CLIENT UNBLOCK

Unblocks a client blocked by a blocking command from a different connection.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	CLIENT UNBLOCK
Catalog group	Connection commands
Upstream since	5.0.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

CLIENT UNBLOCK client-id [TIMEOUT | ERROR]

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(log N) where N is the number of client connections

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

Command flags: ADMIN, NOSCRIPT, LOADING, STALE, SENTINEL.

ACL categories: CONNECTION.

Argument structure

Argument	Type	Constraints / metadata
client-id	integer	Required
unblock-type	oneof	optional
↳ timeout	pure-token	token: TIMEOUT
↳ error	pure-token	token: ERROR

Additional pinned upstream metadata

{
  "group": "connection",
  "since": "5.0.0"
}

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

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.

• Replication WAIT is unblocked by exact client identity (Scenario Outline) — tests/bdd/features/client_control_repair.feature:5; command tag and invocation observed.
• Durable replication waits expose current counts or explicit cancellation (Scenario Outline) — tests/bdd/features/client_control_repair.feature:60; command tag and invocation observed.
• TIMEOUT unblocking preserves acknowledgments already received from a replica (Scenario Outline) — tests/bdd/features/client_control_repair.feature:129; command tag and invocation observed.
• Unblock completes a real list waiter with timeout semantics and does not consume later data — tests/bdd/features/connections.feature:353; command tag and invocation observed.
• Error unblocking removes the actual waiter and exposes the UNBLOCKED error — tests/bdd/features/connections.feature:780; 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.

Unblock completes a real list waiter with timeout semantics and does not consume later data — tests/bdd/features/connections.feature:377 (I execute:)

[
  "CLIENT",
  "UNBLOCK",
  {
    "saved": "waiting-id"
  }
]

Next source assertion: the reply equals:

0

Replication WAIT is unblocked by exact client identity — tests/bdd/features/client_control_repair.feature:17 (I execute:)

Expanded from an actual Examples row: mode=TIMEOUT, reply=0.

[
  "CLIENT",
  "UNBLOCK",
  9223372036854776000,
  "ERROR"
]

Next source assertion: the reply equals:

0

Durable replication waits expose current counts or explicit cancellation — tests/bdd/features/client_control_repair.feature:72 (I execute:)

Expanded from an actual Examples row: mode=ERROR, reply={"type":"error","value":"UNBLOCKED client unblocked via CLIENT UNBLOCK"}.

[
  "CLIENT",
  "UNBLOCK",
  {
    "saved": "durable-id"
  },
  "ERROR"
]

Next source assertion: the reply equals:

1