Protocols overview¶
fastcached speaks four wire protocols off the same storage engine:
| Protocol | Reference | Status |
|---|---|---|
| memcached (text) | memcached protocol.txt | Full |
| memcached (binary) | memcached protocol_binary.xml | Full |
| memcached (meta) | memcached protocol.txt §meta | Full |
| Redis (RESP2) | Redis Serialization Protocol | Key-value subset |
Each connection is routed to one handler based on its first bytes — see Autodetection for the exact rules. A given client speaks one protocol; mixing on a single connection is not supported.
At a glance¶
Each row is a logical capability area; cells show how complete each protocol is in fastcached today.
| Capability area | memcached text | memcached binary | memcached meta | Redis RESP2 |
|---|---|---|---|---|
| Storage (set/add/replace/append/prepend) | Full | Full | Full | Partial (SET only) |
| CAS | Full | Full | Full | Not applicable |
| Retrieval (get / gets) | Full | Full | Full | Full |
| TTL refresh (touch / GAT) | Full | Full | Full | Not supported |
| Arithmetic (incr / decr) | Full | Full | Full | Not supported |
| Deletion | Full | Full | Full | Full |
| Flush | Full | Full | n/a | Full |
| Stats | Sub-commands | Basic | Via me |
INFO only |
| Slabs / LRU tuning | Synthetic stub | n/a | n/a | n/a |
watch event streaming |
Not supported | n/a | n/a | n/a |
| Authentication | n/a | SASL rejected | n/a | AUTH rejected |
| Multiple databases | n/a | n/a | n/a | Single keyspace |
| Pub / sub | n/a | n/a | n/a | Not supported |
| Scripting (EVAL) | n/a | n/a | n/a | Not supported |
Legend: Full = full spec coverage · Partial = subset · n/a = not part of that protocol · Not supported = not implemented in fastcached.
The next page, the Coverage matrix, maps each logical operation to the specific command, opcode, or meta-flag in every protocol.
Per-protocol pages¶
- memcached text — framing, exptime semantics, error tokens.
- memcached binary — header layout, status codes, quiet variants.
- memcached meta — meta-flag conventions.
- Meta flags reference — every single-letter
flag across
mg,ms,md,ma. - Binary opcodes — hex table.
- Binary status codes — every status code fastcached emits.
- Redis RESP2 — supported subset and rationale.
Compatibility¶
See Compatibility with upstream for a per-protocol completeness scorecard.