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Participant replicas can be a kubernetes StatefulSets that consume two different properties file with unique UUIDs consumer groups and unique consumer groupsUUIDs/replica (participants with same UUIDs have different replica number).
The StatefulSet uses the SPRING_CONFIG_NAME environment variable pointing to the spring application properties file unique to each of the participant replica.
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By this approach the participant can have multiple replicas with different UUIDs and kafka consumer groups to work with a shared data.
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Note: In a scenario of two participants in replicas (we are calling "policy-http-ppnt-0" and "policy-http-ppnt-1"), ACM-Runtime will assignee randomly as before any composition definition in prime time to specific participant based of supported element definition type. So we could have a scenario where a composition definition "composition 1.0.0" is assigned to policy-http-ppnt-0 and the instance too; the new composition "composition 1.0.1" is assigned to policy-http-ppnt-1. In that scenario the migration of an instance from "composition 1.0.0" to "composition 1.0.1" wouldn't work, because policy-http-ppnt-0 do not have "composition 1.0.1" assigned.
Issues:
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All participant will receive the same messages and store same data, so all participants are synchronized with ACM-R. Into all messages from ACM-R to participants will be present the replica number to indicate what participant will do the job (like prime or deploy).
Solution 3: Replicas and Database support - no cache
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Solution 4: Distributed Cache
Issues:
- Not persistent - if the application that handles cache server restarts - data is lost.
- Approval issues - with Redis, Etcd, Search Engine.
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