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basho / riak_core

Distributed systems infrastructure used by Riak.
Apache License 2.0
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Improved location claim algorithm #1008

Closed martinsumner closed 1 year ago

martinsumner commented 1 year ago

This PR adds a new v4 claim algorithm, which significantly improves the efficiency of claim with location awareness.

The algorithm has a brute force approach, whereby it will in the plan stage potentially do an exhaustive search of the possible swaps and moves, in order to provide a ring which meets the target n_val for both nodes and locations. Firstly by trying to minimise the number of changes, and if that is unsuccessful it will attempt to find a valid solution without concern for the plan complexity.

To enable the feature, set via riak.conf:

choose_claim_fun -> choose_claim_v4 full_rebalance_onleave -> on target_n_val -> 4 (default) target_location_n_val ->3` (default)

riak_test testa are added and updated in https://github.com/basho/riak_test/pull/1375.

There is a write-up in docs/claim-version4.md.

In some cases cluster plans may take much longer than at present, potentially > 60s.

The new claim algorithm was developed by Ulf Norell and Thomas Arts.

martinsumner commented 1 year ago

@systream - as you did the original location awareness, I suspect you may have an interest in testing this.

martinsumner commented 1 year ago

https://github.com/basho/riak_test/pull/1375