The options that you specify for message flow accounting and statistics
collection determine what information is collected. You can request the following
types of data collection:
- Snapshot data is collected for an interval of approximately 20 seconds.
The exact length of the interval depends on system loading and the level of
current broker activity. You cannot modify the length of time for which snapshot
data is collected. At the end of this interval, the recorded statistics are
written to the output destination and the interval is restarted.
- Archive data is collected for an interval that you have set for the broker
on the mqsicreatebroker or mqsichangebroker command. You can specify
an interval of between 10 and 14400 minutes, the default value is 60 minutes.
At the end of this interval, the recorded statistics are written to the output
destination and the interval is restarted.
An interval is prematurely expired
and restarted when any of the following events occur:
- The message flow is redeployed.
- The set of statistics data to be collected is modified.
- The broker is shut down.
This preserves the integrity of the data already collected when that
event occurs.
On z/OS, you can set the command parameter
to 0, which means that the interval is controlled by an external timer mechanism.
This support is provided by the Event Notification Facility (ENF), which you
can use instead of the broker command parameter if you want to coordinate
the expiration of this timer with other system events.
You can request snapshot data collection, archive data collection, or both.
You can activate snapshot data collection while archive data collection is
active. The data recorded in both reports is the same, but is collected for
different intervals. If you activate both snapshot and archive data collection,
be careful not to combine information from the two different reports, because
you might count information twice.
You can use the statistics generated for the following purposes:
- You can record the load that applications, trading partners, or other
users put on the broker. This allows you to record the relative use that different
users make of the broker, and perhaps to charge them accordingly. For example,
you could levy a nominal charge on every message that is processed by a broker,
or by a specific message flow.
Archive data provides the information that
you need for a use assessment of this kind.
- You can assess the execution of a message flow to determine why it, or
a node within it, is not performing as you expect.
Snapshot data is appropriate
for performance assessment.
- You can determine the route that messages are taking through a message
flow. For example, you might find that an error path is taken more frequently
than you expect and you can use the statistics to understand when the messages
are routed to this error path.
Check the information provided by snapshot
data for routing information; if this is insufficient for your needs, use
archive data.