The amount of memory configured for the Tomcat Maximum memory pool can quite often be too low in large vCenter Server environments. If Tomcat runs out of memory, some or all of the VMware VirtualCenter Management Webservices based features might not function correctly, or at all.
This issue may occur due to a conservative Java Memory Pool setting. The Tomcat service depends on the Java Memory Pool setting for its various functions.
Note: It may take a period of time for the increase in the memory pool value to take effect, up to 15 minutes. A further increase of the Maximum memory pool value may be required, until the issue is resolved and no OutOfMemory errors are recorded in the stdout_datestamp.log file, as noted in the Symptoms section.
This issue may also occur in smaller environments, but is much less likely. If the OutOfMemory errors are present in the stdout_datestamp.log file, use the resolution noted in this article to resolve the issue.
Unable to start the VMware VirtualCenter Management Webservices after upgrading to vCenter Server 4.x or later