Horton

Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-11-14T04:07:30Z
Lists: pgsql-hackers

Commits

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

  1. Tighten the concurrent abort check during decoding.

  2. Improve hash_create()'s API for some added robustness.

  3. Use HASH_BLOBS for xidhash.

  4. Fix initialization of RelationSyncEntry for streaming transactions.

  5. Remove unused function declaration in logicalproto.h.

  6. Add additional tests to test streaming of in-progress transactions.

  7. Fix inline marking introduced in commit 464824323e.

  8. Add support for streaming to built-in logical replication.

  9. Fix the SharedFileSetUnregister API.

  10. Fix comment in procarray.c

  11. Suppress compiler warning in non-cassert builds.

  12. Extend the BufFile interface.

  13. Mark a few logical decoding related variables with PGDLLIMPORT.

  14. Implement streaming mode in ReorderBuffer.

  15. Extend the logical decoding output plugin API with stream methods.

  16. WAL Log invalidations at command end with wal_level=logical.

  17. Immediately WAL-log subtransaction and top-level XID association.

  18. Allow logical replication to transfer data in binary format.

  19. Only superuser can set sslcert/sslkey in postgres_fdw user mappings

  20. Track statistics for spilling of changes from ReorderBuffer.

  21. Add logical_decoding_work_mem to limit ReorderBuffer memory usage.

  22. logical decoding: process ASSIGNMENT during snapshot build

  23. Emit invalidations to standby for transactions without xid.

On Wed, Nov 13, 2019 at 5:55 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Thu, Oct 3, 2019 at 1:18 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
>
> As mentioned by me a few days back that the first patch in this series
> is ready to go [1] (I am hoping Tomas will pick it up), so I have
> started the review of other patches
>
> Review/Questions on 0002-Immediately-WAL-log-assignments.patch
> -------------------------------------------------------------------------------------------------
> 1. This patch adds the top_xid in WAL whenever the first time WAL for
> a subtransaction XID is written to correctly decode the changes of
> in-progress transaction.  This patch also removes logging and applying
> WAL for XLOG_XACT_ASSIGNMENT which might have some effect.  As replay
> of that, it prunes KnownAssignedXids to prevent overflow of that
> array.  See comments in procarray.c (KnownAssignedTransactionIds
> sub-module).  Can you please explain how after removing the WAL for
> XLOG_XACT_ASSIGNMENT, we will handle that or I am missing something
> and there is no impact of same?

It seems like a problem to me as well.   One option could be that
since now we are adding the top transaction id in the first WAL of the
subtransaction we can directly update the pg_subtrans and avoid adding
sub transaction id in the KnownAssignedXids and mark it as
lastOverflowedXid.  But, I don't think we should go in that direction
otherwise it will impact the performance of visibility check on the
hot-standby.  Let's see what Tomas has in mind.

>
> 2.
> +#define XLOG_INCLUDE_INVALS 0x08 /* include invalidations */
>
> This doesn't seem to be used in this patch.

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