SuperCache.Cluster.ThreePhaseCommit (SuperCache v1.3.0)

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Three-phase commit (3PC) coordinator.

Every commit/2 call records a latency sample and increments either the :committed or :aborted counter (plus per-phase failure counters on abort) via SuperCache.Cluster.Stats.record_tpc/2. These are visible in SuperCache.Cluster.Stats.three_phase_commit/0.

Coordinator contract

commit/2 must be called from the partition's primary node. The Router enforces this for all writes that go through SuperCache.Cluster.Router. If commit/2 is called from a non-primary node (e.g. in a direct test), apply_local/2 will write to the wrong node's ETS table and the primary will be left without data.

ops fallback in handle_commit

phase_commit/4 passes the full ops list to every replica alongside the txn_id. handle_commit/3 uses the locally registered ops first (set by handle_prepare/3); if the TxnRegistry entry is absent — due to a prepare message being lost or a race during startup — it falls back to the coordinator-supplied ops so the write still completes rather than being silently skipped.

Summary

Types

op()
op_list()
txn_id()

Functions

commit(partition_idx, ops)
recover()

Types

op()

@type op() ::
  {:put, tuple()}
  | {:delete, any()}
  | {:delete_match, tuple()}
  | {:delete_all, nil}

op_list()

@type op_list() :: [op()]

txn_id()

@type txn_id() :: binary()

Functions

commit(partition_idx, ops)

@spec commit(non_neg_integer(), op_list()) :: :ok | {:error, term()}

recover()

@spec recover() :: :ok