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Home > All Categories > SAP NetWeaver > SAP Java Performance > Java: Garbage Collection Time has Greater than 10% Avg on your EWA
Java: Garbage Collection Time has Greater than 10% Avg on your EWA Problem: Your Solution Manager Java Early Watch Alert Report read as follow: " Garbage Collection Time Time spent on Garbage Collections (GC) prevents the Java virtual machine from executing any other task. In the interval reported, at least one of the server nodes below spent, on average, more than 10% of the overall time on Garbage Collections. It is highly advisable to analyze this behavior with help of other key performance indicators in this report." Solution: - Analyze the Garbage collection using SAP Solution Manager diagnostics tool or some other Java GC analyzing (std_serverN.out log from work directory). - Find out how frequent Minor and Full GCs are running to free up the memory. When the new generation fills up it triggers a minor collection in which surviving objects are moved to the tenured generation. When the tenured generations fills up, it triggers a major collection, which involves the entire object heap  Minor Collection (Regular GC): This performed frequently and has a relatively shor durations (~0.2 seconds) Major Collection (Full GC): Full GC is less frequent and can be very time consuming, between 3 and 5 seconds per cycle. On very large Heaps (1.5G) a full cycle can take more then 10 seconds. Full GC is less frequent and can be very time consuming, between 3 and 5 seconds per cycle. On very large Heaps (> In the std_serverN.out file you can see that after Full GC the JVM is not able to free Java Heap or/and Perm space as result OutOfMemoryError is caught - If you have Minor Collection running too frequently which causing GC Collection time to increase greater than 10%, then you might consider adding another server node using configtool to distribute the loads. For PI Java based System, read the following notes before adding the server any additional server nodes. - 862405 - XI Configuration Options for Lowering Memory Hope that helps! Suresh Authored by: Suresh This question has been viewed 648 times so far. Click Here to View all the questions in SAP Java Performance category. File Attachments There are no attachment file(s) related to this question. How helpful was this article to you? Select a Vote 5 - Very Helpful 4 3 - Somewhat Helpful 2 1 - Not Helpful User Comments There are no user comments for this question. Be the first to post a comment. Click Here Related Questions There are no other questions related to this question. Additional Information Article Number: 23 Created: 2009-10-08 8:10 PM Rating   Article Options Print this Question Email this Question to Friend Export to MS Word del.icio.us Bookmark Digg It Furl It Subscribe to Article   Language Translation --- Select a Language --- To Chinese To French To German To Italian To Japanese To Korean To Portugese To Spanish   Search Knowledge Base
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