Description
Symptoms
Discovery.device.complete events may take a long time to process, which causes the event queue to be backed up.
Release
All currently supported releases.
Cause
The discovery.device.complete event is created when the discovery of a device completes. This event is used to trigger post discovery processing. The post discovery could include creating layer 2 and layer 3 connections, or possibly custom operations. Creating layer 2 and 3 relationships requires a lot of processing, going through different tables etc.
See the following documents for more information about layer 2 discovery and layer 3 mapping:
The layer 2 discovery creates "IP Connection" and "Connects To" relationships which can be seen on the BSM. To view these relationships, open the dependency view for the CI. On the dependency view from one of the CIs select the "Physical Network Connections" option for the "Dependency Type" in the map settings.
The layer 3 relationship provides a logical mapping of the TCP/IP layer for network gears. It loops through the IP addresses of the discovered CI. For each IP address, it searches for router interfaces of classes cmdb_ci_ip_switch and cmdb_ci_ip_router where lo_ip <= IP address <= hi_ip. If a match is found, a relationship is created from the router/switch to the CI.
Resolution
Turn off L2 Mapping:
If the "Physical Network Connections" for the CI dependency view is not used, layer 2 discovery can be turned off via system property sa.create_physical_connections.active (set the value to false). The impact would be that such relationships would no longer be created.
Turn off L3 Mapping:
Often the relationships created by layer 3 mapping are not clear to the team managing the CMDB. The layer 3 mapping can be turned off via system property glide.discovery.L3_mapping (set the value to false). The impact would be that such relationships would no longer be created.
Create a dedicated queue for discovery.device.complete
Open a support incident to have our Performance team create a separate event queue only for “discovery.device.complete” events, so that a delay in processing these events do not create a backlog for other system events.
Apply patches which resolve issues regarding L2 and L3 mapping:
There have been several Known Problems which could cause slowness when processing discovery.device.complete events. Check the following articles to make sure you are not affected by them:
Additional Information
Other knowledge articles which relate to discovery.device.complete: