How To Fix CSM_VMC057 - Fragmentation of Memory Area for Shared Classes

SAP Error Message - Details

• Message type: E = Error

• Message class: CSM_VMC - Messages for VM Container Monitoring

• Message number: 057

• Message text: Fragmentation of Memory Area for Shared Classes

What causes this issue?

Fragmentation of a shared memory area specifies the size of the
discrepancy between occupied and allocated memory for this area. Since
shared memory is reserved in blocks of equal size (allocated), in
certain situations, a large amount of memory may have been allocated,
but the individual blocks contain only a few objects, and for this
reason they cannot be released. This situation is known as large
fragmentation. The memory fragmentation is specified as a percentage.
You can find more information about the memory classes in the VM
Container in the online documentation under
<DS:KENO.001560AA0E081DEB91E241270609CAF7>Memory Management in the VM
Container</>.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CSM_VMC057 - Fragmentation of Memory Area for Shared Classes ?

  The SAP error message CSM_VMC057, which indicates "Fragmentation of Memory Area for Shared Classes," typically arises in the context of Java applications running on the SAP NetWeaver Application Server Java (AS Java). This error is related to memory management, specifically the fragmentation of the memory area allocated for shared classes in the Java Virtual Machine (JVM).
  Cause:
  
  Memory Fragmentation: Over time, as objects are created and destroyed, the memory can become fragmented. This means that there are many small, unused blocks of memory that cannot be utilized effectively for larger objects.
  Insufficient Memory Allocation: If the JVM is not allocated enough memory for shared classes, it can lead to fragmentation issues.
  High Load or Inefficient Code: Applications that have high memory usage or inefficient memory management practices can exacerbate fragmentation issues.
  
  Solution:
  
  
  Increase Memory Allocation:
  
  Adjust the JVM parameters to increase the memory allocated for shared classes. This can be done by modifying the -XX:MaxPermSize or -XX:ReservedCodeCacheSize parameters in the JVM configuration.
  Example: You might set -XX:ReservedCodeCacheSize=256m to allocate more memory for the code cache.
  
  
  
  Optimize Code:
  
  Review and optimize the application code to reduce memory usage and improve object lifecycle management. This includes avoiding memory leaks and ensuring that objects are released when no longer needed.
  
  
  
  Garbage Collection Tuning:
  
  Tune the garbage collection settings to improve memory management. This can help in reducing fragmentation by ensuring that memory is reclaimed more efficiently.
  Consider using different garbage collection algorithms based on the application's needs.
  
  
  
  Monitor Memory Usage:
  
  Use monitoring tools to analyze memory usage patterns and identify potential bottlenecks or areas of high fragmentation. Tools like SAP Solution Manager or Java profiling tools can be helpful.
  
  
  
  Restart the Application Server:
  
  In some cases, a simple restart of the application server can temporarily alleviate fragmentation issues by clearing the memory.
  
  
  
  Upgrade JVM:
  
  If you are using an older version of the JVM, consider upgrading to a newer version that may have improved memory management features.
  
  
  
  Related Information:
  
  SAP Notes: Check SAP Notes related to memory management and JVM tuning for specific recommendations and best practices.
  Documentation: Refer to the official SAP documentation for guidelines on configuring the JVM and optimizing memory usage.
  Community Forums: Engage with the SAP community forums or support channels for insights from other users who may have encountered similar issues.
  
  By addressing the underlying causes of memory fragmentation and implementing the suggested solutions, you can mitigate the impact of the CSM_VMC057 error and improve the performance of your SAP Java applications.