Apama 10.3 | Apama Documentation | Deploying and Managing Apama Applications | Correlator Utilities Reference | Starting the correlator | Determining whether to disconnect slow receivers | Correlator behavior when there is a slow receiver
Correlator behavior when there is a slow receiver
When the correlator has a slow receiver, it can behave in one of two ways:
*The default behavior is that the correlator blocks further processing. This is because a slow receiver causes the correlator's event output queue to become full. When the queue is full, the correlator stops processing because it has no place to put events. The processing thread stops and does not execute any more EPL code. The transport thread does not send any more events to any of the correlator's other receivers. The correlator resumes processing when the slow receiver disconnects or acknowledges the outstanding sequence number.
*The correlator disconnects the slow receiver, and continues processing events and sending them to its other receivers. To obtain this behavior, you specify the -x (or --qdisconnect) option when you start the correlator. The correlator sends a message to the receiver to indicate that the correlator is disconnecting the receiver. It is up to the receiver to reconnect.
To ensure that it has received an acknowledgment for every event sent, the correlator buffers each event that it sends until it receives the message's corresponding acknowledgment. When there is a slow receiver, this can use a lot of memory if the correlator is sending a large number of messages.

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