N3V_HPR_Conn_Path_Switch
A number of path switches have occurred with one or more of the
following path switch triggers:
- TGINOP : The link of the first (or only)
hop of the HPR RTP pipe is not functioning and triggers a path switch.
- SRT (Short Request Timer) Retries: The end
point has repeatedly not responded within the specified time interval
to timing-sensitive packets sent to it. Therefore, the existing path
is assumed to be unusable and triggers a path switch.
- No NCB (Network Control Block): The DLC
associated with the HPR RTP connection can no longer be accessed.
The first hop of the RTP pipe is therefore no longer usable and triggers
a path switch.
- Modify RTP Command
- Auto Path Switch
- Partner Initiated
Note:
The default definition for this situation only tests
for the No NCB value.
This is probably because of lost connectivity to the remote endpoint
or constrained CPU in the remote z/OS Communications server address
space.
To determine this, the following metrics in the HPR connections
table are used:
- Path switches
- Path switch trigger
This situation occurs when the path switches value is greater than
zero for 3 consecutive intervals and the path switch trigger value
is one of the following in the third interval:
- TGINOP
- SRT retries
- No NCB
This is probably because of lost connectivity to the remote endpoint
or constrained CPU in remote VTAM(R) address
space. To resolve this problem, use the following procedures:
- Issue a trace route command to determine the most probable routing
path.
- Determine if this path is using a secondary or backup routing
path. If it is, identify and fix the problem with the primary path.
- Query the routing interfaces on the routing path to determine
the number of packets dropped.
- Identify the routers along the routing path with the highest numbers
of packets dropped.
- Validate the router configuration parameters.
- Check the OSA adapter metrics to determine if adapter constraints
(such as excessive processor utilization or discards at the receive
side) exist.
- Confirm that the CPU utilization is high for the remote system
(that is, the receive side) Communications Server for z/OS address
space.
- Redistribute the Communications Server for z/OS workload on the
remote system (receive side) of the HPR RTP connection.
Formula: Path Switches > 0 AND Path Switch
Trigger <= No_NCB