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As part of 4.0 release, several large contributing companies are undertaking qualification work of real (proprietary) workloads. This patch will implicitly be exercised extensively as part of this work.

This work includes:

• Workload replay testing
• Large real cluster tests like those in CASSANDRA-14746, including those that may involve synthetic workloads
• Canary cluster tests

We should ensure that various extreme scenario are exercised in the process, including clusters of at least 1000 nodes.

Performance Qualification

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Several community members, notably contributors from Netflix and The Last Pickle, have expressed an interest in participating in qualifying the characteristics of the internode messaging that lands in 4.0 using real clusters. The authors of 15066 will work with them to determine the best approaches for exercising behaviours in a real cluster, as well as qualifying the impact of this work versus 3.x and trunk.

We must be sure to check all extremes, including very small clusters of only 3 nodes, and giant clusters of >= 1000 nodes.

Scheduling

Before commit, we anticipate completing all unit and randomised testing to produce a high confidence that the patch is semantically correct. Before we put a bow on things ready for the release of 4.0, we will complete the performance and real cluster verifications that had already haltingly begun. The project is focused exclusively on qualifying the upcoming 4.0 release, and remaining qualification work is best completed in conjunction with that effort.

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