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Hudson commented on HADOOP-2434: -------------------------------- Integrated in Hadoop-Nightly #338 (See [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/338/]) > MapFile.get on HDFS in TRUNK is WAY!!! slower than 0.15.x > --------------------------------------------------------- > > Key: HADOOP-2434 > URL: https://issues.apache.org/jira/browse/HADOOP-2434 > Project: Hadoop > Issue Type: Bug > Components: io > Reporter: stack > Assignee: stack > Priority: Blocker > Fix For: 0.16.0 > > Attachments: 2434.patch, TestMapFile.java, TestMapFile.java > > > Stall happens down in SequenceFile in the first call to getPos inside > readRecordLength. I tried the johano patch from HADOOP-2172 that restores > the positional cache but that didn't seem to be the issue here. > Here is data to support my assertion. > I wrote a little program to make a MapFile of 1M records. I then did 1M > random reads from same file. Below are timings from a 0.15.0 and TRUNK as of > this afternoon run. > 0.15.x branch: > {code} > [EMAIL PROTECTED] branch-0.15]$ ./bin/hadoop org.apache.hadoop.io.TestMapFile > .07/12/15 01:29:02 WARN util.NativeCodeLoader: Unable to load native-hadoop > library for your platform... using builtin-java classes where applicable > 07/12/15 01:29:02 INFO io.TestMapFile: Writing 1000000 rows to > testMapFileRandomAccess > 07/12/15 01:32:04 INFO io.TestMapFile: Writing 1000000 records took 182009ms > 07/12/15 01:32:04 INFO io.TestMapFile: Reading 1000000 random rows > 07/12/15 01:48:02 INFO io.TestMapFile: Reading 1000000 random records took > 958243ms > Time: 1,140.652 > OK (1 test) > {code} > For the below test using TRUNK r604352, I amended the test so it output a log > message every 100k reads: > {code} > [EMAIL PROTECTED] hadoop-trunk]$ ./bin/hadoop org.apache.hadoop.io.TestMapFile > .07/12/15 01:56:34 WARN util.NativeCodeLoader: Unable to load native-hadoop > library for your platform... using builtin-java classes where applicable > 07/12/15 01:56:34 INFO io.TestMapFile: Writing 1000000 rows to > testMapFileRandomAccess > 07/12/15 01:59:38 INFO io.TestMapFile: Writing 1000000 records took 183986ms > 07/12/15 01:59:38 INFO io.TestMapFile: Reading 1000000 random rows > ......... > {code} > After 20 minutes it still hadn't printed out the 'read 100k messages' (I had > to leave -- will fill in final figures later) -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.