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Robert Joseph Evans updated MAPREDUCE-2494: ------------------------------------------- Release Note: Added config option mapreduce.tasktracker.cache.local.keep.pct to the TaskTracker. It is the minimum percentage of the local distributed cache that should be kept in between garbage collection runs. This is a floating point value between 0.0 and 1.0. The default is 0.95. (was: Added config option mapreduce.tasktracker.cache.local.keep.pct to the TaskTracker. It is the minimum percentage of the local distributed cache that should be kept in between garbage collection runs. This is a floating point value between 0.0 and 1.0. The default is 0.75.) Status: Patch Available (was: Open) > Make the distributed cache delete entires using LRU priority > ------------------------------------------------------------ > > Key: MAPREDUCE-2494 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-2494 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: distributed-cache > Affects Versions: 0.21.0, 0.20.205.0 > Reporter: Robert Joseph Evans > Assignee: Robert Joseph Evans > Fix For: 0.20.205.0, 0.23.0 > > Attachments: MAPREDUCE-2494-20.20X-V1.patch, > MAPREDUCE-2494-20.20X-V3.patch, MAPREDUCE-2494-V1.patch, > MAPREDUCE-2494-V2.patch > > > Currently the distributed cache will wait until a cache directory is above a > preconfigured threshold. At which point it will delete all entries that are > not currently being used. It seems like we would get far fewer cache misses > if we kept some of them around, even when they are not being used. We should > add in a configurable percentage for a goal of how much of the cache should > remain clear when not in use, and select objects to delete based off of how > recently they were used, and possibly also how large they are/how difficult > is it to download them again. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira