// runHealthCheck takes the action mutex, runs the health check,
// and if we need to change our state, do it.
// If we are the master, we don't change our type, healthy or not.
// If we are not the master, we change to spare if not healthy,
// or to the passed in targetTabletType if healthy.
//
// Note we only update the topo record if we need to, that is if our type or
// health details changed.
func (agent *ActionAgent) runHealthCheck(targetTabletType pbt.TabletType) {
agent.actionMutex.Lock()
defer agent.actionMutex.Unlock()
// read the current tablet record and tablet control
agent.mutex.Lock()
tablet := agent._tablet
tabletControl := agent._tabletControl
agent.mutex.Unlock()
// figure out if we should be running the query service
shouldQueryServiceBeRunning := false
var blacklistedTables []string
if topo.IsRunningQueryService(targetTabletType) && !agent.BinlogPlayerMap.isRunningFilteredReplication() {
shouldQueryServiceBeRunning = true
if tabletControl != nil {
blacklistedTables = tabletControl.BlacklistedTables
if tabletControl.DisableQueryService {
shouldQueryServiceBeRunning = false
}
}
}
// run the health check
typeForHealthCheck := targetTabletType
if tablet.Type == pbt.TabletType_MASTER {
typeForHealthCheck = pbt.TabletType_MASTER
}
replicationDelay, err := agent.HealthReporter.Report(topo.IsSlaveType(typeForHealthCheck), shouldQueryServiceBeRunning)
health := make(map[string]string)
if err == nil {
if replicationDelay > *unhealthyThreshold {
err = fmt.Errorf("reported replication lag: %v higher than unhealthy threshold: %v", replicationDelay.Seconds(), unhealthyThreshold.Seconds())
} else if replicationDelay > *degradedThreshold {
health[topo.ReplicationLag] = topo.ReplicationLagHigh
}
}
agent.lastHealthMapCount.Set(int64(len(health)))
// Figure out if we should be running QueryService, see if we are,
// and reconcile.
if err != nil {
if tablet.Type != pbt.TabletType_WORKER {
// We are not healthy and must shut down QueryService.
// At the moment, the only exception to this are "worker" tablets which
// still must serve queries e.g. as source tablet during a "SplitClone".
shouldQueryServiceBeRunning = false
}
}
isQueryServiceRunning := agent.QueryServiceControl.IsServing()
if shouldQueryServiceBeRunning {
if !isQueryServiceRunning {
// send the type we want to be, not the type we are
currentType := tablet.Type
if tablet.Type == pbt.TabletType_SPARE {
tablet.Type = targetTabletType
}
// we remember this new possible error
err = agent.allowQueries(tablet.Tablet, blacklistedTables)
// restore the current type
tablet.Type = currentType
}
} else {
if isQueryServiceRunning {
// we are not healthy or should not be running the
// query service, shut it down.
agent.stopQueryService()
}
}
// save the health record
record := &HealthRecord{
Error: err,
ReplicationDelay: replicationDelay,
Time: time.Now(),
}
agent.History.Add(record)
// try to figure out the mysql port if we don't have it yet
if _, ok := tablet.PortMap["mysql"]; !ok {
// we don't know the port, try to get it from mysqld
mysqlPort, err := agent.MysqlDaemon.GetMysqlPort()
if err != nil {
// Don't log if we're already in a waiting-for-mysql state.
agent.mutex.Lock()
if !agent._waitingForMysql {
log.Warningf("Can't get mysql port, won't populate Tablet record in topology (will retry silently at healthcheck interval %v): %v", *healthCheckInterval, err)
agent._waitingForMysql = true
}
agent.mutex.Unlock()
} else {
log.Infof("Updating tablet mysql port to %v", mysqlPort)
if err := agent.TopoServer.UpdateTabletFields(agent.batchCtx, tablet.Alias, func(tablet *pbt.Tablet) error {
tablet.PortMap["mysql"] = int32(mysqlPort)
return nil
}); err != nil {
log.Infof("Error updating mysql port in tablet record: %v", err)
return
}
// save the port so we don't update it again next time
// we do the health check.
agent.mutex.Lock()
agent._tablet.PortMap["mysql"] = int32(mysqlPort)
agent._waitingForMysql = false
agent.mutex.Unlock()
}
}
// remember our health status
agent.mutex.Lock()
agent._healthy = err
agent._healthyTime = time.Now()
agent._replicationDelay = replicationDelay
terTime := agent._tabletExternallyReparentedTime
agent.mutex.Unlock()
// send it to our observers
// (the Target has already been updated when restarting the
// query service earlier)
// FIXME(alainjobart,liguo) add CpuUsage
stats := &pb.RealtimeStats{
SecondsBehindMaster: uint32(replicationDelay.Seconds()),
}
stats.SecondsBehindMasterFilteredReplication, stats.BinlogPlayersCount = agent.BinlogPlayerMap.StatusSummary()
if err != nil {
stats.HealthError = err.Error()
}
defer func() {
var ts int64
if !terTime.IsZero() {
ts = terTime.Unix()
}
agent.QueryServiceControl.BroadcastHealth(ts, stats)
}()
// Update our topo.Server state, start with no change
newTabletType := tablet.Type
if err != nil {
// The tablet is not healthy, let's see what we need to do
if tablet.Type != targetTabletType {
if tablet.Type != pbt.TabletType_SPARE {
// we only log if we're not in spare,
// as the spare state is normal for a
// failed health check.
log.Infof("Tablet not healthy and in state %v, not changing it: %v", tablet.Type, err)
}
return
}
// Note that if the query service is running, we may
// need to stop it. The post-action callback will do
// it, and it will be done after we change our state,
// so it's the right order, let it do it.
log.Infof("Tablet not healthy, converting it from %v to spare: %v", targetTabletType, err)
newTabletType = pbt.TabletType_SPARE
} else {
// We are healthy, maybe with health, see if we need
// to update the record. We only change from spare to
// our target type.
if tablet.Type == pbt.TabletType_SPARE {
newTabletType = targetTabletType
}
if tablet.Type == newTabletType && topo.IsHealthEqual(health, tablet.HealthMap) {
// no change in health, not logging anything,
// and we're done
return
}
// we need to update our state
log.Infof("Updating tablet record as healthy type %v -> %v with health details %v -> %v", tablet.Type, newTabletType, tablet.HealthMap, health)
}
// Change the Type, update the health. Note we pass in a map
// that's not nil, meaning if it's empty, we will clear it.
if err := topotools.ChangeType(agent.batchCtx, agent.TopoServer, tablet.Alias, newTabletType, health); err != nil {
log.Infof("Error updating tablet record: %v", err)
return
}
tablet.HealthMap = health
tablet.Type = newTabletType
// Rebuild the serving graph in our cell, only if we're dealing with
// a serving type
if err := agent.updateServingGraph(tablet, targetTabletType); err != nil {
log.Warningf("updateServingGraph failed (will still run post action callbacks, serving graph might be out of date): %v", err)
}
// run the post action callbacks, not much we can do with returned error
if err := agent.refreshTablet(agent.batchCtx, "healthcheck"); err != nil {
log.Warningf("refreshTablet failed: %v", err)
}
}
// runHealthCheck takes the action mutex, runs the health check,
// and if we need to change our state, do it.
// If we are the master, we don't change our type, healthy or not.
// If we are not the master, we change to spare if not healthy,
// or to the passed in targetTabletType if healthy.
//
// Note we only update the topo record if we need to, that is if our type or
// health details changed.
//
// This will not change the BinlogPlayerMap, but if it is not empty,
// we will think we should not be running the query service.
//
// This will not change the TabletControl record, but will use it
// to see if we should be running the query service.
func (agent *ActionAgent) runHealthCheck(targetTabletType topodatapb.TabletType) {
agent.actionMutex.Lock()
defer agent.actionMutex.Unlock()
// read the current tablet record and tablet control
agent.mutex.Lock()
tablet := proto.Clone(agent._tablet).(*topodatapb.Tablet)
tabletControl := proto.Clone(agent._tabletControl).(*topodatapb.Shard_TabletControl)
agent.mutex.Unlock()
// figure out if we should be running the query service
shouldBeServing := false
if topo.IsRunningQueryService(targetTabletType) && !agent.BinlogPlayerMap.isRunningFilteredReplication() {
shouldBeServing = true
if tabletControl != nil {
if tabletControl.DisableQueryService {
shouldBeServing = false
}
}
}
// run the health check
isSlaveType := true
if tablet.Type == topodatapb.TabletType_MASTER {
isSlaveType = false
}
// Remember the health error as healthErr to be sure we don't accidentally
// overwrite it with some other err.
replicationDelay, healthErr := agent.HealthReporter.Report(isSlaveType, shouldBeServing)
health := make(map[string]string)
if healthErr == nil {
if replicationDelay > *unhealthyThreshold {
healthErr = fmt.Errorf("reported replication lag: %v higher than unhealthy threshold: %v", replicationDelay.Seconds(), unhealthyThreshold.Seconds())
} else if replicationDelay > *degradedThreshold {
health[topo.ReplicationLag] = topo.ReplicationLagHigh
}
}
agent.lastHealthMapCount.Set(int64(len(health)))
// Figure out if we should be running QueryService, see if we are,
// and reconcile.
if healthErr != nil {
if tablet.Type != topodatapb.TabletType_WORKER {
// We are not healthy and must shut down QueryService.
// At the moment, the only exception to this are "worker" tablets which
// still must serve queries e.g. as source tablet during a "SplitClone".
shouldBeServing = false
}
}
isServing := agent.QueryServiceControl.IsServing()
if shouldBeServing {
if !isServing {
// It might be that we're ready to serve, but we just need to start
// queryservice. Send the type we want to be, not the type we are.
desiredType := tablet.Type
if desiredType == topodatapb.TabletType_SPARE {
desiredType = targetTabletType
}
// If starting queryservice fails, that's our new reason for being unhealthy.
healthErr = agent.allowQueries(desiredType)
}
} else {
if isServing {
// We are not healthy or should not be running the query service.
//
// We do NOT enter lameduck in this case, because we should only hit this
// in the following scenarios:
//
// * Healthcheck fails: We're probably serving errors anyway, so no point.
// * Replication lag exceeds unhealthy threshold: This is very rare, so it
// isn't worth optimizing the potential 1s of errors away. It will also
// go away when vtgate is the only one looking at lag.
// * We're in a special state where queryservice should be disabled
// despite being non-SPARE: This is not a live serving instance anyway.
agent.disallowQueries(tablet.Type,
fmt.Sprintf("health-check failure(%v)", healthErr),
)
}
}
// save the health record
record := &HealthRecord{
Error: healthErr,
ReplicationDelay: replicationDelay,
Time: time.Now(),
}
agent.History.Add(record)
// try to figure out the mysql port if we don't have it yet
if _, ok := tablet.PortMap["mysql"]; !ok {
// we don't know the port, try to get it from mysqld
mysqlPort, err := agent.MysqlDaemon.GetMysqlPort()
if err != nil {
// Don't log if we're already in a waiting-for-mysql state.
agent.mutex.Lock()
if !agent._waitingForMysql {
log.Warningf("Can't get mysql port, won't populate Tablet record in topology (will retry silently at healthcheck interval %v): %v", *healthCheckInterval, err)
agent._waitingForMysql = true
}
agent.mutex.Unlock()
} else {
log.Infof("Updating tablet mysql port to %v", mysqlPort)
_, err := agent.TopoServer.UpdateTabletFields(agent.batchCtx, tablet.Alias,
func(tablet *topodatapb.Tablet) error {
if err := topotools.CheckOwnership(agent.initialTablet, tablet); err != nil {
return err
}
tablet.PortMap["mysql"] = mysqlPort
return nil
})
if err != nil {
log.Infof("Error updating mysql port in tablet record (will try again at healthcheck interval): %v", err)
} else {
// save the port so we don't update it again next time
// we do the health check.
agent.mutex.Lock()
agent._tablet.PortMap["mysql"] = mysqlPort
agent._waitingForMysql = false
agent.mutex.Unlock()
}
}
}
// remember our health status
agent.mutex.Lock()
agent._healthy = healthErr
agent._healthyTime = time.Now()
agent._replicationDelay = replicationDelay
agent.mutex.Unlock()
// send it to our observers
agent.broadcastHealth()
// Update our topo.Server state, start with no change
newTabletType := tablet.Type
if healthErr != nil {
// The tablet is not healthy, let's see what we need to do
if tablet.Type != targetTabletType {
if tablet.Type != topodatapb.TabletType_SPARE {
// we only log if we're not in spare,
// as the spare state is normal for a
// failed health check.
log.Infof("Tablet not healthy and in state %v, not changing it: %v", tablet.Type, healthErr)
}
return
}
// Note that if the query service is running, we may
// need to stop it. The post-action callback will do
// it, and it will be done after we change our state,
// so it's the right order, let it do it.
log.Infof("Tablet not healthy, converting it from %v to spare: %v", targetTabletType, healthErr)
newTabletType = topodatapb.TabletType_SPARE
} else {
// We are healthy, maybe with health, see if we need
// to update the record. We only change from spare to
// our target type.
if tablet.Type == topodatapb.TabletType_SPARE {
newTabletType = targetTabletType
}
if tablet.Type == newTabletType && topo.IsHealthEqual(health, tablet.HealthMap) {
// no change in health, not logging anything,
// and we're done
return
}
// we need to update our state
log.Infof("Updating tablet record as healthy type %v -> %v with health details %v -> %v", tablet.Type, newTabletType, tablet.HealthMap, health)
}
// Change the Type, update the health. Note we pass in a map
// that's not nil, meaning if it's empty, we will clear it.
tablet, err := topotools.ChangeOwnType(agent.batchCtx, agent.TopoServer, agent.initialTablet, newTabletType, health)
if err != nil {
log.Infof("Error updating tablet record: %v", err)
return
}
// Rebuild the serving graph in our cell, only if we're dealing with
// a serving type
if err := agent.updateServingGraph(tablet, targetTabletType); err != nil {
log.Warningf("updateServingGraph failed (will still run post action callbacks, serving graph might be out of date): %v", err)
}
// Run the post action callbacks.
// Note that this is where we might block for *gracePeriod, depending on the
// type of state change. See changeCallback() for details.
if err := agent.refreshTablet(agent.batchCtx, "healthcheck"); err != nil {
log.Warningf("refreshTablet failed: %v", err)
}
}