Reasons why a batch can take a long time to complete include a slow network or a channel is using message retry processing.
About this task
When a sender channel has sent a batch of messages it waits for confirmation of that batch from the receiver, unless the channel is pipelined. The factors described in this task can affect how long the sender channel waits.
Procedure
-
Check whether the network is slow.
The NETTIME value is the amount of time, displayed in microseconds, taken to send an end of batch request to the remote end of the channel and receive a response minus the time to process the end of batch request. This value can be large for either of the following reasons:
- The network is slow. A slow network can affect the time it takes to complete a batch. The measurements that result in the indicators for the NETTIME field are measured at the end of a batch. However, the first batch affected by a slowdown in the network is not indicated with a change in the NETTIME value because it is measured at the end of the batch.
- Requests are queued at the remote end, for example a channel can be retrying a put, or a put request may be slow due to page set I/O. Once any queued requests have completed, the duration of the end of batch request is measured. So if you get a large NETTIME value, check for unusual processing at the remote end.
-
Check whether the channel is using message retry.
If the receiver channel fails to put a message to a target queue, it might use message retry
processing, rather than put the message to a dead-letter queue immediately. Retry processing can
cause the batch to slow down. In between MQPUT attempts, the channel will have STATUS(PAUSED),
indicating that it is waiting for the message retry interval to pass.