Working with Redis Functions

1. Creating Functions

Command	Description
`FUNCTION LOAD [REPLACE] code`	Persistent library, replicated via RDB/AOF 7.0+

#!lua name=mylib
redis.register_function('myadd', function(keys, args)
  return redis.call('INCRBY', keys[1], args[1])
end)

Command	Description
`FCALL fname numkeys key ... arg ...`	Execute (read+write)
`FCALL_RO fname numkeys ...`	Replica-safe read-only call

Command	Returns
`FUNCTION LIST [LIBRARYNAME pat] [WITHCODE]`	All libraries

Command	Description
`FUNCTION DELETE libname`	Remove library

Command	Returns
`FUNCTION DUMP`	Binary payload of all libraries

Command	Options
`FUNCTION RESTORE payload [FLUSH\|APPEND\|REPLACE]`	Reload from DUMP

Command	Description
`FUNCTION FLUSH [ASYNC\|SYNC]`	Wipe all libraries

Command	Returns
`FUNCTION STATS`	Currently running function + engine stats

Command	Limitations
`FUNCTION KILL`	Only if no writes performed

Aspect	Functions	EVAL Scripts
Persistence	RDB/AOF replicated	Not persisted; re-load after restart
Naming	Named libraries	SHA1 hash
Use case	App-level extensions	Ad-hoc atomic ops