We are actually facing both capacity and availability issues at the same time.
Our current primary server is a Dell T410 (single processor, 32 GB memory) with a Dell
T310 (single processor, 16GB memory) as backup. Normally, the backup server is running as
a slave to the primary server and we manually switch it over when the primary server fails
(which it did last Saturday morning at 2:00AM.) The switch over process takes 10-15
minutes although I am reducing that to about five minutes with some scripting (the
changeover is a little more complex than you might think because we have a middle piece,
also MySQL, that we use to determine where the real data is.) Until six months ago, the
time delay was not a problem because the customer processes could tolerate such a delay.
However, we now have a couple of water parks using our system at their gate, in their gift
shops and in their concessions so we need to now move the changeover time to a short
enough period that they really don't notice. Hence, the need I have described as 'high
The T410 is normally reasonably capable of processing our transactions, i.e., the
customers are comfortable with the latency. However, we have been on the T310 since last
Saturday and it is awful, basically barely able to keep up and producing unacceptable
latency. Further, our load will double in the next six months and double again the the
following six months.
So, my thought was that since we have to deal with the issue change over time which will
cause us to restructure the servers, that we should also deal with the capacity issue. I
think a couple of Dell T620's will provide the capacity we need (the servers we have
spec'ed should be around 8X faster than the T410) but I have no experience evaluating or
setting up HA systems (I have worked with MySQL for 12 years and am reasonably comfortable
with it and I have read everything I can find about HA options and their implementations.)
Hence, my post asking for help (which we are willing to pay for.)
The web app is primarily JSP's for the administration side and Flash for the operators and
other people doing transactions. The server side code is about 1.25 million lines of code
and there are about 750 JSP's. The data is 950 tables with heavy use of foreign key
constraints. The container is Tomcat which runs on separate servers (the data servers
only run MySQL.)
Any ideas or help in any way are always welcome.
On Jul 18, 2012, at 9:42 AM, Shawn Green wrote:
> On 7/17/2012 8:22 PM, Carl Kabbe wrote:
>> On Monday, I asked if there were consultants out there who could help set up an
> NDB high availability system. As I compared our needs to NDB, it became obvious that NDB
> was not the answer and more obvious that simply adding high availability processes to our
> existing Innodb system was.
>> So, I am back asking if there are consultants lurking on this list that could
> help with this project.
> As has been discussed on this list many times before, there are many ways to measure
> 'high availability'. Most of them deal with what kind of disaster you want to survive or
> return to service from. If all you are looking for is additional production capacity then
> the terms you may want to investigate are 'scale out', 'partitioning', and 'replication'.
> All high-availability solutions require at least some level of hardware redundancy.
> Sometimes they require multiple layers in multiple locations.
> Several of those features of MySQL also help with meeting some high-availability
> Are you willing to discuss your specific desired availability thresholds in public?
> Shawn Green
> MySQL Principal Technical Support Engineer
> Oracle USA, Inc. - Hardware and Software, Engineered to Work Together.
> Office: Blountville, TN
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