Move RaftStats to Status endpoint

command/agent/operator_endpoint.go

@@ -242,5 +242,10 @@ func (s *HTTPServer) OperatorServerHealth(resp http.ResponseWriter, req *http.Re
 		return nil, err
 	}
 
+	// Reply with status 429 if something is unhealthy
+	if !reply.Healthy {
+		resp.WriteHeader(http.StatusTooManyRequests)
+	}
+
 	return reply, nil
 }

command/agent/operator_endpoint_test.go

@@ -8,8 +8,8 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/hashicorp/consul-enterprise/testutil"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/testutil"
 	"github.com/hashicorp/serf/serf"
 )
 

consul/autopilot.go

@@ -92,27 +92,30 @@ func (s *Server) pruneDeadServers() error {
 		return err
 	}
 
-	// Look for dead servers to clean up
+	// Find any failed servers
+	var failed []string
+	if autopilotConf.CleanupDeadServers {
+		for _, member := range s.serfLAN.Members() {
+			valid, _ := agent.IsConsulServer(member)
+			if valid && member.Status == serf.StatusFailed {
+				failed = append(failed, member.Name)
+			}
+		}
+	}
+
 	peers, err := s.numPeers()
 	if err != nil {
 		return err
 	}
 
-	removed := 0
-	if autopilotConf.CleanupDeadServers {
-		for _, member := range s.serfLAN.Members() {
-			// Exit early if we already removed the max amount of servers
-			if removed == peers/2 {
-				break
-			}
-
-			valid, _ := agent.IsConsulServer(member)
-			if valid && member.Status == serf.StatusFailed {
-				removed++
-				s.logger.Printf("[INFO] consul: Attempting removal of failed server: %v", member.Name)
-				go s.serfLAN.RemoveFailedNode(member.Name)
-			}
+	// Only do removals if a minority of servers will be affected
+	if len(failed) <= peers/2 {
+		for _, server := range failed {
+			s.logger.Printf("[INFO] consul: Attempting removal of failed server: %v", server)
+			go s.serfLAN.RemoveFailedNode(server)
 		}
+	} else {
+		s.logger.Printf("[ERR] consul: Failed to remove dead servers: too many dead servers: %d/%d", len(failed), peers)
 	}
 
 	return nil
@@ -125,62 +128,66 @@ func (s *Server) promoteNonVoters(autopilotConf *structs.AutopilotConfig) error
 		return fmt.Errorf("error getting server raft protocol versions: %s", err)
 	}
 
-	if minRaftProtocol >= 3 {
-		future := s.raft.GetConfiguration()
-		if err := future.Error(); err != nil {
-			return fmt.Errorf("failed to get raft configuration: %v", err)
-		}
+	// If we don't meet the minimum version for non-voter features, bail early
+	if minRaftProtocol < 3 {
+		return nil
+	}
 
-		var promotions []raft.Server
-		raftServers := future.Configuration().Servers
-		voterCount := 0
-		for _, server := range raftServers {
-			// If this server has been stable and passing for long enough, promote it to a voter
-			if server.Suffrage == raft.Nonvoter {
-				health := s.getServerHealth(string(server.Address))
-				if health != nil && health.Healthy && time.Now().Sub(health.StableSince) >= autopilotConf.ServerStabilizationTime {
-					promotions = append(promotions, server)
-				}
-			} else {
-				voterCount++
+	future := s.raft.GetConfiguration()
+	if err := future.Error(); err != nil {
+		return fmt.Errorf("failed to get raft configuration: %v", err)
+	}
+
+	var promotions []raft.Server
+	raftServers := future.Configuration().Servers
+	voterCount := 0
+	for _, server := range raftServers {
+		// If this server has been stable and passing for long enough, promote it to a voter
+		if server.Suffrage == raft.Nonvoter {
+			health := s.getServerHealth(string(server.Address))
+			if health != nil && health.Healthy && time.Now().Sub(health.StableSince) >= autopilotConf.ServerStabilizationTime {
+				promotions = append(promotions, server)
 			}
+		} else {
+			voterCount++
 		}
+	}
 
-		// Exit early if there's nothing to promote
-		if len(promotions) == 0 {
-			return nil
+	// Exit early if there's nothing to promote
+	if len(promotions) == 0 {
+		return nil
+	}
+
+	// If there's currently an even number of servers, we can promote the first server in the list
+	// to get to an odd-sized quorum
+	newServers := false
+	if voterCount%2 == 0 {
+		addFuture := s.raft.AddVoter(promotions[0].ID, promotions[0].Address, 0, 0)
+		if err := addFuture.Error(); err != nil {
+			return fmt.Errorf("failed to add raft peer: %v", err)
 		}
+		promotions = promotions[1:]
+		newServers = true
+	}
 
-		// If there's currently an even number of servers, we can promote the first server in the list
-		// to get to an odd-sized quorum
-		newServers := false
-		if voterCount%2 == 0 {
-			addFuture := s.raft.AddVoter(promotions[0].ID, promotions[0].Address, 0, 0)
-			if err := addFuture.Error(); err != nil {
-				return fmt.Errorf("failed to add raft peer: %v", err)
-			}
-			promotions = promotions[1:]
-			newServers = true
+	// Promote remaining servers in twos to maintain an odd quorum size
+	for i := 0; i < len(promotions)-1; i += 2 {
+		addFirst := s.raft.AddVoter(promotions[i].ID, promotions[i].Address, 0, 0)
+		if err := addFirst.Error(); err != nil {
+			return fmt.Errorf("failed to add raft peer: %v", err)
 		}
-
-		// Promote remaining servers in twos to maintain an odd quorum size
-		for i := 0; i < len(promotions)-1; i += 2 {
-			addFirst := s.raft.AddVoter(promotions[i].ID, promotions[i].Address, 0, 0)
-			if err := addFirst.Error(); err != nil {
-				return fmt.Errorf("failed to add raft peer: %v", err)
-			}
-			addSecond := s.raft.AddVoter(promotions[i+1].ID, promotions[i+1].Address, 0, 0)
-			if err := addSecond.Error(); err != nil {
-				return fmt.Errorf("failed to add raft peer: %v", err)
-			}
-			newServers = true
+		addSecond := s.raft.AddVoter(promotions[i+1].ID, promotions[i+1].Address, 0, 0)
+		if err := addSecond.Error(); err != nil {
+			return fmt.Errorf("failed to add raft peer: %v", err)
 		}
+		newServers = true
+	}
 
-		// If we added a new server, trigger a check to remove dead servers
-		if newServers {
-			go func() {
-				s.autopilotRemoveDeadCh <- struct{}{}
-			}()
+	// If we added a new server, trigger a check to remove dead servers
+	if newServers {
+		select {
+		case s.autopilotRemoveDeadCh <- struct{}{}:
+		default:
 		}
 	}
 
@@ -190,47 +197,35 @@ func (s *Server) promoteNonVoters(autopilotConf *structs.AutopilotConfig) error
 // queryServerHealth fetches the raft stats for the given server and uses them
 // to update its ServerHealth
 func (s *Server) queryServerHealth(member serf.Member, server *agent.Server, autopilotConf *structs.AutopilotConfig) *structs.ServerHealth {
+	stats, err := s.getServerStats(server)
+	if err != nil {
+		s.logger.Printf("[DEBUG] consul: error getting server's raft stats: %s", err)
+	}
+
 	health := &structs.ServerHealth{
 		ID:             server.ID,
 		Name:           server.Name,
 		SerfStatusRaw:  member.Status,
 		SerfStatus:     member.Status.String(),
 		LastContactRaw: -1,
-		LastContact:    "never",
+		LastContact:    stats.LastContact,
+		LastTerm:       stats.LastTerm,
+		LastIndex:      stats.LastIndex,
 	}
 
-	stats, err := s.getServerStats(server)
-	if err != nil {
-		s.logger.Printf("[DEBUG] consul: error getting server's raft stats: %s", err)
-	}
-
-	if v, ok := stats["last_contact"]; ok && v != "never" {
-		health.LastContactRaw, err = time.ParseDuration(v)
+	if health.LastContact != "never" {
+		health.LastContactRaw, err = time.ParseDuration(health.LastContact)
 		if err != nil {
 			s.logger.Printf("[DEBUG] consul: error parsing server's last_contact value: %s", err)
 		}
-		health.LastContact = health.LastContactRaw.String()
 	}
-	// Set LastContact to 0 if we're the leader
+
+	// Set LastContact to 0 for the leader
 	if s.config.NodeName == member.Name {
 		health.LastContactRaw = 0
 		health.LastContact = "leader"
 	}
 
-	if v, ok := stats["last_log_index"]; ok {
-		health.LastIndex, err = strconv.ParseUint(v, 10, 64)
-		if err != nil {
-			s.logger.Printf("[DEBUG] consul: error parsing server's last_log_index value: %s", err)
-		}
-	}
-
-	if v, ok := stats["last_log_term"]; ok {
-		health.LastTerm, err = strconv.ParseUint(v, 10, 64)
-		if err != nil {
-			s.logger.Printf("[DEBUG] consul: error parsing server's last_log_term value: %s", err)
-		}
-	}
-
 	health.Healthy = s.isServerHealthy(health, autopilotConf)
 
 	// If this is a new server or the health changed, reset StableSince
@@ -254,10 +249,10 @@ func (s *Server) getServerHealth(addr string) *structs.ServerHealth {
 	return h
 }
 
-func (s *Server) getServerStats(server *agent.Server) (map[string]string, error) {
+func (s *Server) getServerStats(server *agent.Server) (structs.ServerStats, error) {
 	var args struct{}
-	var reply map[string]string
-	err := s.connPool.RPC(s.config.Datacenter, server.Addr, server.Version, "Operator.RaftStats", &args, &reply)
+	var reply structs.ServerStats
+	err := s.connPool.RPC(s.config.Datacenter, server.Addr, server.Version, "Status.RaftStats", &args, &reply)
 	return reply, err
 }
 

consul/leader.go

@@ -624,9 +624,10 @@ func (s *Server) joinConsulServer(m serf.Member, parts *agent.Server) error {
 	}
 
 	// Trigger a check to remove dead servers
-	go func() {
-		s.autopilotRemoveDeadCh <- struct{}{}
-	}()
+	select {
+	case s.autopilotRemoveDeadCh <- struct{}{}:
+	default:
+	}
 
 	return nil
 }

consul/operator_endpoint.go

@@ -185,12 +185,6 @@ func (op *Operator) AutopilotSetConfiguration(args *structs.AutopilotSetConfigRe
 	return nil
 }
 
-// Used by Autopilot to query the raft stats of the local server.
-func (op *Operator) RaftStats(args struct{}, reply *map[string]string) error {
-	*reply = op.srv.raft.Stats()
-	return nil
-}
-
 // ServerHealth is used to get the current health of the servers.
 func (op *Operator) ServerHealth(args *structs.DCSpecificRequest, reply *structs.OperatorHealthReply) error {
 	// This must be sent to the leader, so we fix the args since we are

consul/status_endpoint.go

@@ -1,5 +1,12 @@
 package consul
 
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/hashicorp/consul/consul/structs"
+)
+
 // Status endpoint is used to check on server status
 type Status struct {
 	server *Server
@@ -33,3 +40,21 @@ func (s *Status) Peers(args struct{}, reply *[]string) error {
 	}
 	return nil
 }
+
+// Used by Autopilot to query the raft stats of the local server.
+func (s *Status) RaftStats(args struct{}, reply *structs.ServerStats) error {
+	stats := s.server.raft.Stats()
+
+	var err error
+	reply.LastContact = stats["last_contact"]
+	reply.LastIndex, err = strconv.ParseUint(stats["last_log_index"], 10, 64)
+	if err != nil {
+		return fmt.Errorf("error parsing server's last_log_index value: %s", err)
+	}
+	reply.LastTerm, err = strconv.ParseUint(stats["last_log_term"], 10, 64)
+	if err != nil {
+		return fmt.Errorf("error parsing server's last_log_term value: %s", err)
+	}
+
+	return nil
+}

consul/structs/operator.go

@@ -132,6 +132,18 @@ type ServerHealth struct {
 	StableSince time.Time
 }
 
+// ServerStats holds miscellaneous Raft metrics for a server
+type ServerStats struct {
+	// LastContact is the time since this node's last contact with the leader.
+	LastContact string
+
+	// LastTerm is the highest leader term this server has a record of in its Raft log.
+	LastTerm uint64
+
+	// LastIndex is the last log index this server has a record of in its Raft log.
+	LastIndex uint64
+}
+
 // OperatorHealthReply is a representation of the overall health of the cluster
 type OperatorHealthReply struct {
 	// Healthy is true if all the servers in the cluster are healthy.