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




echo 1 > /proc/sys/vm/drop_caches




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.