Allow Vitess HTTP client timeout override

Author: timvaillancourt

pkg/config/config.go

@@ -108,21 +108,23 @@ type ConfigurationSettings struct {
 	BackendMySQLPassword string
 	MemcacheServers      []string // if given, freno will report to aggregated values to given memcache
 	MemcachePath         string   // use as prefix to metric path in memcache key, e.g. if `MemcachePath` is "myprefix" the key would be "myprefix/mysql/maincluster". Default: "freno"
+	VitessHTTPTimeoutSec int
 	Stores               StoresSettings
 }
 
 func newConfigurationSettings() *ConfigurationSettings {
 	return &ConfigurationSettings{
-		ListenPort:         8087,
-		RaftBind:           "127.0.0.1:10008",
-		RaftDataDir:        "",
-		DefaultRaftPort:    0,
-		RaftNodes:          []string{},
-		BackendMySQLHost:   "",
-		BackendMySQLSchema: "",
-		BackendMySQLPort:   3306,
-		MemcacheServers:    []string{},
-		MemcachePath:       "freno",
+		ListenPort:           8087,
+		RaftBind:             "127.0.0.1:10008",
+		RaftDataDir:          "",
+		DefaultRaftPort:      0,
+		RaftNodes:            []string{},
+		BackendMySQLHost:     "",
+		BackendMySQLSchema:   "",
+		BackendMySQLPort:     3306,
+		MemcacheServers:      []string{},
+		MemcachePath:         "freno",
+		VitessHTTPTimeoutSec: 3,
 		//Debug:                                        false,
 		//ListenSocket:                                 "",
 		//AnExampleListOfStrings:                       []string{"*"},

pkg/throttle/throttler.go

@@ -323,7 +323,8 @@ func (throttler *Throttler) refreshMySQLInventory() error {
 				log.Debugf("getting vitess data from %s", clusterSettings.VitessSettings.API)
 				keyspace := clusterSettings.VitessSettings.Keyspace
 				shard := clusterSettings.VitessSettings.Shard
-				tablets, err := vitess.ParseTablets(clusterSettings.VitessSettings.API, keyspace, shard)
+				vtManager := vitess.NewManager(config.Settings().VitessHTTPTimeoutSec)
+				tablets, err := vtManager.ParseTablets(clusterSettings.VitessSettings.API, keyspace, shard)
 				if err != nil {
 					return log.Errorf("Unable to get vitess hosts from %s, %s/%s: %+v", clusterSettings.VitessSettings.API, keyspace, shard, err)
 				}

pkg/vitess/api_client.go

@@ -15,8 +15,16 @@ type Tablet struct {
 	MysqlPort     int32  `json:"mysql_port,omitempty"`
 }
 
-var httpClient = http.Client{
-	Timeout: 1 * time.Second,
+// Manager gathers info from Vitess
+type Manager struct {
+	httpClient http.Client
+}
+
+// NewManager returns a new manager for Vitess
+func NewManager(timeoutSec int) *Manager {
+	return &Manager{httpClient: http.Client{
+		Timeout: time.Duration(timeoutSec) * time.Second,
+	}}
 }
 
 func constructAPIURL(api string, keyspace string, shard string) (url string) {
@@ -31,9 +39,9 @@ func constructAPIURL(api string, keyspace string, shard string) (url string) {
 
 // ParseTablets reads from vitess /api/ks_tablets/<keyspace>/[shard] and returns a
 // tblet (mysql_hostname, mysql_port) listing
-func ParseTablets(api string, keyspace string, shard string) (tablets []Tablet, err error) {
+func (m *Manager) ParseTablets(api string, keyspace string, shard string) (tablets []Tablet, err error) {
 	url := constructAPIURL(api, keyspace, shard)
-	resp, err := httpClient.Get(url)
+	resp, err := m.httpClient.Get(url)
 	if err != nil {
 		return tablets, err
 	}