Re: WAL log shipping + Streaming replication PG 9.0 questions

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Fujii Masao wrote:
On Tue, Oct 19, 2010 at 2:48 AM, Isabella Ghiurea
<isabella.ghiurea@xxxxxxxxxxxxxx> wrote:
I have some questions regarding hot standby  + streaming replication (PG
9.0) : what is   master/primary  server  behavior if  archive_command fails
 due to  archive  directory off line/unavailable?

Unarchived WAL files continue to accumulate in pg_xlog directory while
the archive directory is unavailable. Then, if pg_xlog directory is
filled up, the PostgreSQL server causes the PANIC error.

How about standby server  behavior if restore command fails due to
archive_master directory not available?

After restore_command fails, the standby tries to read WAL file from
its pg_xlog directory. And, if there is no WAL file to recover in pg_xlog,
the standby tries to connect to the master and read the streamed WAL files
from the master.

Regards,

Thank you for all details.
For the last question I ' m still a bit confused: if master_archive off line ( no archived WAL's available) what will be state of standby server ? Basically we are trying to design a solution where WAL archived directory is not a "single point of failure" for whole system ( we are planing to have WAL archived master directory on a separate machine and both server primary and standby will have read/write here) if this servers fails , we want to be able to continue normal user operation on master while standby server will have some latency.
Isabella


--
-----------------------------------------------------------
Isabella A. Ghiurea
Isabella.Ghiurea@xxxxxxxxxxxxxx
Canadian Astronomy Data Centre |http://www.nrc-cnrc.gc.ca/eng/services/hia/data-centre.html National Research Council of Canada, Herzberg Institute of Astrophysics 5071 West Saanich Road, Victoria BC V9E 2E7, Canada
Phone: 250 363-3446 fax: 250 363-0045


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