Hi All, 

We are having a problem with our streaming replication read only node. It has 
crashed a few times with a couple of different reasons, mostly "segmentation 
fault". The latest log are listed below: 


2012-05-30 23:56:37.385 UTC::: LOG: server process (PID 19476) was terminated 
by signal 11: Segmentation fault 
2012-05-30 23:56:37.385 UTC::: LOG: terminating any other active server 
processes 
2012-05-30 23:56:37.385 UTC:10.43.6.61:webmaster:panorama WARNING: terminating 
connection because of crash of another server process 
2012-05-30 23:56:37.385 UTC:10.43.6.61:webmaster:panorama 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. 
2012-05-30 23:56:37.385 UTC:10.43.6.61:webmaster:panorama HINT: In a moment you 
should be able to reconnect to the database and repeat your command. 
2012-05-30 23:56:37.385 UTC:10.43.6.81:webmaster:panorama WARNING: terminating 
connection because of crash of another server process 
2012-05-30 23:56:37.385 UTC:10.43.6.81:webmaster:panorama 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. 
2012-05-30 23:56:37.385 UTC:10.43.6.81:webmaster:panorama HINT: In a moment you 
should be able to reconnect to the database and repeat your command. 
2012-05-30 23:56:37.385 UTC:10.43.6.81:webmaster:panorama WARNING: terminating 
connection because of crash of another server process 
2012-05-30 23:56:37.385 UTC:10.43.6.81:webmaster:panorama 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. 
2012-05-30 23:56:37.385 UTC:10.43.6.81:webmaster:panorama HINT: In a moment you 
should be able to reconnect to the database and repeat your command. 
2012-05-30 23:56:37.575 UTC:10.43.6.81:webmaster:panorama FATAL: the database 
system is in recovery mode 




Our setup: 
2x physical server - Dell PE R815, 64GB ECC RAM, 2 CPUs (12 cores each), 
storing pgsql data on SAN backed volumes. 
CentOS 5.6 
PostgreSQL 9.0.8, compiled *without* int64 datetime. 
Both servers are identically configured (or at least as much as we could 
ensure) 
One is master, another is streaming read-only node. 
The master runs two instances of postgreSQL, where the slave runs 5 instances 
of postgreSQL. 2 out of 5 are streaming replication from the master, rest 3 are 
streaming replication from other DB nodes. Those 2 instances serves clients as 
Read Only. The master node never had any crash so far. However, the 2 instances 
on slave have crashed 3 times by now, 1 time on one readonly instance, twice on 
another readonly instance. Above log was generated from one of the instances. 


All three crashes happened when the database was doing vacuuming. we 
automatically purge some data every night, and run vacuum analyze right after 
that... Our the CPU load is generally on 40%-60% mark. 


I have run a complete set of hardware diagnostics on the slave , with no faulty 
hardware detected. Can someone kindly shed some lights on me? I am not sure 
where to look into at this point.... 




Cheers, 



Bo Jin 


Operating/IT Manager 
Troo Corporation [ www.troo.com ] 
43 Auriga Drive, Suite 102, Ottawa, ON K2E 7Y8 
Ph: +1 877.702.8766 x156 
Fax: +1 855.726.8766 

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