How To Fix CSM_VMC038 - Frequency of Failed GC Memory Read Attempts

SAP Error Message - Details

• Message type: E = Error

• Message class: CSM_VMC - Messages for VM Container Monitoring

• Message number: 038

• Message text: Frequency of Failed GC Memory Read Attempts

What causes this issue?

This performance attribute measures the frequency of failed attempts to
read the memory during garbage collection procedures in all active VMs
within a certain time frame (usually measured in minutes). The attribute
value is calculated as follows: During a GC procedure all the relevant
areas of the Java heap must be examined for obsolete Java objects. The
VM attempts to access these memory areas while they are being read. Many
operating systems however optimize the runtime memory of their processes
by copying memory areas that have not been read or written to for some
time to fixed temporary memory locations (for example, the hard drive).
This means they are not immediately available and the fast memory can be
made available to other processes. This procedure is known as memory sw
apping. If a swapped memory area (a page) is read by the VM garbage
collection, first of all a failed read attempt is reported. The
operating system starts a physical memory swap which restores the
missing page from the fixed memory and possibly swaps it against other
memory areas.

System Response

A high frequency of attempts to read the memory (usually 1000 and more
missing pages per minute) considerably slows down the garbage
collection, and in particular system performance. This state is an
indication of insufficient hardware memory or of unusually high memory
usage on the host in question. Though the VM Container can continue to
run, performance is reduced considerably.
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</>.

How to fix this error?

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

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_VMC038 - Frequency of Failed GC Memory Read Attempts ?

  The SAP error message CSM_VMC038, which indicates "Frequency of Failed GC Memory Read Attempts," typically relates to issues with the Garbage Collection (GC) process in the Java Virtual Machine (JVM) used by SAP applications. This error suggests that the JVM is experiencing difficulties in reading memory during garbage collection, which can lead to performance degradation or application instability.
  Causes:
  
  Memory Pressure: The JVM may be under memory pressure, leading to frequent garbage collection attempts that fail.
  Configuration Issues: Incorrect JVM parameters or insufficient heap size can cause the garbage collector to struggle.
  Resource Contention: Other processes or applications on the same server may be consuming resources, leading to contention.
  Hardware Limitations: Insufficient hardware resources (CPU, RAM) can impact the performance of the JVM and its garbage collection process.
  Fragmentation: Memory fragmentation can lead to inefficient memory usage, causing the garbage collector to fail in reclaiming memory.
  
  Solutions:
  
  Increase Heap Size: Adjust the JVM heap size parameters (-Xms and -Xmx) to provide more memory for the application.
  Optimize GC Settings: Review and optimize the garbage collection settings. Consider using different garbage collection algorithms (e.g., G1GC, CMS) based on your application's needs.
  Monitor Memory Usage: Use monitoring tools to analyze memory usage patterns and identify potential memory leaks or excessive memory consumption.
  Review Application Code: Check for inefficient code that may lead to excessive object creation or memory leaks.
  Upgrade Hardware: If the server is under-resourced, consider upgrading the hardware to provide more CPU and RAM.
  Isolate Resources: If other applications are running on the same server, consider isolating the SAP application to reduce resource contention.
  
  Related Information:
  
  SAP Notes: Check SAP Notes related to JVM performance and garbage collection for specific recommendations and patches.
  JVM Documentation: Review the documentation for the specific version of the JVM you are using to understand the garbage collection mechanisms and tuning options.
  Monitoring Tools: Utilize tools like SAP Solution Manager, JVisualVM, or other APM tools to monitor JVM performance and garbage collection metrics.
  Performance Tuning: Regularly perform performance tuning and capacity planning to ensure that the application runs optimally.
  
  If the issue persists after trying the above solutions, it may be beneficial to engage SAP support for further assistance, as they can provide more tailored guidance based on your specific environment and configuration.