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

Kuntal Ghosh <kuntalghosh.2007@gmail.com>

From: Kuntal Ghosh <kuntalghosh.2007@gmail.com>

To: Dilip Kumar <dilipbalaut@gmail.com>

Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>

Date: 2020-04-16T20:10:09Z

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 →

Tighten the concurrent abort check during decoding.
- 2ce353fc1902 14.0 landed
Improve hash_create()'s API for some added robustness.
- b3817f5f7746 14.0 landed
Use HASH_BLOBS for xidhash.
- a1b8aa1e4eec 14.0 landed
Fix initialization of RelationSyncEntry for streaming transactions.
- 69bd60672af6 14.0 landed
Remove unused function declaration in logicalproto.h.
- ddd5f6d2609b 14.0 landed
Add additional tests to test streaming of in-progress transactions.
- 58b5ae9d62bd 14.0 landed
Fix inline marking introduced in commit 464824323e.
- ac15b499f7f9 14.0 landed
Add support for streaming to built-in logical replication.
- 464824323e57 14.0 landed
Fix the SharedFileSetUnregister API.
- 4ab77697f67a 14.0 landed
Fix comment in procarray.c
- 77c7267c37f7 14.0 cited
Suppress compiler warning in non-cassert builds.
- e942af7b8261 14.0 cited
Extend the BufFile interface.
- 808e13b282ef 14.0 landed
Mark a few logical decoding related variables with PGDLLIMPORT.
- b48cac3b10a0 14.0 landed
Implement streaming mode in ReorderBuffer.
- 7259736a6e5b 14.0 landed
Extend the logical decoding output plugin API with stream methods.
- 45fdc9738b36 14.0 landed
WAL Log invalidations at command end with wal_level=logical.
- c55040ccd017 14.0 landed
Immediately WAL-log subtransaction and top-level XID association.
- 0bead9af484c 14.0 landed
Allow logical replication to transfer data in binary format.
- 9de77b545313 14.0 cited
Only superuser can set sslcert/sslkey in postgres_fdw user mappings
- cebf9d6e6ee1 13.0 cited
Track statistics for spilling of changes from ReorderBuffer.
- 9290ad198b15 13.0 landed
Add logical_decoding_work_mem to limit ReorderBuffer memory usage.
- cec2edfa7859 13.0 landed
logical decoding: process ASSIGNMENT during snapshot build
- bac2fae05c77 13.0 cited
Emit invalidations to standby for transactions without xid.
- c6ff84b06a68 9.6.0 cited

On Tue, Apr 14, 2020 at 3:41 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>

Few review comments from 0006-Add-support-for-streaming*.patch

+ subxacts[nsubxacts].offset = lseek(stream_fd, 0, SEEK_END);
lseek can return (-)ve value in case of error, right?

+ /*
+ * We might need to create the tablespace's tempfile directory, if no
+ * one has yet done so.
+ *
+ * Don't check for error from mkdir; it could fail if the directory
+ * already exists (maybe someone else just did the same thing).  If
+ * it doesn't work then we'll bomb out when opening the file
+ */
+ mkdir(tempdirpath, S_IRWXU);
If that's the only reason, perhaps we can use something like following:

if (mkdir(tempdirpath, S_IRWXU) < 0 && errno != EEXIST)
throw error;

+
+ CloseTransientFile(stream_fd);
Might failed to close the file. We should handle the case.

Also, I think we need some implementations in dumpSubscription() to
dump the (streaming = 'on') option.

-- 
Thanks & Regards,
Kuntal Ghosh
EnterpriseDB: http://www.enterprisedb.com