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The concurrent low pause collector seems to be doing full collections much of the time. How can the concurrent collection be sped up?

April 26, 2017collection collections Collector concurrent doing low pause SPED time

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The concurrent low pause collector seems to be doing full collections much of the time. How can the concurrent collection be sped up?

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The concurrent collection generally cannot be sped up but it can be started earlier. A concurrent collection starts running when the percentage of allocated space in the old generation crosses a threshold. This threshold is calculated based on general experience with the concurrent collector. If full collections are occurring, the concurrent collections may need to be started earlier. The command line flag CMSInitiatingOccupancyFraction can be used to set the level at which the collection is started. Its default value is approximately 68%. The command line to adjust the value is -XX:CMSInitiatingOccupancyFraction= The concurrent collector also keeps statistics on the promotion rate into the old generation for the application and makes a prediction on when to start a concurrent collection based on that promotion rate and the available free space in the old generation. Whereas the use of CMSInitiatingOccupancyFraction must be conservative to avoid full collections over the life