Engineering / advanced
Replication beyond a single leader
Compare reconciliation strategies, causal metadata, and convergent replicated structures while making conflict semantics explicit.
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Module 01 advanced
Replication beyond a single leader
Compare reconciliation strategies, causal metadata, and convergent replicated structures while making conflict semantics explicit.
- 01
Anti-entropy: locate disagreement before choosing a winner
Build comparable Merkle summaries and distinguish detecting divergent replicas from defining their reconciliation semantics.
25 min - 02
Version vectors: distinguish later from concurrent
Compare componentwise causal histories and preserve incomparable updates instead of inventing an ordering from clock time.
25 min - 03
Last writer wins: a deterministic choice with a clock problem
Trace timestamp arbitration, tie-breaking, and clock skew while separating convergence from the user’s intended last edit.
25 min - 04
State-based CRDTs: merge information with a join
Use a grow-only counter to derive convergent state exchange and distinguish monotone metadata from the visible query value.
25 min - 05
Operation-based CRDTs: commutativity needs a delivery contract
Separate preparing an update, delivering its effect, deduplicating retries, and respecting causal dependencies.
25 min - 06
Observed-remove sets: remove the additions you actually saw
Trace unique add tags, observed removal, and the add-wins outcome for a concurrent unseen addition.
25 min - 07
Replicated sequences: identity is more stable than an index
Explain concurrent insertion, deterministic ties, stable references, and the limits of a simple fractional-position illustration.
25 min - 08
Causal consistency: carry the history a session depends on
Use dependency frontiers to connect read-your-writes, monotonic reads, monotonic writes, and writes-follow-reads.
25 min - 09
Reclaiming tombstones: deletion needs stable knowledge
Trace resurrection from an old replica and derive a fixed-membership stable frontier without replacing proof with elapsed time.
25 min - 10
Conflict resolution: converge on behavior users can accept
Choose field-specific concurrency semantics and identify invariants that require coordination or preallocated rights.
25 min