Lag when 2 users accessing simultaneously?


I have been test running this great app for about a week now, and it is awesome!

I was wondering… Today I was showing someone how to use the app, and when they added a new product the app slowed down significantly.

Is this a known issue with simultaneous users (lag)? Or is this an issue with my web host? I’m running DigitalOcean 4gb RAM, 2 CPUs as recommended.


No you shouldn’t have any lags.

Next time that happens take a look at the catalina.out log file (or send the file to me for analysis).

There are two things that might be happening.

The first is that you might not have changed the Tomcat memory settings according to the docs so Tomcat is hitting the max heap size often and spending a lot of time garbage collecting.

Run the following command and send me the output

ps -ef | grep tomcat

The other is that you may have had two users updating the same database record at the same time which may have caused a deadlock or at least a lock acquisition error. I believe the default isolation level is set to Repeatable Read which isn’t quite serializable slow but can definitely cause slow performance.

With that said, neither of these scenarios should be happening on a new system. In fact you shouldn’t run into these types of issues until you have a lot more users.

There are other possibilities as well, including actual performance bugs with the feature you were using. If you can reliably reproduce the issue over and over then please provide specific steps to reproduce (or a video) and we can try to investigate.

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