Re: Add WAL read stats to pg_stat_wal

2023-02-20 Thread Kyotaro Horiguchi
At Mon, 20 Feb 2023 20:15:00 +0530, Bharath Rupireddy wrote in > Having said that, what's the problem if we use shared memory to report > the shutdown checkpoint to the postmaster? In case of abnormal > shutdown where shared memory gets corrupted, we don't even write a > shutdown checkpoint,

Re: Add WAL read stats to pg_stat_wal

2023-02-20 Thread Kyotaro Horiguchi
At Mon, 20 Feb 2023 08:29:06 -0800, Andres Freund wrote in > Hi, > > On 2023-02-20 14:21:39 +0900, Kyotaro Horiguchi wrote: > > I totally agree that it will be useful, but I'm not quite sure how > > checkpointer would be able to let postmaster know about that state > > without requiring access

Re: Add WAL read stats to pg_stat_wal

2023-02-20 Thread Andres Freund
Hi, On 2023-02-20 14:21:39 +0900, Kyotaro Horiguchi wrote: > I totally agree that it will be useful, but I'm not quite sure how > checkpointer would be able to let postmaster know about that state > without requiring access to shared memory.

Re: Add WAL read stats to pg_stat_wal

2023-02-20 Thread Bharath Rupireddy
On Mon, Feb 20, 2023 at 10:51 AM Kyotaro Horiguchi wrote: > > At Thu, 16 Feb 2023 11:11:38 -0800, Andres Freund wrote > in > > I wonder if we should keep the checkpointer around for longer. If we have > > checkpointer signal postmaster after it wrote the shutdown checkpoint, > > postmaster

Re: Add WAL read stats to pg_stat_wal

2023-02-20 Thread Bharath Rupireddy
On Fri, Feb 17, 2023 at 12:41 AM Andres Freund wrote: > > On 2023-02-16 23:39:00 +0530, Bharath Rupireddy wrote: > > While working on [1], I was in need to know WAL read stats (number of > > times and amount of WAL data read from disk, time taken to read) to > > measure the benefit. I had to

Re: Add WAL read stats to pg_stat_wal

2023-02-19 Thread Kyotaro Horiguchi
At Thu, 16 Feb 2023 11:11:38 -0800, Andres Freund wrote in > I wonder if we should keep the checkpointer around for longer. If we have > checkpointer signal postmaster after it wrote the shutdown checkpoint, > postmaster could signal walsenders to shut down, and checkpointer could do > some

Re: Add WAL read stats to pg_stat_wal

2023-02-16 Thread Andres Freund
Hi, On 2023-02-16 23:39:00 +0530, Bharath Rupireddy wrote: > While working on [1], I was in need to know WAL read stats (number of > times and amount of WAL data read from disk, time taken to read) to > measure the benefit. I had to write a developer patch to capture WAL > read stats as

Add WAL read stats to pg_stat_wal

2023-02-16 Thread Bharath Rupireddy
c123e4f5e94cbb4881ce4d65c9dec3c4d5d72778 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy Date: Wed, 15 Feb 2023 13:29:22 + Subject: [PATCH v1] Add WAL read stats to pg_stat_wal --- doc/src/sgml/monitoring.sgml | 32 + src/backend/access/transam/xlogreader.c | 32 + src