Hi, I have just set up a small Linux machine cluster with 3 physical
machines (dual core, with RedHat Enterprise 5.) to run Hadoop and HBase. No
virtual machines are involved at this time in the test bed. The version of
HBase and Hadoop that I chose is hbase-0.19.0 and hadoop-0.19.0.
To better understand the performance, I run the PerformanceEvaluation which
is supported in the test directory comes with the release. When I used the
client number N=1, all the testing about sequentialWrite, sequentialRead,
randomWrite, randomRead, scan, just work fine, for the row number chosen by
default, which is R = 1024*1024, with each row containing 1 KB of data.
However, when I choose N= 4, with row number selected for 102400 (even
smaller than 1024*1024 described above), and run the following command:
bin/hadoop org.apache.hadoop.hbase.PerformanceEvaluation --rows=10240
sequentialWrite 10
the Map/Reduce fails, and I check the logs, It has the error message of:
org.apache.hadoop.hbase.client.RetriesExhaustedException: Trying to
contact region server 15.25.119.59:60020 for region
TestTable,,1238136022072, row '0000010239', but failed after 10
attempts.
Exceptions:
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
at
org.apache.hadoop.hbase.client.HConnectionManager$TableServers.getRegionServerWithRetries(HConnectionManager.java:841)
at
org.apache.hadoop.hbase.client.HConnectionManager$TableServers.processBatchOfRows(HConnectionManager.java:932)
at org.apache.hadoop.hbase.client.HTable.flushCommits(HTable.java:1372)
at
org.apache.hadoop.hbase.PerformanceEvaluation$Test.testTakedown(PerformanceEvaluation.java:370)
at
org.apache.hadoop.hbase.PerformanceEvaluation$Test.test(PerformanceEvaluation.java:393)
at
org.apache.hadoop.hbase.PerformanceEvaluation.runOneClient(PerformanceEvaluation.java:583)
at
org.apache.hadoop.hbase.PerformanceEvaluation$EvaluationMapTask.map(PerformanceEvaluation.java:182)
at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:50)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:332)
at org.apache.hadoop.mapred.Child.main(Child.java:155)
All my HBase runtime configuration parameters, such as JVM Heap, are chosen
by the default setting. Could you provide help on addressing this issue?
Also, it seems the on the Wiki page,
http://wiki.apache.org/hadoop/Hbase/PerformanceEvaluation, the focus is on
the case of N=1. Could you share with me what is the higher number of N
(concurrent clients) that have been tested on HBase, given the comparable
number of rows at the range of 1024*1024, or above?
Thank you and Best Regards.
