Undestanding the message format over websockets


I want to create load tests with Neoload for our Vaadin (7.1.8) applicaiton which uses Push with websockets.

I managed to record scenarios and run them a single time parallel for multiple users (e.g. Login - Create a new Customer - Logout). The challanges I solved is that the first part of the message is the length of the message and the second part is a unique ID for each session, which must be dynamically adopted.

My Goal is to run them severals times (Login - Create a new Customer - Create a new Customer - Create a new Customer - … - Logout) which is much more realistic.

When I run the second iteration I get a resynchronizing error in the log file

WARNING: RPC call to v.v received for connector 194 but no such connector could be found. Resynchronizing client. and no event listener is called on the java side. Is there a documentation how I can understand the message format, to change the connector Ids dynamically for a second run?

Hi, could you clear your session on the way? Those connector identifiers are incrementing integer ids assigned by the framework automatically. They are deterministic, but only if you have fresh session each time.

I haven’t played with Neoload, but I’d guess you could adapt e.g. JMeter specific hints from our wiki to it as well. We are also working on an article about using Gatling for load testing and especially for WebSocket load testing. That is so far the best tool I have used. Tips to be presented in that article might help you too. It should be published within next couple of weeks.


Thanks for your reply. Do you have a link to the mentioned wiki page, I could not find it.