
>> >>> >>> -                */
>> >>> >>> -               pool_debug("find_primary_node: not in streaming
>> >>> >>> replication mode");
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       for(i=0;i<NUM_BACKENDS;i++)
>> >>> >>> -       {
>> >>> >>> -               if (!VALID_BACKEND(i))
>> >>> >>> -                       continue;
>> >>> >>> -
>> >>> >>> -               /*
>> >>> >>> -                * Check to see if this is a standby node or not.
>> >>> >>> -                */
>> >>> >>> -               is_standby = false;
>> >>> >>> -
>> >>> >>> -               bkinfo = pool_get_node_info(i);
>> >>> >>> -               s =
>> >>> >>> make_persistent_db_connection(bkinfo->backend_hostname,
>> >>> >>> -
>> >>> >>>         bkinfo->backend_port,
>> >>> >>> -
>> >>> >>>         "postgres",
>> >>> >>> -
>> >>> >>>         pool_config->sr_check_user,
>> >>> >>> -
>> >>> >>>         pool_config->sr_check_password, true);
>> >>> >>> -               if (!s)
>> >>> >>> -               {
>> >>> >>> -                       pool_error("find_primary_node:
>> >>> >>> make_persistent_connection failed");
>> >>> >>> -                       return -1;
>> >>> >>> -               }
>> >>> >>> -               con = s->con;
>> >>> >>> -               status = do_query(con, "SELECT
>> pg_is_in_recovery()",
>> >>> >>> -                                                 &res,
>> >>> PROTO_MAJOR_V3);
>> >>> >>> -               if (res->numrows <= 0)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("find_primary_node: do_query
>> returns
>> >>> no
>> >>> >>> rows");
>> >>> >>> -               }
>> >>> >>> -               if (res->data[0] == NULL)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("find_primary_node: do_query
>> returns
>> >>> no
>> >>> >>> data");
>> >>> >>> -               }
>> >>> >>> -               if (res->nullflags[0] == -1)
>> >>> >>> -               {
>> >>> >>> -                       pool_log("find_primary_node: do_query
>> returns
>> >>> >>> NULL");
>> >>> >>> -               }
>> >>> >>> -               if (res->data[0] && !strcmp(res->data[0], "t"))
>> >>> >>> -               {
>> >>> >>> -                       is_standby = true;
>> >>> >>> -               }
>> >>> >>> -               free_select_result(res);
>> >>> >>> -               discard_persistent_db_connection(s);
>> >>> >>> -
>> >>> >>> -               /*
>> >>> >>> -                * If this is a standby, we continue to look for
>> >>> primary
>> >>> >>> node.
>> >>> >>> -                */
>> >>> >>> -               if (is_standby)
>> >>> >>> -               {
>> >>> >>> -                       pool_debug("find_primary_node: %d node is
>> >>> >>> standby", i);
>> >>> >>> -               }
>> >>> >>> -               else
>> >>> >>> -               {
>> >>> >>> -                       break;
>> >>> >>> -               }
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       if (i == NUM_BACKENDS)
>> >>> >>> -       {
>> >>> >>> -               pool_debug("find_primary_node: no primary node
>> found");
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       pool_log("find_primary_node: primary node id is %d", i);
>> >>> >>> -       return i;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -static int find_primary_node_repeatedly(void)
>> >>> >>> +/* Call back function to unlink the file */
>> >>> >>> +/* Call back function to unlink the file */
>> >>> >>> +static void FileUnlink(int code, Datum path)
>> >>> >>>  {
>> >>> >>> -       int sec;
>> >>> >>> -       int node_id = -1;
>> >>> >>> -
>> >>> >>> -       /* Streaming replication mode? */
>> >>> >>> -       if (pool_config->master_slave_mode == 0 ||
>> >>> >>> -               strcmp(pool_config->master_slave_sub_mode,
>> >>> >>> MODE_STREAMREP))
>> >>> >>> -       {
>> >>> >>> -               /* No point to look for primary node if not in
>> >>> streaming
>> >>> >>> -                * replication mode.
>> >>> >>> -                */
>> >>> >>> -               pool_debug("find_primary_node: not in streaming
>> >>> >>> replication mode");
>> >>> >>> -               return -1;
>> >>> >>> -       }
>> >>> >>> -
>> >>> >>> -       /*
>> >>> >>> -        * Try to find the new primary node and keep trying for
>> >>> >>> -        * search_primary_node_timeout seconds.
>> >>> >>> -        * search_primary_node_timeout = 0 means never timeout and
>> keep
>> >>> >>> searching
>> >>> >>> -        * indefinitely
>> >>> >>> +       char* filePath = (char*)path;
>> >>> >>> +       if (unlink(filePath) == 0) return;
>> >>> >>> +       /*
>> >>> >>> +        * We are already exiting the system just produce a log
>> entry
>> >>> to
>> >>> >>> report an error
>> >>> >>>          */
>> >>> >>> -       pool_log("find_primary_node_repeatedly: waiting for
>> finding a
>> >>> >>> primary node");
>> >>> >>> -       for (sec = 0; (pool_config->search_primary_node_timeout ==
>> 0 ||
>> >>> >>> -                               sec <
>> >>> >>> pool_config->search_primary_node_timeout); sec++)
>> >>> >>> -       {
>> >>> >>> -               node_id = find_primary_node();
>> >>> >>> -               if (node_id != -1)
>> >>> >>> -                       break;
>> >>> >>> -               pool_sleep(1);
>> >>> >>> -       }
>> >>> >>> -       return node_id;
>> >>> >>> -}
>> >>> >>> -
>> >>> >>> -/*
>> >>> >>> -* fork a follow child
>> >>> >>> -*/
>> >>> >>> -pid_t fork_follow_child(int old_master, int new_primary, int
>> >>> old_primary)
>> >>> >>> -{
>> >>> >>> -       pid_t pid;
>> >>> >>> -       int i;
>> >>> >>> -
>> >>> >>> -       pid = fork();
>> >>> >>> -
>> >>> >>> -       if (pid == 0)
>> >>> >>> -       {
>> >>> >>> -               pool_log("start triggering follow command.");
>> >>> >>> -               for (i = 0; i <
>> >>> pool_config->backend_desc->num_backends;
>> >>> >>> i++)
>> >>> >>> -               {
>> >>> >>> -                       BackendInfo *bkinfo;
>> >>> >>> -                       bkinfo = pool_get_node_info(i);
>> >>> >>> -                       if (bkinfo->backend_status == CON_DOWN)
>> >>> >>> -                               trigger_failover_command(i,
>> >>> >>> pool_config->follow_master_command,
>> >>> >>> -
>> >>> >>>        old_master, new_primary, old_primary);
>> >>> >>> -               }
>> >>> >>> -               exit(0);
>> >>> >>> -       }
>> >>> >>> -       else if (pid == -1)
>> >>> >>> -       {
>> >>> >>> -               pool_error("follow fork() failed. reason: %s",
>> >>> >>> strerror(errno));
>> >>> >>> -               exit(1);
>> >>> >>> -       }
>> >>> >>> -       return pid;
>> >>> >>> +       ereport(LOG,
>> >>> >>> +               (errmsg("unlink failed for file at path \"%s\"",
>> >>> >>> filePath),
>> >>> >>> +                       errdetail("\"%s\"", strerror(errno))));
>> >>> >>>  }
>> >>> >>>
>> >>> >>> ...
>> >>> >>>
>> >>> >>> [Message clipped]
>> >>> >>
>> >>> >>
>> >>> >>
>> >>> >>
>> >>> >> --
>> >>> >> Ahsan Hadi
>> >>> >> Snr Director Product Development
>> >>> >> EnterpriseDB Corporation
>> >>> >> The Enterprise Postgres Company
>> >>> >>
>> >>> >> Phone: +92-51-8358874
>> >>> >> Mobile: +92-333-5162114
>> >>> >>
>> >>> >> Website: www.enterprisedb.com
>> >>> >> EnterpriseDB Blog: http://blogs.enterprisedb.com/
>> >>> >> Follow us on Twitter: http://www.twitter.com/enterprisedb
>> >>> >>
>> >>> >> This e-mail message (and any attachment) is intended for the use of
>> the
>> >>> >> individual or entity to whom it is addressed. This message contains
>> >>> >> information from EnterpriseDB Corporation that may be privileged,
>> >>> >> confidential, or exempt from disclosure under applicable law. If
>> you are
>> >>> >> not the intended recipient or authorized to receive this for the
>> >>> intended
>> >>> >> recipient, any use, dissemination, distribution, retention,
>> archiving,
>> >>> or
>> >>> >> copying of this communication is strictly prohibited. If you have
>> >>> received
>> >>> >> this e-mail in error, please notify the sender immediately by reply
>> >>> e-mail
>> >>> >> and delete this message.
>> >>> >>
>> >>>
>> > _______________________________________________
>> > pgpool-hackers mailing list
>> > pgpool-hackers at pgpool.net
>> > http://www.pgpool.net/mailman/listinfo/pgpool-hackers
>>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pool_parser.h.diff
Type: text/x-patch
Size: 618 bytes
Desc: not available
URL: <http://www.sraoss.jp/pipermail/pgpool-hackers/attachments/20131026/a55f3b1c/attachment-0001.bin>


More information about the pgpool-hackers mailing list