Support for strongly consistent Riak #441
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Fix issue where handoff_cancelled was not called on vnode modules if handoff failed to start due to concurrency limit. Add new optional set_vnode_forwarding callback that vnode modules can implement to track riak_core's implicit forwarding behavior that occurs between a primary handoff finishing and actual ownership being changed. All of the above changes are necessary for riak_kv_vnode to properly support strongly consistent operations during handoff and ownership transitions.
Conflicts: rebar.config src/riak_core.app.src src/riak_core_bucket.erl src/riak_core_claimant.erl src/riak_core_sup.erl src/riak_core_vnode.erl
| RingID -> | ||
| {ok, Ring} = riak_core_ring_manager:get_raw_ring(), | ||
| maybe_bootstrap_root_ensemble(Ring), | ||
| maybe_force_ring_update(Ring), |
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@jtuple this caught my attention because we no longer run maybe_force_ring_update in some cases. From my reading, these cases would always result in maybe_force_ring_update doing nothing, so its safe and one case I know hits this code path, ring resizing on a single node, acts the same w/ or w/o this change. Just wanted to double check.
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Focused on the 3 areas that have changed when +1 re: |
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As discussed internally, going ahead and merging with the understanding that strong consistency and the consensus subsystem are disabled by default. Likewise, updated A full review of basho/riak_ensemble#1 is forth coming, and will involve a more detailed review of the code paths in this PR that are hit when the consensus system is enabled. |
This is the
riak_corerelated pull-request for on-going work to add strong consistency to Riak.First, this pull-request integrates Riak with riak_ensemble, pulling in
riak_ensembleas an included-app dependency, hooking upriak_ensemble_supinto theriak_core_sup, and bootstrapping the root ensemble (root consensus group).Second, this pull-request fixes some issues/extends the handoff/forwarding API exposed by
riak_core_vnodeto implementing vnode modules. This is needed in riak_kv to properly extendriak_kv_vnodefor strong consistency.See commit messages for more details.
Note: The
riak_ensemblesubsystem is disabled by default. Changingenable_consensusto true in top-levelriak.confor by defining theriak_core/enable_consensusenvironment variable is necessary for this system to be activated on start-up. When disabled, most of the code in this pull-request is intentionally not executed.Sibling pull-requests: basho/riak_kv#710, basho/riak_ensemble#1