CLIENT TRACKING

Controls server-assisted client-side caching for the connection.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	CLIENT TRACKING
Catalog group	Connection commands
Upstream since	6.0.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

CLIENT TRACKING <ON | OFF> [REDIRECT client-id] [PREFIX prefix
  [PREFIX prefix ...]] [BCAST] [OPTIN] [OPTOUT] [NOLOOP]

ffkv behavior and limits

Connection state, selected database, authentication and protocol negotiation belong to the same persistent connection. RESP2 is the default; HELLO 3 selects RESP3. Streamed/unknown-length RESP3 frames are not supported.

Source: README.md:96–120, 391–395; tests/bdd/features/connections.feature.

All requests share the 8 MiB framing/1,024-argument ingress limit; normal RESP replies have 64 MiB wire/logical budgets with bounded nesting/value counts. Management and Lua origins impose smaller budgets. These are not a process RSS cap. Catalog inclusion is not exhaustive option or wire-format parity. See limits and compatibility.

Upstream metadata

The following fields come from the pinned Redis metadata, not measured ffkv performance or an assertion that ffkv enforces every upstream flag. Running COMMAND INFO/COMMAND DOCS describe the current engine.

Upstream Redis complexity: O(1). Some options may introduce additional complexity.

Upstream arity: -3 (includes the command name; a negative number is a minimum).

Command flags: NOSCRIPT, LOADING, STALE, SENTINEL.

ACL categories: CONNECTION.

Argument structure

Argument	Type	Constraints / metadata
status	oneof	Required
↳ on	pure-token	token: ON
↳ off	pure-token	token: OFF
client-id	integer	optional; token: REDIRECT
prefix	string	optional; multiple; multiple token; token: PREFIX
BCAST	pure-token	optional; token: BCAST
OPTIN	pure-token	optional; token: OPTIN
OPTOUT	pure-token	optional; token: OPTOUT
NOLOOP	pure-token	optional; token: NOLOOP

Additional pinned upstream metadata

{
  "group": "connection",
  "since": "6.0.0"
}

Metadata source · Local snapshot: src/command_metadata.json, key client|tracking.

BDD coverage and source examples

These are source observations, not a test run performed by this documentation build. A tag identifies scenario intent; an extracted vector identifies a command invocation, which may intentionally produce an error. Scenarios may require setup, multiple connections, persistence, cluster nodes or native-module fixtures.

• SORT_RO tracks real scalar and hash lookups rather than wildcard patterns — tests/bdd/features/client_control_repair.feature:571; command tag and invocation observed.
• RESP3 tracking invalidates stale cached values and subsequent reads see new values — tests/bdd/features/connections.feature:445; command tag and invocation observed.
• RESP2 redirects invalidations only to the requested persistent subscriber — tests/bdd/features/connections.feature:495; command tag and invocation observed.
• OPTIN tracks only the next opted-in read and reports the active tracking flags — tests/bdd/features/connections.feature:550; invocation observed.
• OPTOUT can skip a read and NOLOOP suppresses only the originating writer — tests/bdd/features/connections.feature:605; command tag and invocation observed.
• Broadcast prefixes filter writes without requiring reads and flush clears the entire cache — tests/bdd/features/connections.feature:656; command tag and invocation observed.
• RESET clears subscriptions, database, names, protocol and tracking without closing the connection — tests/bdd/features/connections.feature:686; invocation observed.
• Expiration invalidates tracked values instead of leaving an expired cache entry — tests/bdd/features/connections.feature:811; command tag and invocation observed.
• Tracking shares Redis key names across databases and FLUSHDB invalidates cached results — tests/bdd/features/connections.feature:849; command tag and invocation observed.
• Opting in before MULTI tracks all reads in that transaction — tests/bdd/features/connections.feature:912; command tag and invocation observed.

Extracted command vectors

The following JSON arrays are the test harness’s argument vectors, not shell commands. Numeric arguments are converted by the harness; objects of the form {"base64":"…"} represent decoded binary bytes, not a literal JSON command argument. Preserve scenario setup and connection ordering. See the CLI guide for shell quoting and binary stdin. No reply is invented or inferred.

RESP3 tracking invalidates stale cached values and subsequent reads see new values — tests/bdd/features/connections.feature:452 (client “cache” executes:)

[
  "CLIENT",
  "TRACKING",
  "ON"
]

Next source assertion: the reply equals:

"OK"

RESP2 redirects invalidations only to the requested persistent subscriber — tests/bdd/features/connections.feature:510 (client “cache” executes:)

[
  "CLIENT",
  "TRACKING",
  "ON",
  "REDIRECT",
  {
    "saved": "redirect-id"
  }
]

Next source assertion: the reply equals:

"OK"

OPTIN tracks only the next opted-in read and reports the active tracking flags — tests/bdd/features/connections.feature:553 (client “cache” executes:)

[
  "CLIENT",
  "TRACKING",
  "ON",
  "OPTIN"
]