Thread: [HACKERS] inconsistent application_name use in logical workers
The logical replication code is supposed to use the subscription name as the fallback_application_name, but in some cases it uses the slot name, which could be different. See attached patch to correct this. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
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On 06/06/17 04:19, Peter Eisentraut wrote: > The logical replication code is supposed to use the subscription name as > the fallback_application_name, but in some cases it uses the slot name, > which could be different. See attached patch to correct this. > Hmm, well the differentiation has a reason though. The application_name is used for sync rep and having synchronization connection using same application_name might have adverse effects there because synchronization connection can be in-front of main apply one, so sync rep will think something is consumed while it's not. -- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
On 6/6/17 06:51, Petr Jelinek wrote: > On 06/06/17 04:19, Peter Eisentraut wrote: >> The logical replication code is supposed to use the subscription name as >> the fallback_application_name, but in some cases it uses the slot name, >> which could be different. See attached patch to correct this. > > Hmm, well the differentiation has a reason though. The application_name > is used for sync rep and having synchronization connection using same > application_name might have adverse effects there because > synchronization connection can be in-front of main apply one, so sync > rep will think something is consumed while it's not. True, we should use a different name for tablesync.c. But the one in worker.c appears to be a mistake then? -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
On 06/06/17 15:07, Peter Eisentraut wrote: > On 6/6/17 06:51, Petr Jelinek wrote: >> On 06/06/17 04:19, Peter Eisentraut wrote: >>> The logical replication code is supposed to use the subscription name as >>> the fallback_application_name, but in some cases it uses the slot name, >>> which could be different. See attached patch to correct this. >> >> Hmm, well the differentiation has a reason though. The application_name >> is used for sync rep and having synchronization connection using same >> application_name might have adverse effects there because >> synchronization connection can be in-front of main apply one, so sync >> rep will think something is consumed while it's not. > > True, we should use a different name for tablesync.c. But the one in > worker.c appears to be a mistake then? > Yes. -- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
On 6/6/17 13:24, Petr Jelinek wrote: > On 06/06/17 15:07, Peter Eisentraut wrote: >> On 6/6/17 06:51, Petr Jelinek wrote: >>> On 06/06/17 04:19, Peter Eisentraut wrote: >>>> The logical replication code is supposed to use the subscription name as >>>> the fallback_application_name, but in some cases it uses the slot name, >>>> which could be different. See attached patch to correct this. >>> >>> Hmm, well the differentiation has a reason though. The application_name >>> is used for sync rep and having synchronization connection using same >>> application_name might have adverse effects there because >>> synchronization connection can be in-front of main apply one, so sync >>> rep will think something is consumed while it's not. >> >> True, we should use a different name for tablesync.c. But the one in >> worker.c appears to be a mistake then? > > Yes. Committed and added a comment. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services