Обсуждение: HOT standby with ONLY WAL shipping?
Hi All; We would like to setup a hot standby server with a forced delay. Is it possible to setup a hot standby based ONLY on WAL shipping and NOT use streaming replication? Thanks in advance
On 06/12/14 10:01, CS_DBA wrote: > > We would like to setup a hot standby server with a forced delay. > Is it possible to setup a hot standby based ONLY on WAL shipping and NOT > use streaming replication? Yes it is. Though, I assume you mean 'forced max sync period' as opposed to 'forced delay'. Transfers will happen as WAL's fill or the timeout expires. The slave will also be read-only. Here's a setup for every 10 mins (600 secs). On master (postgresql.conf): wal_level = hot_standby archive_mode = on archive_command = '<your_archive_command>' archive_timeout = 600 # Or whatever timeout you want On slave (postgresql.conf): hot_standby = on On slave (recovery.conf): standby_mode = 'on' restore_command = '<your_restore_command>' archive_cleanup_command = '<your_cleanup_command>' I don't recall if a full re-sync is required prior to changing the wal_level or whether simply restarting both servers will suffice. Usual caveats and disclaimers apply. :-) HTH, Bosco.
On Fri, Jun 13, 2014 at 1:01 AM, CS_DBA <cs_dba@consistentstate.com> wrote:
Is it possible to setup a hot standby based ONLY on WAL shipping and NOT use streaming replication?
If I am not wrong then what you are looking for is Archive Shipping.
Any specific reason why you want to do that?
Anyways, you can use pg_receivexlog as well for setting up archives or for setting up a replica. But if you are trying to avoid some other issue w.r.t. streaming mechanism in PostgreSQL (which I assume will be very specific to your environment), then this may not be very helpful as pg_receivexlog too works on same streaming protocol and needs wal-sender processes.
Best Regards,
Sameer Kumar | Database Consultant
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Вложения
On Thu, Jun 12, 2014 at 1:01 PM, CS_DBA <cs_dba@consistentstate.com> wrote:
Hi All;
We would like to setup a hot standby server with a forced delay.
Is it possible to setup a hot standby based ONLY on WAL shipping and NOT use streaming replication?
Thanks in advance
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The omnipitr tool can provide the delayed slave feature you're looking for.
https://github.com/omniti-labs/omnipitr/
Look into the --recovery-delay (-w) feature of the omnipitr-restore command which is used in the recovery.conf of the slave
https://github.com/omniti-labs/omnipitr/blob/master/doc/omnipitr-restore.pod
Whether a slave is a hot standby is not determined by whether you're using streaming replication or WAL replay. It is determined by setting the parameter "hot_standby" on the slave and ensuring the master has a minimum "wal_level" of "hot_standby" as well. So both streaming and wal replay slaves can be hot standbys.https://github.com/omniti-labs/omnipitr/
Look into the --recovery-delay (-w) feature of the omnipitr-restore command which is used in the recovery.conf of the slave
https://github.com/omniti-labs/omnipitr/blob/master/doc/omnipitr-restore.pod