DROP queries are hanged if powa is enabled

[anikin-aa]

Hi !

We are facing next issue during using POWA and PostgreSQL 15:

1. Deploy PostgreSQL + POWA related extensions in shared_preload_libraries
2. Create some test data
3. Issue drop database query
4. It will hang, with next PostgreSQL logs:

[2023-01-30 15:01:16.758 UTC][source=postgresql]STATEMENT:  drop database testdb_kmlbp_0;
[2023-01-30 15:01:21.760 UTC][source=postgresql]LOG:  still waiting for backend with PID 3173 to accept ProcSignalBarrier

process with 3173 is POWA:

postgres   3173  0.0  0.2 333920 54248 ?        Ss   14:30   0:01 postgres: patroni: powa idle

I am using local mode of powa with the bgworker

I've found similar issue for timescaledb, may be it related somehow timescale/timescaledb#4838

[anikin-aa]

@rjuju , i will try to prepare local test case during the day if it's still needed

[rjuju]

Thanks, but it shouldn't be necessary as the error message you mentioned clarified the problem.

I just pushed 085d379 which should solve the problem. If you can test a local build, could you confirm that it also solves the problem for you?

[anikin-aa]

ok, will try during the day and share results

[anikin-aa]

@rjuju , yes, it's working with your latest changes ! Thank you !

[rjuju]

Great news, thanks for the feedback!