I'm using ema-220.127.116.11.jar, sometimes I get "Failed to make subscription" StatusMsg with DataState.SUSPECT data state when subscribing to instruments, the instruments seem fine as subscribing again would work fine although sometimes a few more tries are needed.
So if I subscribe/unsubscribe to some instruments continuously every second, sometimes I get data back, sometimes I get that StatusMsg. What's the likely cause of this error?
A couple of different ideas here, as I do not recall seeing this message before.
Are you, per chance, subscribing and unsubscribing in rapid succession, from multiple threads, and one action is not completed before l the next action is attempted?
If the case, for your use case, issuing a snapshot, non-streaming request would be more suitable (See Snapshot & Streaming Requests in EMA Developer Guide)?
Examining EMA source code for ESDK 1.4 (you can download the full open source code via Elektron SDK on GitHub) I am not finding this or similar message. Looking at OmmState.java implementation, so not see it. Is the message perhaps originating from custom code? Then you can try to find out more about the cause at the point in custom consumer code where it's being generated.
Another potential way to find out more is to enable tracing via XmlTraceToStdout ( see EMA Config Guide).