vFabric Elastic Memory for Java (EM4J) 1.1 Release Notes

vFabric EM4J 1.1 | 22 MAY 2012

Last Document Update: 22 MAY 2012

What's in the Release Notes

These release notes cover the following topics:

What's New in vFabric EM4J 1.1

This VMware® vFabric™ Elastic Memory for Java (EM4J) release includes the following new features:

  • Support for Oracle HotSpot 7 JVM and Red Hat Enterprise Linux 6.
  • The maximum EM4J balloon size for EM4J has increased from 2G to 4GB.
  • The Console Guest Collector (CGC) component is redesigned. It can be installed as a service, and is no longer run from crontab.
  • The CGC maintains historical VM memory usage statistics over a period of up to a week.
  • The vSphere Web Client plug-in for EM4J adds a new History tab to display the historical memory statistics the CGC collects. The graphs on this tab illustrate memory utilization over time and can reveal opportunities to resize VM memory and Java heap sizes to use the host's memory resources more efficiently. This feature is useful for vSphere Administrators even when EM4J is not enabled in the VM.

Known Issues

The following issues have been identified in this release of vFabric EM4J. When available, a workaround is provided.

Issue Component Description Workaround
JEM-332 Console UI The Virtual Machine Memory Usage graph in the History tab may not appear to refresh after selecting "Reset EM4J historical data..." from the context menu. Manually refresh the vSphere Web Client by clicking the Refresh icon on the toolbar.
JEM-343 Console UI CGC and Plug-in version information is not easily found unless the selected VM has at least one Java process running. If the Summary tab is hidden, as is the case when there are no workloads, version information can be found here:
  • Console UI Plug-in: Applications menu > Plug-in Management (see Version column of plug-ins table).
  • CGC: Alerts tab: look for start-up message from CGC, which reports the version.
JEM-404 Console UI The Virtual Machine Memory Usage graph's 'Export to CSV...' context menu item works correctly only for VMs configured to use the Guest Balloon. No workaround. Do not use this feature for VMs configured to use EM4J ballooning.
JEM-411 Console UI A NullPointerException occurs upon reading SystemInfo for a workload with no main class. None. 1.1 Console UI expects all workloads to have a valid main class name.

Resolved Issues

The following issues have been resolved in this release of vFabric EM4J.

Issue Component Description
JEM-79 Agent EM4J prints "AgentGCFinish_Thread awoke" messages to catalina.out when logLevel is INFO. Before EM4J agent has finished initializing, some messages are logged that should not appear in the log at the configured log level.
JEM-84 Agent When EM4J is not enabled in an ESXi 5.0 VM (sched.mem.pshare.guestHintsSyncEnable is not set to true) and a JVM is started with the EM4J agent specified, the EM4J agent gets a vFabric license and fails to release it when the JVM shuts down.
JEM-141 Agent Very early GC, before the EM4J agent has initialized, can cause NPE on startup.
JEM-186, JEM-272 CGC The CGC is not getting the adjusted value for HeapMemoryUsage; JConsole reports the adjusted value.
JEM-209 Agent When an EM4J-enabled JVM running an Apache Tomcat 6 or 7 instance shuts down, the logs/vf.emj-events.txt license audit trail file sometimes shows state=on.