harmonia · research · also Harmonia in-network conflict detection

Harmonia

Harmonia is a replicated-storage research architecture that uses a programmable switch to detect read-write conflicts and route eligible reads to individual replicas.

Absence from the dirty set is insufficient. The recipient also checks progress against the read's commit stamp. Read-ahead and read-behind integrations use opposite comparison directions. [1]

The design requires one active scheduler and ordered writes; an untrackable write is dropped rather than forwarded unseen. It is not a generic load-balancer configuration. [1]

Hesela's six synthetic witnesses isolate the receiver predicates; they do not reproduce a cluster or prove protocol correctness. [2]

Relations

related

CRAQ, Chain replication, Linearizability

Citations

1. Hang Zhu et al.: Harmonia, PVLDB 13(3), 375-388 (2019), sections 6-8; DOI 10.14778/3368289.3368301 (accessed 2026-11-09)
2. Hesela: synthetic receiver-predicate inputs, outputs and code hash (accessed 2026-11-09)

Further reading

3. Hesela: a clean routing decision can expire in transit (accessed 2026-11-09)

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