<div dir="ltr">Hi Gabriel.<div><br></div><div>I think pgpool uses status file for recording nodes status. I only manage pgpool using pcp commands, but once I got status 0 for a node and I did resolve this situation removing status file. </div><div>I think its a pgpool internal file.</div><div><br></div><div>For pgpool version 2.3 (link <a href="http://www.pgpool.net/docs/pgpool-II-2.3/pgpool-en.html">http://www.pgpool.net/docs/pgpool-II-2.3/pgpool-en.html</a> ) I get this information about status file. I hope this help you.</div><div><br></div><div>############################################</div><div><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px">pgpool records backend status into [logdir]/pgpool_status file. When pgpool restarts it reads the file and restore the backend status. This will prevent data difference among DB nodes which might be caused by following scenario:</p><ol style="margin-left:40px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px"><li style="color:rgb(102,51,51)">One of backend suddenly stopps and pgpool execute fail over</li><li style="color:rgb(102,51,51)">Update one of active DB through pgpool</li><li style="color:rgb(102,51,51)">Our administrator decides to stop pgpool</li><li style="color:rgb(102,51,51)">Someone decides to restart the stopping DB without letting our admin know</li><li style="color:rgb(102,51,51)">Our poor administrator restarts pgpool</li></ol><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px"></p><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px">If for some reason, for example, the stopping DB is synched with the active DB by hand, you could remove pgpool_status safely before starting pgpool.</p><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px"><span style="font-family:arial,sans-serif;font-size:small;color:rgb(34,34,34)">######################</span><span style="font-family:arial,sans-serif;font-size:small;color:rgb(34,34,34)">###########</span><span style="font-family:arial,sans-serif;font-size:small;color:rgb(34,34,34)">###########</span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small">###</span><br></p><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small"><br></span></p><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small">Kind regards.</span></p><p style="padding-left:15px;padding-right:15px;margin-left:25px;margin-right:25px;color:rgb(0,0,0);font-family:verdana,arial,helvetica,sans-serif;font-size:12px"><br></p></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, May 15, 2017 at 2:08 PM, PVY <span dir="ltr"><<a href="mailto:balroga3@yandex.ru" target="_blank">balroga3@yandex.ru</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<span style="font-family:'Courier New';font-size:10pt">Hello Gabriel.<br>
<br>
You can also start pgpool with "-D" command-line option, it tells pgpool to discard the status file on startup.<br>
<br>
</span><span class="HOEnZb"><font color="#888888">
</font></span><span class="HOEnZb"><font color="#888888">
</font></span><table>
<tbody><tr>
<td width="2" bgcolor="#0000ff"><br>
</td>
<td><span style="font-family:'times new roman';font-size:11pt;color:#1f497d">Hi Lucas,<br>
<br>
Thank you show much for your response, it works <span style="font-family:'wingdings'">⚐<br>
<br>
<span style="font-family:'times new roman'">In the status file before follow your sequence we can find the following values:<br>
up<br>
unused<br>
<br>
Once I have apply your suggested action plan now shows:<br>
up<br>
up<br>
<br>
Please can you let me know where I can get more details about the usage of this file, I can see on some documents that this file is it read during the start-up and I can see that the file it is not removed after the application shutdown (I do not know if it is the expected behavior).<br>
<br>
Regards<br>
<br>
<span style="color:#000000"><b>From:</b> Lucas Luengas [mailto:<a href="mailto:lucasluengas@gmail.com" target="_blank">lucasluengas@gmail.com</a><wbr>] <br>
<b>Sent:</b> miércoles, 10 de mayo de 2017 20:09<br>
<b>To:</b> Gabriel Fernández Martínez <<a href="mailto:gfernandez@hotelbeds.com" target="_blank">gfernandez@hotelbeds.com</a>><br>
<b>Cc:</b> <a href="mailto:pgpool-general@pgpool.net" target="_blank">pgpool-general@pgpool.net</a><br>
<b>Subject:</b> Re: [pgpool-general: 5445] FW: show pool_nodes status 0<br>
<br>
<span style="font-size:12pt">Hello.<br>
<br>
I don't use your pgpool-II version. I am using pgpool-II version 3.4.6.<br>
<br>
You can check pgpool status file. With pgpool-II version 3.4.6 the file is /tmp/pgpool_status by default. Check configuration "logdir" in your pgpool.conf.<br>
<br>
You can try:<br>
- Stop pgpool.<br>
- Remove pgpool status file (/tmp/pgpool_status by default)<br>
- Start pgpool.<br>
- Check node status.<br>
<br>
Kind regards.<br>
<br>
<br>
On Tue, May 9, 2017 at 12:00 PM, Gabriel Fernández Martínez <</span></span></span></span></span><a style="font-family:'times new roman';font-size:12pt" href="mailto:gfernandez@hotelbeds.com" target="_blank">gfernandez@hotelbeds.com</a><span style="font-family:'times new roman';font-size:12pt">> wrote:<br>
Hi,<br>
<br>
I am evaluating if PgPool can be useful to support the business activity of one application. For testing purposes, I have deploy a 3.5.2 pgpool release on the same server where I am running the primary PostgresSQL 9.5.<br>
<br>
I had deployed a two PosgresSQL nodes using streaming replication and I am trying to configure the pgpool like a load balancer, but I am stuck with the configuration because the standby server it is in status <span style="color:#1f497d">0<span style="color:#000000"> and no selects are run on this server<br>
<br>
******-web=> show pool_nodes;<br>
node_id | hostname | port | status | lb_weight | role | select_cnt<br>
---------+--------------------<wbr>--+------+--------+-----------<wbr>+---------+------------<br>
0 | *************196.*** | 5<span style="color:#1f497d">***<span style="color:#000000"> | 2 | 0.500000 | primary | 0<br>
1 | *************198.*** | 5<span style="color:#1f497d">***<span style="color:#000000"> | 0 | 0.500000 | standby | 0<br>
(2 filas)<br>
<br>
I had used the template pgpool.conf.sample-stream and I have modify the following parameters to adapt to my environment:<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">listen_addresses = '*'<br>
<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_hostname0 = '**********196.***'<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_port0 = 5***<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_weight0 = 1<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_data_directory0 = '/data/******1'<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_flag0 = 'ALLOW_TO_FAILOVER'<br>
<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_hostname1 = '**********198.***'<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_port1 = 5***<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_weight1 = 1<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_data_directory1 = '/data/******2'<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">backend_flag1 = 'ALLOW_TO_FAILOVER'<br>
<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">enable_pool_hba = on<br>
<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">logdir = '/var/log/pgpool-II-95'<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">pid_file_name = '/data/node1/pgpool-II-95/<wbr>pgpool.pid'<br>
<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">sr_check_user = 'pgpool'<br>
-<span style="font-size:7pt"> <span style="font-size:12pt">sr_check_password = '*********' <br>
<br>
I have created a user in the PostgreSQL cluster called pgpool and I have check that I can connect with this user to the Postgres database running on 196 & 198 nodes.<br>
<br>
>From the pgpool startup output log, I can see that the primary it is properly identified, but no explanation about why the standby show a status 0:<br>
2017-05-08 18:05:05: pid 17334: LOG: pgpool-II successfully started. version 3.5.2 (ekieboshi)<br>
2017-05-08 18:05:05: pid 17334: LOG: find_primary_node: checking backend no 0<br>
2017-05-08 18:05:05: pid 17368: DEBUG: I am 17368<br>
2017-05-08 18:05:05: pid 17368: DEBUG: initializing backend status<br>
2017-05-08 18:05:05: pid 17334: DEBUG: pool_read: read 13 bytes from backend 0<br>
2017-05-08 18:05:05: pid 17334: DEBUG: authenticate kind = 5<br>
2017-05-08 18:05:05: pid 17334: DEBUG: pool_write: to backend: kind:p<br>
2017-05-08 18:05:05: pid 17368: DEBUG: pool_read: read 13 bytes from backend 0<br>
2017-05-08 18:05:05: pid 17368: DEBUG: authenticate kind = 5<br>
2017-05-08 18:05:05: pid 17368: DEBUG: pool_write: to backend: kind:p<br>
2017-05-08 18:05:05: pid 17368: DEBUG: pool_read: read 327 bytes from backend 0<br>
2017-05-08 18:05:05: pid 17368: DEBUG: authenticate kind = 0<br>
2017-05-08 18:05:05: pid 17368: DEBUG: authenticate backend: key data received<br>
2017-05-08 18:05:05: pid 17334: DEBUG: pool_read: read 327 bytes from backend 0<br>
2017-05-08 18:05:05: pid 17368: DEBUG: authenticate backend: transaction state: I<br>
2017-05-08 18:05:05: pid 17334: DEBUG: authenticate kind = 0<br>
2017-05-08 18:05:05: pid 17368: DEBUG: pool_write: to backend: kind:X<br>
2017-05-08 18:05:05: pid 17334: DEBUG: authenticate backend: key data received<br>
2017-05-08 18:05:05: pid 17334: DEBUG: authenticate backend: transaction state: I<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: extended:0 query:"SELECT pg_is_in_recovery()"<br>
2017-05-08 18:05:05: pid 17334: DEBUG: pool_write: to backend: kind:Q<br>
2017-05-08 18:05:05: pid 17334: DEBUG: pool_read: read 75 bytes from backend 0<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: kind: 'T'<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: received ROW DESCRIPTION ('T')<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: row description: num_fileds: 1<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: kind: 'D'<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: received DATA ROW ('D')<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: kind: 'C'<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: received COMMAND COMPLETE ('C')<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: kind: 'Z'<br>
2017-05-08 18:05:05: pid 17334: DEBUG: do_query: received READY FOR QUERY ('Z')<br>
2017-05-08 18:05:05: pid 17334: DEBUG: pool_write: to backend: kind:X<br>
2017-05-08 18:05:05: pid 17334: LOG: find_primary_node: primary node id is 0<br>
<br>
I have executed the pgbench to verify the load balancing between nodes and I can show that only the master is supporting load:<br>
<span style="color:#1f497d">$ pgbench –h ********196.*** -p 9999 -c 10 -S -T 10 -U ******-web test<br>
Password:<br>
starting vacuum...end.<br>
transaction type: SELECT only<br>
scaling factor: 1<br>
query mode: simple<br>
number of clients: 10<br>
number of threads: 1<br>
duration: 10 s<br>
number of transactions actually processed: 218728<br>
latency average: 0.457 ms<br>
tps = 21871.048129 (including connections establishing)<br>
tps = 21879.150205 (excluding connections establishing)<br>
<br>
<span style="color:#000000">******-web=> show pool_nodes;<br>
node_id | hostname | port | status | lb_weight | role | select_cnt<br>
---------+--------------------<wbr>--+------+--------+-----------<wbr>+---------+------------<br>
0 | *************196.*** | 5*** | 2 | 0.500000 | primary | 218560<br>
1 | *************198.*** | 5*** | 0 | 0.500000 | standby | 0<br>
(2 filas)<br>
<br>
<br>
I had configured the pcp management in order to be able to use pcp_node_info, and I got the same output (as expected):<br>
<br>
[postgres@********196 ~]$ pcp_node_info -U pgpool -h ip-10-222-64-196.ods --node=0 -v<br>
Password:<br>
Hostname: *******196.***<br>
Port : 5***<br>
Status : 2<br>
Weight : 0.500000<br>
[postgres@********196~]$ pcp_node_info -U pgpool -h ip-10-222-64-196.ods --node=1 -v<br>
Password:<br>
Hostname: ********198.***<br>
Port : 5322<br>
Status : 0<br>
Weight : 0.500000<br>
<br>
<br>
Any suggestion is welcome, I have try to go thought the documentation and I cannot find any clue who help me to resolve the issue.<br>
<br>
Best regards<br>
<br>
<span style="color:#cc0066">Gabriel Fernández <br>
<span style="color:#5c5c5c"><b>Technology <br>
</b>Architecture<br>
<br>
<span style="color:#1f497d">tel: </span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><a style="font-family:'times new roman';font-size:12pt" href="tel:+34%20971%2018%2091%2088" target="_blank">(+34) 971 189 188</a><br>
<span style="font-family:'times new roman';font-size:12pt;color:#1f497d">Ed. Mirall Cami de Son Fangos 100, B-2<br>
E-07007, Palma de Mallorca, Spain <br>
</span><a style="font-family:'times new roman';font-size:10pt;font-weight:bold" href="mailto:gfernandez@hotelbeds.com" target="_blank">gfernandez@hotelbeds.com</a><br>
<br>
<a href="http://group.hotelbeds.com/" target="_blank"><img width="400" height="75" alt="" style="padding:1px" src="cid:FF23BD49.01D2CD73.08951B70.6C938B32_csseditor"></a><br>
<br>
<br>
<span style="font-family:'times new roman';font-size:12pt">______________________________<wbr>_________________<br>
pgpool-general mailing list<br>
</span><a style="font-family:'times new roman';font-size:12pt" href="mailto:pgpool-general@pgpool.net" target="_blank">pgpool-general@pgpool.net</a><br>
<a style="font-family:'times new roman';font-size:12pt" href="https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.pgpool.net%2Fmailman%2Flistinfo%2Fpgpool-general&data=02%7C01%7Cgfernandez%40hotelbeds.com%7C8c4054261a2c4f14b88508d497cfb45e%7Cde51db7560c744dfa7ec886324f5e521%7C0%7C0%7C636300365735508276&sdata=kt44KUzZ16TZIJVR7YmLBb%2B728ZSSU80mlPX50jGtIU%3D&reserved=0" target="_blank">http://www.pgpool.net/mailman/<wbr>listinfo/pgpool-general</a></td></tr></tbody></table><span class="HOEnZb"><font color="#888888">
<br><br>
<br>
<br>
<br>
<span style="font-family:'arial';font-size:10pt;color:#c0c0c0"><i>-- <br>
С уважением,<br>
PVY </i></span><a style="font-family:'arial';font-size:10pt" href="mailto:balroga3@yandex.ru" target="_blank">mailto:balroga3@yandex.ru</a> </font></span></div><br>______________________________<wbr>_________________<br>
pgpool-general mailing list<br>
<a href="mailto:pgpool-general@pgpool.net">pgpool-general@pgpool.net</a><br>
<a href="http://www.pgpool.net/mailman/listinfo/pgpool-general" rel="noreferrer" target="_blank">http://www.pgpool.net/mailman/<wbr>listinfo/pgpool-general</a><br>
<br></blockquote></div><br></div>