Re: async streaming and recovery_target_timeline=latest

Anybody?

On Jul 3, 2013, at 3:23 PM, Ben Chobot wrote:

> We have an async streaming setup using 9.1.9 and 3 nodes - let's call them A, B, and C. A is the master, B and C are slaves. Today, A crashed, so we made B be the master and told C to follow along with the switch by changing the primary_conninfo in it's recovery.conf, making sure the history file had made it to the WAL archive, then restarting it. That's worked very well for us in the past, but not so much today. When C came back online, it started complaining about missing WALs:
>
> 2013-07-03T21:22:42.441347+00:00 pgdb41-vpc postgres[25779]: [18184-1] db=,user= LOG: shutting down
> 2013-07-03T21:22:42.457728+00:00 pgdb41-vpc postgres[25779]: [18185-1] db=,user= LOG: database system is shut down
> 2013-07-03T21:22:46.852845+00:00 pgdb41-vpc postgres[28942]: [1-1] db=,user= LOG: database system was shut down in recovery at 2013-07-03 21:22:42 UTC
> 2013-07-03T21:22:46.866127+00:00 pgdb41-vpc postgres[28947]: [1-1] db=[unknown],user=[unknown] LOG: incomplete startup packet
> 2013-07-03T21:22:47.368871+00:00 pgdb41-vpc postgres[28942]: [2-1] db=,user= LOG: restored log file "00000010.history" from archive
> 2013-07-03T21:22:47.413588+00:00 pgdb41-vpc postgres[28956]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:22:47.767182+00:00 pgdb41-vpc postgres[28942]: [3-1] db=,user= LOG: restored log file "00000010.history" from archive
> 2013-07-03T21:22:47.767289+00:00 pgdb41-vpc postgres[28942]: [4-1] db=,user= LOG: entering standby mode
> 2013-07-03T21:22:47.930394+00:00 pgdb41-vpc postgres[28978]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:22:48.410056+00:00 pgdb41-vpc postgres[28942]: [5-1] db=,user= LOG: redo starts at 1469/A2604868
> 2013-07-03T21:22:48.445921+00:00 pgdb41-vpc postgres[28986]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:22:48.962090+00:00 pgdb41-vpc postgres[28994]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:22:49.477279+00:00 pgdb41-vpc postgres[29020]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:22:49.993021+00:00 pgdb41-vpc postgres[29027]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:22:50.508848+00:00 pgdb41-vpc postgres[29034]: [1-1] db=postgres,user=postgres FATAL: the database system is starting up
> 2013-07-03T21:23:30.651775+00:00 pgdb41-vpc postgres[28942]: [6-1] db=,user= LOG: consistent recovery state reached at 146A/14FFFA8
> 2013-07-03T21:23:30.651805+00:00 pgdb41-vpc postgres[28942]: [7-1] db=,user= LOG: invalid magic number 0000 in log file 5226, segment 1, offset 5242880
> 2013-07-03T21:23:30.653214+00:00 pgdb41-vpc postgres[28917]: [1-1] db=,user= LOG: database system is ready to accept read only connections
> 2013-07-03T21:23:31.123588+00:00 pgdb41-vpc postgres[29754]: [2-1] db=,user= LOG: streaming replication successfully connected to primary
> 2013-07-03T21:23:31.123647+00:00 pgdb41-vpc postgres[29754]: [3-1] db=,user= FATAL: could not receive data from WAL stream: FATAL: requested WAL segment 000000100000146A00000001 has already been removed
>
> At this point, my understanding of postgres must be wrong, because it appears to me that the slave is looking for WAL 146A/01 because that's where it reached consistent state. However, that was in the previous timeline - we didn't get to the 10 history timeline till 146A/0C:
>
> # cat 00000010.history
> 15 0000000F0000146A0000000C no recovery target specified
>
>
> Shouldn't postgres know to be looking for "0000000F0000146A00000001", not "000000100000146A00000001"? I'm trying to see what part of our process we have wrong to have ended up in this state but I'm missing it.
>
>
> For what it's worth the new master (node B) certainly seems to have all the WAL files you might expect. Here's some snippets of an ls -l, but all the files are there in between the snippets.
>
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F000014690000009F
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A0
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A1
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A2
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A3
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A4
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A5
> -rw------- 1 postgres postgres 16777216 Jul 3 21:13 0000000F00001469000000A6
> .
> .
> .
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000000
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000001 <- the consistent state seems to be found here
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000002
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000003
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000004
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000005
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000006
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000007
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000008
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A00000009
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A0000000A
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A0000000B
> -rw------- 1 postgres postgres 16777216 Jul 3 21:15 0000000F0000146A0000000C
> -rw------- 1 postgres postgres 16777216 Jul 3 20:56 0000000F0000146A0000000D
> -rw------- 1 postgres postgres 16777216 Jul 3 20:57 0000000F0000146A0000000E
> -rw------- 1 postgres postgres 16777216 Jul 3 20:57 0000000F0000146A0000000F
> -rw------- 1 postgres postgres 16777216 Jul 3 20:57 0000000F0000146A00000010
> -rw------- 1 postgres postgres 16777216 Jul 3 20:57 0000000F0000146A00000011
> .
> .
> .
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000CF
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000D0
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000D1
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000D2
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000D3
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000D4
> -rw------- 1 postgres postgres 16777216 Jul 3 20:58 0000000F0000146A000000D5
> -rw------- 1 postgres postgres 16777216 Jul 3 21:23 000000100000146A0000000C <- timeline switches here
> -rw------- 1 postgres postgres 16777216 Jul 3 21:25 000000100000146A0000000D
> -rw------- 1 postgres postgres 16777216 Jul 3 21:27 000000100000146A0000000E
> -rw------- 1 postgres postgres 16777216 Jul 3 21:28 000000100000146A0000000F
> -rw------- 1 postgres postgres 16777216 Jul 3 21:30 000000100000146A00000010
> -rw------- 1 postgres postgres 16777216 Jul 3 21:32 000000100000146A00000011
> -rw------- 1 postgres postgres 16777216 Jul 3 21:34 000000100000146A00000012
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