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Valkey (RESP)

The valkey data store speaks RESP, the request/response protocol that Valkey and Redis share. The wire format is vendor neutral: the engine parses and routes RESP without any Valkey- or Redis-specific assumptions, so the historical data_store: redis alias and a data_store: valkey value select the exact same code path.

The implementation lives in dynomite::proto::redis.

Wire format

RESP frames are length-prefixed. A request is an array of bulk strings; the first element is the command name and the remainder are its arguments:

*2\r\n$3\r\nGET\r\n$3\r\nfoo\r\n

The engine consumes the stream with two byte-driven state machines: one for requests (redis_parse_req) and one for responses (redis_parse_rsp). The parser is total: any byte sequence either yields a complete message or a parse error, never a panic.

Command handling

Each parsed request is classified into a MsgType (for example ReqRedisGet, ReqRedisSet, ReqRedisDel). Classification drives:

  • Routing -- the key (or hash tag, when hash_tag: is set) selects the target peers through the configured distribution.
  • Multi-key fragmentation -- commands that carry several keys (MGET, MSET, DEL, ...) are split into per-peer fragments and the per-fragment replies are coalesced back into one client reply.
  • Read repair -- on a quorum read whose replicas disagree, the repair surface issues corrective writes. Read repair fires on GET-class reads.
  • Verification -- request shape is validated before dispatch.

Backend authentication

When redis_requirepass: is set, the engine sends AUTH <pw> on every backend connection immediately after the TCP (or Unix-socket) handshake. See Configuration.

Search extension (FT.*)

When dynomited is built with the search feature, the dynomite-search extension layers the RediSearch FT.* command family on top of the RESP dispatcher: FT.CREATE, FT.SEARCH, FT.REGEX, FT.AGGREGATE, and the FT.SUG* suggestion commands, plus vector KNN. Indexes are cluster-coordinated: a query fans out to every primary peer and the per-peer hits are merged and ranked. Set search_index_dir: to make the index registry durable across restarts. See the search tutorial for an end-to-end walk-through.