Stitcher selection using event maps

Use this information to understand how the Event Gateway is configured to enable event maps to call specific Event Gateway stitchers.

Configuration of event maps to select specific Event Gateway stitchers is configured using the Event Gateway config.eventMaps table. The config.eventMaps table is configured in the EventGatewaySchema.cfg configuration file. This file is located at: $NCHOME/etc/precision/EventGatewaySchema.cfg.

The following example shows how part of the config.eventMaps table is configured in the EventGatewaySchema.cfg configuration file.This example insert configures the event maps listed in the following table to call the stitchers listed.

Table 1. Event maps and stitcher selected
Event map	Selected stitcher
PollFailure	LookupIp.stch
ItnmMonitorEventNoRca	LookupEntityId.stch
PrecisionMonitorEvent	LookupEntityId.stch
LinkDownIfIndex	LookupIfEntry.stch

The part of the code that is relevant to configuration of event maps to select specific Event Gateway stitchers is listed in the following lines from the example. The following table describes the relevant lines from this example.

Note: The code fragment shown below might be interspersed with other inserts in the actual code.

Table 2. Lines of code relevant to the incoming event filter
Line numbers	Description
1-12	Configure the event map PollFailure to select the stitcher LookupIp.stch.
14-23	Configure the event map ItnmMonitorEventNoRca to select the stitcher LookupEntityId.stch.
25-34	Configure the event map PrecisionMonitorEvent to select the stitcher LookupEntityId.stch.
36-49	Configure the event map LinkDownIfIndex to select the stitcher LookupIfEntry.stch. As this is a trap event, it is possible for the event to flap. Flapping is a condition where a device or interface connects to and then disconnects from the network repeatedly in a short space of time. This causes problem and clear events to be received one after the other for the same device or interface. Setting the EventCanFlap flag to 1 informs the RCA plug-in of this condition. The RCA plug-in checks if events with this flag set to 1 are actually flapping, that is the device or interface is continually going up and down, and if so, RCA waits until the event has settled down. Events that can flap are passed from the Event Gateway with an `EventCanFlap = 1` setting. These events are placed on the mojo.events database with `TimedEscalation = 1` and are left there for 30 seconds. After 30 seconds the TimedEventSuppression RCA stitcher processes all events that are at least 30 seconds old and have the `TimedEscalation = 1` setting.

insert into config.eventMaps 
(
    EventMapName,
    Stitcher
    IsPollingEvent
)
values
(
    "PollFailure",
    "LookupIp"
    1
);

insert into config.eventMaps 
(
    EventMapName,
    Stitcher
)
values
(
    "ItnmMonitorEventNoRca",
    "LookupEntityId"
);

insert into config.eventMaps 
(
    EventMapName,
    Stitcher
)
values
(
    "PrecisionMonitorEvent",
    "LookupEntityId"
);

insert into config.eventMaps 
(
    EventMapName,
    Stitcher,
    IsPollingEvent
    EventCanFlap
)
values
(
    "LinkDownIfIndex",
    "LookupIfEntry",
    0
    1
);