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: 2020-06-26T06:17:42Z
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 Thu, Jun 25, 2020 at 7:11 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Wed, Jun 24, 2020 at 4:04 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> >
> > Review comments on various patches.
> >
> > poc_shared_fileset_cleanup_on_procexit
> > =================================
> > 1.
> > - ent->subxact_fileset =
> > - MemoryContextAlloc(ApplyContext, sizeof(SharedFileSet));
> > + MemoryContext oldctx;
> >
> > + /* Shared fileset handle must be allocated in the persistent context */
> > + oldctx = MemoryContextSwitchTo(ApplyContext);
> > + ent->subxact_fileset = palloc(sizeof(SharedFileSet));
> >   SharedFileSetInit(ent->subxact_fileset, NULL);
> > + MemoryContextSwitchTo(oldctx);
> >   fd = BufFileCreateShared(ent->subxact_fileset, path);
> >
> > Why is this change required for this patch and why we only cover
> > SharedFileSetInit in the Apply context and not BufFileCreateShared?
> > The comment is also not very clear on this point.
>
> Added the comments for the same.
>

1.
+ /*
+ * Shared fileset handle must be allocated in the persistent context.
+ * Also, SharedFileSetInit allocate the memory for sharefileset list
+ * so we need to allocate that in the long term meemory context.
+ */

How about "We need to maintain shared fileset across multiple stream
open/close calls.  So, we allocate it in a persistent context."

2.
+ /*
+ * If the caller is following the dsm based cleanup then we don't
+ * maintain the filesetlist so return.
+ */
+ if (filesetlist == NULL)
+ return;

The check here should use 'NIL' instead of 'NULL'

Other than that the changes in this particular patch looks good to me.

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