[pgpool-hackers: 379] Re: Exception Manager for pgpool

Tatsuo Ishii ishii at postgresql.org
Wed Oct 23 18:46:34 JST 2013


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.

Maybe now is the time to add Usama to one of pgpool-II committers?
--
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.
>>> >>
>>>
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