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  • Latest Post - ‏2013-04-17T11:43:35Z by bpaskin
SystemAdmin
SystemAdmin
37422 Posts

Pinned topic WebSphere 7 heap dump doesn't show entire consumed heap

‏2013-03-29T22:05:23Z |
Hi all,

I am looking into a potential memory leak for a Java web application running in WebSphere 7. I am fairly new to WebSphere 7 and have been supporting applications on WebSphere 6 for many years. In the past on WAS 6, anytime I was provided a heap dump, the size of objects indicated in the dump would match what the garbage collection logs showed for the used memory. However, I am currently seeing the heap dumps only show a fraction of the objects that the garbage collection logs show is in use. As an example on a 6 GB heap (1 GB nursery, 5 GB tenure), the GC logs show about 5.5 GB of used space but when I take a heap dump across all files I only have 3.2 GB of objects. I am wondering if there is a difference from WAS 6 to WAS 7 in regards to heap dumps or if my current client has some type of configuration that doesn't dump out the entire heap. Does anyone know why I am seeing this behavior and what I might be able to do to get a full heap dump which matches the used space reported in the GC logs?

Please let me know if any addition information can help shed light on this?

Cheers,

Todd
  • bpaskin
    bpaskin
    4201 Posts

    Re: WebSphere 7 heap dump doesn't show entire consumed heap

    ‏2013-04-17T11:43:35Z  

    Hi, you need to analyze the garbage collection statistics.  Usually if the head is not entirely consumed then it indicates an Object bigger than what is available in the heap was trying to be allocated.

     

    Regards,

    Brian