Overview

The TIBCO Hawk Event Service is a separate process that collects information about TIBCO Hawk agents. Because it runs independently from other TIBCO Hawk processes, the Event Service can detect and report the event if an agent process should fail.

The main tasks of the Event Service are:

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Record events reported by agents in text files or relational databases using JDBC

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Detect and respond to agent termination

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Asynchronously notify using AMI

For instructions on installing and starting the TIBCO Hawk Event Service, see TIBCO Hawk Installation, Configuration, and Administration Guide.

AMI Instrumentation

The Event Service is implemented as an AMI microagent, which allows users to be asynchronously notified on instances of agent activation, expiration, alerts generated and alerts cleared by Hawk Agents on a particular Hawk domain.

The microagent COM.TIBCO.hawk.microagent.HawkEventService exposes the following asynchronous methods:

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For more information on these methods, see the TIBCO Hawk Microagent Reference.

Persistence of TIBCO Hawk Events using JDBC

All alerts generated and cleared by TIBCO Hawk Agents across the network, as well as agent activation and expiration events, are written to a relational database using JDBC. Data is stored in two separate tables, created automatically at startup (if they are not already present in the specified database):

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HawkAgentInfo. The events onAgentAlive, onAgentExpired, onMicroAgentAdded, onMicroAgentRemoved, onRulebaseAdded and onRulebaseRemoved add rows to this table.

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HawkAlertClearInfo. Events onAlert and onClear add rows to this table.

Fault Tolerance

You will normally run the TIBCO Hawk Event Service on a single system in a TIBCO Hawk managed network. However, multiple instances of the TIBCO Hawk Event Service can run on separate machines for fault tolerance.

For TIBCO Rendezvous transport, the Fault tolerance is implemented using TIBCO Rendezvous Fault Tolerance (TRFT). Each instance of a TIBCO Hawk Event Service process joins a fault tolerant group named HawkEventService:hawkdomain, where hawkdomain is the value of the -hawk_domain command line option.

To rank the members of a group, fault tolerance software sorts the members by weight. Weight is assigned using the -ft command line option. The member with the highest weight receives rank 1 (so it outranks all other members). When an instance fails, the next-highest instance is activated and the member with the next highest weight receives rank 2; and so on. When two or more members have the same weight, fault tolerance software ranks them in a way that is opaque to programs.

Refer to TIBCO Rendezvous documentation for details regarding fault tolerance while using the TIBCO Rendezvous transport.