Does JBoss do anything every half an hour by default?

[chengwen]

Hello, everyone.

I use jboss 6.0.0.final as a web & app server. It is keeping "hang suddenly" for nearly two months recently.

These days , I collected "netstat status" every 5 seconds in the server computer to watch the net connection. The result of the collection is as follows:

The vertical axis of the pic is "the number of tcp connections ", and the Horizontal axis is the time.

From the result, you can see that every half an hour, the tcp connections(or you can say the requests from the clients) raises from 20 to 200. The "peak traffic" lasts for nearly 3 minutes and then it returns normal.

I am quite sure that the real requests from the clients are very smooth, it cannot raise suddenly.

So, the only explaination for the peak is, every half an hour, the server does something else, this "something" is consuming, using a lot of system resources. It slows the response to the client request, which makes the client request connection lasting for more time than normal.

My question is : what is the server doing when the "traffic peak" happens? Does JBoss do anything every half an hour by default?

Thanks very much!

[jaikiran]

Wen Cheng wrote:

So, the only explaination for the peak is, every half an hour, the server does something else, this "something" is consuming, using a lot of system resources.

I can't think of anything that the server would do every 30 minutes that would result in this.

Try enabling the access log valve on the server and get the access logs which will show you what URLs are being requested.

[chengwen]

Thanks jarkiran.

The access log is already opened.

I wrote programs to analysis the log, the result shows that the http requests are smoonth, no strange requests when the "peak" happens, nealy 70 requests every seconds.

And all the requests is the same kind —— the clients report to the server "hey, I am still alive! " . So the consuming of every request is nearly the same.

If jboss doesn't do that half-an-hour-regular job,  I will looking for other causes.