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Jira | ||||||
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Assumptions
Assumption | Notes | |
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1 | Solution should be CPS-Core based not just in NCMP | Caffeine Cache is a CPS-Core solution Upgrade is also possible without NCMP |
2 | Upgrades are backward compatible |
Issues & Decisions
# | Issue | Notes | Decision | |
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1 | Preferred Alternative | CPS Team prefers Alternative 2 | Team and stakeholders agreed on Alternative 2 | |
2 | Integration or jUnit Test First |
Solution Proposal
Assumption
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Agreed but only possible using Unit Test (stil using real cache etc.) |
Solution Proposals
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Alternative 0: Remove existing cache
- tried but mush much slower and ODL memory leak experienced
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Pro | Con | |
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1 | Update CPS-Core to produce and consume Kafka messages | |
2 | More Kafka messages (new interface) | |
3 | No unnecessary validation | |
4 | Upgrade itself not delayed |
Alternative 2 (chosen): Clear Cache upon validation error
- Worst case scenario: an update (with newly modelled data) happens before cache expiry. Update gets reject (fails validation)
- mitigation: Invalidate cache upon validation error and try again (consider this as an extension alternative 2 once)
Pro | Con | |
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1 | 10 minutes window where additional validation might occur | |
2 | fails-safe wil cover all scenarios | |
3 | NO new message/interface | |
4 | Simplest solution | |
5 | Upgrade itself not delayed | |
6 | Real validation errors will always tried twice and perform relatively slowly |
Alternative 3: (existing) Kafka Message with (new) Kafka Confirmation
Not viable without knowing how many instances need to form ie need Hazelcast Cache
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Alternative 4:
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New COS-Core Kafka Message with (new) Hazelcast Cache (semaphore)
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Confirmation
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Just an extension of Alternative 1 which is not the preferred option
Alternative 5: (existing) Polling (status watchdog) with (new) confirmation
Not viable because upgrades can be completed well withing polling time
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Alternative 6: Add version info the cache-key
Pro | Con | |
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1 | No issue with non-distributed cache | |
2 | NCMP specific solution? | |
23 | Version infor info NOT readily avaialble availably (many impacts) |