Horton

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

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Erik Rijkers <er@xs4all.nl>, Kuntal Ghosh <kuntalghosh.2007@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-07-22T10:50:18Z
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, Jul 22, 2020 at 10:20 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Wed, Jul 22, 2020 at 9:18 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > On Mon, Jul 20, 2020 at 6:46 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > >
> > > There was one warning in release mode in the last version in 0004 so
> > > attaching a new version.
> > >
> >
> > Today, I was reviewing patch
> > v38-0001-WAL-Log-invalidations-at-command-end-with-wal_le and found a
> > small problem with it.
> >
> > + /*
> > + * Execute the invalidations for xid-less transactions,
> > + * otherwise, accumulate them so that they can be processed at
> > + * the commit time.
> > + */
> > + if (!ctx->fast_forward)
> > + {
> > + if (TransactionIdIsValid(xid))
> > + {
> > + ReorderBufferAddInvalidations(reorder, xid, buf->origptr,
> > +   invals->nmsgs, invals->msgs);
> > + ReorderBufferXidSetCatalogChanges(ctx->reorder, xid,
> > +   buf->origptr);
> > + }
> >
> > I think we need to set ReorderBufferXidSetCatalogChanges even when
> > ctx->fast-forward is true because we are dependent on that flag for
> > snapshot build (see SnapBuildCommitTxn).  We are already doing the
> > same way in DecodeCommit where even though we skip adding
> > invalidations for fast-forward cases but we do set the flag to
> > indicate that this txn has catalog changes.  Is there any reason to do
> > things differently here?
>
> I think it is wrong,  we should set the
> ReorderBufferXidSetCatalogChanges, even if it is in fast-forward mode.
>

Thanks for the change.  I have one more minor comment in the patch
0001-WAL-Log-invalidations-at-command-end-with-wal_le.

 /*
+ * Invalidations logged with wal_level=logical.
+ */
+typedef struct xl_xact_invalidations
+{
+ int nmsgs; /* number of shared inval msgs */
+ SharedInvalidationMessage msgs[FLEXIBLE_ARRAY_MEMBER];
+} xl_xact_invalidations;

I see that we already have a structure xl_xact_invals in the code
which has the same members, so I think it is better to use that
instead of defining a new one.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com