Re: Maximum number of WAL files in the pg_xlog directory - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Maximum number of WAL files in the pg_xlog directory
Date
Msg-id 20141126230050.GB15839@momjian.us
Whole thread Raw
In response to Re: Maximum number of WAL files in the pg_xlog directory  (Jeff Janes <jeff.janes@gmail.com>)
Responses Re: Maximum number of WAL files in the pg_xlog directory  (Guillaume Lelarge <guillaume@lelarge.info>)
List pgsql-hackers
On Mon, Nov  3, 2014 at 12:39:26PM -0800, Jeff Janes wrote:
> It looked to me that the formula, when descending from a previously stressed
> state, would be:
> 
> greatest(1 + checkpoint_completion_target) * checkpoint_segments,
> wal_keep_segments) + 1 + 
> 2 * checkpoint_segments + 1 

I don't think we can assume checkpoint_completion_target is at all
reliable enough to base a maximum calculation on, assuming anything
above the maximum is cause of concern and something to inform the admins
about.

Assuming checkpoint_completion_target is 1 for maximum purposes, how
about:
max(2 * checkpoint_segments, wal_keep_segments) + 2 * checkpoint_segments + 2

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + Everyone has their own god. +



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