Horton

Re: [HACKERS] make async slave to wait for lsn to be replayed

Alexander Korotkov <aekorotkov@gmail.com>

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From: Alexander Korotkov <aekorotkov@gmail.com>
To: Andy Fan <zhihuifan1213@163.com>
Cc: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Kartyshov Ivan <i.kartyshov@postgrespro.ru>, Euler Taveira <euler@eulerto.com>, Thomas Munro <thomas.munro@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, Amit Kapila <amit.kapila16@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Peter Smith <smithpb2250@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-04-02T08:08:17Z
Lists: pgsql-hackers 
Hi, Andy!

On Tue, Apr 2, 2024 at 6:29 AM Andy Fan <zhihuifan1213@163.com> wrote:
> >  Did you forget to attach the new patch?
> >
> > Yes, here it is.
> >
> > [4. text/x-diff; v17-0001-Implement-pg_wal_replay_wait-stored-procedure.patch]...
>
> +        </indexterm>
> +        <function>pg_wal_replay_wait</function> (
> +          <parameter>target_lsn</parameter> <type>pg_lsn</type>,
> +          <parameter>timeout</parameter> <type>bigint</type> <literal>DEFAULT</literal> <literal>0</literal>)
> +        <returnvalue>void</returnvalue>
> +       </para>
>
> Should we return the millseconds of waiting time?  I think this
> information may be useful for customer if they want to know how long
> time it waits for for minitor purpose.

Please, check it more carefully.  In v17 timeout is in integer milliseconds.

------
Regards,
Alexander Korotkov

Commits

  1. Ensure standby promotion point in 043_wal_replay_wait.pl

  2. Minor cleanup related to pg_wal_replay_wait() procedure

  3. Adjust pg_wal_replay_wait() procedure behavior on promoted standby

  4. pg_wal_replay_wait(): Fix typo in the doc

  5. Implement pg_wal_replay_wait() stored procedure

  6. Revert: Implement pg_wal_replay_wait() stored procedure

  7. Call WaitLSNCleanup() in AbortTransaction()

  8. Clarify what is protected by WaitLSNLock

  9. Use an LWLock instead of a spinlock in waitlsn.c

  10. Use the pairing heap instead of a flat array for LSN replay waiters

  11. Minor improvements for waitlsn.c

  12. Make the order of the header file includes consistent