Problem with tomcat hanging on Shib 2.4

[Cantor, Scott]

On 8/29/14, 11:40 AM, "Brian Koehmstedt" <bkoehmstedt at ucmerced.edu> wrote:

>In a previous "hang" a few weeks ago (not the latest one John is
>describing), I noticed an Out of Memory error in the log file.  John
>should check for this in the latest hang-up logs, but I am definitely
>suspecting either:
>- A memory leak

If you have a leak, it's in some component you've added to the system. A
driver or what not.

>- The JVM just flat out running out of memory due to growing Incommon
>metdata file, but it seems like -Xmx1024M should be sufficient even when
>the current size of the metadata file.  Matthew, I'd be curious to know
>what you had your -Xmx parameter set at when
> you were experiencing the hang-ups.

That isn't the cause. It's possible you're handling too much traffic and
caching attribute resolution results for too long, but that's a choice.
Otherwise, you shouldn't have any trouble with heap.

>I've already begun taking heap dumps and analyzing them with jhat.
>Analyzing the heap isn't always straight forward, but there is a
>"tremendous" amount of char[], String, HashMapEntry, and various XML
>objects in the heap.  I put "tremendous" in quotes because
> I don't yet know if it's a normal amount or abnormal amount.  You can't
>tell just by looking at a heap.  Most of these objects look related to
>storing data from the Incommon metadata file.  Since this file is growing
>quite big, the data in the heap could be normal, in which case -Xmx1024M
>is no longer sufficient?

It's sufficient. Those objects are dropped after processing the file, they
don't stay in use.

-- Scott