View Issue Details

IDProjectCategoryView StatusLast Update
0000223Pgpool-IIBugpublic2016-12-20 14:03
Reporterrmwpl Assigned Tot-ishii  
PriorityhighSeveritymajorReproducibilitysometimes
Status closedResolutionopen 
Platformx86_64OSGNU/LinuxOS VersionCentOS 6.6
Summary0000223: PgPool performs load balancing even when it's disabled
DescriptionHi,

I'm running PgPool with:
load_balance_mode = off
master_slave_mode = on
master_slave_sub_mode = 'stream'

I have 4 nodes. Node ID=1 is the primary.

Most of the time everything works fine - new connections are routed to the primary DB node.
But sometimes I'm getting an error like this:
"ERROR - DBIx::Class::Storage::DBI::_dbh_execute(): DBI Exception: DBD::Pg::st execute failed: FATAL: unable to read data from DB node 0
DETAIL: EOF encountered with backend
FATAL: unable to read data from DB node 0
DETAIL: EOF encountered with backend [for Statement "INSERT INTO public...."

Basically, although load balancing is specifically disabled, PgPool routes some INSERT queries to a standby DB node.

We've been doing a lot of INSERTs and it was all fine. But few weeks ago we've disabled connection_cache. It's the only change made to PgPool's configuration lately.
Steps To ReproduceSet master_slave_mode to on/stream and load_balance_mode to off.
Have 4 nodes, do a lot of INSERTs.
Probably also disable connection_cache.
Tagsconnection cache, load balancing, master slave, streaming replication

Activities

t-ishii

2016-07-26 23:34

developer   ~0000933

Which version of pgpool-II?

rmwpl

2016-07-26 23:51

reporter   ~0000934

pgpool-II-95-3.4.3-4.rhel6.x86_64

t-ishii

2016-07-27 00:11

developer   ~0000935

It's not the rpm file name I know of. Anyway, I guess it's too old version. Please upgrade to the latest version (hint: 3.4.7).

rmwpl

2016-07-27 00:17

reporter   ~0000936

# pgpool --version
pgpool-II version 3.4.3 (tataraboshi)

rmwpl

2016-07-27 00:18

reporter   ~0000937

Do you mean that's a known bug that has been fixed in the latest version?

rmwpl

2016-07-27 00:22

reporter   ~0000938

Oh, I see a potential bug that might have caused the problem for me.
Do you gather it's the same case as in the "Deal with the case when the primary is not node 0 in streaming replication mode. (Tatsuo Ishii)" changelog item?

t-ishii

2016-07-27 00:26

developer   ~0000939

Yes, that's my thought.

rmwpl

2016-07-27 00:29

reporter   ~0000940

Thanks, that's helpful. I will upgrade then and report back if the error persists.

rmwpl

2016-08-25 20:43

reporter   ~0001023

Tried upgrading to 3.5.3, but it doesn't work properly. I brings the delegate ip up and after a seconds it brings it down and shuts down.

t-ishii

2016-09-23 15:28

developer   ~0001082

Do you know how to reproduce the problem?
Without knowing it, it's pretty hard to debug...

t-ishii

2016-12-20 14:03

developer   ~0001240

No action from the reporter over 1 month. Issue closed.

Issue History

Date Modified Username Field Change
2016-07-26 22:03 rmwpl New Issue
2016-07-26 22:03 rmwpl Tag Attached: connection cache
2016-07-26 22:03 rmwpl Tag Attached: load balancing
2016-07-26 22:03 rmwpl Tag Attached: master slave
2016-07-26 22:03 rmwpl Tag Attached: streaming replication
2016-07-26 23:33 t-ishii Assigned To => t-ishii
2016-07-26 23:33 t-ishii Status new => assigned
2016-07-26 23:34 t-ishii Note Added: 0000933
2016-07-26 23:51 rmwpl Note Added: 0000934
2016-07-27 00:11 t-ishii Note Added: 0000935
2016-07-27 00:17 rmwpl Note Added: 0000936
2016-07-27 00:18 rmwpl Note Added: 0000937
2016-07-27 00:22 rmwpl Note Added: 0000938
2016-07-27 00:26 t-ishii Note Added: 0000939
2016-07-27 00:29 rmwpl Note Added: 0000940
2016-07-27 07:44 t-ishii Status assigned => feedback
2016-08-25 20:43 rmwpl Note Added: 0001023
2016-08-25 20:43 rmwpl Status feedback => assigned
2016-09-23 15:28 t-ishii Note Added: 0001082
2016-09-23 15:28 t-ishii Status assigned => feedback
2016-12-20 14:03 t-ishii Note Added: 0001240
2016-12-20 14:03 t-ishii Status feedback => closed