In the Cisco CallManager 4.0 cluster, RTMT sends alerts about low memory availability on the publisher and that SQL uses most of the memory

[TCC_2]

Core Issue

Real-Time Monitoring Tool (RTMT) shows a LowAvailableMemory alert, indicating that there is less than 10 percent free physical memory on the system (using the default threshold). This usually occurs for the publisher. 

The warning is most likely cosmetic.

Through DLLHOST processes, Windows expands and utilizes the physical memory that is available for caching, especially Structured Query Language (SQL) and Internet Information Server (IIS). This can cause a low amount of available physical memory to be seen, especially in a publisher. These processes are intelligent about the amount of memory they use, and if the physical memory available gets very low (less than ~5MB), they release cache memory so other processes do not get swapped out to disk.

For more information about SQL behavior, refer to SQL Server Memory Usage. 

Resolution

This issue is tracked in Cisco bug ID CSCeg41834. 

For a workaround, perform these steps: 

1. Verify that the system does not show symptoms of a memory leak.
2. Check that the committed memory usage does not greatly exceed the amount of physical memory in the system.
3. In most cases, the total commit charge as shown by task manager is only slightly higher than the physical memory total shown.
4. After you verify that there is no memory leak issue, perform one of these workarounds:   
   • Lower the threshold for the LowAvailableMemory alert to a lower percentage.
   • Disable the alert.
   • Disable the alert and create a new alert based on committed bytes in use. Consider a threshold of 70 percent, depending on the system.
5. If this does not help, go through the physical memory recommendations. With Cisco CallManager 4.0 and later, memory recommendations depend on the platform. Refer to Physical Memory Recommendations for Cisco CallManager Vers. 4.0.