Memory inspection commands no longer return loading errors

src/commands.def

@@ -7289,11 +7289,11 @@ struct COMMAND_ARG MEMORY_USAGE_Args[] = {
 
 /* MEMORY command table */
 struct COMMAND_STRUCT MEMORY_Subcommands[] = {
-{MAKE_CMD("doctor","Outputs a memory problems report.","O(1)","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_DOCTOR_History,0,MEMORY_DOCTOR_Tips,3,memoryCommand,2,0,0,MEMORY_DOCTOR_Keyspecs,0,NULL,0)},
+{MAKE_CMD("doctor","Outputs a memory problems report.","O(1)","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_DOCTOR_History,0,MEMORY_DOCTOR_Tips,3,memoryCommand,2,CMD_LOADING,0,MEMORY_DOCTOR_Keyspecs,0,NULL,0)},
 {MAKE_CMD("help","Returns helpful text about the different subcommands.","O(1)","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_HELP_History,0,MEMORY_HELP_Tips,0,memoryCommand,2,CMD_LOADING|CMD_STALE,0,MEMORY_HELP_Keyspecs,0,NULL,0)},
-{MAKE_CMD("malloc-stats","Returns the allocator statistics.","Depends on how much memory is allocated, could be slow","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_MALLOC_STATS_History,0,MEMORY_MALLOC_STATS_Tips,3,memoryCommand,2,0,0,MEMORY_MALLOC_STATS_Keyspecs,0,NULL,0)},
-{MAKE_CMD("purge","Asks the allocator to release memory.","Depends on how much memory is allocated, could be slow","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_PURGE_History,0,MEMORY_PURGE_Tips,2,memoryCommand,2,0,0,MEMORY_PURGE_Keyspecs,0,NULL,0)},
-{MAKE_CMD("stats","Returns details about memory usage.","O(1)","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_STATS_History,0,MEMORY_STATS_Tips,3,memoryCommand,2,0,0,MEMORY_STATS_Keyspecs,0,NULL,0)},
+{MAKE_CMD("malloc-stats","Returns the allocator statistics.","Depends on how much memory is allocated, could be slow","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_MALLOC_STATS_History,0,MEMORY_MALLOC_STATS_Tips,3,memoryCommand,2,CMD_LOADING,0,MEMORY_MALLOC_STATS_Keyspecs,0,NULL,0)},
+{MAKE_CMD("purge","Asks the allocator to release memory.","Depends on how much memory is allocated, could be slow","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_PURGE_History,0,MEMORY_PURGE_Tips,2,memoryCommand,2,CMD_LOADING,0,MEMORY_PURGE_Keyspecs,0,NULL,0)},
+{MAKE_CMD("stats","Returns details about memory usage.","O(1)","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_STATS_History,0,MEMORY_STATS_Tips,3,memoryCommand,2,CMD_LOADING,0,MEMORY_STATS_Keyspecs,0,NULL,0)},
 {MAKE_CMD("usage","Estimates the memory usage of a key.","O(N) where N is the number of samples.","4.0.0",CMD_DOC_NONE,NULL,NULL,"server",COMMAND_GROUP_SERVER,MEMORY_USAGE_History,0,MEMORY_USAGE_Tips,0,memoryCommand,-3,CMD_READONLY,0,MEMORY_USAGE_Keyspecs,1,NULL,2),.args=MEMORY_USAGE_Args},
 {0}
 };

src/commands/memory-doctor.json

@@ -12,6 +12,9 @@
             "REQUEST_POLICY:ALL_SHARDS",
             "RESPONSE_POLICY:SPECIAL"
         ],
+        "command_flags": [
+            "LOADING"
+        ],
         "reply_schema": {
             "description": "Memory problems report.",
             "type": "string"

src/commands/memory-malloc-stats.json

@@ -12,6 +12,9 @@
             "REQUEST_POLICY:ALL_SHARDS",
             "RESPONSE_POLICY:SPECIAL"
         ],
+        "command_flags": [
+            "LOADING"
+        ],
         "reply_schema": {
             "type": "string",
             "description": "The memory allocator's internal statistics report."

src/commands/memory-purge.json

@@ -11,6 +11,9 @@
             "REQUEST_POLICY:ALL_SHARDS",
             "RESPONSE_POLICY:ALL_SUCCEEDED"
         ],
+        "command_flags": [
+            "LOADING"
+        ],
         "reply_schema": {
             "const": "OK"
         }

src/commands/memory-stats.json

@@ -12,6 +12,9 @@
             "REQUEST_POLICY:ALL_SHARDS",
             "RESPONSE_POLICY:SPECIAL"
         ],
+        "command_flags": [
+            "LOADING"
+        ],
         "reply_schema": {
             "description": "Memory usage details.",
             "type": "object",

tests/unit/loading.tcl

@@ -0,0 +1,38 @@
+start_server [list overrides [list "key-load-delay" 50 loading-process-events-interval-bytes 1024]] {
+    test "Memory inspection commands no longer return loading errors" {
+        # Set up some initial data
+        r debug populate 100000 key 1000
+
+        # Save and restart
+        r save
+        restart_server 0 false false
+
+        # At this point, keys are loaded one at time, busy looping 50usec
+        # between each. Further, other events are processed every 1024 bytes
+        # of RDB. We're sending all our commands deferred, so they have a
+        # chance to be processed all at once between loading two keys.
+
+        set rd [valkey_deferring_client]
+
+        # The ping at the end should still return LOADING error
+        $rd memory doctor
+        $rd memory malloc-stats
+        $rd memory stats
+        $rd memory help
+        # Memory usage on key while loading is not well defined -> keep error
+        $rd memory usage key:1
+        $rd memory purge
+        $rd ping
+
+        assert_match {Hi Sam, *} [$rd read]
+        assert_match {*} [$rd read]
+        assert_match {peak.allocated *} [$rd read]
+        assert_match {{MEMORY <subcommand> *}} [$rd read]
+        # Memory usage keeps getting rejected in loading because the dataset is not visible
+        assert_error {*LOADING*} {$rd read}
+        assert_match OK [$rd read]
+        assert_error {*LOADING*} {$rd read}
+
+        $rd close
+    }
+}