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

vignesh C <vignesh21@gmail.com>

From: vignesh C <vignesh21@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Amit Kapila <amit.kapila16@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-12-22T11:34:19Z
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 Mon, Dec 2, 2019 at 2:02 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Sun, Dec 1, 2019 at 7:58 AM Michael Paquier <michael@paquier.xyz> wrote:
> >
> > On Fri, Nov 22, 2019 at 01:18:11PM +0530, Dilip Kumar wrote:
> > > I have rebased the patch on the latest head and also fix the issue of
> > > "concurrent abort handling of the (sub)transaction." and attached as
> > > (v1-0013-Extend-handling-of-concurrent-aborts-for-streamin) along with
> > > the complete patch set.  I have added the version number so that we
> > > can track the changes.
> >
> > The patch has rotten a bit and does not apply anymore.  Could you
> > please send a rebased version?  I have moved it to next CF, waiting on
> > author.
>
> I have rebased the patch set on the latest head.
>

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);

Add the typedefs like below in typedefs.lst common across the patches:
xl_xact_invalidations, ReorderBufferStreamIterTXNEntry,
ReorderBufferStreamIterTXNState, SubXactInfo

"are written" appears twice in commit message of
v2-0002-Issue-individual-invalidations-with-wal_level-log.patch:
The individual invalidations are written are written using a new
xlog record type XLOG_XACT_INVALIDATIONS, from RM_XACT_ID resource
manager. See LogLogicalInvalidations for details.

v2-0002-Issue-individual-invalidations-with-wal_level-log.patch patch
does not compile by itself:
reorderbuffer.c:1822:9: error: ‘ReorderBufferTXN’ has no member named
‘is_schema_sent’
+
LocalExecuteInvalidationMessage(&change->data.inval.msg);
+                                       txn->is_schema_sent = false;
+                                       break;

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);

There is some code duplication in stream_change_cb_wrapper,
stream_truncate_cb_wrapper, stream_message_cb_wrapper,
stream_abort_cb_wrapper, stream_commit_cb_wrapper,
stream_start_cb_wrapper and stream_stop_cb_wrapper functions in
v2-0003-Extend-the-output-plugin-API-with-stream-methods.patch patch.
Should we have a separate function for common code?

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);

Should we add function header for ReorderBufferDestroyTupleCidHash in
v2-0006-Implement-streaming-mode-in-ReorderBuffer.patch:
+static void
+ReorderBufferDestroyTupleCidHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
+{
+       if (txn->tuplecid_hash != NULL)
+       {
+               hash_destroy(txn->tuplecid_hash);
+               txn->tuplecid_hash = NULL;
+       }
+}
+

Should we add function header for ReorderBufferStreamCommit in
v2-0006-Implement-streaming-mode-in-ReorderBuffer.patch:
+static void
+ReorderBufferStreamCommit(ReorderBuffer *rb, ReorderBufferTXN *txn)
+{
+       /* we should only call this for previously streamed transactions */
+       Assert(rbtxn_is_streamed(txn));
+
+       ReorderBufferStreamTXN(rb, txn);
+
+       rb->stream_commit(rb, txn, txn->final_lsn);
+
+       ReorderBufferCleanupTXN(rb, txn);
+}
+

Should we add function header for ReorderBufferCanStream in
v2-0006-Implement-streaming-mode-in-ReorderBuffer.patch:
+static bool
+ReorderBufferCanStream(ReorderBuffer *rb)
+{
+       LogicalDecodingContext *ctx = rb->private_data;
+
+       return ctx->streaming;
+}

patch v2-0008-Add-support-for-streaming-to-built-in-replication.patch
does not apply:
Hunk #18 FAILED at 2035.
Hunk #19 succeeded at 2199 (offset -16 lines).
1 out of 19 hunks FAILED -- saving rejects to file
src/backend/replication/logical/worker.c.rej

Header inclusion may not be required in patch
v2-0008-Add-support-for-streaming-to-built-in-replication.patch:
+++ b/src/backend/replication/logical/launcher.c
@@ -14,6 +14,8 @@
  *
  *-------------------------------------------------------------------------
  */
+#include <sys/types.h>
+#include <unistd.h>

Regards,
Vignesh
EnterpriseDB: http://www.enterprisedb.com