On 18/07/12 18:11, Carl Kabbe wrote:
> 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 availability'.
Hello. May I direct you to these guys: http://www.hastexo.com/ ? They do
High Availability consulting and implementation. They seem to know their
stuff and I'm certain they could help you.
> 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 goals.
>> Are you willing to discuss your specific desired availability
>> thresholds in public?