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Ideally, Holmes comprises three kinds of functional modules: rule management, engine management and data source adapter. For the actual internal architecture, please refer to the corresponding doc under the release folders (from Casablanca on).
Rule Management Module
The rule management module mainly works as a broker between the rule designer(DCAE-CBS) and the engine management module. This module is responsible for interactions with external systems for rule deployment. All rules get into Holmes and then are stored into the database and deployed into the Drools engine if the status of the rules is enabled. When it comes to the horizontal scaling scenario, this module is responsible for re-distribution of existing rules.
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