REPLICAOF

Configures a server as replica of another, or promotes it to a master.

Browse all commands · Upstream source documentation

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

Syntax

REPLICAOF <host port | NO ONE>

ffkv behavior and limits

Server introspection describes ffkv, not a Redis process. MEMORY reports owned-allocation estimates, not jemalloc accounting. Administrative changes can affect all clients or persistent data; consult the scenario and operations guide before using destructive forms.

Source: README.md:393–395, 601–642; tests/bdd/features/server.feature; tests/bdd/features/catalog.feature.

Native RESP replication is asynchronous and distinct from HTTP snapshot polling. WAIT/WAITAOF barriers belong on the writing connection; acknowledgements do not certify failover safety. Upstream network policy and persistent storage must be configured deliberately (README.md:601–628).

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)

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

Command flags: NO_ASYNC_LOADING, ADMIN, NOSCRIPT, STALE.

Argument structure

Argument	Type	Constraints / metadata
args	oneof	Required
↳ host-port	block	Required
↳ ↳ host	string	Required
↳ ↳ port	integer	Required
↳ no-one	block	Required
↳ ↳ no	pure-token	token: NO
↳ ↳ one	pure-token	token: ONE

Additional pinned upstream metadata

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

Metadata source · Local snapshot: src/command_metadata.json, key replicaof.

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.

• Initial synchronization replaces stale data and streams later writes — tests/bdd/features/replication.feature:7; command tag and invocation observed.
• Explicit promotion retains data and accepts new writes (Scenario Outline) — tests/bdd/features/replication.feature:49; command tag and invocation observed.
• Protected-network refusal does not leak upstream credentials or install data — tests/bdd/features/replication.feature:367; 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.

Explicit promotion retains data and accepts new writes — tests/bdd/features/replication.feature:59 (node “replica” executes:)

Expanded from an actual Examples row: command=REPLICAOF.

[
  "REPLICAOF",
  "NO",
  "ONE"
]

Next source assertion: the reply equals:

"OK"

Initial synchronization replaces stale data and streams later writes — tests/bdd/features/replication.feature:17 (node “replica” executes:)

Fixture-dependent: {{…}} tokens are replaced by the BDD runtime (for example, node ports, generated IDs or temporary paths). This is not a standalone executable command.

[
  "REPLICAOF",
  "{{master_host}}",
  "{{master_port}}"
]

Next source assertion: the reply equals:

"OK"