TOMCAT failed with JVM error with OM Web Viewer 12.1

Products

• Output Management Web Viewer

Issue/Introduction

There was a TOMCAT failure last night in the PROD system. There was an alert that the URL was not available. Users could not get to the signon screen. Recycling TOMCAT resolved the issue.  

Environment

• Output Management Web Viewer 12.1
• Apache Tomcat®

Cause

There were OutofMemory exceptions with the heap space.  The exception occurred with a user accessing Cross Report Index Values at the point where we were making the fetch data request to DRAS.   That would include during the process for Tomcat to allocate the space needed to hold the incoming data.

Resolution

There is a setting that controls the number of index values (either Cross Report or Logical View indexes), to be requested at one time.  If that setting is not limited, all values will be requested, one request at a time until they are all brought down.  This is where the heap size ran out.

 

The setting for this can be found at the 

Administration Tab->Preferences->Display Preferences 

..under the "Index Values" header. 

 

It is not necessary to recycle Tomcat after making this change.  It will be picked by each user when they log on. 

 

Our recommendation for this for sites that have very large indexed reports, with 5,000 plus values - which of course can be multi-level indexes up to 8 deep - is to set it as Limited to 500 or less values allowed to be requested at a time.

 

The values are presented 20 at a time to the user, so in actual usage, they would proceed to filter to the index value they are looking for.  Please note that if that Index Value is not contained within the first 500 or less values, and are somewhere beyond them, we will call out to DRAS again and get that value in any case, so the value they need does not have to be included from the initial call(s) made.  Of course values can be wild carded as per standards as well, but the point is there is nothing to be gained from bringing in every value for an index that exceeds the number returned so far.

 

Also increase the maximum heap size.   If there is a larger heap size available on your LPAR, you can increase it to what would be allowed by Systems.  You can test how much is available by increasing the -Xmx by 512m or 1024m at a time, and restart Tomcat.  If the space you request is not available, Tomcat will fail to come up and output a message.