Re: streaming replication and recovery

From: Anupama Ramaswamy <anumr_0123(at)yahoo(dot)com>
To: Sergey Konoplev <gray(dot)ru(at)gmail(dot)com>
Cc: "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org>
Subject: Re: streaming replication and recovery
Date: 2014-04-12 06:12:40
Message-ID: 1397283160.80366.YahooMailNeo@web160303.mail.bf1.yahoo.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Thanks for your response.

>>There are two lag types to consider about in case of a normal
>>streaming replication - delivery lag and replay lag. The secondary
>>will completely catch up to what have been delivered, but what have
>>not been is going to be lost. See [1][2].

Ok, I understand. I want to understand exact sequence of events that will happen. 
Lets say I have specified the following in my recovery.conf

trigger_file =/tmp/pgsql.failover

I detect that the master has failed and immediately I do the following on the standby
touch /tmp/pgsql.failover

Lets suppose at this point there is 0 delivery lag but XXXX bytes of replay lag. 

a) Will the replay complete before the standby stops replicating (because it sees the trigger file) ?
b) If I want to run this as new master and attach other secondaries to point to this master, can I do it soon after "touch /tmp/pgsql.failover" OR should I wait till the secondary has finished replaying all the delivered stream ?
c) How do I know if the replay is over and it is ready for a standalone operation ?

Thanks for your help
Anupama.

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Tony Theodore 2014-04-12 06:57:58 Re: Database Design: Maintain Audit Trail of Changes
Previous Message Dave Cramer 2014-04-11 21:50:17 Re: Is it possible to load two different versions of the JDBC driver in the same application?