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: vignesh C <vignesh21@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Michael Paquier <michael@paquier.xyz>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-12-24T04:24:13Z
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 Sun, Dec 22, 2019 at 5:04 PM vignesh C <vignesh21@gmail.com> wrote:
>
> Few comments:
> assert variable should be within #ifdef USE_ASSERT_CHECKING in patch
> v2-0008-Add-support-for-streaming-to-built-in-replication.patch:
> +               int64           subidx;
> +               bool            found = false;
> +               char            path[MAXPGPATH];
> +
> +               subidx = -1;
> +               subxact_info_read(MyLogicalRepWorker->subid, xid);
> +
> +               /* FIXME optimize the search by bsearch on sorted data */
> +               for (i = nsubxacts; i > 0; i--)
> +               {
> +                       if (subxacts[i - 1].xid == subxid)
> +                       {
> +                               subidx = (i - 1);
> +                               found = true;
> +                               break;
> +                       }
> +               }
> +
> +               /* We should not receive aborts for unknown subtransactions. */
> +               Assert(found);
>

We can use PG_USED_FOR_ASSERTS_ONLY for that variable.

>
> Should we include printing of id here like in earlier cases in
> v2-0002-Issue-individual-invalidations-with-wal_level-log.patch:
> +                       appendStringInfo(buf, " relcache %u", msg->rc.relId);
> +               /* not expected, but print something anyway */
> +               else if (msg->id == SHAREDINVALSMGR_ID)
> +                       appendStringInfoString(buf, " smgr");
> +               /* not expected, but print something anyway */
> +               else if (msg->id == SHAREDINVALRELMAP_ID)
> +                       appendStringInfo(buf, " relmap db %u", msg->rm.dbId);
>

I am not sure if this patch is logging these invalidations, so not
sure if it makes sense to add more ids in the cases you are referring
to.  However, if we change it to logging all invalidations at command
end as being discussed in this thread, then it might be better to do
what you are suggesting.

>
> Should we can add function header for AssertChangeLsnOrder in
> v2-0006-Implement-streaming-mode-in-ReorderBuffer.patch:
> +static void
> +AssertChangeLsnOrder(ReorderBuffer *rb, ReorderBufferTXN *txn)
> +{
>
> This "Assert(txn->first_lsn != InvalidXLogRecPtr)"can be before the
> loop, can be checked only once:
> +       dlist_foreach(iter, &txn->changes)
> +       {
> +               ReorderBufferChange *cur_change;
> +
> +               cur_change = dlist_container(ReorderBufferChange,
> node, iter.cur);
> +
> +               Assert(txn->first_lsn != InvalidXLogRecPtr);
> +               Assert(cur_change->lsn != InvalidXLogRecPtr);
> +               Assert(txn->first_lsn <= cur_change->lsn);
>

This makes sense to me.  Another thing about this function, do we
really need "ReorderBuffer *rb" parameter in this function?


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