Performance evaluation

[curiousgally]

We are evaluating the performance of SmartGWT. We observed that GC gets kicked off every 20 seconds. I have used the builtinds sample and changed it according to my needs. I have a form and a list grid which fetches data as per the filled form. When user enters the form and retrieves the report i create a listgrid with sql datasource to fill the data.

Now we wanted to see how it was performing under load. So we deployed it in tomcat server and using Jmeter and other tools put a load of 40 users. The same form entries fire a query which results in different response times. Strange part is, the time is same for most of the users but suddenly the response time jumps up to x10. Also the Garbage Collector gets kicked of every 20 seconds.

Another detail: A user can fill the form and retrieve a report which would create a tab with the data in list grid. User can retreive the report again by changing the form entries, which would create a new tab with a new listgrid with data for this criteria.

So do I need to clean up something or any pointers on the GC kicking off every 20 seconds.

Thanks

[Isomorphic]

Sounds like an artifact of your test environment since this has never been reported for real users.

You didn't mention lots of relevant details:
- browser and OS and versions
- what the actual observed latency is
- whether/how you've isolated it to browser time instead of something else (JMeter is not particularly good at this)
- why you think it's related to GC

As a general tip, you do need to call destroy() on any Canvas subclass you've directly created that you don't want anymore. See the docs for this method.

[Isomorphic]

We would also recommend you get a basic grounding in what you want to measure - what would be relevant to end user performance and scalability. See the QuickStart Guide, Evaluating SmartGWT chapter.