The solution is not necessarily related to the question here but as I came here, I feel it proper to put my solution here.
I was getting 'Could not open plan.jmx'
If you are getting simply that in the command line, then make sure that you have given the file name correctly considering capital small abcd in your command.
[I am using ubuntu so command got ...
Looking into ServiceSocket line 189 it appears that the session object is null, check jmeter.log file for any suspicious entries, it might be the case you plugin installation is corrupt (i.e. missing dependencies)
In general I would recommend switching to WebSocket Samplers by Peter Doornbosch which can be installed using JMeter Plugins Manager
Your configuration is wrong, you should put only devadmin.modetrans.com bit to the "Server Name or IP" field of the HTTP Request sampler like:
You might also be interested in JMeter WebSocket Samplers - A Practical Guide which explains the usage of the JMeter WebSocket Samplers plugin (the same limitations apply there as well, only valid DNS hostname is ...
If by encrypted you mean SSL or TLS then you don't even need to do anything, according to SSL Encryption chapter of the JMeter documentation
The JMeter HTTP samplers are configured to accept all certificates, whether trusted or not, regardless of validity periods, etc. This is to allow the maximum flexibility in testing servers.
If the server ...
You cannot use Loop Controller for this as it will read one entry per Loop Controller's iteration.
If you want to create a request having many JSON objects originating from CSV file I would recommend doing it via JSR223 PreProcessor and Groovy language.
The Groovy class you're looking for is JsonBuilder.
If you need further help consider providing:
I don't know what you're reading however I would recommend stopping referring this source as they don't really realize what they're talking about.
According to The WebSocket API documentation:
The WebSocket API is an advanced technology that makes it possible to open a two-way interactive communication session between the user's browser and a server. ...