snapshot of https://github.com/seaweedfs/seaweedfs.git (master, 2026-09-16; blobs > 131072B omitted)

weed/shell/command_cluster_raft_leader_transfer.go

@@ -0,0 +1,143 @@
+package shell
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"io"
+	"time"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/master_pb"
+)
+
+func init() {
+	Commands = append(Commands, &commandRaftLeaderTransfer{})
+}
+
+type commandRaftLeaderTransfer struct{}
+
+func (c *commandRaftLeaderTransfer) Name() string {
+	return "cluster.raft.transferLeader"
+}
+
+func (c *commandRaftLeaderTransfer) Help() string {
+	return `transfer raft leadership to another master server
+
+	This command initiates a graceful leadership transfer from the current
+	leader to another server. Use this before performing maintenance on
+	the current leader to reduce errors in filers and other components.
+
+	Examples:
+		# Transfer to any eligible follower (auto-selection)
+		cluster.raft.transferLeader
+
+		# Transfer to a specific server
+		cluster.raft.transferLeader -id <server_id> -address <server_grpc_address>
+
+	Notes:
+		- Requires hashicorp raft (-raftHashicorp=true on master)
+		- This command must be sent to the current leader
+		- The target server must be a voting member of the raft cluster
+		- Use 'cluster.raft.ps' to list available servers and identify the leader
+`
+}
+
+func (c *commandRaftLeaderTransfer) HasTag(CommandTag) bool {
+	return false
+}
+
+func (c *commandRaftLeaderTransfer) Do(args []string, commandEnv *CommandEnv, writer io.Writer) error {
+	leaderTransferCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+	targetId := leaderTransferCommand.String("id", "", "target server id (must be used with -address)")
+	targetAddress := leaderTransferCommand.String("address", "", "target server grpc address (must be used with -id)")
+
+	if err := leaderTransferCommand.Parse(args); err != nil {
+		return err
+	}
+
+	// Validate: id and address must be specified together
+	if *targetId != "" && *targetAddress == "" {
+		return fmt.Errorf("-address is required when -id is specified")
+	}
+	if *targetAddress != "" && *targetId == "" {
+		return fmt.Errorf("-id is required when -address is specified")
+	}
+
+	// First, show current cluster status
+	fmt.Fprintf(writer, "Checking current raft cluster status...\n")
+
+	var currentLeader string
+	err := commandEnv.MasterClient.WithClient(context.Background(), false, func(client master_pb.SeaweedClient) error {
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+
+		resp, err := client.RaftListClusterServers(ctx, &master_pb.RaftListClusterServersRequest{})
+		if err != nil {
+			return fmt.Errorf("failed to list cluster servers: %v", err)
+		}
+
+		if len(resp.ClusterServers) == 0 {
+			fmt.Fprintf(writer, "No raft cluster configured (single master mode)\n")
+			return fmt.Errorf("leadership transfer not available in single master mode")
+		}
+
+		fmt.Fprintf(writer, "Raft cluster has %d servers:\n", len(resp.ClusterServers))
+		for _, server := range resp.ClusterServers {
+			suffix := ""
+			if server.IsLeader {
+				suffix = " <- current leader"
+				currentLeader = server.Id
+			}
+			fmt.Fprintf(writer, "  %s %s [%s]%s\n", server.Id, server.Address, server.Suffrage, suffix)
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	if currentLeader == "" {
+		return fmt.Errorf("no leader found in cluster")
+	}
+
+	// Perform the transfer
+	targetDesc := "any eligible follower"
+	if *targetId != "" {
+		targetDesc = fmt.Sprintf("server %s (%s)", *targetId, *targetAddress)
+	}
+	fmt.Fprintf(writer, "\nTransferring leadership from %s to %s...\n", currentLeader, targetDesc)
+
+	err = commandEnv.MasterClient.WithClient(context.Background(), true, func(client master_pb.SeaweedClient) error {
+		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+		defer cancel()
+
+		resp, err := client.RaftLeadershipTransfer(ctx, &master_pb.RaftLeadershipTransferRequest{
+			TargetId:      *targetId,
+			TargetAddress: *targetAddress,
+		})
+		if err != nil {
+			return fmt.Errorf("leadership transfer failed: %v", err)
+		}
+
+		if resp.PreviousLeader != resp.NewLeader {
+			fmt.Fprintf(writer, "Leadership successfully transferred.\n")
+			fmt.Fprintf(writer, "  Previous leader: %s\n", resp.PreviousLeader)
+			fmt.Fprintf(writer, "  New leader: %s\n", resp.NewLeader)
+		} else {
+			fmt.Fprintf(writer, "Leadership transfer initiated, but the same leader was re-elected.\n")
+			fmt.Fprintf(writer, "  Current leader: %s\n", resp.NewLeader)
+		}
+		return nil
+	})
+
+	if err != nil {
+		fmt.Fprintf(writer, "\nLeadership transfer failed: %v\n", err)
+		fmt.Fprintf(writer, "\nTroubleshooting:\n")
+		fmt.Fprintf(writer, "  - Ensure you are connected to the current leader\n")
+		fmt.Fprintf(writer, "  - Ensure target server is a voting member (use 'cluster.raft.ps')\n")
+		fmt.Fprintf(writer, "  - Ensure target server is healthy and reachable\n")
+		return err
+	}
+
+	return nil
+}