Considerations for the CMNRCYLMT parameter that can affect error recovery
The QCMNRCYLMT system value or the recovery limits (CMNRCYLMT) parameter
on the configuration object controls automatic communications error recovery.
The CMNRCYLMT parameter is on the CHGCTLxxx, CHGLINxxx, CHGNWIxxx, CRTCTLxxx,
CRTLINxxx, or CRTNWIxxx commands. These parameter values contain two related
numbers that you can set:
- The number of second-level recovery attempts automatically performed by
the system (count limit)
- The length of time (time interval) in which the specified number of second-level
recoveries can occur.
The default value on CMNRCYLMT on lines and controllers is two retries
within 5 minutes (2 5).
To configure the CMNRCYLMT parameter, consider the following:
- If automatic communication fails for personal computers on a local area
network (LAN); and the iSeries™ attempts to recover the connection, this places
unnecessary work on the system.
Note:
If automatic communications
error recovery is not used, manual recovery is necessary, that requires operator
intervention. A good compromise is to set the automatic recovery limits to
just one retry.
- Use a count limit 0 and a time interval of more than 0 to turn off second-level
error recovery. Turning off second-level recovery may cause the devices and
controllers to go into recovery pending (RCYPND) state. A message is sent
to QSYSOPR, or the configured message queue, that requires operator intervention.
Use manual recovery to either respond to the message in QSYSOPR, or the configured
message queue, or vary the objects off and back on.
Note:
First-level
error recovery is still done. On a LAN, the Inactivity Timer is used to determine
if the remote system is still available. Once the inactivity time expires,
first-level error recovery is driven by the LANFRMRTY parameter and the LANRSPTMR
parameter.
- Write applications that can determine if a failure has occurred, and then
handle the errors.
- Monitor the error messages in QSYSOPR, or the configured message queue,
when they occur and handle the condition.
- Monitor the status of the configuration objects by using Retrieve Configuration
Status (QDCRCFGS) and List Configuration Descriptions (QDCLCFGD) application
programming interfaces (API).
See the following references for more detail:
For related information, see:
