Re: Race condition in recovery?

Dilip Kumar <dilipbalaut@gmail.com>

From: Dilip Kumar <dilipbalaut@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>, hlinnaka <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-06-08T08:47:06Z
Lists: pgsql-hackers

Attachments

On Tue, Jun 8, 2021 at 11:13 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> # Wait until the node exits recovery.
> $standby->poll_query_until('postgres', "SELECT pg_is_in_recovery() = 'f';")
> or die "Timed out while waiting for promotion";
>
> I will try to generate a version for 9.6 based on this idea and see how it goes

I have changed for as per 9.6 but I am seeing some crash (both
with/without fix), I could not figure out the reason, it did not
generate any core dump, although I changed pg_ctl in PostgresNode.pm
to use "-c" so that it can generate core but it did not generate any
core file.

This is log from cascading node (025_stuck_on_old_timeline_cascade.log)
-------------
cp: cannot stat
‘/home/dilipkumar/work/PG/postgresql/src/test/recovery/tmp_check/data_primary_52dW/archives/000000010000000000000003’:
No such file or directory
WARNING:  terminating connection because of crash of another server process
DETAIL:  The postmaster has commanded this server process to roll back
the current transaction and exit, because another server process
exited abnormally and possibly corrupted shared memory.
HINT:  In a moment you should be able to reconnect to the database and
repeat your command.
FATAL:  could not receive database system identifier and timeline ID
from the primary server: server closed the connection unexpectedly
                This probably means the server terminated abnormally
                before or while processing the request.
--------------

The attached logs are when I ran without a fix.

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

Commits

  1. Further refinement of stuck_on_old_timeline recovery test

  2. Adjust new test case to set wal_keep_segments.

  3. Adjust new test case to set wal_keep_size.

  4. Fix corner case failure of new standby to follow new primary.

  5. Back-port a few PostgresNode.pm methods.

  6. Allow PostgresNode.pm's backup method to accept backup_options.

  7. Add end-to-end testing of pg_basebackup's tar-format output.

  8. Allow PostgresNode.pm tests to wait for catchup

  9. Delay reading timeline history file until it's fetched from master.