feat(feat-set-binlogsyncer-maxreconnectattempts): feat-set-binlogsyncer-maxreconnectattempts (#1279)

Co-authored-by: shaohoukun <shaohoukun@meituan.com>

doc/command-line-flags.md

@@ -61,6 +61,9 @@ It is not reliable to parse the `ALTER` statement to determine if it is instant
 
 `gh-ost` will automatically fallback to the normal DDL process if the attempt to use instant DDL is unsuccessful.
 
+### binlogsyncer-max-reconnect-attempts
+`--binlogsyncer-max-reconnect-attempts=0`, the maximum number of attempts to re-establish a broken inspector connection for sync binlog. `0` or `negative number` means infinite retry, default `0`
+
 ### conf
 
 `--conf=/path/to/my.cnf`: file where credentials are specified. Should be in (or contain) the following format:

go/base/context.go

@@ -232,6 +232,8 @@ type MigrationContext struct {
 
 	recentBinlogCoordinates mysql.BinlogCoordinates
 
+	BinlogSyncerMaxReconnectAttempts int
+
 	Log Logger
 }
 

go/binlog/gomysql_reader.go

@@ -36,14 +36,15 @@ func NewGoMySQLReader(migrationContext *base.MigrationContext) *GoMySQLReader {
 		currentCoordinates:      mysql.BinlogCoordinates{},
 		currentCoordinatesMutex: &sync.Mutex{},
 		binlogSyncer: replication.NewBinlogSyncer(replication.BinlogSyncerConfig{
-			ServerID:   uint32(migrationContext.ReplicaServerId),
-			Flavor:     gomysql.MySQLFlavor,
-			Host:       connectionConfig.Key.Hostname,
-			Port:       uint16(connectionConfig.Key.Port),
-			User:       connectionConfig.User,
-			Password:   connectionConfig.Password,
-			TLSConfig:  connectionConfig.TLSConfig(),
-			UseDecimal: true,
+			ServerID:             uint32(migrationContext.ReplicaServerId),
+			Flavor:               gomysql.MySQLFlavor,
+			Host:                 connectionConfig.Key.Hostname,
+			Port:                 uint16(connectionConfig.Key.Port),
+			User:                 connectionConfig.User,
+			Password:             connectionConfig.Password,
+			TLSConfig:            connectionConfig.TLSConfig(),
+			UseDecimal:           true,
+			MaxReconnectAttempts: migrationContext.BinlogSyncerMaxReconnectAttempts,
 		}),
 	}
 }

go/cmd/gh-ost/main.go

@@ -134,6 +134,7 @@ func main() {
 	flag.Int64Var(&migrationContext.HooksStatusIntervalSec, "hooks-status-interval", 60, "how many seconds to wait between calling onStatus hook")
 
 	flag.UintVar(&migrationContext.ReplicaServerId, "replica-server-id", 99999, "server id used by gh-ost process. Default: 99999")
+	flag.IntVar(&migrationContext.BinlogSyncerMaxReconnectAttempts, "binlogsyncer-max-reconnect-attempts", 0, "when master node fails, the maximum number of binlog synchronization attempts to reconnect. 0 is unlimited")
 
 	maxLoad := flag.String("max-load", "", "Comma delimited status-name=threshold. e.g: 'Threads_running=100,Threads_connected=500'. When status exceeds threshold, app throttles writes")
 	criticalLoad := flag.String("critical-load", "", "Comma delimited status-name=threshold, same format as --max-load. When status exceeds threshold, app panics and quits")