How To Fix CSM_VMC064 - Maximum Frequency of GC Runs of Individual Virtual Machines

SAP Error Message - Details

• Message type: E = Error

• Message class: CSM_VMC - Messages for VM Container Monitoring

• Message number: 064

• Message text: Maximum Frequency of GC Runs of Individual Virtual Machines

What causes this issue?

Each of the active virtual machines in the VM Container has reserved
memory for its Java heap. The size of this memory is bound to specified
limits when the VM is started and cannot be changed at runtime. Once
this memory is used up, the VM activates the garbage collection (GC)
procedure, in which memory allocated but no longer needed is freed up
again. There are two stages to this procedure - partial and full
garbage collection. The partial GC cleans up dedicated memory areas only
and uses much less resources. It is therefore much faster than the full
GC. This partial GC is performed more frequently and is part of normal
operation. The full GC is started when the permanent memory usage
(objects that have survived several partial GCs) exceeds specified
limits. Full GC empties all the objects from the Java heap that are no
longer needed, and therefore reduces the amount of memory occupied to
the smallest possible amount. This process involves a complex analysis
of the Java object references and takes a long time and uses up alot of
VM resources.

System Response

This monitor displays the maximum frequency of GC runs in one of the
active virtual machines in the VM Container. This figure is usually
dominated by the frequency of the partial GCs, and can have values up to
100 [1/min].

How to fix this error?

For a more detailed picture of Java memory states in the VM Container
this monitor should always be considered together with the values of the
full GC rate monitor and with the monitors for memory usage.
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</>.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CSM_VMC064 - Maximum Frequency of GC Runs of Individual Virtual Machines ?

  The SAP error message CSM_VMC064, which indicates "Maximum Frequency of GC Runs of Individual Virtual Machines," typically relates to the garbage collection (GC) process in the context of SAP's Java Virtual Machine (JVM) or other environments where memory management is crucial. This error suggests that the frequency of garbage collection runs for individual virtual machines has exceeded a predefined limit, which can lead to performance issues.
  Cause:
  
  High Memory Usage: The application may be consuming a large amount of memory, leading to frequent garbage collection cycles.
  Inefficient Memory Management: Poorly optimized code or memory leaks can cause the JVM to trigger garbage collection more often than necessary.
  Configuration Limits: The system may have a configuration that limits the frequency of garbage collection, and the application is exceeding this limit.
  Resource Constraints: Insufficient resources (CPU, memory) allocated to the JVM can lead to increased GC activity.
  
  Solution:
  
  
  Analyze Memory Usage:
  
  Use monitoring tools (like SAP Solution Manager, JVisualVM, or other profiling tools) to analyze memory usage patterns and identify memory leaks or inefficient memory usage.
  
  
  
  Optimize Code:
  
  Review and optimize the application code to reduce memory consumption. This may involve optimizing data structures, reducing object creation, and ensuring proper resource management.
  
  
  
  Adjust JVM Parameters:
  
  Modify the JVM parameters related to garbage collection. For example, you can adjust the heap size (-Xms and -Xmx), or change the garbage collection algorithm (e.g., using G1GC or CMS).
  Example parameters:
  
  -XX:MaxGCPauseMillis=<time>: Set a maximum pause time for garbage collection.
  -XX:GCTimeRatio=<ratio>: Adjust the ratio of time spent in GC versus application execution.
  
  
  
  
  
  Increase Resources:
  
  If the application is running on a virtual machine, consider increasing the allocated memory and CPU resources to reduce the frequency of garbage collection.
  
  
  
  Monitor and Tune:
  
  Continuously monitor the application performance and garbage collection metrics after making changes. Fine-tune the settings based on observed behavior.
  
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may provide specific guidance or patches related to this error.
  Documentation: Refer to the official SAP documentation for best practices on memory management and performance tuning for Java applications.
  Community Forums: Engage with SAP community forums or support channels for insights from other users who may have encountered similar issues.
  
  By addressing the underlying causes and implementing the suggested solutions, you can mitigate the frequency of garbage collection runs and improve the overall performance of your SAP application.