func convertUpdate(rule *config.Rule, rows [][]interface{}) ([]elastic.BulkableRequest, error) {
if len(rows)%2 != 0 {
return nil, errors.Errorf("invalid update rows event, must have 2x rows, but %d", len(rows))
}
reqs := make([]elastic.BulkableRequest, 0, len(rows))
var err error = nil
for i := 0; i < len(rows); i += 2 {
beforeID, err := rule.DocId(rows[i])
if err != nil {
log.Warnf("skipping row update due to problem with before update values: %v\n", err)
continue
}
afterID, err := rule.DocId(rows[i+1])
if err != nil {
log.Warnf("skipping row update due to problem with update values: %v\n", err)
continue
}
beforeParentID, afterParentID := "", ""
beforeParentID, err = rule.ParentId(rows[i])
if err != nil {
return nil, errors.Trace(err)
}
afterParentID, err = rule.ParentId(rows[i+1])
if err != nil {
return nil, errors.Trace(err)
}
var req elastic.BulkableRequest
req = elastic.NewBulkUpdateRequest().Index(rule.Index).Type(rule.Type).Parent(beforeParentID).Id(beforeID).Routing(beforeParentID)
if beforeID != afterID || beforeParentID != afterParentID {
// if an id is changing, delete the old document and insert a new one
req = elastic.NewBulkDeleteRequest().Index(rule.Index).Type(rule.Type).Id(beforeID).Routing(beforeParentID)
reqs = append(reqs, req)
temp, err := convertInsert(rule, [][]interface{}{rows[i+1]})
if err == nil {
req = temp[0]
}
} else {
doc := convertUpdateRow(rule, rows[i], rows[i+1])
req = elastic.NewBulkUpdateRequest().Index(rule.Index).Type(rule.Type).Parent(beforeParentID).Id(beforeID).Routing(beforeParentID).Doc(doc)
}
reqs = append(reqs, req)
}
return reqs, err
}
// Interrupt releases a lock that's held.
func (zm *zMutex) Interrupt() {
select {
case zm.interrupted <- struct{}{}:
default:
log.Warnf("zmutex interrupt blocked")
}
}
func (r *River) makeReqColumnData(col *schema.TableColumn, value interface{}) interface{} {
switch col.Type {
case schema.TYPE_ENUM:
switch value := value.(type) {
case int64:
// for binlog, ENUM may be int64, but for dump, enum is string
eNum := value - 1
if eNum < 0 || eNum >= int64(len(col.EnumValues)) {
// we insert invalid enum value before, so return empty
log.Warnf("invalid binlog enum index %d, for enum %v", eNum, col.EnumValues)
return ""
}
return col.EnumValues[eNum]
}
case schema.TYPE_SET:
switch value := value.(type) {
case int64:
// for binlog, SET may be int64, but for dump, SET is string
bitmask := value
sets := make([]string, 0, len(col.SetValues))
for i, s := range col.SetValues {
if bitmask&int64(1<<uint(i)) > 0 {
sets = append(sets, s)
}
}
return strings.Join(sets, ",")
}
}
return value
}
func (e *RotateEvent) Decode(data []byte) error {
e.Position = binary.LittleEndian.Uint64(data[0:])
e.NextLogName = data[8:]
if e.Position != 4 {
// FIXME: why is this happening?
log.Warnf("RotateEvent(%s, %v) doesn't specify expected offset 4; forcing to 4 to continue", string(e.NextLogName), e.Position)
e.Position = 4
}
return nil
}
func (r *River) createIndex(idx string, settings map[string]interface{}) error {
exists, err := r.es.IndexExists(idx).Do()
if exists {
log.Warnf("Index '%s' already exists; settings and mappings not updated", idx)
return nil
}
log.Infof("Creating index with settings from %v: %v", idx, settings)
_, err = r.es.CreateIndex(idx).BodyJson(settings).Do()
return err
}
func (t *electorTask) Stop() {
t.z.noticeLeaderCh(false)
t.interrupted.Set(false)
select {
case t.stop <- struct{}{}:
default:
log.Warnf("stop chan blocked")
}
}
func (z *Zk) noticeLeaderCh(b bool) {
z.isLeader.Set(b)
for {
select {
case z.leaderCh <- b:
return
default:
log.Warnf("%s leader chan blocked, leader: %v", z.c.Addr, b)
select {
case <-z.leaderCh:
default:
}
}
}
}
func (t *electorTask) Run() error {
t.z.wg.Add(1)
defer t.z.wg.Done()
log.Infof("begin leader %s, run", t.z.c.Addr)
if err := t.z.getMasters(); err != nil {
t.interrupted.Set(true)
log.Errorf("get masters err %v", err)
return err
}
t.z.noticeLeaderCh(true)
for {
select {
case <-t.z.quit:
log.Info("zk close, interrupt elector running task")
t.z.noticeLeaderCh(false)
t.interrupted.Set(true)
return nil
case <-t.stop:
log.Info("stop elector running task")
return nil
case a := <-t.z.actionCh:
if a.timeout.Get() {
log.Warnf("wait action %s masters %v timeout, skip it", a.a.Cmd, a.a.Masters)
} else {
err := t.z.handleAction(a.a)
a.ch <- err
}
}
}
return nil
}
// for insert and delete
func convertAction(rule *config.Rule, action string, rows [][]interface{}) ([]elastic.BulkableRequest, error) {
reqs := make([]elastic.BulkableRequest, 0, len(rows))
for _, values := range rows {
if id, err := rule.DocId(values); err != nil {
log.Warnf("skipping row %s due to: %v\n", action, err)
continue
} else {
var req elastic.BulkableRequest
if parentId, err := rule.ParentId(values); err != nil {
return nil, err
} else if action == canal.DeleteAction {
req = elastic.NewBulkDeleteRequest().Index(rule.Index).Type(rule.Type).Id(id).Routing(parentId)
} else {
doc := convertRow(rule, values)
req = elastic.NewBulkIndexRequest().Index(rule.Index).Type(rule.Type).Id(id).Parent(parentId).Doc(doc)
}
reqs = append(reqs, req)
}
}
return reqs, nil
}
func (c *Canal) startSyncBinlog() error {
pos := mysql.Position{c.master.Name, c.master.Position}
log.Infof("Start sync'ing binlog from %v", pos)
s, err := c.syncer.StartSync(pos)
if err != nil {
return errors.Errorf("Failed starting sync at %v: %v", pos, err)
}
originalTimeout := time.Second
timeout := originalTimeout
forceSavePos := false
for {
ev, err := s.GetEventTimeout(timeout)
if err != nil && err != replication.ErrGetEventTimeout {
return errors.Trace(err)
} else if err == replication.ErrGetEventTimeout {
if timeout == 2*originalTimeout {
log.Debugf("Flushing event handlers since sync has gone idle")
if err := c.flushEventHandlers(); err != nil {
log.Warnf("Error occurred during flush: %v", err)
}
}
timeout = 2 * timeout
continue
}
timeout = time.Second
//next binlog pos
pos.Pos = ev.Header.LogPos
forceSavePos = false
log.Debugf("Syncing %v", ev)
switch e := ev.Event.(type) {
case *replication.RotateEvent:
c.flushEventHandlers()
pos.Name = string(e.NextLogName)
pos.Pos = uint32(e.Position)
// r.ev <- pos
forceSavePos = true
log.Infof("Rotate binlog to %v", pos)
case *replication.RowsEvent:
// we only focus row based event
if err = c.handleRowsEvent(ev); err != nil {
log.Errorf("Error handling rows event: %v", err)
return errors.Trace(err)
}
case *replication.QueryEvent:
if err = c.handleQueryEvent(ev); err != nil {
log.Errorf("Error handling rows event: %v", err)
return errors.Trace(err)
}
default:
log.Debugf("Ignored event: %+v", e)
}
c.master.Update(pos.Name, pos.Pos)
c.master.Save(forceSavePos)
}
return nil
}
// LockWithTimeout returns nil when the lock is acquired. A lock is
// held if the file exists and you are the creator. Setting the wait
// to zero makes this a nonblocking lock check.
//
// FIXME(msolo) Disallow non-super users from removing the lock?
func (zm *zMutex) LockWithTimeout(wait time.Duration, desc string) (err error) {
timer := time.NewTimer(wait)
defer func() {
if panicErr := recover(); panicErr != nil || err != nil {
zm.deleteLock()
}
}()
// Ensure the rendezvous node is here.
// FIXME(msolo) Assuming locks are contended, it will be cheaper to assume this just
// exists.
_, err = zkhelper.CreateRecursive(zm.zconn, zm.path, "", 0, zk.WorldACL(zkhelper.PERM_DIRECTORY))
if err != nil && !zkhelper.ZkErrorEqual(err, zk.ErrNodeExists) {
return err
}
lockPrefix := path.Join(zm.path, "lock-")
zflags := zk.FlagSequence
if zm.ephemeral {
zflags = zflags | zk.FlagEphemeral
}
// update node content
var lockContent map[string]interface{}
err = json.Unmarshal([]byte(zm.contents), &lockContent)
if err != nil {
return err
}
lockContent["desc"] = desc
newContent, err := json.Marshal(lockContent)
if err != nil {
return err
}
createlock:
lockCreated, err := zm.zconn.Create(lockPrefix, newContent, int32(zflags), zk.WorldACL(zkhelper.PERM_FILE))
if err != nil {
return err
}
name := path.Base(lockCreated)
zm.mu.Lock()
zm.name = name
zm.mu.Unlock()
trylock:
children, _, err := zm.zconn.Children(zm.path)
if err != nil {
return fmt.Errorf("zkutil: trylock failed %v", err)
}
sort.Strings(children)
if len(children) == 0 {
return fmt.Errorf("zkutil: empty lock: %v", zm.path)
}
if children[0] == name {
// We are the lock owner.
return nil
}
if zm.onRetryLock != nil {
zm.onRetryLock()
}
// This is the degenerate case of a nonblocking lock check. It's not optimal, but
// also probably not worth optimizing.
if wait == 0 {
return zkhelper.ErrTimeout
}
prevLock := ""
for i := 1; i < len(children); i++ {
if children[i] == name {
prevLock = children[i-1]
break
}
}
if prevLock == "" {
// This is an interesting case. The node disappeared
// underneath us, probably due to a session loss. We can
// recreate the lock node (with a new sequence number) and
// keep trying.
log.Warnf("zkutil: no lock node found: %v/%v", zm.path, zm.name)
goto createlock
}
zkPrevLock := path.Join(zm.path, prevLock)
exist, stat, watch, err := zm.zconn.ExistsW(zkPrevLock)
if err != nil {
// FIXME(msolo) Should this be a retry?
return fmt.Errorf("zkutil: unable to watch previous lock node %v %v", zkPrevLock, err)
}
if stat == nil || !exist {
goto trylock
}
select {
case <-timer.C:
return zkhelper.ErrTimeout
case <-zm.interrupted:
return zkhelper.ErrInterrupted
case event := <-watch:
log.Infof("zkutil: lock event: %v", event)
// The precise event doesn't matter - try to read again regardless.
goto trylock
}
panic("unexpected")
}
// RunTask returns nil when the underlyingtask ends or the error it
// generated.
func (ze *zElector) RunTask(task *electorTask) error {
leaderPath := path.Join(ze.path, "leader")
for {
_, err := zkhelper.CreateRecursive(ze.zconn, leaderPath, "", 0, zk.WorldACL(zkhelper.PERM_FILE))
if err == nil || zkhelper.ZkErrorEqual(err, zk.ErrNodeExists) {
break
}
log.Warnf("election leader create failed: %v", err)
time.Sleep(500 * time.Millisecond)
}
for {
err := ze.Lock("RunTask")
if err != nil {
log.Warnf("election lock failed: %v", err)
if err == zkhelper.ErrInterrupted {
return zkhelper.ErrInterrupted
}
continue
}
// Confirm your win and deliver acceptance speech. This notifies
// listeners who will have been watching the leader node for
// changes.
_, err = ze.zconn.Set(leaderPath, []byte(ze.contents), -1)
if err != nil {
log.Warnf("election promotion failed: %v", err)
continue
}
log.Infof("election promote leader %v", leaderPath)
taskErrChan := make(chan error)
go func() {
taskErrChan <- task.Run()
}()
watchLeader:
// Watch the leader so we can get notified if something goes wrong.
data, _, watch, err := ze.zconn.GetW(leaderPath)
if err != nil {
log.Warnf("election unable to watch leader node %v %v", leaderPath, err)
// FIXME(msolo) Add delay
goto watchLeader
}
if string(data) != ze.contents {
log.Warnf("election unable to promote leader")
task.Stop()
// We won the election, but we didn't become the leader. How is that possible?
// (see Bush v. Gore for some inspiration)
// It means:
// 1. Someone isn't playing by the election rules (a bad actor).
// Hard to detect - let's assume we don't have this problem. :)
// 2. We lost our connection somehow and the ephemeral lock was cleared,
// allowing someone else to win the election.
continue
}
// This is where we start our target process and watch for its failure.
waitForEvent:
select {
case <-ze.interrupted:
log.Warn("election interrupted - stop child process")
task.Stop()
// Once the process dies from the signal, this will all tear down.
goto waitForEvent
case taskErr := <-taskErrChan:
// If our code fails, unlock to trigger an election.
log.Infof("election child process ended: %v", taskErr)
ze.Unlock()
if task.Interrupted() {
log.Warnf("election child process interrupted - stepping down")
return zkhelper.ErrInterrupted
}
continue
case zevent := <-watch:
// We had a zk connection hiccup. We have a few choices,
// but it depends on the constraints and the events.
//
// If we get SESSION_EXPIRED our connection loss triggered an
// election that we won't have won and the thus the lock was
// automatically freed. We have no choice but to start over.
if zevent.State == zk.StateExpired {
log.Warnf("election leader watch expired")
task.Stop()
continue
}
// Otherwise, we had an intermittent issue or something touched
// the node. Either we lost our position or someone broke
// protocol and touched the leader node. We just reconnect and
// revalidate. In the meantime, assume we are still the leader
// until we determine otherwise.
//
// On a reconnect we will be able to see the leader
// information. If we still hold the position, great. If not, we
// kill the associated process.
//
// On a leader node change, we need to perform the same
// validation. It's possible an election completes without the
// old leader realizing he is out of touch.
log.Warnf("election leader watch event %v", zevent)
goto watchLeader
}
}
panic("unreachable")
}
// Close the release channel when you want to clean up nicely.
func CreatePidNode(zconn Conn, zkPath string, contents string, done chan struct{}) error {
// On the first try, assume the cluster is up and running, that will
// help hunt down any config issues present at startup
if _, err := zconn.Create(zkPath, []byte(contents), zk.FlagEphemeral, zk.WorldACL(PERM_FILE)); err != nil {
if ZkErrorEqual(err, zk.ErrNodeExists) {
err = zconn.Delete(zkPath, -1)
}
if err != nil {
return fmt.Errorf("zkutil: failed deleting pid node: %v: %v", zkPath, err)
}
_, err = zconn.Create(zkPath, []byte(contents), zk.FlagEphemeral, zk.WorldACL(PERM_FILE))
if err != nil {
return fmt.Errorf("zkutil: failed creating pid node: %v: %v", zkPath, err)
}
}
go func() {
for {
_, _, watch, err := zconn.GetW(zkPath)
if err != nil {
if ZkErrorEqual(err, zk.ErrNoNode) {
_, err = zconn.Create(zkPath, []byte(contents), zk.FlagEphemeral, zk.WorldACL(zk.PermAll))
if err != nil {
log.Warnf("failed recreating pid node: %v: %v", zkPath, err)
} else {
log.Infof("recreated pid node: %v", zkPath)
continue
}
} else {
log.Warnf("failed reading pid node: %v", err)
}
} else {
select {
case event := <-watch:
if ZkEventOk(event) && event.Type == zk.EventNodeDeleted {
// Most likely another process has started up. However,
// there is a chance that an ephemeral node is deleted by
// the session expiring, yet that same session gets a watch
// notification. This seems like buggy behavior, but rather
// than race too hard on the node, just wait a bit and see
// if the situation resolves itself.
log.Warnf("pid deleted: %v", zkPath)
} else {
log.Infof("pid node event: %v", event)
}
// break here and wait for a bit before attempting
case <-done:
log.Infof("pid watcher stopped on done: %v", zkPath)
return
}
}
select {
// No one likes a thundering herd, least of all zk.
case <-time.After(5*time.Second + time.Duration(rand.Int63n(55e9))):
case <-done:
log.Infof("pid watcher stopped on done: %v", zkPath)
return
}
}
}()
return nil
}
func (a *App) checkMaster(wg *sync.WaitGroup, g *Group) {
defer wg.Done()
// later, add check strategy, like check failed n numbers in n seconds and do failover, etc.
// now only check once.
err := g.Check()
if err == nil {
return
}
oldMaster := g.Master.Addr
if err == ErrNodeType {
log.Errorf("server %s is not master now, we will skip it", oldMaster)
// server is not master, we will not check it.
a.delMasters([]string{oldMaster})
return
}
errNum := time.Duration(g.CheckErrNum.Get())
downTime := errNum * time.Duration(a.c.CheckInterval) * time.Millisecond
if downTime < time.Duration(a.c.MaxDownTime)*time.Second {
log.Warnf("check master %s err %v, down time: %0.2fs, retry check", oldMaster, err, downTime.Seconds())
return
}
// If check error, we will remove it from saved masters and not check.
// I just want to avoid some errors if below failover failed, at that time,
// handling it manually seems a better way.
// If you want to recheck it, please add it again.
a.delMasters([]string{oldMaster})
log.Errorf("check master %s err %v, do failover", oldMaster, err)
if err := a.onBeforeFailover(oldMaster); err != nil {
//give up failover
return
}
// first elect a candidate
newMaster, err := g.Elect()
if err != nil {
// elect error
return
}
log.Errorf("master is down, elect %s as new master, do failover", newMaster)
// promote the candiate to master
err = g.Promote(newMaster)
if err != nil {
log.Fatalf("do master %s failover err: %v", oldMaster, err)
return
}
a.addMasters([]string{newMaster})
a.onAfterFailover(oldMaster, newMaster)
}