Need answers on what C-Runtime heap is

Posted on 2009-05-18
Last Modified: 2013-11-23
We recently did an upgrade to DB2 and even more recently OnDemand (an IBM image archive app) on our AIX box and now we're having huge problems running an application.  We are trying to configure JProbe to help, but in the meantime I'd like more information on the error.  The error is the following:

JVMCL052 - Cannot allocate memory in initializeHeap for heap segment

From my understanding, this is NOT the java heap.  Read these comments below:

"The C-runtime heap of the process (not the Java object heap) is full. Increase the heap if that is possible in your environment. In a shared classes environment, see the shared classes User Guide for options that control shared memory, because the storage is managed by the JVM in this case."

The app is being ran on AIX version 5.3.  I don't know what C-runtime heap is or how to increase it.  I'm not the AIX administrator and my request has fallen on deaf ears.  This app ran much smoother in the past, so I know something with the OnDemand or DB2 upgrade has leached the AIX resources.  

Can someone help??
Question by:jackjeckyl
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
LVL 62

Expert Comment

ID: 24419436
This is JVM error (not able) allocating data pages from system.

Author Comment

ID: 24426897
So what do I do?
LVL 62

Accepted Solution

gheist earned 25 total points
ID: 24429241
check ulimit -a
then use smitty to increase allowed (data ?) size to -1 or something less.
NFR key for Veeam Backup for Microsoft Office 365

Veeam is happy to provide a free NFR license (for 1 year, up to 10 users). This license allows for the non‑production use of Veeam Backup for Microsoft Office 365 in your home lab without any feature limitations.

LVL 68

Assisted Solution

woolmilkporc earned 25 total points
ID: 24464805
Might be that your Java heap is too big, so that no C heap is left for non-java-heap purposes (internal JVM functions etc.) Try to reduce it (-Xmx ... option)

Author Comment

ID: 24519009
gheist - everything is set to unlimited, except stack (32768), coredump (2048) and nofiles (2000).  Does any of that need to be changed.

woolmilkporc - I'll try reducing the java heap, although this was set low to begin with when I had these problems.  
LVL 62

Expert Comment

ID: 24520100
Yes - it uses stack extensively.

Author Comment

ID: 24522004
woolmilkporc - Your suggestion worked, somewhat.  I lowered it, and now it seems to be running better on the bigger jobs the application encounters.  However, I do get java heap errors sporadically.  I went from 2GB to 1.5GB.  Maybe I'll bump it to 1.75GB and see what happens.  

gheist - Increase the stack to what value?  I'm AIX illiterate, so if I suggest something to the AIX admins, I need to tell them what and how come.  
LVL 62

Expert Comment

ID: 24524852
I suggest doubling.
Might be you hit 13x256MB limit - patching java with ML package is known to help. Also thruput GC is better.

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article is the second of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers the basic installation and configuration of the test automation tools used by…
In this post we will learn different types of Android Layout and some basics of an Android App.
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
This tutorial covers a step-by-step guide to install VisualVM launcher in eclipse.
Suggested Courses

617 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question