SCRIPT DEBUG

Sets the debug mode of server-side Lua scripts.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	SCRIPT DEBUG
Catalog group	Scripting commands
Upstream since	3.2.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

SCRIPT DEBUG <YES | SYNC | NO>

ffkv behavior and limits

Sandboxed Lua 5.1 is bounded to 1 million instructions, 32 MiB Lua memory, 64 nesting levels, 8 MiB scripts/bridge values/replies, 10,000 bridge calls and 16 MiB cumulative bridge arguments. Writes before runtime errors commit. The volatile SHA cache holds 256 scripts/16 MiB with FIFO eviction; durable function libraries cap at 256 and one 16 MiB encoded WAL frame.

Source: README.md:426–449; tests/bdd/features/scripting.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)

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

Command flags: NOSCRIPT.

ACL categories: SCRIPTING.

Argument structure

Argument	Type	Constraints / metadata
mode	oneof	Required
↳ yes	pure-token	token: YES
↳ sync	pure-token	token: SYNC
↳ no	pure-token	token: NO

Additional pinned upstream metadata

{
  "group": "scripting",
  "since": "3.2.0"
}

Metadata source · Local snapshot: src/command_metadata.json, key script|debug.

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.

• Disposable debugging restores an absent cross-database destination (Scenario Outline) — tests/bdd/features/client_control_repair.feature:247; command tag and invocation observed.
• A disconnected debugger queued behind a native command cannot strand the actor (Scenario Outline) — tests/bdd/features/client_control_repair.feature:300; command tag and invocation observed.
• A line debugger pauses a live script and kill interrupts its eligible execution — tests/bdd/features/scripting.feature:377; command tag and invocation observed.
• Debug stepping exposes the first write and prevents unsafe cancellation — tests/bdd/features/scripting.feature:418; command tag and invocation observed.
• Fork style debug execution discards effects while retaining a useful result — tests/bdd/features/scripting.feature:471; command tag and invocation observed.
• Debug mode validates its argument and NO restores ordinary execution — tests/bdd/features/scripting.feature:719; command tag and invocation observed.
• Disposable Lua debugging sees staged search changes without publishing catalog changes — tests/bdd/features/search.feature:1316; 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.

Fork style debug execution discards effects while retaining a useful result — tests/bdd/features/scripting.feature:473 (client “debugger” executes:)

[
  "SCRIPT",
  "DEBUG",
  "YES"
]

Next source assertion: the reply equals:

"OK"

A line debugger pauses a live script and kill interrupts its eligible execution — tests/bdd/features/scripting.feature:379 (client “debugger” executes:)

[
  "SCRIPT",
  "DEBUG",
  "SYNC"
]

Next source assertion: the reply equals:

"OK"

Debug mode validates its argument and NO restores ordinary execution — tests/bdd/features/scripting.feature:726 (the following commands succeed:)

[
  "SCRIPT",
  "DEBUG",
  "NO"
]