Horton

Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Neha Sharma <neha.sharma@enterprisedb.com>
Cc: Bruce Momjian <bruce@momjian.us>, Greg Nancarrow <gregn4422@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Ashutosh Sharma <ashu.coek88@gmail.com>
Date: 2021-12-21T12:04:09Z
Lists: pgsql-hackers 
On Thu, Dec 16, 2021 at 9:26 PM Neha Sharma
<neha.sharma@enterprisedb.com> wrote:
>
> Hi,
>
> While testing the v8 patches in a hot-standby setup, it was observed the master is crashing with the below error;
>
> 2021-12-16 19:32:47.757 +04 [101483] PANIC:  could not fsync file "pg_tblspc/16385/PG_15_202112111/16386/16391": No such file or directory
> 2021-12-16 19:32:48.917 +04 [101482] LOG:  checkpointer process (PID 101483) was terminated by signal 6: Aborted
>
> Parameters configured at master:
> wal_level = hot_standby
> max_wal_senders = 3
> hot_standby = on
> max_standby_streaming_delay= -1
> wal_consistency_checking='all'
> max_wal_size= 10GB
> checkpoint_timeout= 1d
> log_min_messages=debug1
>
> Test Case:
> create tablespace tab1 location '/home/edb/PGsources/postgresql/inst/bin/test1';
> create tablespace tab location '/home/edb/PGsources/postgresql/inst/bin/test';
> create database test tablespace tab;
> \c test
> create table t( a int PRIMARY KEY,b text);
> CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS 'select array_agg(md5(g::text))::text from generate_series(1, 256) g';
> insert into t values (generate_series(1,100000), large_val());
> alter table t set tablespace tab1 ;
> \c postgres
> create database test1 template test;
> \c test1
> alter table t set tablespace tab;
> \c postgres
> alter database test1 set tablespace tab1;
>
> --cancel the below command
> alter database test1 set tablespace pg_default; --press ctrl+c
> \c test1
> alter table t set tablespace tab1;
>
>
> Log file attached for reference.

Seems like this is an existing issue and I am able to reproduce on the
PostgreSQL head as well [1]

[1] https://www.postgresql.org/message-id/CAFiTN-szX%3DayO80EnSWonBu1YMZrpOr9V0R3BzHBSjMrMPAeMg%40mail.gmail.com

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. When using the WAL-logged CREATE DATABASE strategy, bulk extend.

  2. Avoid using a fake relcache entry to own an SmgrRelation.

  3. Fix data-corruption hazard in WAL-logged CREATE DATABASE.

  4. initdb: When running CREATE DATABASE, use STRATEGY = WAL_COPY.

  5. Simplify a needlessly-complicated regular expression.

  6. In 020_createdb.pl, change order of command-line arguments.

  7. Add new block-by-block strategy for CREATE DATABASE.

  8. Fix replay of create database records on standby

  9. Refactor code for reading and writing relation map files.

  10. Replace RelationOpenSmgr() with RelationGetSmgr().

  11. Refactor the fsync queue for wider use.