I found a way to increase network performance but only for write. When I run a read dfsio it only seems to be sending to the local drive from 1 system and not reading from multiple systems. I need the system to read through the network and not locally can any body help on how to force network reads using dfsio? ... View more

I found this article which was super helpful.   http://www.linuxsecrets.com/categories/linux-performance/performance-tips/redhat-prerequisites-benchmarking-and-stress-testing-on-hadoop-cluster ... View more

I would also like to cut down on local hhd writes so I can evenly distribute data to all machines so I get more network traffic as well.   @nauseous wrote: I'm trying to get maximum throughput with Cloudera on RedHat 6.6 on 6 - Dell R730's with kernel 3.18.1, and using 2 - 850MB, 3G ssd transfer per second hhd with modified drivers which have been tested. Currently I've tried decommissioning "mapReduce tasktracker" on all nodes except 1 single node as suggested but didn't really make any differences in nic speed. I want to max out the connection speed on all nodes if possible.   I've tried : sudo -u hdfs hadoop jar /opt/cloudera/parcels/CDH-5.3.1-1.cdh5.3.1.p0.5/jars/hadoop-test-2.5.0-mr1-cdh5.3.1.jar  TestDFSIO -write -nrFiles 100000 -fileSize 50   and    sudo -u hdfs hadoop jar /opt/cloudera/parcels/CDH-5.3.1-1.cdh5.3.1.p0.5/jars/hadoop-test-2.5.0-mr1-cdh5.3.1.jar  TestDFSIO -write -nrFiles 500 -fileSize 10GB   without good results.   I've already tested throughput with netperf but can't seem to get cloudera to perform network tests to maximum level like I have with netperf using dfsio.     Any suggestions would help greatly.     @nauseous wrote: I'm trying to get maximum throughput with Cloudera on RedHat 6.6 on 6 - Dell R730's with kernel 3.18.1, and using 2 - 850MB, 3G ssd transfer per second hhd with modified drivers which have been tested. Currently I've tried decommissioning "mapReduce tasktracker" on all nodes except 1 single node as suggested but didn't really make any differences in nic speed. I want to max out the connection speed on all nodes if possible.   I've tried : sudo -u hdfs hadoop jar /opt/cloudera/parcels/CDH-5.3.1-1.cdh5.3.1.p0.5/jars/hadoop-test-2.5.0-mr1-cdh5.3.1.jar  TestDFSIO -write -nrFiles 100000 -fileSize 50   and    sudo -u hdfs hadoop jar /opt/cloudera/parcels/CDH-5.3.1-1.cdh5.3.1.p0.5/jars/hadoop-test-2.5.0-mr1-cdh5.3.1.jar  TestDFSIO -write -nrFiles 500 -fileSize 10GB   without good results.   I've already tested throughput with netperf but can't seem to get cloudera to perform network tests to maximum level like I have with netperf using dfsio.     Any suggestions would help greatly.     ... View more

I wasn't able to find my post sense I don't have my machine but here is a great article here http://tinyurl.com/lr3gfx4   Hope this helps 🙂 ... View more

Great job.   I try to keep the names as simple as possible so I can run thousands of scripts.   My hosts files is like:   127.0.0.1     localhost   Looping interfaces from multiple machines. AWS or for example Linode looping you just would use the internal looping device. Fast and quickly managed.   #Cloudera Machines   192.168.2.1     n1 192.168.2.2     n2 192.168.2.3     n3          "              n4          "              n5          "              n6          "              n7   and so on to make it easier for changes across machines.   Such as:   for i in {1..300}; do ssh n$i date; done   <-- Checks dates on all machines to make sure each machine is sync'ed.   Makes life easier to make it simple. ... View more

Great job.   I try to keep the names as simple as possible so I can run thousands of scripts.   My hosts files is like:   127.0.0.1   ... View more