RE: LWLocks by LockManager slowing large DB

[Paul Friedman <paul.friedman@xxxxxxxxxxxxxxxxxxx>]

Thanks for this – these tools (and the raw selects on pg_stat_activity and pg_locks) are all showing wait events being created by LockManager waiting on an LWLock.

 

---Paul

 

Paul Friedman

CTO

 

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M: (650) 270-7676

E-mail: paul.friedman@xxxxxxxxxxxxxxxxxxx

 

From: Nikolay Samokhvalov <samokhvalov@xxxxxxxxx>
Sent: Monday, April 12, 2021 4:34 PM
To: Andres Freund <andres@xxxxxxxxxxx>
Cc: Paul Friedman <paul.friedman@xxxxxxxxxxxxxxxxxxx>; pgsql-performance@xxxxxxxxxxxxxxxxxxxx
Subject: Re: LWLocks by LockManager slowing large DB

 

 

 

On Mon, Apr 12, 2021 at 14:57 Andres Freund <andres@xxxxxxxxxxx> wrote:

Without knowing the proportion of LockManager wait events compared to
the rest it's hard to know what to make of it.

 

These OSS tools can be useful to understand the proportion:

 

- pgCenter 

https://github.com/lesovsky/pgcenter

- pg_wait_sampling (can be used together with POWA monitoring) 

https://github.com/postgrespro/pg_wait_sampling

- pgsentinel 

https://github.com/pgsentinel/pgsentinel

- PASH Viewer (good for visualization, integrates with pgsentinel) 

https://github.com/dbacvetkov/PASH-Viewer