Add CLIENT NO-TOUCH for clients to run commands without affecting LRU/LFU of keys (#11483)

When no-touch mode is enabled, the client will not touch LRU/LFU of the
keys it accesses, except when executing command `TOUCH`.
This allows inspecting or modifying the key-space without affecting their eviction.

Changes:
- A command `CLIENT NO-TOUCH ON|OFF` to switch on and off this mode.
- A client flag `#define CLIENT_NOTOUCH (1ULL<<45)`, which can be shown
  with `CLIENT INFO`, by the letter "T" in the "flags" field.
- Clear `NO-TOUCH` flag in `clearClientConnectionState`, which is used by `RESET`
  command and resetting temp clients used by modules.
- Also clear `NO-EVICT` flag in `clearClientConnectionState`, this might have been an
  oversight, spotted by @madolson.
- A test using `DEBUG OBJECT` command to verify that LRU stat is not touched when
  no-touch mode is on.
 

Co-authored-by: chentianjie <chentianjie@alibaba-inc.com>
Co-authored-by: Madelyn Olson <34459052+madolson@users.noreply.github.com>
Co-authored-by: sundb <sundbcn@gmail.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/commands.c b/src/commands.c
index 7698f2055..e24ab9dfc 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -890,6 +890,27 @@ struct redisCommandArg CLIENT_NO_EVICT_Args[] = {
 {0}
 };
 
+/********** CLIENT NO_TOUCH ********************/
+
+/* CLIENT NO_TOUCH history */
+#define CLIENT_NO_TOUCH_History NULL
+
+/* CLIENT NO_TOUCH tips */
+#define CLIENT_NO_TOUCH_tips NULL
+
+/* CLIENT NO_TOUCH enabled argument table */
+struct redisCommandArg CLIENT_NO_TOUCH_enabled_Subargs[] = {
+{"on",ARG_TYPE_PURE_TOKEN,-1,"ON",NULL,NULL,CMD_ARG_NONE},
+{"off",ARG_TYPE_PURE_TOKEN,-1,"OFF",NULL,NULL,CMD_ARG_NONE},
+{0}
+};
+
+/* CLIENT NO_TOUCH argument table */
+struct redisCommandArg CLIENT_NO_TOUCH_Args[] = {
+{"enabled",ARG_TYPE_ONEOF,-1,NULL,NULL,NULL,CMD_ARG_NONE,.subargs=CLIENT_NO_TOUCH_enabled_Subargs},
+{0}
+};
+
 /********** CLIENT PAUSE ********************/
 
 /* CLIENT PAUSE history */
@@ -1027,6 +1048,7 @@ struct redisCommand CLIENT_Subcommands[] = {
 {"kill","Kill the connection of a client","O(N) where N is the number of client connections","2.4.0",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_KILL_History,CLIENT_KILL_tips,clientCommand,-3,CMD_ADMIN|CMD_NOSCRIPT|CMD_LOADING|CMD_STALE|CMD_SENTINEL,ACL_CATEGORY_CONNECTION,.args=CLIENT_KILL_Args},
 {"list","Get the list of client connections","O(N) where N is the number of client connections","2.4.0",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_LIST_History,CLIENT_LIST_tips,clientCommand,-2,CMD_ADMIN|CMD_NOSCRIPT|CMD_LOADING|CMD_STALE|CMD_SENTINEL,ACL_CATEGORY_CONNECTION,.args=CLIENT_LIST_Args},
 {"no-evict","Set client eviction mode for the current connection","O(1)","7.0.0",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_NO_EVICT_History,CLIENT_NO_EVICT_tips,clientCommand,3,CMD_ADMIN|CMD_NOSCRIPT|CMD_LOADING|CMD_STALE|CMD_SENTINEL,ACL_CATEGORY_CONNECTION,.args=CLIENT_NO_EVICT_Args},
+{"no-touch","Controls whether commands sent by the client will alter the LRU/LFU of the keys they access.","O(1)",NULL,CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_NO_TOUCH_History,CLIENT_NO_TOUCH_tips,clientCommand,3,CMD_NOSCRIPT|CMD_LOADING|CMD_STALE,ACL_CATEGORY_CONNECTION,.args=CLIENT_NO_TOUCH_Args},
 {"pause","Stop processing commands from clients for some time","O(1)","3.0.0",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_PAUSE_History,CLIENT_PAUSE_tips,clientCommand,-3,CMD_ADMIN|CMD_NOSCRIPT|CMD_LOADING|CMD_STALE|CMD_SENTINEL,ACL_CATEGORY_CONNECTION,.args=CLIENT_PAUSE_Args},
 {"reply","Instruct the server whether to reply to commands","O(1)","3.2.0",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_REPLY_History,CLIENT_REPLY_tips,clientCommand,3,CMD_NOSCRIPT|CMD_LOADING|CMD_STALE|CMD_SENTINEL,ACL_CATEGORY_CONNECTION,.args=CLIENT_REPLY_Args},
 {"setname","Set the current connection name","O(1)","2.6.9",CMD_DOC_NONE,NULL,NULL,COMMAND_GROUP_CONNECTION,CLIENT_SETNAME_History,CLIENT_SETNAME_tips,clientCommand,3,CMD_NOSCRIPT|CMD_LOADING|CMD_STALE|CMD_SENTINEL,ACL_CATEGORY_CONNECTION,.args=CLIENT_SETNAME_Args},