JMeter user & system properties
In case you need to add properties to JMeter’s default “user.properties” file, go to the Files tab of the relevant test and upload your “user.properties” file. JMeter in the Cloud will identify it and will add it to the JMeterEngines and console servers. Similarly, "system.properties" can be uploaded to update system properties.
New jar files
Users that develop and/or enhance their JMeter components can upload their own JMeter components and add-ons.
To do this, jar your JMeter components and then upload the jar files. JMeter in the Cloud will identify the uploaded jar files and will automatically copy them to the JMETER_HOME/lib/ext directiry.
System hosts file
You can control the “hosts” file of the launched servers. As a result, you are able to add additional local DNS entries as if you were editing the hosts file locally. One important use for this feature is to provide permanent DNS resolution for certain DNS names. This can reduce the number of times JMeter in the Cloud calls on your DNS for name resolution.
To do this, upload your “hosts.txt” file. This file will replace the "/etc/hosts" file on every launched server. Please note that the new hosts file should include at least one line of the form: 127.0.0.1 localhost. The name of the file must be "hosts.txt".