Horton

Re: [bug fix] Cascading standby cannot catch up and get stuck emitting the same message repeatedly

Tsunakawa, Takayuki <tsunakawa.takay@jp.fujitsu.com>

View thread View on postgr.es
From: "Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com>
To: 'Amit Kapila' <amit.kapila16@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2016-11-15T02:21:10Z
Lists: pgsql-hackers 
From: pgsql-hackers-owner@postgresql.org
> [mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Amit Kapila
> It looks like the code in 9.3 or later version uses the recptr as the target
> segment location
> (targetSegmentPtr) whereas 9.2 uses recptr as beginning of segment (readOff
> = 0;).  If above understanding is right then it will set different values
> for latestPagePtr in 9.2 and 9.3 onwards code.
> 

In 9.2, the relevant variable is not recptr but recaddr.  recaddr in 9.2 and recptr in later releases point to the beginning of a page just read, which is not always the beginning of the segment (targetSegmentPtr).

Regards
Takayuki Tsunakawa

Commits

  1. Fix bug in verifying TLI (timeline ID) in WAL page header during recovery..

  2. Split out XLog reading as an independent facility