w3wp.exe instance for the EnterpriseVaultAPI application pool taking up a large amount of CPU and memory

Problem

For Enterprise Vault (EV) versions 14.0 and higher, resources used by the w3wp.exe instance hosting the EnterpriseVaultAPI application pool in IIS increase over time leading to very high usage, for example 14GB of memory and 90% CPU.  If the application pool is restarted the memory and CPU usage go back to normal for a period of time.  

Error Message

N/A

Cause

An issue where memory is not released properly during normal operation.  

Solution

Workaround 1

To mitigate the impact of the issue, the application pool can be configured to recycle more often than the default of approximately 6 days. For example, it can be configured to recycle every 12 hours.

Other conditions can be used, for example triggering the reset when the memory usage gets to 4GB or recycling at specific times of the day.

Workaround 2 

As an alternate workaround it is possible to implement the registry key CacheData on the Enterprise Vault Server

Create a new DWORD value named CacheData setting it to 0 

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\KVS\Enterprise Vault\EVIndexing\CacheData] 

A value of 0 (zero) indicates that the caching mechanism used while searching results will not be employed, the default value is 1.

It is required to either execute an IIS Reset operation or restart the EV Server after having created the new registry key

Note: This registry value is available in EV 14.2.1 and higher.

Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.