Return http 100 before sync is complete

Author: sttts

healthcheck/healthcheck.go

@@ -5,8 +5,10 @@ import (
 )
 
 const (
-	SYNCED_STATE         = "4"
+	JOINING_STATE        = "1"
 	DONOR_DESYNCED_STATE = "2"
+	JOINED_STATE         = "3"
+	SYNCED_STATE         = "4"
 )
 
 type Healthchecker struct {
@@ -19,35 +21,52 @@ type HealthcheckerConfig struct {
 	AvailableWhenReadOnly bool
 }
 
+type HealthResult struct {
+	Healthy bool
+}
+
 func New(db *sql.DB, config HealthcheckerConfig) *Healthchecker {
 	return &Healthchecker{
 		db:     db,
 		config: config,
 	}
 }
 
-func (h *Healthchecker) Check() (bool, string) {
+var was_joined = false
+var old_state = "0"
+
+func (h *Healthchecker) Check() (*HealthResult, string) {
 	var variable_name string
-	var value string
-	err := h.db.QueryRow("SHOW STATUS LIKE 'wsrep_local_state'").Scan(&variable_name, &value)
+	var state string
+	err := h.db.QueryRow("SHOW STATUS LIKE 'wsrep_local_state'").Scan(&variable_name, &state)
 
+	var res, msg = &HealthResult{Healthy: false}, "not synced"
 	switch {
 	case err != nil:
-		return false, err.Error()
-	case value == SYNCED_STATE || (value == DONOR_DESYNCED_STATE && h.config.AvailableWhenDonor):
+		res, msg = &HealthResult{Healthy: false}, err.Error()
+	case state != SYNCED_STATE && !was_joined:
+		if old_state == JOINED_STATE && state != JOINED_STATE {
+			res, msg = &HealthResult{Healthy: false}, "no synced"
+			was_joined = true
+		} else {
+			res, msg = nil, "syncing"
+		}
+	case state == SYNCED_STATE || (state == DONOR_DESYNCED_STATE && h.config.AvailableWhenDonor):
+		was_joined = true
+		res, msg = &HealthResult{Healthy: true}, "synced"
 		if !h.config.AvailableWhenReadOnly {
 			var ro_variable_name string
 			var ro_value string
 			ro_err := h.db.QueryRow("SHOW GLOBAL VARIABLES LIKE 'read_only'").Scan(&ro_variable_name, &ro_value)
 			switch {
 			case ro_err != nil:
-				return false, ro_err.Error()
+				res, msg = &HealthResult{Healthy: false}, ro_err.Error()
 			case ro_value == "ON":
-				return false, "read-only"
+				res, msg = &HealthResult{Healthy: false}, "read-only"
 			}
 		}
-		return true, "synced"
-	default:
-		return false, "not synced"
 	}
+	
+	old_state = state
+	return res, msg
 }

server.go

@@ -9,8 +9,8 @@ import (
 	"os"
 	"strconv"
 
-	"github.com/cloudfoundry-incubator/galera-healthcheck/healthcheck"
-	. "github.com/cloudfoundry-incubator/galera-healthcheck/logger"
+	"github.com/sttts/galera-healthcheck/healthcheck"
+	. "github.com/sttts/galera-healthcheck/logger"
 	_ "github.com/go-sql-driver/mysql"
 )
 
@@ -60,10 +60,12 @@ var healthchecker *healthcheck.Healthchecker
 
 func handler(w http.ResponseWriter, r *http.Request) {
 	result, msg := healthchecker.Check()
-	if result {
+	if result != nil && result.Healthy {
 		w.WriteHeader(http.StatusOK)
-	} else {
+	} else if result != nil && !result.Healthy {
 		w.WriteHeader(http.StatusServiceUnavailable)
+	} else {
+		w.WriteHeader(http.StatusContinue)
 	}
 
 	fmt.Fprintf(w, "Galera Cluster Node status: %s", msg)