Re: Repeated requests for feedback in logical standby

On Thu, Apr 14, 2016 at 1:21 PM, Magnus Hagander <magnus(at)hagander(dot)net>
wrote:

>
>
> On Thu, Apr 14, 2016 at 1:14 PM, Marko Tiikkaja <marko(at)joh(dot)to> wrote:
>
>> On 14/04/16 12:51, Magnus Hagander wrote:
>>
>>> I should add that yes, this patch does seem to remove the problem for me
>>> as
>>> well. But I can't confirm if it breaks something else.
>>>
>>
>> Did you also see whether it fixes the problem on the bigger box which
>> seemed to not shut down at all?
>
>
> Not yet, but those symptoms sound even more like those of Nick. I have it
> fixing two different installations that I have locally here though.
>
>
Finally got around to test this properly. And no, it does not work - 9.5.3
with logical replication. I captured a couple of stack traces, and they all
look like this:

#0 0x00007f8fa933e6b0 in __read_nocancel () at
../sysdeps/unix/syscall-template.S:81
#1 0x00005641a49aded3 in read (__nbytes=8192, __buf=0x5641a53d9090,
__fd=6) at /usr/include/x86_64-linux-gnu/bits/unistd.h:44
#2 XLogRead (buf=buf(at)entry=0x5641a53d9090 "\207\320\002",
startptr=startptr(at)entry=1056964608, count=count(at)entry=8192)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/replication/walsender.c:2124
#3 0x00005641a49af0db in logical_read_xlog_page (state=<optimized out>,
targetPagePtr=1056964608, reqLen=<optimized out>, targetRecPtr=<optimized
out>,
cur_page=0x5641a53d9090 "\207\320\002", pageTLI=<optimized out>)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/replication/walsender.c:772
#4 0x00005641a480f4d2 in ReadPageInternal (state=state(at)entry=0x5641a53d6b08,
pageptr=pageptr(at)entry=1062813696, reqLen=reqLen(at)entry=360)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/access/transam/xlogreader.c:524
#5 0x00005641a480fed1 in XLogReadRecord (state=0x5641a53d6b08,
RecPtr=1062814032, errormsg=errormsg(at)entry=0x7ffe3bd8ee48)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/access/transam/xlogreader.c:243
#6 0x00005641a49ae17b in XLogSendLogical () at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/replication/walsender.c:2437
#7 0x00005641a49afc63 in WalSndLoop (send_data=send_data(at)entry=0x5641a49ae150
<XLogSendLogical>)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/replication/walsender.c:1852
#8 0x00005641a49b0aa2 in StartLogicalReplication (cmd=<optimized out>)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/replication/walsender.c:1015
#9 exec_replication_command (cmd_string=cmd_string(at)entry=0x5641a53a3c50
"START_REPLICATION SLOT \"nineone\" LOGICAL 0/3F5244F8
(\"include_transaction\" 'on')")
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/replication/walsender.c:1344
#10 0x00005641a49ed8b4 in PostgresMain (argc=<optimized out>,
argv=argv(at)entry=0x5641a5335118, dbname=0x5641a5335030 "db",
username=<optimized out>)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/tcop/postgres.c:4028
#11 0x00005641a47925b8 in BackendRun (port=0x5641a5354bb0) at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/postmaster/postmaster.c:4239
#12 BackendStartup (port=0x5641a5354bb0) at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/postmaster/postmaster.c:3913
#13 ServerLoop () at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/postmaster/postmaster.c:1684
#14 0x00005641a4993e7b in PostmasterMain (argc=5, argv=<optimized out>)
at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/postmaster/postmaster.c:1292
#15 0x00005641a47932b2 in main (argc=5, argv=0x5641a53341f0) at
/build/postgresql-9.5-h9JXst/postgresql-9.5-9.5.3/build/../src/backend/main/main.c:228

They all come out at approximately the same place there.

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/