[pgpool-general: 7236] Re: Node status "lost" not recognized by standby PgPool

Bo Peng pengbo at sraoss.co.jp
Mon Aug 31 21:30:55 JST 2020


Hello,

On Fri, 28 Aug 2020 12:27:48 +0300 (FLE Daylight Time)
Anssi Kanninen <anssi at iki.fi> wrote:

> Hi everyone!
> 
> I'm having a problem with information exchange between PgPool instances. I 
> have 3 nodes, each containing one DB backend instance and one PgPool 
> instance.
> 
> If I shut down one standby node cleanly, everything seems to go ok. The 
> master PgPool notices that and informs the remaining standby PgPool about 
> it.
> 
> But the situation changes if a standby node just vahishes from the network 
> by powering it off without clean shutdown. The master PgPool marks the 
> node as "lost" but the remaining standby PgPool still thinks we are having 
> another standby PgPool. It doesn't get any information about a lost node.

How did you shutdown pgpool node?
Could you share the pgpool.log of each node?

> Here it goes. In the example I'm checking the statuses by connecting each 
> node with pcp_watchdog_info . I have sorted the results by node hostname.
> 
> Nodes are:
> * ID 0 (centos8i1-int)
> * ID 1 (centos8i2-int)
> * ID 2 (centos8i3-int).
> 
> ***** INITIAL SETUP *****
> 
> $ pcp_watchdog_info -w -h centos8i1-int
> 3 YES centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> $ pcp_watchdog_info -w -h centos8i2-int
> 3 NO centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> $ pcp_watchdog_info -w -h centos8i3-int
> 3 NO centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> ***** SHUTDOWN node ID 1 *****
> 
> $ pcp_watchdog_info -w -h centos8i1-int
> 3 YES centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 10 SHUTDOWN
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> $ pcp_watchdog_info -w -h centos8i3-int
> 3 NO centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 10 SHUTDOWN
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> ***** RESTART node ID 1 *****
> 
> $ pcp_watchdog_info -w -h centos8i1-int
> 3 YES centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> $ pcp_watchdog_info -w -h centos8i2-int
> 3 NO centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> $ pcp_watchdog_info -w -h centos8i3-int
> 3 NO centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> ***** POWER OFF node ID 1 *****
> 
> $ pcp_watchdog_info -w -h centos8i1-int
> 3 YES centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 8 LOST
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> $ pcp_watchdog_info -w -h centos8i3-int
> 3 NO centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int
> 
> centos8i1-int:5432 Linux centos8i1.localdomain centos8i1-int 5432 9000 4 MASTER
> centos8i2-int:5432 Linux centos8i2.localdomain centos8i2-int 5432 9000 7 STANDBY
> centos8i3-int:5432 Linux centos8i3.localdomain centos8i3-int 5432 9000 7 STANDBY
> 
> 
> Best regards,
> Anssi Kanninen
> 
> 
> 
> 
> -- 
> anssi at iki.fi
> _______________________________________________
> pgpool-general mailing list
> pgpool-general at pgpool.net
> http://www.pgpool.net/mailman/listinfo/pgpool-general


-- 
Bo Peng <pengbo at sraoss.co.jp>
SRA OSS, Inc. Japan


More information about the pgpool-general mailing list