Running Slow at busy times, same time every day

Submitted by garry edgar on Mon, 18/07/2016 - 12:21

General User's Discussion

Having just read Pyevets question. We run slow every day at key times like generating the order or doing the banking. We end up having to reset the Tomcat every day, which I was told we didn't need to do, but seems to be the only fix.

Do we have a similar problem to Pye and what do we do????

Re: Running Slow at busy times, same time every day

Submitted by tanderson on Mon, 18/07/2016 - 12:37.

If you are running 1.8.1, you may see slowdowns if MySQL or Tomcat haven't been allocated enough memory. There are some guidelines for MySQL here.

If you are running an earlier version, consider upgrading, as a number of memory issues were corrected in 1.8.1.

Tomcat memory requirements are determined by how many users you have accessing the system concurrently. There are a number of tools (e.g. jvisualvm) that can help you determine how much you need to allocate. Alternatively, start with a value >= 500MB and increase in 100MB increments until it runs smoothly under peak conditions.

Re: Running Slow at busy times, same time every day

Submitted by garry edgar on Tue, 19/07/2016 - 13:14.

we are on 1.8 so is there somewhere i can find out how to increase our tomcat memory?

Re: Running Slow at busy times, same time every day

Submitted by tanderson on Tue, 19/07/2016 - 13:35.

If you are running the Tomcat Windows service, see here: http://stackoverflow.com/a/5984656

If you are running the catalina script, then memory options are typically set in the <TOMCAT_HOME>/bin/setenv.bat or setenv.sh script.

E.g. for Windows:

set CATALINA_OPTS=-Xms512m -Xmx768m

Re: Running Slow at busy times, same time every day

Submitted by garry edgar on Tue, 19/07/2016 - 19:55.

Thanks TA.

I found initial memory was 1024 MB, Max memory was 1536.

I tried to set both as 5000 but i couldn't restart tomcat.

I settled on both at 1536 and could start tomcat.

I will see how that goes.

Cheers for now.

Re: Running Slow at busy times, same time every day

Submitted by tanderson on Tue, 19/07/2016 - 21:57.

If you set the Initial memory pool to 1536, it means that 1.5G of memory will be allocated to Tomcat when the server starts up, and it won't grow. If your process is low on memory during peak conditions, then you should increase the Maximum memory pool.

There is little point increasing it to a value greater than physical memory on the machine. You should base it physical memory size - how much memory is allocated to mysql - how much memory allocated to other processes such as OpenOffice.