Allow CLUSTER NODES/INFO/MYID/MYSHARDID during loading state (#596)

Allow CLUSTER subcommands NODES, INFO, MYID, MYSHARDID while loading
data.

It's safe to allow them and it's helpful for clients to get cluster
nodes/info information
during a node failover and while loading data to monitor the
state of the cluster.

---------

Signed-off-by: Harkrishn Patro <harkrisp@amazon.com>

src/commands.def

@@ -966,13 +966,13 @@ struct COMMAND_STRUCT CLUSTER_Subcommands[] = {
 {MAKE_CMD("forget","Removes a node from the nodes table.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_FORGET_History,0,CLUSTER_FORGET_Tips,0,clusterCommand,3,CMD_NO_ASYNC_LOADING|CMD_ADMIN|CMD_STALE,0,CLUSTER_FORGET_Keyspecs,0,NULL,1),.args=CLUSTER_FORGET_Args},
 {MAKE_CMD("getkeysinslot","Returns the key names in a hash slot.","O(N) where N is the number of requested keys","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_GETKEYSINSLOT_History,0,CLUSTER_GETKEYSINSLOT_Tips,1,clusterCommand,4,CMD_STALE,0,CLUSTER_GETKEYSINSLOT_Keyspecs,0,NULL,2),.args=CLUSTER_GETKEYSINSLOT_Args},
 {MAKE_CMD("help","Returns helpful text about the different subcommands.","O(1)","5.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_HELP_History,0,CLUSTER_HELP_Tips,0,clusterCommand,2,CMD_LOADING|CMD_STALE,0,CLUSTER_HELP_Keyspecs,0,NULL,0)},
-{MAKE_CMD("info","Returns information about the state of a node.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_INFO_History,0,CLUSTER_INFO_Tips,1,clusterCommand,2,CMD_STALE,0,CLUSTER_INFO_Keyspecs,0,NULL,0)},
+{MAKE_CMD("info","Returns information about the state of a node.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_INFO_History,0,CLUSTER_INFO_Tips,1,clusterCommand,2,CMD_LOADING|CMD_STALE,0,CLUSTER_INFO_Keyspecs,0,NULL,0)},
 {MAKE_CMD("keyslot","Returns the hash slot for a key.","O(N) where N is the number of bytes in the key","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_KEYSLOT_History,0,CLUSTER_KEYSLOT_Tips,0,clusterCommand,3,CMD_STALE,0,CLUSTER_KEYSLOT_Keyspecs,0,NULL,1),.args=CLUSTER_KEYSLOT_Args},
 {MAKE_CMD("links","Returns a list of all TCP links to and from peer nodes.","O(N) where N is the total number of Cluster nodes","7.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_LINKS_History,0,CLUSTER_LINKS_Tips,1,clusterCommand,2,CMD_STALE,0,CLUSTER_LINKS_Keyspecs,0,NULL,0)},
 {MAKE_CMD("meet","Forces a node to handshake with another node.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_MEET_History,1,CLUSTER_MEET_Tips,0,clusterCommand,-4,CMD_NO_ASYNC_LOADING|CMD_ADMIN|CMD_STALE,0,CLUSTER_MEET_Keyspecs,0,NULL,3),.args=CLUSTER_MEET_Args},
-{MAKE_CMD("myid","Returns the ID of a node.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_MYID_History,0,CLUSTER_MYID_Tips,0,clusterCommand,2,CMD_STALE,0,CLUSTER_MYID_Keyspecs,0,NULL,0)},
-{MAKE_CMD("myshardid","Returns the shard ID of a node.","O(1)","7.2.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_MYSHARDID_History,0,CLUSTER_MYSHARDID_Tips,1,clusterCommand,2,CMD_STALE,0,CLUSTER_MYSHARDID_Keyspecs,0,NULL,0)},
-{MAKE_CMD("nodes","Returns the cluster configuration for a node.","O(N) where N is the total number of Cluster nodes","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_NODES_History,0,CLUSTER_NODES_Tips,1,clusterCommand,2,CMD_STALE,0,CLUSTER_NODES_Keyspecs,0,NULL,0)},
+{MAKE_CMD("myid","Returns the ID of a node.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_MYID_History,0,CLUSTER_MYID_Tips,0,clusterCommand,2,CMD_LOADING|CMD_STALE,0,CLUSTER_MYID_Keyspecs,0,NULL,0)},
+{MAKE_CMD("myshardid","Returns the shard ID of a node.","O(1)","7.2.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_MYSHARDID_History,0,CLUSTER_MYSHARDID_Tips,1,clusterCommand,2,CMD_LOADING|CMD_STALE,0,CLUSTER_MYSHARDID_Keyspecs,0,NULL,0)},
+{MAKE_CMD("nodes","Returns the cluster configuration for a node.","O(N) where N is the total number of Cluster nodes","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_NODES_History,0,CLUSTER_NODES_Tips,1,clusterCommand,2,CMD_LOADING|CMD_STALE,0,CLUSTER_NODES_Keyspecs,0,NULL,0)},
 {MAKE_CMD("replicas","Lists the replica nodes of a master node.","O(N) where N is the number of replicas.","5.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_REPLICAS_History,0,CLUSTER_REPLICAS_Tips,1,clusterCommand,3,CMD_ADMIN|CMD_STALE,0,CLUSTER_REPLICAS_Keyspecs,0,NULL,1),.args=CLUSTER_REPLICAS_Args},
 {MAKE_CMD("replicate","Configure a node as replica of a master node.","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_REPLICATE_History,0,CLUSTER_REPLICATE_Tips,0,clusterCommand,3,CMD_NO_ASYNC_LOADING|CMD_ADMIN|CMD_STALE,0,CLUSTER_REPLICATE_Keyspecs,0,NULL,1),.args=CLUSTER_REPLICATE_Args},
 {MAKE_CMD("reset","Resets a node.","O(N) where N is the number of known nodes. The command may execute a FLUSHALL as a side effect.","3.0.0",CMD_DOC_NONE,NULL,NULL,"cluster",COMMAND_GROUP_CLUSTER,CLUSTER_RESET_History,0,CLUSTER_RESET_Tips,0,clusterCommand,-2,CMD_ADMIN|CMD_STALE|CMD_NOSCRIPT,0,CLUSTER_RESET_Keyspecs,0,NULL,1),.args=CLUSTER_RESET_Args},

src/commands/cluster-info.json

@@ -8,6 +8,7 @@
         "container": "CLUSTER",
         "function": "clusterCommand",
         "command_flags": [
+            "LOADING",
             "STALE"
         ],
         "command_tips": [

src/commands/cluster-myid.json

@@ -8,6 +8,7 @@
         "container": "CLUSTER",
         "function": "clusterCommand",
         "command_flags": [
+            "LOADING",
             "STALE"
         ],
         "reply_schema": {

src/commands/cluster-myshardid.json

@@ -8,6 +8,7 @@
         "container": "CLUSTER",
         "function": "clusterCommand",
         "command_flags": [
+            "LOADING",
             "STALE"
         ],
         "command_tips": [

src/commands/cluster-nodes.json

@@ -8,6 +8,7 @@
         "container": "CLUSTER",
         "function": "clusterCommand",
         "command_flags": [
+            "LOADING",
             "STALE"
         ],
         "command_tips": [