Is there a way to setup database load balancing or failover support, I found some php files and references to it but I can't find any directives in default settings or local settings to turn it on or configure it.
Is this possible?
Is there a WikiMedia help file that I missed?
Thanks
Arthur
mailto:arthur@astarsolutions.co.uk arthur@astarsolutions.co.uk
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Arthur Guy wrote:
Is there a way to setup database load balancing or failover support, I found some php files and references to it but I can't find any directives in default settings or local settings to turn it on or configure it.
MediaWiki can use multiple replicated MySQL database servers as a datasource, but isn't currently designed for automatic failover: that is, if your master dies you need to manually reconfigure both on the MySQL end (to change which machine thinks it is the master and where the other slaves pull updates from) and MediaWiki (so it knows which is the new master to use for read/write queries).
Set $wgDBservers as documented in DefaultSettings.php.
Is this possible?
Is there a WikiMedia help file that I missed?
There is little or no reliable documentation outside the source code; if you find what looks like documentation, don't believe it without checking the source code! Sometimes well-meaning people write 'documentation' on the wiki that's not actually accurate, or it just gets really out of date. :)
-- brion vibber (brion @ pobox.com)
You say it doesn't have failover support. If you configure a master and a salve in the settings and the master goes down won't it detect this and just use the slave until the master is available?
I found the options in the defaultsettings file but it doesn't provide an example, how do you write a suitable instruction containing the database information?
Thanks for your help Arthur
arthur@astarsolutions.co.uk -----Original Message----- From: mediawiki-l-bounces@Wikimedia.org [mailto:mediawiki-l-bounces@Wikimedia.org] On Behalf Of Brion Vibber Sent: 22 June 2005 18:26 To: MediaWiki announcements and site admin list Subject: Re: [Mediawiki-l] Load balancing
Arthur Guy wrote:
Is there a way to setup database load balancing or failover support, I
found
some php files and references to it but I can't find any directives in default settings or local settings to turn it on or configure it.
MediaWiki can use multiple replicated MySQL database servers as a datasource, but isn't currently designed for automatic failover: that is, if your master dies you need to manually reconfigure both on the MySQL end (to change which machine thinks it is the master and where the other slaves pull updates from) and MediaWiki (so it knows which is the new master to use for read/write queries).
Set $wgDBservers as documented in DefaultSettings.php.
Is this possible?
Is there a WikiMedia help file that I missed?
There is little or no reliable documentation outside the source code; if you find what looks like documentation, don't believe it without checking the source code! Sometimes well-meaning people write 'documentation' on the wiki that's not actually accurate, or it just gets really out of date. :)
-- brion vibber (brion @ pobox.com)
'a star solutions' disclaimer The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. If you are not the intended recipient of this message you are hereby notified that any use, review, retransmission, dissemination, distribution, reproduction or any action taken in reliance upon this message is prohibited. If you received this in error, please contact the sender and delete the material from any computer. Any views expressed in this message are those of the individual sender and may not necessarily reflect the views of the company. We believe that this communication is free from viruses and other potentially dangerous programmes, but the recipient opens this communication at their own risk. We assume no responsibility for any loss or damage arising from the receipt or use of this communication
Arthur Guy wrote:
You say it doesn't have failover support. If you configure a master and a salve in the settings and the master goes down won't it detect this and just use the slave until the master is available?
No. Loss of the master will produce a connection error. It's possible to switch the wiki to read-only mode and use a slave temporarily, but it's important that you never write to a slave directly. The read_only setting in MySQL should be used for extra safety. The reasons for this, and the procedure for permanently switching the master, are described in the MySQL manual.
If a slave goes down, long connection timeouts will cause poor performance until the load ratios are adjusted.
I found the options in the defaultsettings file but it doesn't provide an example, how do you write a suitable instruction containing the database information?
http://wikimedia.org/conf/db.php.html
-- Tim Starling
mediawiki-l@lists.wikimedia.org