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Re: some ideas for QJM and NFS
Hi,

I did it on hadoop-2.0.3-alpha without HA as following:

[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_15:20:01
13/02/18 15:20:02 WARN util.NativeCodeLoader: Unable to load native-hadoop
library for your platform... using builtin-java classes where applicable
2013-02-18_15:20:30

so the performance is a little bit better than hadoop-1.0.4.

On Mon, Feb 18, 2013 at 2:53 PM, Azuryy Yu <[EMAIL PROTECTED]> wrote:

> 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.
>>
>>
>>
>