Oh, yes, you are right, George. I'll probably do it in the next days.
On Mon, Feb 18, 2013 at 2:47 PM, George Datskos < [email protected]> wrote: > Hi Azuryy, > > So you have measurements for hadoop-1.0.4 and hadoop-2.0.3+QJM, but I > think you should also measure hadoop-2.0.3 _wihout_ QJM so you can know for > sure if the performance degrade is actually related to QJM or not. > > > George > > > Hi, > > HarshJ is a good guy, I've seen this JIRA: > https://issues.apache.org/jira/browse/HDFS-4508 > > I have a test cluster hadoop-1.0.4, I've upgrade to hadoop-2.0.3-alpha. > mu cluster is very small, four nodes totally. > > then I did some test on the original Hadoop and new Hadoop, the testing > is very simple: I have a data file with 450MB, I just put it on the HDFS. > > block size: 128MB, replica: 2 > > the following is the result: > > [root@webdm test]# ll testspeed.tar.gz > -rw-r--r-- 1 root root 452M Feb 18 13:54 testspeed.tar.gz > [root@webdm test]# > > //On the hadoop-1.0.4 > [root@webdm test]# date +%Y-%m-%d_%H:%M:%S; hadoop dfs -put > testspeed.tar.gz / ; date +%Y-%m-%d_%H:%M:%S > 2013-02-18_13:54:24 > Warning: $HADOOP_HOME is deprecated. > 2013-02-18_13:54:58 > > //On the hadoop-2.0.3-alpha with QJM > [root@webdm test]# date +%Y-%m-%d_%H:%M:%S; hdfs dfs -put > testspeed.tar.gz / ; date +%Y-%m-%d_%H:%M:%S > 2013-02-18_14:13:29 > 13/02/18 14:13:30 WARN util.NativeCodeLoader: Unable to load native-hadoop > library for your platform... using builtin-java classes where applicable > 2013-02-18_14:14:33 > > I do think QJM HA feature affect the performance, because each writer > from QJM, it will do: fence old writer; sync in-progress log; start new log > segment; then write. only if writer received a successful response from a > quorum of JNs, writer finished for this time. > > But NFS HA just write log segment in the local and NFS, when it receive > successful response from NFS, it finished this time. > > So, I just suggest we always keep these two HA features in future, even > in the stable release. which one should be used, which depends on yourself > based on your infrastructure. > > Thanks. > > >
