[HyperDB] Splitting READs and WRITEs

Barry Abrahamson barry at automattic.com
Tue Mar 2 23:55:57 UTC 2010

On Mar 2, 2010, at 12:05 PM, J M wrote:

> i have this configuration:
> add_db_server('global',0,'slave1',1,0,'','
> // Slave DB
> add_db_server('global',0,'master1',2,1,'','
> // Master DB
> -- enabled logging in mysql but some reason not select's are being thrown to
> the "slave1" node.. all SQL are being executed on "master"
> any ideas why? did i miss something?

This shouldn't happen unless:

1) The slave is not available (are you sure you are able to connect?)
2) There is a write query on the same page load as the read queries - if there is a write, HyperDB will send all subsequent reads on that page load to the master to try and alleviate possible data inconsistency caused by replication lag.

Any errors in your logs?

Barry Abrahamson | Systems Wrangler | Automattic
Blog: http://barry.wordpress.com

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