Exceeded the maximum number of allowed client connections in ActiveMQ

Question

I am facing this issue for ActiveMQ Master/Slave config where the client nodes are not able to make connection to Master ActiveMQ node.

In the master ActiveMQ node I am seeing the error as:

ERROR | Could not accept connection : org.apache.activemq.transport.tcp.ExceededMaximumConnectionsException: Exceeded the maximum number of allowed client connections. See the 'maximumConnections' property on the TCP transport configuration URI in the ActiveMQ configuration file (e.g., activemq.xml) | org.apache.activemq.broker.TransportConnector | ActiveMQ Transport Server Thread Handler: tcp://0.0.0.0:61616?maximumConnections=1000&wireformat.maxFrameSize=104857600"

Where as on the client node, the Jetty process is showing the below message in the logs:

Transport (tcp://xxx.xxxx.xxxx.xxxxxxxx:61616) failed, reason:  java.io.IOException: Wire format negotiation timeout: peer did not send his wire format., attempting to automatically reconnect

Transport (tcp://xxx.xxx.xxx.xxxxxx:61616) failed, reason:  java.net.SocketException: Connection reset, attempting to automatically reconnect

Answer 1

The error message tells you exactly what the problem is:

Exceeded the maximum number of allowed client connections. See the 'maximumConnections' property on the TCP transport configuration URI in the ActiveMQ configuration file (e.g., activemq.xml)

It even tells you what the connector's configuration is, i.e.:

tcp://0.0.0.0:61616?maximumConnections=1000&wireformat.maxFrameSize=104857600

Notice that the it's using maximumConnections=1000. If you want to allow more connections than 1000 then you should change this configuration.