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Re: increasing the default WAL segment size

tushar <tushar.ahuja@enterprisedb.com>

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From: tushar <tushar.ahuja@enterprisedb.com>
To: Beena Emerson <memissemerson@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: Kuntal Ghosh <kuntalghosh.2007@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Stephen Frost <sfrost@snowman.net>, David Steele <david@pgmasters.net>, Prabhat Sahu <prabhat.sahu@enterprisedb.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Jim Nasby <Jim.Nasby@bluetreble.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>
Date: 2017-07-06T09:51:41Z
Lists: pgsql-hackers 
On 07/06/2017 12:04 PM, Beena Emerson wrote:
> The 04-initdb-walsegsize_v2.patch has the following improvements:
> - Rebased over new 03 patch
> - Pass the wal-segsize intidb option as command-line option rathern
> than in an environment variable.
> - Since new function check_wal_size had only had two checks and was
> sed once, moved the code to ReadControlFile where it is used and
> removed this function.
> - improve comments and add validations where required.
> - Use DEFAULT_XLOG_SEG_SIZE to set the min_wal_size and
> max_wal_size,instead of the value 16.
> - Use XLogSegMaxSize and XLogSegMinSize to calculate the range of guc
> wal_segment_size instead 16 - INT_MAX.
Thanks Beena. I tested with below following scenarios  and all are 
working as expected
.)Different WAL segment size i.e 1,2,8,16,32,64,512,1024 at the time of 
initdb
.)SR setup in place.
.)Combinations of  max/min_wal_size in postgresql.conf with different 
wal_segment_size.
.)shutdown the server forcefully (kill -9) / promote slave / to make 
sure -recovery happened successfully.
.)with different utilities like pg_resetwal/pg_upgrade/pg_waldump
.)running pg_bench for substantial workloads (~ 1 hour)
.)WAL segment size is not default (changed at the time of ./configure) + 
different wal_segment_size (at the time of initdb) .

Things looks fine.

-- 
regards,tushar
EnterpriseDB  https://www.enterprisedb.com/
The Enterprise PostgreSQL Company

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Make WAL segment size configurable at initdb time.

  2. Perform only one ReadControlFile() during startup.

  3. Introduce BYTES unit for GUCs.

  4. Remove useless duplicate inclusions of system header files.

  5. Refactor other replication commands to use DestRemoteSimple.

  6. Add a SHOW command to the replication command language.

  7. Add a new DestReceiver for printing tuples without catalog access.

  8. Support fls().

  9. Extend yesterday's patch making BLCKSZ and RELSEG_SIZE configurable to also

  10. Commit the reasonably uncontroversial parts of J.R. Nield's PITR patch, to

  11. XLOG (also known as WAL -:)) Bootstrap/Startup/Shutdown.

  12. Transaction log manager core code.