503: Too Many Connections For VPN



that's my first post on this community :)

I need your help/support because my client application (Boomi application) that is listening on severals solace queues is receiving this error on some listners when i try to start the application :

[com.solacesystems.jcsmp.protocol.impl.TcpClientChannel$ClientChannelConnect call] Connection attempt failed to host 'XXXXX.messaging.solace.cloud' ConnectException ((Client name: atom02.XXXXX.awseuw2.boom/20018/#002b0008/Tjk_c3q1X0  Local addr: 10.5.X.XXX Local port: 54488  Remote addr: XXXXXXX.messaging.solace.cloud Remote port: 55443) - ) com.solacesystems.jcsmp.JCSMPErrorResponseException: 503: Too Many Connections For VPN ((Client name: atom02.XXXXX.awseuw2.boom/20018/#002b0008/Tjk_c3q1X0  Local addr: 10.5.X.XXX Local port: 54488  Remote addr: XXXX.messaging.solace.cloud Remote port: 55443) - )

I just added some XXX to obscure IPs and DNS. It seems that there is something wrong when the client application is trying to connect to queues.

Any suggests?

Thank you in advance


  • Aaron
    Aaron Member, Administrator, Moderator, Employee Posts: 541 admin

    Hi there @FrancescoA, welcome to the Community!

    From your exception, it sounds like you've reached the connection limit for your Solace broker. Or more specifically: you've reached the configured connection limit for the specific Message VPN that you are connecting to.

    These are essentially the TCP connections from your client apps into Solace. This is not necessarily how many queues you have connected to, as a single connection can connect to multiple queues. But this would depend on how the Boomi binder is configured. Does it force a 1-to-1 connection-to-queue-bind configuration? I'm not sure.

    Do you have any visibility of the broker? Are you running it yourself, or using Solace Cloud? There are metrics and logs you can go look at. Perhaps some misconfiguration in an app is causing it to spawn too many connections and using up all the resources?

  • FrancescoA
    FrancescoA Member Posts: 2

    Hello Aaron,

    yes! I have visibility on the broker, it's a Solace Cloud Broker (Developer Class).

    I'm agree with you, i'm quite sure it's something related to spawn connections but i don't have visibility about mechanism on the client that force the application to say " Too Many Connections For VPN".

    Anyway i just see to options :

    a) increase the maximum incoming connections on Solace Cloud. At the moment is 100.

    b) undeploy unnecessary processes that try to connect to Solace Cloud

    Any other suggests?