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HDFS >> mail # user >> RE: why my test result on dfs short circuit read is slower?


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Re: why my test result on dfs short circuit read is slower?

On Feb 17, 2013, at 7:09 PM, "Liu, Raymond" <[EMAIL PROTECTED]> wrote:

> io.file.buffer.size
Drop this down to 64KB not 128KB.

You have 16 cpu which really means 8 cores and 4 disks.

Do you have Ganglia up and running?

I'll wager that you'll see a lot of wait cpu cycles in both cases.

Also how much memory do you have on each machine?
Tuning is going to be hardware specific and without really understanding what each parameter does, you can hurt performance.

Michael Segel  | (m) 312.755.9623

Segel and Associates
The opinions expressed here are mine, while they may reflect a cognitive thought, that is purely accidental.
Use at your own risk.
Michael Segel
michael_segel (AT) hotmail.com

NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB