feat: minor refactor and summary changes

Signed-off-by: Manan Gupta <[email protected]>

changelog/22.0/22.0.0/summary.md

@@ -13,6 +13,7 @@
   - **[Support for LAST_INSERT_ID(x)](#last-insert-id)**
   - **[Support for Maximum Idle Connections in the Pool](#max-idle-connections)**
   - **[Stalled Disk Recovery in VTOrc](#stall-disk-recovery)**
+  - **[KeyRanges in `--clusters_to_watch` in VTOrc](#key-range-vtorc)**
 - **[Minor Changes](#minor-changes)**
   - **[VTTablet Flags](#flags-vttablet)**
   - **[Topology read concurrency behaviour changes](#topo-read-concurrency-changes)**
@@ -106,6 +107,11 @@ VTOrc can now identify and recover from stalled disk errors. VTTablets test whet
 
 To opt into this feature, `--enable-primary-disk-stalled-recovery` flag has to be specified on VTOrc, and `--disk-write-dir` flag has to be specified on the vttablets. `--disk-write-interval` and `--disk-write-timeout` flags can be used to configure the polling interval and timeout respectively. 
 
+### <a id="key-range-vtorc"/>KeyRanges in `--clusters_to_watch` in VTOrc</a>
+VTOrc now supports specifying KeyRanges in the `--clusters_to_watch` flag. This is useful in scenarios where you don't need to restart a VTOrc instance if you run a reshard.
+For example, if a VTOrc is configured to watch `ks/-80`, then it would watch all the shards that fall under the KeyRange `-80`. If a reshard is run and, `-80` is split into new shards `-40`, and `40-80`, the VTOrc instance will automatically start watching the new shard without needing a restart.
+The users can still continue to specify exact key ranges too, and the new feature is backward compatible.
+
 ## <a id="minor-changes"/>Minor Changes</a>
 
 #### <a id="flags-vttablet"/>VTTablet Flags</a>

go/flags/endtoend/vtorc.txt

@@ -24,7 +24,7 @@ Flags:
       --bind-address string                                         Bind address for the server. If empty, the server will listen on all available unicast and anycast IP addresses of the local system.
       --catch-sigpipe                                               catch and ignore SIGPIPE on stdout and stderr if specified
       --change-tablets-with-errant-gtid-to-drained                  Whether VTOrc should be changing the type of tablets with errant GTIDs to DRAINED
-      --clusters_to_watch strings                                   Comma-separated list of keyspaces or keyspace/shards that this instance will monitor and repair. Defaults to all clusters in the topology. Example: "ks1,ks2/-80"
+      --clusters_to_watch strings                                   Comma-separated list of keyspaces or keyspace/key-ranges that this instance will monitor and repair. Defaults to all clusters in the topology. Example: "ks1,ks2/-80"
       --config-file string                                          Full path of the config file (with extension) to use. If set, --config-path, --config-type, and --config-name are ignored.
       --config-file-not-found-handling ConfigFileNotFoundHandling   Behavior when a config file is not found. (Options: error, exit, ignore, warn) (default warn)
       --config-name string                                          Name of the config file (without extension) to search for. (default "vtconfig")

go/vt/vtorc/logic/tablet_discovery.go

@@ -60,7 +60,7 @@ var (
 
 // RegisterFlags registers the flags required by VTOrc
 func RegisterFlags(fs *pflag.FlagSet) {
-	fs.StringSliceVar(&clustersToWatch, "clusters_to_watch", clustersToWatch, "Comma-separated list of keyspaces or keyspace/shards that this instance will monitor and repair. Defaults to all clusters in the topology. Example: \"ks1,ks2/-80\"")
+	fs.StringSliceVar(&clustersToWatch, "clusters_to_watch", clustersToWatch, "Comma-separated list of keyspaces or keyspace/key-ranges that this instance will monitor and repair. Defaults to all clusters in the topology. Example: \"ks1,ks2/-80\"")
 	fs.DurationVar(&shutdownWaitTime, "shutdown_wait_time", shutdownWaitTime, "Maximum time to wait for VTOrc to release all the locks that it is holding before shutting down on SIGTERM")
 }
 

go/vt/vtorc/logic/tablet_discovery_test.go

@@ -179,6 +179,14 @@ func TestTabletsPartOfWatch(t *testing.T) {
 			},
 			expectedPartOfWatch: false,
 		},
+		{
+			in: []string{"ks/50-70"},
+			tablet: &topodatapb.Tablet{
+				Keyspace: "ks",
+				KeyRange: key.NewKeyRange([]byte{0x50}, []byte{0x70}),
+			},
+			expectedPartOfWatch: true,
+		},
 		{
 			in: []string{"ks2/-70", "ks2/70-", "unknownKs/-", "ks/-80"},
 			tablet: &topodatapb.Tablet{