Command Restrictions

Some Redis commands are supported by Redis Cluster DCS instances for multi-key operations in the same slot. For details, see Table 1.

Some commands support multiple keys but do not support cross-slot access. For details, see Table 2.

Table 3 lists commands restricted for Proxy Cluster DCS Redis 4.0 instances.

**Table 1** Redis commands restricted in Redis Cluster DCS instances
Category	Description
Set
SINTER	Returns the members of the set resulting from the intersection of all the given sets.
SINTERSTORE	Equal to SINTER, but instead of returning the result set, it is stored in destination.
SUNION	Returns the members of the set resulting from the union of all the given sets.
SUNIONSTORE	Equal to SUNION, but instead of returning the result set, it is stored in destination.
SDIFF	Returns the members of the set resulting from the difference between the first set and all the successive sets.
SDIFFSTORE	Equal to SDIFF, but instead of returning the result set, it is stored in destination.
SMOVE	Moves member from the set at source to the set at destination.
Sorted Set
ZUNIONSTORE	Computes the union of numkeys sorted sets given by the specified keys.
ZINTERSTORE	Computes the intersection of numkeys sorted sets given by the specified keys.
HyperLogLog
PFCOUNT	Returns the approximated cardinality computed by the HyperLogLog data structure stored at the specified variable.
PFMERGE	Merges multiple HyperLogLog values into a unique value.
Keys
RENAME	Renames key to newkey.
RENAMENX	Renames key to newkey if newkey does not yet exist.
BITOP	Performs a bitwise operation between multiple keys (containing string values) and stores the result in the destination key.
RPOPLPUSH	Returns and removes the last element (tail) of the list stored at source, and pushes the element at the first element (head) of the list stored at destination.
String
MSETNX	Merges multiple HyperLogLog values into a unique value.

While running commands that take a long time to run, such as FLUSHALL, DCS instances may not respond to other commands and may change to the faulty state. After the command finishes executing, the instance will return to normal.

**Table 2** Multi-key commands of Proxy Cluster instances
Category	Command
Multi-key commands that support cross-slot access	DEL, MGET, MSET, EXISTS, SUNION, SINTER, SDIFF, SUNIONSTORE, SINTERSTORE, SDIFFSTORE, ZUNIONSTORE, ZINTERSTORE
Multi-key commands that do not support cross-slot access	SMOVE, SORT, BITOP, MSETNX, RENAME, RENAMENX, BLPOP, BRPOP, RPOPLPUSH, BRPOPLPUSH, PFMERGE, PFCOUNT, BLMOVE, COPY, GEOSEARCHSTORE, LMOVE, ZRANGESTORE

**Table 3** Redis commands restricted for Proxy Cluster DCS Redis instances
Category	Command	Restriction
Set	SMOVE	For a Proxy Cluster instance, the source and destination keys must be in the same slot.
Sorted sets	BZPOPMAX	For a Proxy Cluster instance, all keys transferred must be in the same slot.
Sorted sets	BZPOPMIN
Geo	GEORADIUS	For a Proxy Cluster instance, all keys transferred must be in the same slot. For a Proxy Cluster instance with multiple databases, the STORE option is not supported.
	GEORADIUSBYMEMBER
	GEOSEARCHSTORE
Connection	CLIENT KILL	Only the following two formats are supported: CLIENT KILL ip:port CLIENT KILL ADDR ip:port The id field has a random value, and it does not meet the idc1<idc2→Tc1<Tc2 requirement.
	CLIENT LIST	Only the following two formats are supported: CLIENT LIST CLIENT LIST [TYPE normal\|master\|replica\|pubsub] The id field has a random value, and it does not meet the idc1<idc2→Tc1<Tc2 requirement.
	SELECT index	Multi-DB of Proxy Cluster instances can be implemented by changing the keys. This solution is not recommended. Constraints on supporting multi-DB for a Proxy Cluster instance: The backend storage rewrites keys based on certain rules. Keys in the exported RDB file are not the original keys but can still be accessed through the Redis protocol. The FLUSHDB command deletes keys one by one, which takes a long time. SWAPDB is not supported. The INFO KEYSPACE command does not return data of multi-DB. The DBSIZE command is time-consuming. Do not use it in the code. If multi-DB is used, the performance of the KEYS and SCAN commands deteriorates by up to 50%. LUA scripts do not support multi-DB. The RANDOMKEY command does not support multi-DB. By default, multi-DB is disabled. Before enabling or disabling this option for an instance, clear the instance data.
HyperLogLog	PFCOUNT	For a Proxy Cluster instance, all keys transferred must be in the same slot.
HyperLogLog	PFMERGE
Keys	RENAME	For a Proxy Cluster instance, all keys transferred must be in the same slot.
	RENAMENX
	SCAN	Proxy Cluster instances do not support the SCAN command in pipelines.
Lists	BLPOP	For a Proxy Cluster instance, all keys transferred must be in the same slot.
	BRPOP
	BRPOPLPUSH
Pub/Sub	PSUBSCRIBE	Proxy Cluster instances do not support keyspace event subscription, so there would be no keyspace event subscription failure.
Scripting	EVAL	For a Proxy Cluster instance, all keys transferred must be in the same slot. When the multi-DB function is enabled for a Proxy Cluster instance, the KEYS parameter is modified. Pay attention to the KEYS parameter used in the Lua script.
Scripting	EVALSHA
Server	MEMORY DOCTOR	For a Proxy Cluster instance, add the ip:port of the node at the end of the command. Do as follows to obtain the IP address and port number of a node (MEMORY USAGE is used as an example): Run the cluster keyslot key command to query the slot number of a key. Run the icluster nodes command to query the IP address and port number corresponding to the slot where the key is. If the required information is not returned after you run the icluster nodes command, your Proxy Cluster instance may be of an earlier version. In this case, run the cluster nodes command. Run the MEMORY USAGE key ip:port command. If multi-DB is enabled for the Proxy Cluster instance, run the MEMORY USAGE xxx:As {key} ip:port command, where xxx indicates the DB where the key value is. For example, DB0, DB1, and DB255 correspond to 000, 001, and 255, respectively. The following is an example for a single-DB Proxy Cluster instance: set key1 value1 OK get key1 value1 cluster keyslot key1 9189 icluster nodes xxx 192.168.00.00:1111@xxx xxx connected 10923-16383 xxx 192.168.00.01:2222@xxx xxx connected 0-5460 xxx 192.168.00.02:3333@xxx xxx connected 5461-10922 MEMORY USAGE key1 192.168.00.02:3333 54
	MEMORY HELP
	MEMORY MALLOC-STATS
	MEMORY PURGE
	MEMORY STATS
	MEMORY USAGE
	MONITOR
Strings	BITOP	For a Proxy Cluster instance, all keys transferred must be in the same slot.
Strings	MSETNX
Transactions	WATCH	For a Proxy Cluster instance, all keys transferred must be in the same slot.
	MULTI	The order of cross-slot commands in a transaction is not guaranteed. The following commands cannot be used in transactions: WATCH, MONITOR, RANDOMKEY, KEYS, SCAN, SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, SCRIPT, EVAL, EVALSHA, DBSIZE, AUTH, FLUSHDB, FLUSHALL, CLIENT, MEMORY
	EXEC
Streams	XACK	Currently, Proxy Cluster instances do not support Streams.
	XADD
	XCLAIM
	XDEL
	XGROUP
	XINFO
	XLEN
	XPENDING
	XRANGE
	XTRIM
	XREVRANGE
	XREAD
	XREADGROUP GROUP
	XAUTOCLAIM