Re: pgpool question - Mailing list pgsql-hackers

From Jeff Hoffmann
Subject Re: pgpool question
Date
Msg-id 47f7c1a9504d7b3f5188bc8fa01353ed@propertykey.com
Whole thread Raw
In response to Re: pgpool question  (Tatsuo Ishii <t-ishii@sra.co.jp>)
List pgsql-hackers
On Mar 9, 2005, at 7:25 PM, Tatsuo Ishii wrote:
>
> That's an intended behavior. Or at least a side effect of failover
> design. If we allow unlimited switching between the master and the
> secondary, pgpool could repeat switching forever if we have unliable
> network or hardware.

I didn't really think of it that way, I had just expected it to toggle 
back and forth for some reason.  At first I thought it was just me, but 
apparently Oleg got the same impression as I did.  After you explained 
it, though, it makes sense why someone would want it to work that way.

> However it would be easy to modify pgpool to allow automatic switch
> back (with a risk of unwanted repeating switching, of course). Is
> this what you want?

How about making it a switch at run-time?  Like "--cycle" for the 
automatic fail-over toggling.  It seems that there are valid reasons 
for both options.  What makes the most sense to me would be to make the 
"-s" switch always be able to switch to the server specified in the 
command line or toggle between the two if you don't specify either 
master or secondary.  That way an administrator can always have control 
or which server is being used & then either leave the automatic 
behavior as is or create a cycle switch in case the user preferred that 
behavior.

--
Jeff Hoffmann
jeff@propertykey.com



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