func (mysqld *Mysqld) initConfig(root string) error {
var err error
var configData string
switch hr := hook.NewSimpleHook("make_mycnf").Execute(); hr.ExitStatus {
case hook.HOOK_DOES_NOT_EXIST:
log.Infof("make_mycnf hook doesn't exist, reading default template files")
cnfTemplatePaths := []string{
path.Join(root, "config/mycnf/default.cnf"),
path.Join(root, "config/mycnf/master.cnf"),
path.Join(root, "config/mycnf/replica.cnf"),
}
if extraCnf := os.Getenv("EXTRA_MY_CNF"); extraCnf != "" {
parts := strings.Split(extraCnf, ":")
cnfTemplatePaths = append(cnfTemplatePaths, parts...)
}
configData, err = mysqld.config.makeMycnf(cnfTemplatePaths)
case hook.HOOK_SUCCESS:
configData, err = mysqld.config.fillMycnfTemplate(hr.Stdout)
default:
return fmt.Errorf("make_mycnf hook failed(%v): %v", hr.ExitStatus, hr.Stderr)
}
if err != nil {
return err
}
return ioutil.WriteFile(mysqld.config.path, []byte(configData), 0664)
}
func (mysqld *Mysqld) ValidateCloneTarget(hookExtraEnv map[string]string) error {
// run a hook to check local things
h := hook.NewSimpleHook("preflight_restore")
h.ExtraEnv = hookExtraEnv
if err := h.ExecuteOptional(); err != nil {
return err
}
qr, err := mysqld.fetchSuperQuery("SHOW DATABASES")
if err != nil {
return fmt.Errorf("mysqlctl: ValidateCloneTarget failed, %v", err)
}
for _, row := range qr.Rows {
if strings.HasPrefix(row[0].String(), "vt_") {
dbName := row[0].String()
tableQr, err := mysqld.fetchSuperQuery("SHOW TABLES FROM " + dbName)
if err != nil {
return fmt.Errorf("mysqlctl: ValidateCloneTarget failed, %v", err)
} else if len(tableQr.Rows) == 0 {
// no tables == empty db, all is well
continue
}
return fmt.Errorf("mysqlctl: ValidateCloneTarget failed, found active db %v", dbName)
}
}
return nil
}
func (wr *Wrangler) checkMasterElect(ti *topo.TabletInfo) error {
// Check the master-elect is fit for duty - call out for hardware checks.
// if the server was already serving live traffic, it's probably good
if ti.IsInServingGraph() {
return nil
}
return wr.ExecuteOptionalTabletInfoHook(ti, hook.NewSimpleHook("preflight_serving_type"))
}
func (mysqld *Mysqld) StopSlave(hookExtraEnv map[string]string) error {
h := hook.NewSimpleHook("preflight_stop_slave")
h.ExtraEnv = hookExtraEnv
if err := h.ExecuteOptional(); err != nil {
return err
}
return mysqld.ExecuteSuperQuery("STOP SLAVE")
}
func (mysqld *Mysqld) StartSlave(hookExtraEnv map[string]string) error {
if err := mysqld.ExecuteSuperQuery("START SLAVE"); err != nil {
return err
}
h := hook.NewSimpleHook("postflight_start_slave")
h.ExtraEnv = hookExtraEnv
return h.ExecuteOptional()
}
// This piece runs on the presumably empty machine acting as the target in the
// create replica action.
//
// validate target (self)
// shutdown_mysql()
// create temp data directory /vt/target/vt_<keyspace>
// copy compressed data files via HTTP
// verify hash of compressed files
// uncompress into /vt/vt_<target-uid>/data/vt_<keyspace>
// start_mysql()
// clean up compressed files
func (mysqld *Mysqld) RestoreFromSnapshot(logger logutil.Logger, snapshotManifest *SnapshotManifest, fetchConcurrency, fetchRetryCount int, dontWaitForSlaveStart bool, hookExtraEnv map[string]string) error {
if snapshotManifest == nil {
return errors.New("RestoreFromSnapshot: nil snapshotManifest")
}
logger.Infof("ValidateCloneTarget")
if err := mysqld.ValidateCloneTarget(hookExtraEnv); err != nil {
return err
}
logger.Infof("Shutdown mysqld")
if err := mysqld.Shutdown(true, MysqlWaitTime); err != nil {
return err
}
logger.Infof("Fetch snapshot")
if err := mysqld.fetchSnapshot(snapshotManifest, fetchConcurrency, fetchRetryCount); err != nil {
return err
}
logger.Infof("Restart mysqld")
if err := mysqld.Start(MysqlWaitTime); err != nil {
return err
}
cmdList, err := mysqld.StartReplicationCommands(snapshotManifest.ReplicationStatus)
if err != nil {
return err
}
if err := mysqld.ExecuteSuperQueryList(cmdList); err != nil {
return err
}
if !dontWaitForSlaveStart {
if err := mysqld.WaitForSlaveStart(SlaveStartDeadline); err != nil {
return err
}
}
h := hook.NewSimpleHook("postflight_restore")
h.ExtraEnv = hookExtraEnv
if err := h.ExecuteOptional(); err != nil {
return err
}
return nil
}
// Scrap will update the tablet type to 'Scrap', and remove it from
// the serving graph.
//
// 'force' means we are not on the tablet being scrapped, so it is
// probably dead. So if 'force' is true, we will also remove pending
// remote actions. And if 'force' is false, we also run an optional
// hook.
func Scrap(ts topo.Server, tabletAlias topo.TabletAlias, force bool) error {
tablet, err := ts.GetTablet(tabletAlias)
if err != nil {
return err
}
// If you are already scrap, skip updating replication data. It won't
// be there anyway.
wasAssigned := tablet.IsAssigned()
tablet.Type = topo.TYPE_SCRAP
tablet.Parent = topo.TabletAlias{}
// Update the tablet first, since that is canonical.
err = topo.UpdateTablet(context.TODO(), ts, tablet)
if err != nil {
return err
}
if wasAssigned {
err = topo.DeleteTabletReplicationData(ts, tablet.Tablet)
if err != nil {
if err == topo.ErrNoNode {
log.V(6).Infof("no ShardReplication object for cell %v", tablet.Alias.Cell)
err = nil
}
if err != nil {
log.Warningf("remove replication data for %v failed: %v", tablet.Alias, err)
}
}
}
// run a hook for final cleanup, only in non-force mode.
// (force mode executes on the vtctl side, not on the vttablet side)
if !force {
hk := hook.NewSimpleHook("postflight_scrap")
ConfigureTabletHook(hk, tablet.Alias)
if hookErr := hk.ExecuteOptional(); hookErr != nil {
// we don't want to return an error, the server
// is already in bad shape probably.
log.Warningf("Scrap: postflight_scrap failed: %v", hookErr)
}
}
return nil
}
// change a tablet type to RESTORE and set all the other arguments.
// from now on, we can go to:
// - back to IDLE if we don't use the tablet at all (after for instance
// a successful ReserveForRestore but a failed Snapshot)
// - to SCRAP if something in the process on the target host fails
// - to SPARE if the clone works
func (agent *ActionAgent) changeTypeToRestore(ctx context.Context, tablet, sourceTablet *topo.TabletInfo, parentAlias topo.TabletAlias, keyRange key.KeyRange) error {
// run the optional preflight_assigned hook
hk := hook.NewSimpleHook("preflight_assigned")
topotools.ConfigureTabletHook(hk, agent.TabletAlias)
if err := hk.ExecuteOptional(); err != nil {
return err
}
// change the type
tablet.Parent = parentAlias
tablet.Keyspace = sourceTablet.Keyspace
tablet.Shard = sourceTablet.Shard
tablet.Type = topo.TYPE_RESTORE
tablet.KeyRange = keyRange
tablet.DbNameOverride = sourceTablet.DbNameOverride
if err := topo.UpdateTablet(ctx, agent.TopoServer, tablet); err != nil {
return err
}
// and create the replication graph items
return topo.UpdateTabletReplicationData(ctx, agent.TopoServer, tablet.Tablet)
}
// Start will start the mysql daemon, either by running the 'mysqld_start'
// hook, or by running mysqld_safe in the background.
// If a mysqlctld address is provided in a flag, Start will run remotely.
func (mysqld *Mysqld) Start(mysqlWaitTime time.Duration) error {
// Execute as remote action on mysqlctld if requested.
if *socketFile != "" {
log.Infof("executing Mysqld.Start() remotely via mysqlctld server: %v", *socketFile)
client, err := mysqlctlclient.New("unix", *socketFile, mysqlWaitTime)
if err != nil {
return fmt.Errorf("can't dial mysqlctld: %v", err)
}
defer client.Close()
return client.Start(mysqlWaitTime)
}
var name string
ts := fmt.Sprintf("Mysqld.Start(%v)", time.Now().Unix())
// try the mysqld start hook, if any
switch hr := hook.NewSimpleHook("mysqld_start").Execute(); hr.ExitStatus {
case hook.HOOK_SUCCESS:
// hook exists and worked, we can keep going
name = "mysqld_start hook"
case hook.HOOK_DOES_NOT_EXIST:
// hook doesn't exist, run mysqld_safe ourselves
log.Infof("%v: No mysqld_start hook, running mysqld_safe directly", ts)
dir, err := vtenv.VtMysqlRoot()
if err != nil {
return err
}
name = path.Join(dir, "bin/mysqld_safe")
arg := []string{
"--defaults-file=" + mysqld.config.path}
env := []string{os.ExpandEnv("LD_LIBRARY_PATH=$VT_MYSQL_ROOT/lib/mysql")}
cmd := exec.Command(name, arg...)
cmd.Dir = dir
cmd.Env = env
log.Infof("%v mysqlWaitTime:%v %#v", ts, mysqlWaitTime, cmd)
stderr, err := cmd.StderrPipe()
if err != nil {
return nil
}
stdout, err := cmd.StdoutPipe()
if err != nil {
return nil
}
go func() {
scanner := bufio.NewScanner(stderr)
for scanner.Scan() {
log.Infof("%v stderr: %v", ts, scanner.Text())
}
}()
go func() {
scanner := bufio.NewScanner(stdout)
for scanner.Scan() {
log.Infof("%v stdout: %v", ts, scanner.Text())
}
}()
err = cmd.Start()
if err != nil {
return nil
}
mysqld.mutex.Lock()
mysqld.cancelWaitCmd = make(chan struct{})
go func(cancel <-chan struct{}) {
// Wait regardless of cancel, so we don't generate defunct processes.
err := cmd.Wait()
log.Infof("%v exit: %v", ts, err)
// The process exited. Trigger OnTerm callbacks, unless we were cancelled.
select {
case <-cancel:
default:
mysqld.mutex.Lock()
for _, callback := range mysqld.onTermFuncs {
go callback()
}
mysqld.mutex.Unlock()
}
}(mysqld.cancelWaitCmd)
mysqld.mutex.Unlock()
default:
// hook failed, we report error
return fmt.Errorf("mysqld_start hook failed: %v", hr.String())
}
// give it some time to succeed - usually by the time the socket emerges
// we are in good shape
for i := mysqlWaitTime; i >= 0; i -= time.Second {
_, statErr := os.Stat(mysqld.config.SocketFile)
if statErr == nil {
// Make sure the socket file isn't stale.
conn, connErr := mysqld.dbaPool.Get(0)
if connErr == nil {
conn.Recycle()
return nil
}
} else if !os.IsNotExist(statErr) {
return statErr
}
log.Infof("%v: sleeping for 1s waiting for socket file %v", ts, mysqld.config.SocketFile)
time.Sleep(time.Second)
}
return errors.New(name + ": deadline exceeded waiting for " + mysqld.config.SocketFile)
}
// Shutdown will stop the mysqld daemon that is running in the background.
//
// waitForMysqld: should the function block until mysqld has stopped?
// This can actually take a *long* time if the buffer cache needs to be fully
// flushed - on the order of 20-30 minutes.
//
// If a mysqlctld address is provided in a flag, Shutdown will run remotely.
func (mysqld *Mysqld) Shutdown(waitForMysqld bool, mysqlWaitTime time.Duration) error {
log.Infof("Mysqld.Shutdown")
// Execute as remote action on mysqlctld if requested.
if *socketFile != "" {
log.Infof("executing Mysqld.Shutdown() remotely via mysqlctld server: %v", *socketFile)
client, err := mysqlctlclient.New("unix", *socketFile, mysqlWaitTime)
if err != nil {
return fmt.Errorf("can't dial mysqlctld: %v", err)
}
defer client.Close()
return client.Shutdown(waitForMysqld, mysqlWaitTime)
}
// We're shutting down on purpose. We no longer want to be notified when
// mysqld terminates.
mysqld.mutex.Lock()
if mysqld.cancelWaitCmd != nil {
close(mysqld.cancelWaitCmd)
mysqld.cancelWaitCmd = nil
}
mysqld.mutex.Unlock()
// possibly mysql is already shutdown, check for a few files first
_, socketPathErr := os.Stat(mysqld.config.SocketFile)
_, pidPathErr := os.Stat(mysqld.config.PidFile)
if socketPathErr != nil && pidPathErr != nil {
log.Warningf("assuming mysqld already shut down - no socket, no pid file found")
return nil
}
// try the mysqld shutdown hook, if any
h := hook.NewSimpleHook("mysqld_shutdown")
hr := h.Execute()
switch hr.ExitStatus {
case hook.HOOK_SUCCESS:
// hook exists and worked, we can keep going
case hook.HOOK_DOES_NOT_EXIST:
// hook doesn't exist, try mysqladmin
log.Infof("No mysqld_shutdown hook, running mysqladmin directly")
dir, err := vtenv.VtMysqlRoot()
if err != nil {
return err
}
name := path.Join(dir, "bin/mysqladmin")
arg := []string{
"-u", "vt_dba", "-S", mysqld.config.SocketFile,
"shutdown"}
env := []string{
os.ExpandEnv("LD_LIBRARY_PATH=$VT_MYSQL_ROOT/lib/mysql"),
}
_, err = execCmd(name, arg, env, dir)
if err != nil {
return err
}
default:
// hook failed, we report error
return fmt.Errorf("mysqld_shutdown hook failed: %v", hr.String())
}
// wait for mysqld to really stop. use the sock file as a proxy for that since
// we can't call wait() in a process we didn't start.
if waitForMysqld {
for i := mysqlWaitTime; i >= 0; i -= time.Second {
_, statErr := os.Stat(mysqld.config.SocketFile)
if statErr != nil && os.IsNotExist(statErr) {
return nil
}
log.Infof("Mysqld.Shutdown: sleeping for 1s waiting for socket file %v", mysqld.config.SocketFile)
time.Sleep(time.Second)
}
return errors.New("gave up waiting for mysqld to stop")
}
return nil
}
// ChangeType changes the type of the tablet and possibly also updates
// the health informaton for it. Make this external, since these
// transitions need to be forced from time to time.
//
// - if health is nil, we don't touch the Tablet's Health record.
// - if health is an empty map, we clear the Tablet's Health record.
// - if health has values, we overwrite the Tablet's Health record.
func ChangeType(ts topo.Server, tabletAlias topo.TabletAlias, newType topo.TabletType, health map[string]string, runHooks bool) error {
tablet, err := ts.GetTablet(tabletAlias)
if err != nil {
return err
}
if !topo.IsTrivialTypeChange(tablet.Type, newType) || !topo.IsValidTypeChange(tablet.Type, newType) {
return fmt.Errorf("cannot change tablet type %v -> %v %v", tablet.Type, newType, tabletAlias)
}
if runHooks {
// Only run the preflight_serving_type hook when
// transitioning from non-serving to serving.
if !topo.IsInServingGraph(tablet.Type) && topo.IsInServingGraph(newType) {
if err := hook.NewSimpleHook("preflight_serving_type").ExecuteOptional(); err != nil {
return err
}
}
}
tablet.Type = newType
if newType == topo.TYPE_IDLE {
if tablet.Parent.IsZero() {
si, err := ts.GetShard(tablet.Keyspace, tablet.Shard)
if err != nil {
return err
}
rec := concurrency.AllErrorRecorder{}
wg := sync.WaitGroup{}
for _, cell := range si.Cells {
wg.Add(1)
go func(cell string) {
defer wg.Done()
sri, err := ts.GetShardReplication(cell, tablet.Keyspace, tablet.Shard)
if err != nil {
log.Warningf("Cannot check cell %v for extra replication paths, assuming it's good", cell)
return
}
for _, rl := range sri.ReplicationLinks {
if rl.Parent == tabletAlias {
rec.RecordError(fmt.Errorf("Still have a ReplicationLink in cell %v", cell))
}
}
}(cell)
}
wg.Wait()
if rec.HasErrors() {
return rec.Error()
}
}
tablet.Parent = topo.TabletAlias{}
tablet.Keyspace = ""
tablet.Shard = ""
tablet.KeyRange = key.KeyRange{}
tablet.Health = health
}
if health != nil {
if len(health) == 0 {
tablet.Health = nil
} else {
tablet.Health = health
}
}
return topo.UpdateTablet(context.TODO(), ts, tablet)
}
