lock: improve locker initialization at init (#8776)

Use reference format to initialize lockers
during startup, also handle `nil` for NetLocker
in dsync and remove *errorLocker* implementation

Add further tuning parameters such as

 - DialTimeout is now 15 seconds from 30 seconds
 - KeepAliveTimeout is not 20 seconds, 5 seconds
   more than default 15 seconds
 - ResponseHeaderTimeout to 10 seconds
 - ExpectContinueTimeout is reduced to 3 seconds
 - DualStack is enabled by default remove setting
   it to `true`
 - Reduce IdleConnTimeout to 30 seconds from
   1 minute to avoid idleConn build up

Fixes #8773

cmd/background-newdisks-heal-ops.go

@@ -62,10 +62,9 @@ func monitorLocalDisksAndHeal() {
 		time.Sleep(time.Second)
 	}
 
-	// Perform automatic disk healing when a new one is inserted
+	// Perform automatic disk healing when a disk is replaced locally.
 	for {
-		time.Sleep(defaultMonitorNewDiskInterval)
-
+		// Attempt a heal as the server starts-up first.
 		localDisksInZoneHeal := make([]Endpoints, len(z.zones))
 		for i, ep := range globalEndpoints {
 			localDisksToHeal := Endpoints{}
@@ -88,9 +87,12 @@ func monitorLocalDisksAndHeal() {
 
 		// Reformat disks
 		bgSeq.sourceCh <- SlashSeparator
+
 		// Ensure that reformatting disks is finished
 		bgSeq.sourceCh <- nopHeal
 
+		time.Sleep(defaultMonitorNewDiskInterval)
+
 		var erasureSetInZoneToHeal = make([][]int, len(localDisksInZoneHeal))
 		// Compute the list of erasure set to heal
 		for i, localDisksToHeal := range localDisksInZoneHeal {