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Expert Contributor
Posts: 61
Registered: ‎03-06-2015

SUT testing on hadoop for all disk reads/writes

Current CDH5 and RedHat 6.6 and I have dn to a SSD drive but I need to change cloudera to read/write more or not to write any data to memory but to disk. What setting would I change to produce 100% disk reads and writes?

New Contributor
Posts: 1
Registered: ‎04-16-2015

Re: SUT testing on hadoop for all disk reads/writes

I know of two linux options but no idea if this works with cloudera.

 

Try creating a script to test with:

 

-------------------------------- start of script

 

#!/bin/bash

 

echo 1 > /proc/sys/vm/drop_caches

 

or

 

echo 100 > /proc/sys/vm/dirty_expire_centisecs
echo 100 > /proc/sys/vm/dirty_writeback_centisecs

 

-------------------------------- end of script

 

You can test the results if you have run terasort and memory is in use.

 

Try htop watch memory with "alt - f6" pick memory  from htop menu and watch it when you exec the script. Memory will flush and dirty cache will be purged.

 

Thanks for your previous solutions and shutdown techique.