[Pacemaker] MySQL startup slow on OCFS2

[daniel qian]

On 2010-05-27, at 10:21 AM, Florian Haas wrote:

> 
> 
> On 2010-05-27 16:12, daniel qian wrote:
>> 
>> On 2010-05-27, at 5:06 AM, Florian Haas wrote:
>> 
>>> On 2010-05-26 16:26, daniel qian wrote:
>>>> I followed this link to setup a two-node cluster on Ubuntu 10.4 - https://wiki.ubuntu.com/ClusterStack/LucidTesting#Pacemaker,%20drbd8%20and%20OCFS2%20or%20GFS2
>>>> 
>>>> Everything is working fine except for running MySQL on both nodes with MySQL datadir set to the drbd based OCFS2 disk space.  Everytime I run command 'service mysql start'  on the second node to start up MySQL it takes a much longer time than it does on the first one to start. I tried changing the order of the two nodes to start MySQL it is always the node that starts the second MySQL. 
>>> 
>>> Don't do that.
>>> Don't do that.
>>> Don't do that.
>>> 
>> 
>> I assume you mean that for only MySQL part. Any explanation?
> 
> MySQL was not built for multiple MySQL daemons (whether they are on
> physically separate hosts or not) to handle a single set of MySQL data
> files. And it's completely irrelevant what storage those data files are on.
> 
> There is an extremely cruel workaround to force MySQL to do this if you
> only ever use MyISAM tables, but I won't even get into that. There are
> also a few 3rd party storage engines not typically bundled with MySQL
> distro packages that allow this under some circumstances. But InnoDB, at
> this point, won't. Don't try to pretend that it does.
> 

Thanks for the information.  I came across a 3rd party storage engine called ScaleDB while searching for answers because I WAS pretending Innodb works but it doesnt quite :)  Do you know other 3rd party storage engine products that allow for my load balancing setup and have you heard any words about them?  Sorry if this is a little off topic and we can take it offline if thats more appropriate.


Regards,
Daniel