AMQ339009 Exception getting session: blocking behaviour

[Tom Davis]

Just leaving this information here in case anyone else experiences this error message as a result of being blocked. The following is a response from CACI:

The system detects multiple connection attempts in a 15 minute period, I believe this is 100 connection attempts, after which a user is blocked for around 20 minutes, unless they try and connect within that time which resets the 20 minute count in effect blocking you until you cease all attempts for 20 minutes or so.

If you stop all connections for around 20 minutes, then try again you should be able to get straight back on.  Just be mindful of using a limited number of connection attempts otherwise it will block you again for 20 minutes until you stop any attempts.  Users get around this by having a delay after every connection attempt.

Clearly having an exponential backoff on your reconnection policy is key here.

[Christoper Stafford]

FWIW they told me the same thing last time I got blocked, but I'm confident it was for radically fewer connection requests than this - less than 1 a minute on the approved account and half that on the public account. 

[Aleksa Jakovljevic]

New to this but pretty much to see if I got it right I set up a php-stomp client (based on example codes, I just added enough to make it a durable connection) connecting to the VSTP feed for a few seconds once every five minutes (!!!) [managed with Task Scheduler] and after a few hours of running in the background without issue I seem to be getting this error as well. I've tried waiting 20 minutes and still not resolved.

Cheers,

A

[Peter Hicks]

On Friday, 22 August 2025 at 08:41, Aleksa Jakovljevic <alex.jako...@gmail.com> wrote:

New to this but pretty much to see if I got it right I set up a php-stomp client (based on example codes, I just added enough to make it a durable connection) connecting to the VSTP feed for a few seconds once every five minutes (!!!) [managed with Task Scheduler] and after a few hours of running in the background without issue I seem to be getting this error as well. I've tried waiting 20 minutes and still not resolved.

I think your best option here is to ditch the idea of scheduling a task every few minutes.  Think of it like a toilet at a festival (sorry, it's the only analogy I could come up with) - much better for it to drain in to the sewer when required, than build up and be emptied once a day.

Use a long-lived task that consumes data and does something quick with it in real-time - whether that be logging it to disk, storing it in a database, or queueing it and having another task or tasks processing it.  PHP might not be the best option here.

Peter