Setting up JMeter for Distributed testing in AWS with connectivity issues

Question

I have to do distributed testing using JMeter. The objective is to have multiple remote servers in AWS controlled by one local server send a file download request to another server in AWS.

How can I set up the different servers in AWS?
How can I connect to them remotely?

Can someone provide some step by step instructions on how to do it?
I have tried several things but keep running into connectivity issues across networks.

Answer 1

We had a similar task and we ran into a bunch of issues as well. Here are the details of the whole process and what we did to resolve the issues we encountered. Hope it helps.

We needed to send requests from 5 servers located in various regions of the world. So we launched 5 micro instances in AWS, each in a different region. We chose the regions to be as geographically apart as possible.

Remote (server) JMeters config

Here is how we set up each instance.

1. Installed java:

   $ sudo apt-get update $ sudo apt-get install default-jre  

2. Installed JMeter:

   $ mkdir jmeter $ cd jmeter; $ wget ftp://apache.mirrors.pair.com//jmeter/binaries/apache-jmeter-2.9.tgz $ gunzip apache-jmeter-2.9.tgz;tar xvf apache-jmeter-2.9.tar 

3. Edited the jmeter.properties file in the /bin folder of the JMeter installation and uncomment the line containing the server.rmi.localport setting. We changed the port to 50000.

   server.rmi.localport=50000 

4. Started JMeter server. Make sure the address and the port the server reports listening to are correct.

   $ cd ~/jmeter/apache-jmeter-2.9/bin $ vi jmeter-server 

Local (client) JMeter config

Then we set up JMeter to run tests remotely on these instances on our local client machine:

• Ensured to use the same version of JMeter as was running on the servers. Installed Java and JMeter as described above.
• Enabled remote testing by editing the jmeter.properties file that can be found in the bin folder of the JMeter installation. The parameter remote_hosts needed to be set with the public DNS of the remote servers we were connecting to.
• remote_hosts=54.x.x.x,54.x.x.x,54.x.x.x,54.x.x.x,54.x.x.x

We were now able to tell our client JMeter instance to run tests on any or all of our specified remote servers.

Issues and resolutions

Here are the issues we encountered and how we resolved them:

1. The client failed with:

   ERROR - jmeter.engine.ClientJMeterEngine: java.rmi.ConnectException: Connection - refused to host: 127.0.0.1

   It was due to the server host returning the private IP address as its address because of Amazon NAT. We fixed this by setting the parameter RMI_HOST_DEF that the /usr/local/jmeter/bin/jmeter-server script includes in starting the server:

   RMI_HOST_DEF=-Djava.rmi.server.hostname=54.xx.xx.xx 

   Now, the AWS instance returned the server’s external IP, and we could start the test.

2. When the server node attempted to return the result and tried to connect to the client, the server tried to connect to the external IP address of my local machine. But it threw a connection refused error:

   2013/05/16 12:23:37 ERROR - jmeter.samplers.RemoteListenerWrapper: testStarted(host) java.rmi.ConnectException: Connection refused to host: xxx.xxx.xxx.xx;

   We resolved this issue by setting up reverse tunnels at the client side.

   • First, we edited the jmeter.properties file in the /bin folder of the JMeter installation and uncommented the line containing the client.rmi.localport setting. We changed the port to 60000:

     client.rmi.localport=60000 

   • Then we connected to each of the servers using SSH, and setup a reverse tunnel to port 60000 on the client.

     $ ssh -i ~/.ssh/54-x-x-x.us-east.pem -R 60000:localhost:60000 [email protected] 

   We kept each of these sessions open, as the JMeter server needs to be able to deliver the test results to the client.

   • Then we set up the JVM_ARGS environment variable on the client, in the jmeter.sh file in the /bin folder:

     export JVM_ARGS="-Djava.rmi.server.hostname=localhost" 

   By doing this, JMeter will tell the servers to connect to localhost:60000 for delivering their results. This ends up being tunneled back to the client.

3. The SSH connections to the servers kept dropping after staying idle for a little bit. To prevent that from happening, we added a parameter to each of the SSH tunnel set up directing the client to wait 60 seconds before sending a null packet to the server to keep the connection alive:

   $ ssh -i ~/.ssh/54-x-x-x.us-east.pem -o ServerAliveInterval=60 -R 60000:localhost:60000 [email protected] 

(.ssh/config version of all required SSH settings:

 Host 54.x.x.x    HostName 54.x.x.x    Port 22    User ubuntu    ServerAliveInterval 60    RemoteForward 127.0.0.1:60000 127.0.0.1:60000    IdentityFile  ~/.ssh/54-x-x-x.us-east.pem    IdentitiesOnly yes 

Just use ssh 54.x.x.x after setting this up. )