Horton

Re: Restricting maximum keep segments by repslots

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

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From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Cc: pgsql-hackers@postgresql.org
Date: 2017-03-03T19:47:20Z
Lists: pgsql-hackers 
On 3/1/17 19:54, Kyotaro HORIGUCHI wrote:
>> Please measure it in size, not in number of segments.
> It was difficult to dicide which is reaaonable but I named it
> after wal_keep_segments because it has the similar effect.
> 
> In bytes(or LSN)
>  max_wal_size
>  min_wal_size
>  wal_write_flush_after
> 
> In segments
>  wal_keep_segments

We have been moving away from measuring in segments.  For example,
checkpoint_segments was replaced by max_wal_size.

Also, with the proposed patch that allows changing the segment size more
easily, this will become more important.  (I wonder if that will require
wal_keep_segments to change somehow.)

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Save slot's restart_lsn when invalidated due to size

  2. Fix checkpoint signalling

  3. Check slot->restart_lsn validity in a few more places

  4. Allow users to limit storage reserved by replication slots

  5. Remove header noise from test_decoding test

  6. Rework WAL-reading supporting structs

  7. Flip argument order in XLogSegNoOffsetToRecPtr