Re: Critical failure of standby - Mailing list pgsql-general

Hello,

We recently experienced a critical failure when failing to a DR environment.

This is in the following environment:

• 3 x PostgreSQL machines in Prod in a sync replication cluster
• 3 x PostgreSQL machines in DR, with a single machine async and the other two cascading from the first machine.

There was network failure which isolated Production from everything else, Production has no errors during this time (and has now come back OK).

DR did not tolerate the break, the following appeared in the logs and none of them can start postgres. There were no queries coming into DR at the time of the break.

Please note that the "Host Key verification failed" messages are due to the scp command not functioning. This means restore_command is not working to restore from the XLOG archive, but should not effect anything else.

2016-08-12 02:52:55 GMT [23205]: [9077-1] user=,db=,client=  (0:00000)LOG:  restartpoint starting: time

2016-08-12 02:57:25 GMT [23205]: [9078-1] user=,db=,client=  (0:00000)LOG:  restartpoint complete: wrote 13361 buffers (0.6%); 0 transaction log file(s) added, 0 removed, 3 recycled; write=269.972 s, sync=0.031 s, total=270.008 s; sync files=41, longest=0.004 s, average=0.000 s; distance=37747 kB, estimate=48968 kB

2016-08-12 02:57:25 GMT [23205]: [9079-1] user=,db=,client=  (0:00000)LOG:  recovery restart point at 3/7C7B0228

2016-08-12 02:57:25 GMT [23205]: [9080-1] user=,db=,client=  (0:00000)DETAIL:  last completed transaction was at log time 2016-08-12 02:57:24.033588+00

2016-08-12 02:57:55 GMT [23205]: [9081-1] user=,db=,client=  (0:00000)LOG:  restartpoint starting: time

2016-08-12 03:02:25 GMT [23205]: [9082-1] user=,db=,client=  (0:00000)LOG:  restartpoint complete: wrote 7196 buffers (0.3%); 0 transaction log file(s) added, 0 removed, 2 recycled; write=269.988 s, sync=0.014 s, total=270.007 s; sync files=42, longest=0.002 s, average=0.000 s; distance=79888 kB, estimate=79888 kB

2016-08-12 03:02:25 GMT [23205]: [9083-1] user=,db=,client=  (0:00000)LOG:  recovery restart point at 3/815B42C8

2016-08-12 03:02:25 GMT [23205]: [9084-1] user=,db=,client=  (0:00000)DETAIL:  last completed transaction was at log time 2016-08-12 03:02:15.07639+00

2016-08-12 03:02:55 GMT [23205]: [9085-1] user=,db=,client=  (0:00000)LOG:  restartpoint starting: time

2016-08-12 03:04:00 GMT [22350]: [2-1] user=,db=,client=  (0:XX000)FATAL:  terminating walreceiver due to timeout

Host key verification failed.^M

Host key verification failed.^M

2016-08-12 03:04:00 GMT [23188]: [9-1] user=,db=,client=  (0:XX000)FATAL:  invalid memory alloc request size 3445219328

2016-08-12 03:04:01 GMT [23182]: [5-1] user=,db=,client=  (0:00000)LOG:  startup process (PID 23188) exited with exit code 1

2016-08-12 03:04:01 GMT [23182]: [6-1] user=,db=,client=  (0:00000)LOG:  terminating any other active server processes

2016-08-12 03:04:01 GMT [22285]: [1-1] user=replication,db=[unknown],client=10.8.0.14 10.8.0.14(55826) (0:57P02)WARNING:  terminating connection because of crash of another server process

2016-08-12 03:04:01 GMT [22285]: [2-1] user=replication,db=[unknown],client=10.8.0.14 10.8.0.14(55826) (0:57P02)DETAIL:  The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.

2016-08-12 03:04:01 GMT [22285]: [3-1] user=replication,db=[unknown],client=10.8.0.14 10.8.0.14(55826) (0:57P02)HINT:  In a moment you should be able to reconnect to the database and repeat your command.

2016-08-12 03:04:01 GMT [22286]: [1-1] user=replication,db=[unknown],client=10.8.0.32 10.8.0.32(56442) (0:57P02)WARNING:  terminating connection because of crash of another server process

2016-08-12 03:04:01 GMT [22286]: [2-1] user=replication,db=[unknown],client=10.8.0.32 10.8.0.32(56442) (0:57P02)DETAIL:  The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.

2016-08-12 03:04:01 GMT [22286]: [3-1] user=replication,db=[unknown],client=10.8.0.32 10.8.0.32(56442) (0:57P02)HINT:  In a moment you should be able to reconnect to the database and repeat your command.

2016-08-12 03:04:01 GMT [23182]: [7-1] user=,db=,client=  (0:00000)LOG:  archiver process (PID 23207) exited with exit code 1

2016-08-12 04:43:51 GMT [23614]: [1-1] user=,db=,client=  (0:00000)LOG:  database system was interrupted while in recovery at log time 2016-08-12 02:53:19 GMT

2016-08-12 04:43:51 GMT [23614]: [2-1] user=,db=,client=  (0:00000)HINT:  If this has occurred more than once some data might be corrupted and you might need to choose an earlier recovery target.

2016-08-12 04:43:51 GMT [23615]: [1-1] user=postgres,db=postgres,client=[local] [local] (0:57P03)FATAL:  the database system is starting up

Host key verification failed.^M

2016-08-12 04:43:51 GMT [23614]: [3-1] user=,db=,client=  (0:00000)LOG:  entering standby mode

Host key verification failed.^M

Host key verification failed.^M

2016-08-12 04:43:51 GMT [23614]: [4-1] user=,db=,client=  (0:00000)LOG:  redo starts at 3/815B42C8

Host key verification failed.^M

Host key verification failed.^M

Host key verification failed.^M

2016-08-12 04:43:52 GMT [23643]: [1-1] user=postgres,db=postgres,client=[local] [local] (0:57P03)FATAL:  the database system is starting up

Host key verification failed.^M

Host key verification failed.^M

Host key verification failed.^M

Host key verification failed.^M

2016-08-12 04:43:53 GMT [23614]: [5-1] user=,db=,client=  (0:00000)LOG:  consistent recovery state reached at 3/8811DFF0

2016-08-12 04:43:53 GMT [23614]: [6-1] user=,db=,client=  (0:XX000)FATAL:  invalid memory alloc request size 3445219328

2016-08-12 04:43:53 GMT [23612]: [3-1] user=,db=,client=  (0:00000)LOG:  database system is ready to accept read only connections

2016-08-12 04:43:53 GMT [23612]: [4-1] user=,db=,client=  (0:00000)LOG:  startup process (PID 23614) exited with exit code 1

2016-08-12 04:43:53 GMT [23612]: [5-1] user=,db=,client=  (0:00000)LOG:  terminating any other active server processes

2016-08-12 04:43:53 GMT [23612]: [6-1] user=,db=,client=  (0:00000)LOG:  archiver process (PID 23627) exited with exit code 1

2016-08-12 04:44:04 GMT [23710]: [1-1] user=,db=,client=  (0:00000)LOG:  database system was interrupted while in recovery at log time 2016-08-12 02:53:19 GMT

2016-08-12 04:44:04 GMT [23710]: [2-1] user=,db=,client=  (0:00000)HINT:  If this has occurred more than once some data might be corrupted and you might need to choose an earlier recovery target.

Does anyone have any ideas? It looks to me like some sort of bug / error with the replication protocol or maybe some corruption on the master which wasn't noticed and fed across?

If that's the case would checksums help here? Are the computed on the standby?

Cheers,

James Sewell,

Solutions Architect 

 

Suite 112, Jones Bay Wharf, 26-32 Pirrama Road, Pyrmont NSW 2009

P (+61) 2 8099 9000  W www.jirotech.com  F (+61) 2 8099 9099

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