The client connection was aborted by the server, possibly because the connection was disallowed.
This may be because the connection was disallowed. Abort messages are also sent to clients that have unrecognised client IDs. This may be because the server closed the client previously but the client is unaware of this and tried to continue interacting with the server.
The client had become unresponsive. Recoverable.
The client has either failed to respond to a ping message in a timely manner or the client has failed to open an HTTP poll for messages. The client does not appear to be receiving messages.
The client requested close. Not recoverable (unless TEST_RECONNECT is true).
A control session initiated the client close.
The connection to the client was lost - possibly dropped by the client. Recoverable.
A client may be closed for may reasons that are presented as CONNECTION_LOST.
During connection the connection can be lost. The server might have received a connection or reconnection request from a client already connected. The server might have received a reconnection request without a client ID. The connection may not have been authorised because the credentials are wrong. The maximum number of clients might already be connected.
Once connected the connection can be lost for different reasons. If the client closes its connection while the server is writing a message to the client. With the chunked encoding based connection the HTTP response is completed by the server. If the client does not open a new request within a timeout the client will be closed. If a poll request times out and the server finds that the connection has already been closed by the client.
The client has failed over to a different server.
The session is still open but is now connected to a different Diffusion server. This server has evicted its view of the client from its set of local clients.
An internal error occurred.
An inbound message with an invalid format was received.
A message received by the server is not a valid Diffusion message. The server is unable to process this and closes the client that sent it.
An unexpected IO Exception occurred. Recoverable.
While trying to perform an I/O operation an exception was generated. This often means that Diffusion attempted to read from a closed TCP connection.
When Diffusion is handling SSL connections if there is a problem encrypting or decrypting a message the client will be closed for this reason.
Loss of messages from the client has been detected. For example, whilst waiting for the arrival of missing messages in a sequence of messages a timeout has occurred.
HTTP based transports use multiple TCP connections. This can cause the messages to be received out of order. To reorder the messages those sent to the server may contain a sequence number indicating the correct order.
If a message is received out of order there is a short time for the earlier messages to be received. If the messages are not received in this time the client is closed.
Missing, invalid or duplicate sequence numbers will also close the client for this reason.
This cannot be recovered from as the client and the server are in inconsistent states.
The maximum outbound queue size was reached for the client. Not recoverable.
Messages sent to the client are placed in a queue. This queue has a maximum allowed size. If the queue limit is reached the client is closed and the queue discarded. The queue is intended to protect against slow patches, reaching the queue limit is taken to mean that the client cannot keep up with the number of messages sent to it.
The client sent a message that exceeded the maximum message size.
The server has a maximum message size. If a client sends a message larger than this the server is unable to process it. When this happens the message is discarded and the client is closed.
The session has been closed to make way for a new session.
This is used by MQTT. See MQTT-3.1.4-3.
The server's view of why a client session was closed.