[ https://issues.apache.org/jira/browse/SPARK-20446?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Apache Spark reassigned SPARK-20446: ------------------------------------ Assignee: Apache Spark > Optimize the process of MLLIB ALS recommendForAll > ------------------------------------------------- > > Key: SPARK-20446 > URL: https://issues.apache.org/jira/browse/SPARK-20446 > Project: Spark > Issue Type: Improvement > Components: ML, MLlib > Affects Versions: 2.3.0 > Reporter: Peng Meng > Assignee: Apache Spark > > The recommendForAll of MLLIB ALS is very slow. > GC is a key problem of the current method. > The task use the following code to keep temp result: > val output = new Array[(Int, (Int, Double))](m*n) > m = n = 4096 (default value, no method to set) > so output is about 4k * 4k * (4 + 4 + 8) = 256M. This is a large memory and > cause serious GC problem, and it is frequently OOM. > Actually, we don't need to save all the temp result. Support we recommend > topK (topK is about 10, or 20) product for each user, we only need 4k * topK > * (4 + 4 + 8) memory to save the temp result. > -- This message was sent by Atlassian JIRA (v6.3.15#6346) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org