Re: Fastpath while arranging the changes in LSN order in logical decoding

Hi Dilip,

I repeated the same test cases again and can't reproduce the
disconnection issue after applied your new patch.

Best regards,

David

On 2020-03-02 9:11 p.m., Dilip Kumar wrote:
> On Wed, Feb 19, 2020 at 6:00 AM David Zhang <david(dot)zhang(at)highgo(dot)ca> wrote:
>> After manually applied the patch, a diff regenerated is attached.
>>
>> On 2020-02-18 4:16 p.m., David Zhang wrote:
>>> 1. Tried to apply the patch to PG 12.2 commit 45b88269a353ad93744772791feb6d01bc7e1e42 (HEAD -> REL_12_2, tag: REL_12_2), it doesn't work. Then tried to check the patch, and found the errors showing below.
>>> $ git apply --check 0001-Fastpath-for-sending-changes-to-output-plugin-in-log.patch
>>> error: patch failed: contrib/test_decoding/logical.conf:1
>>> error: contrib/test_decoding/logical.conf: patch does not apply
>>> error: patch failed: src/backend/replication/logical/reorderbuffer.c:1133
>>> error: src/backend/replication/logical/reorderbuffer.c: patch does not apply
>>>
>>> 2. Ran a further check for file "logical.conf", and found there is only one commit since 2014, which doesn't have the parameter, "logical_decoding_work_mem = 64kB"
>>>
>>> 3. Manually apply the patch including src/backend/replication/logical/reorderbuffer.c, and then ran a simple logical replication test. A connection issue is found like below,
>>> "table public.pgbench_accounts: INSERT: aid[integer]:4071 bid[integer]:1 abalance[integer]:0 filler[character]:' '
>>> pg_recvlogical: error: could not receive data from WAL stream: server closed the connection unexpectedly
>>> This probably means the server terminated abnormally
>>> before or while processing the request.
>>> pg_recvlogical: disconnected; waiting 5 seconds to try again"
>>>
>>> 4. This connection issue can be reproduced on PG 12.2 commit mentioned above, the basic steps,
>>> 4.1 Change "wal_level = logical" in "postgresql.conf"
>>> 4.2 create a logical slot and listen on it,
>>> $ pg_recvlogical -d postgres --slot test --create-slot
>>> $ pg_recvlogical -d postgres --slot test --start -f -
>>>
>>> 4.3 from another terminal, run the command below,
>>> $ pgbench -i -p 5432 -d postgres
>>>
>>> Let me know if I did something wrong, and if a new patch is available, I can re-run the test on the same environment.
> Thanks for testing and rebasing. I think one of the hunks is missing
> in your rebased version. That could be the reason for failure. Can
> you test on my latest version?
>
--
David

Software Engineer
Highgo Software Inc. (Canada)
www.highgo.ca