// UpdateEndPoints is part of the topo.Server interface
func (zkts *Server) UpdateEndPoints(ctx context.Context, cell, keyspace, shard string, tabletType topodatapb.TabletType, addrs *topodatapb.EndPoints, existingVersion int64) error {
path := zkPathForVtName(cell, keyspace, shard, tabletType)
data, err := json.MarshalIndent(addrs, "", " ")
if err != nil {
return err
}
if existingVersion == -1 {
// Update or create unconditionally.
_, err := zk.CreateRecursive(zkts.zconn, path, string(data), 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
// Node already exists - just stomp away. Multiple writers shouldn't be here.
// We use RetryChange here because it won't update the node unnecessarily.
f := func(oldValue string, oldStat zk.Stat) (string, error) {
return string(data), nil
}
err = zkts.zconn.RetryChange(path, 0, zookeeper.WorldACL(zookeeper.PERM_ALL), f)
}
}
return err
}
// Compare And Set
if _, err = zkts.zconn.Set(path, string(data), int(existingVersion)); err != nil {
if zookeeper.IsError(err, zookeeper.ZBADVERSION) {
err = topo.ErrBadVersion
} else if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
}
return err
}
// Create implements Conn.
func (conn *MetaConn) Create(path, value string, flags int, aclv []zookeeper.ACL) (pathCreated string, err error) {
var zconn Conn
for i := 0; i < maxAttempts; i++ {
zconn, err = conn.connCache.ConnForPath(path)
if err != nil {
return
}
path = resolveZkPath(path)
pathCreated, err = zconn.Create(path, value, flags, aclv)
if err != nil && zookeeper.IsError(err, zookeeper.ZNONODE) {
parts := strings.Split(path, "/")
if len(parts) == 3 && parts[0] == "" && parts[1] == MagicPrefix {
// We were asked to create a /zk/<cell> path, but /zk doesn't exist.
// We should create /zk automatically in this case, because it's
// impossible to create /zk via MetaConn, since there's no cell name.
_, err = zconn.Create("/"+MagicPrefix, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if shouldRetry(err) {
continue
}
if !zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
return "", err
}
}
// Now try the original path again.
pathCreated, err = zconn.Create(path, value, flags, aclv)
}
}
if !shouldRetry(err) {
return
}
}
return
}
func (conn *zconn) RetryChange(path string, flags int, acl []zookeeper.ACL, changeFunc zk.ChangeFunc) error {
for {
oldValue, oldStat, err := conn.Get(path)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return err
}
newValue, err := changeFunc(oldValue, oldStat)
if err != nil {
return err
}
if oldStat == nil {
_, err := conn.Create(path, newValue, flags, acl)
if err == nil || !zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
return err
}
continue
}
if newValue == oldValue {
return nil // Nothing to do.
}
_, err = conn.Set(path, newValue, oldStat.Version())
if err == nil || !zookeeper.IsError(err, zookeeper.ZBADVERSION) && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return err
}
}
}
func DeleteRecursive(zconn Conn, zkPath string, version int) error {
// version: -1 delete any version of the node at path - only applies to the top node
err := zconn.Delete(zkPath, version)
if err == nil {
return nil
}
if !zookeeper.IsError(err, zookeeper.ZNOTEMPTY) {
return err
}
// Remove the ability for other nodes to get created while we are trying to delete.
// Otherwise, you can enter a race condition, or get starved out from deleting.
err = zconn.SetACL(zkPath, zookeeper.WorldACL(zookeeper.PERM_ADMIN|zookeeper.PERM_DELETE|zookeeper.PERM_READ), version)
if err != nil {
return err
}
children, _, err := zconn.Children(zkPath)
if err != nil {
return err
}
for _, child := range children {
err := DeleteRecursive(zconn, path.Join(zkPath, child), -1)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return fmt.Errorf("zkutil: recursive delete failed: %v", err)
}
}
err = zconn.Delete(zkPath, version)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNOTEMPTY) {
err = fmt.Errorf("zkutil: nodes getting recreated underneath delete (app race condition): %v", zkPath)
}
return err
}
func (zkts *Server) UpdateKeyspace(ki *topo.KeyspaceInfo) error {
keyspacePath := path.Join(globalKeyspacesPath, ki.KeyspaceName())
data := jscfg.ToJson(ki.Keyspace)
_, err := zkts.zconn.Set(keyspacePath, data, -1)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
// The code should be:
// err = topo.ErrNoNode
// Temporary code until we have Keyspace object
// everywhere:
_, err = zkts.zconn.Create(keyspacePath, data, 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
// the directory doesn't even exist
err = topo.ErrNoNode
}
return err
}
event.Dispatch(&events.KeyspaceChange{
KeyspaceInfo: *ki,
Status: "updated (had to create Keyspace object)",
})
return nil
}
return err
}
event.Dispatch(&events.KeyspaceChange{
KeyspaceInfo: *ki,
Status: "updated",
})
return nil
}
// Create the persistence node in zookeeper
func (zk *ZK) Create(path string, node string) error {
// create zk root path
tpath := ""
for _, str := range strings.Split(path, "/")[1:] {
tpath += "/" + str
Log.Debug("create zookeeper path:%s", tpath)
_, err := zk.conn.Create(tpath, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
Log.Warn("zk.Create(\"%s\") exists", tpath)
} else {
Log.Error("zk.Create(\"%s\") failed (%s)", tpath, err.Error())
return err
}
}
}
// create node path
fpath := path + "/" + node
Log.Debug("create zookeeper path:%s", fpath)
_, err := zk.conn.Create(fpath, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
Log.Warn("zk.Create(\"%s\") exists", fpath)
} else {
Log.Error("zk.Create(\"%s\") failed (%s)", fpath, err.Error())
return err
}
}
return nil
}
// PurgeActions removes all queued actions, leaving the action node
// itself in place.
//
// This inherently breaks the locking mechanism of the action queue,
// so this is a rare cleanup action, not a normal part of the flow.
//
// This can be used for tablets, shards and keyspaces.
func (zkts *Server) PurgeActions(zkActionPath string, canBePurged func(data string) bool) error {
if path.Base(zkActionPath) != "action" {
return fmt.Errorf("not action path: %v", zkActionPath)
}
children, _, err := zkts.zconn.Children(zkActionPath)
if err != nil {
return err
}
sort.Strings(children)
// Purge newer items first so the action queues don't try to process something.
for i := len(children) - 1; i >= 0; i-- {
actionPath := path.Join(zkActionPath, children[i])
data, _, err := zkts.zconn.Get(actionPath)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return fmt.Errorf("PurgeActions(%v) err: %v", zkActionPath, err)
}
if !canBePurged(data) {
continue
}
err = zk.DeleteRecursive(zkts.zconn, actionPath, -1)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return fmt.Errorf("PurgeActions(%v) err: %v", zkActionPath, err)
}
}
return nil
}
// Create the persistence node in zookeeper
func (zk *ZK) create() error {
// create zk root path
tpath := ""
for _, str := range strings.Split(Conf.ZookeeperPath, "/")[1:] {
tpath += "/" + str
Log.Debug("create zookeeper path:%s", tpath)
_, err := zk.conn.Create(tpath, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
Log.Warn("zk.create(\"%s\") exists", tpath)
} else {
Log.Error("zk.create(\"%s\") error(%v)", tpath, err)
return err
}
}
}
// create node path
fpath := fmt.Sprintf("%s/%s", Conf.ZookeeperPath, Conf.ZookeeperNode)
Log.Debug("create zookeeper path:%s", fpath)
_, err := zk.conn.Create(fpath, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
Log.Warn("zk.Create(\"%s\") exists", fpath)
} else {
Log.Error("zk.Create(\"%s\") error(%v)", fpath, err)
return err
}
}
return nil
}
// return a few values that need to be refreshed
func (zkc *ZkCache) refreshSomeValues(zconn zk.Conn, maxToRefresh int) {
// build a list of a few values we want to refresh
refreshThreshold := time.Now().Add(-10 * time.Minute)
// range will randomize the traversal order, so we will not always try
// the same entries in the same order
dataEntries := make([]*zkCacheEntry, 0, maxToRefresh)
childrenEntries := make([]*zkCacheEntry, 0, maxToRefresh)
zkc.mutex.Lock()
for _, entry := range zkc.Cache {
shouldBeDataRefreshed, shouldBeChildrenRefreshed := entry.checkForRefresh(refreshThreshold)
if shouldBeDataRefreshed {
dataEntries = append(dataEntries, entry)
}
if shouldBeChildrenRefreshed {
childrenEntries = append(childrenEntries, entry)
}
// check if we have enough work to do
if len(dataEntries) == maxToRefresh || len(childrenEntries) == maxToRefresh {
break
}
}
zkc.mutex.Unlock()
// now refresh the values
for _, entry := range dataEntries {
data, stat, watch, err := zconn.GetW(entry.node.Path)
if err == nil {
zkStat := &zk.ZkStat{}
zkStat.FromZookeeperStat(stat)
entry.updateData(data, zkStat, watch)
} else if zookeeper.IsError(err, zookeeper.ZCLOSING) {
// connection is closing, no point in asking for more
relog.Warning("failed to refresh cache: %v (and stopping refresh)", err.Error())
return
} else {
// individual failure
relog.Warning("failed to refresh cache: %v", err.Error())
}
}
for _, entry := range childrenEntries {
children, stat, watch, err := zconn.ChildrenW(entry.node.Path)
if err == nil {
zkStat := &zk.ZkStat{}
zkStat.FromZookeeperStat(stat)
entry.updateChildren(children, zkStat, watch)
} else if zookeeper.IsError(err, zookeeper.ZCLOSING) {
// connection is closing, no point in asking for more
relog.Warning("failed to refresh cache: %v (and stopping refresh)", err.Error())
return
} else {
// individual failure
relog.Warning("failed to refresh cache: %v", err.Error())
}
}
}
func (zkd *Zkd) init(preserveData bool) error {
log.Infof("zkd.Init")
for _, path := range zkd.config.DirectoryList() {
if err := os.MkdirAll(path, 0775); err != nil {
log.Errorf(err.Error())
return err
}
// FIXME(msolomon) validate permissions?
}
configData, err := zkd.makeCfg()
if err == nil {
err = ioutil.WriteFile(zkd.config.ConfigFile(), []byte(configData), 0664)
}
if err != nil {
log.Errorf("failed creating %v: %v", zkd.config.ConfigFile(), err)
return err
}
err = zkd.config.WriteMyid()
if err != nil {
log.Errorf("failed creating %v: %v", zkd.config.MyidFile(), err)
return err
}
if err = zkd.Start(); err != nil {
log.Errorf("failed starting, check %v", zkd.config.LogDir())
return err
}
zkAddr := fmt.Sprintf("localhost:%v", zkd.config.ClientPort)
zk, session, err := zookeeper.Dial(zkAddr, StartWaitTime*time.Second)
if err != nil {
return err
}
event := <-session
if event.State != zookeeper.STATE_CONNECTED {
return err
}
defer zk.Close()
if !preserveData {
_, err = zk.Create("/zk", "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil && !zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
return err
}
if zkd.config.Global {
_, err = zk.Create("/zk/global", "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil && !zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
return err
}
}
}
return nil
}
// DeleteEndPoints is part of the topo.Server interface
func (zkts *Server) DeleteEndPoints(ctx context.Context, cell, keyspace, shard string, tabletType topodatapb.TabletType, existingVersion int64) error {
path := zkPathForVtName(cell, keyspace, shard, tabletType)
if err := zkts.zconn.Delete(path, int(existingVersion)); err != nil {
switch {
case zookeeper.IsError(err, zookeeper.ZNONODE):
err = topo.ErrNoNode
case zookeeper.IsError(err, zookeeper.ZBADVERSION):
err = topo.ErrBadVersion
}
return err
}
return nil
}
func (zkts *Server) DeleteReplicationPath(keyspace, shard, repPath string) error {
replicationPath := path.Join(globalKeyspacesPath, keyspace, "shards", shard, repPath)
err := zkts.zconn.Delete(replicationPath, -1)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
} else if zookeeper.IsError(err, zookeeper.ZNOTEMPTY) {
err = topo.ErrNotEmpty
}
return err
}
return nil
}
func (entry *zkCacheEntry) checkForRefresh(refreshThreshold time.Time) (shouldBeDataRefreshed, shouldBeChildrenRefreshed bool) {
entry.mutex.Lock()
defer entry.mutex.Unlock()
if entry.dataTime.IsZero() {
// the entry was never set
// if we had an error getting it, it means we asked for it,
// see if we can get a good value
if entry.dataError != nil {
if zookeeper.IsError(entry.dataError, zookeeper.ZNONODE) {
// we had no node, we can try next time a client asks
entry.dataError = nil
// at this point, we have both
// dataTime.IsZero() and
// entry.dataError = nil, as if we
// never asked for it
} else {
// we had a valid error, let's try again
shouldBeDataRefreshed = true
}
}
} else {
// 1. we got a value at some point, then it got stale
// 2. we got a value a long time ago, refresh it
shouldBeDataRefreshed = entry.dataError != nil || entry.dataTime.Before(refreshThreshold)
}
if entry.childrenTime.IsZero() {
// the entry was never set
// if we had an error getting it, it means we asked for it,
// see if we can get a good value
if entry.childrenError != nil {
if zookeeper.IsError(entry.childrenError, zookeeper.ZNONODE) {
// we had no node, we can try next time a client asks
entry.childrenError = nil
// at this point, we have both
// childrenTime.IsZero() and
// entry.childrenError = nil, as if we
// never asked for it
} else {
shouldBeChildrenRefreshed = true
// we had a valid error, let's try again
}
}
} else {
// 1. we got a value at some point, then it got stale
// 2. we got a value a long time ago, refresh it
shouldBeChildrenRefreshed = entry.childrenError != nil || entry.childrenTime.Before(refreshThreshold)
}
return
}
func (zkts *Server) UpdateTablet(tablet *topo.TabletInfo, existingVersion int) (int, error) {
zkTabletPath := TabletPathForAlias(tablet.Alias())
stat, err := zkts.zconn.Set(zkTabletPath, tablet.Json(), existingVersion)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZBADVERSION) {
err = topo.ErrBadVersion
} else if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return 0, err
}
return stat.Version(), nil
}
// StaleActions returns a list of queued actions that have been
// sitting for more than some amount of time.
func (zkts *Server) StaleActions(zkActionPath string, maxStaleness time.Duration, isStale func(data string) bool) ([]string, error) {
if path.Base(zkActionPath) != "action" {
return nil, fmt.Errorf("not action path: %v", zkActionPath)
}
children, _, err := zkts.zconn.Children(zkActionPath)
if err != nil {
return nil, err
}
staleActions := make([]string, 0, 16)
// Purge newer items first so the action queues don't try to process something.
sort.Strings(children)
for i := 0; i < len(children); i++ {
actionPath := path.Join(zkActionPath, children[i])
data, stat, err := zkts.zconn.Get(actionPath)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return nil, fmt.Errorf("stale action err: %v", err)
}
if stat == nil || time.Since(stat.MTime()) <= maxStaleness {
continue
}
if isStale(data) {
staleActions = append(staleActions, data)
}
}
return staleActions, nil
}
func (zkts *Server) CreateKeyspace(keyspace string) error {
keyspacePath := path.Join(globalKeyspacesPath, keyspace)
pathList := []string{
keyspacePath,
path.Join(keyspacePath, "action"),
path.Join(keyspacePath, "actionlog"),
path.Join(keyspacePath, "shards"),
}
alreadyExists := false
for _, zkPath := range pathList {
_, err := zk.CreateRecursive(zkts.zconn, zkPath, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
alreadyExists = true
} else {
return fmt.Errorf("error creating keyspace: %v %v", zkPath, err)
}
}
}
if alreadyExists {
return topo.ErrNodeExists
}
return nil
}
// DeleteKeyspaceShards is part of the topo.Server interface
func (zkts *Server) DeleteKeyspaceShards(ctx context.Context, keyspace string) error {
shardsPath := path.Join(globalKeyspacesPath, keyspace, "shards")
if err := zk.DeleteRecursive(zkts.zconn, shardsPath, -1); err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
return err
}
return nil
}
func (zkts *Server) UpdateTabletFields(tabletAlias topo.TabletAlias, update func(*topo.Tablet) error) error {
zkTabletPath := TabletPathForAlias(tabletAlias)
f := func(oldValue string, oldStat zk.Stat) (string, error) {
if oldValue == "" {
return "", fmt.Errorf("no data for tablet addr update: %v", tabletAlias)
}
tablet, err := topo.TabletFromJson(oldValue)
if err != nil {
return "", err
}
if err := update(tablet); err != nil {
return "", err
}
return jscfg.ToJson(tablet), nil
}
err := zkts.zconn.RetryChange(zkTabletPath, 0, zookeeper.WorldACL(zookeeper.PERM_ALL), f)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return err
}
return nil
}
// DeleteTablet is part of the topo.Server interface
func (zkts *Server) DeleteTablet(ctx context.Context, alias topo.TabletAlias) error {
// We need to find out the keyspace and shard names because
// those are required in the TabletChange event.
ti, tiErr := zkts.GetTablet(ctx, alias)
zkTabletPath := TabletPathForAlias(alias)
err := zk.DeleteRecursive(zkts.zconn, zkTabletPath, -1)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return err
}
// Only try to log if we have the required information.
if tiErr == nil {
// We only want to copy the identity info for the tablet (alias, etc.).
// The rest has just been deleted, so it should be blank.
event.Dispatch(&events.TabletChange{
Tablet: topo.Tablet{
Alias: ti.Tablet.Alias,
Keyspace: ti.Tablet.Keyspace,
Shard: ti.Tablet.Shard,
},
Status: "deleted",
})
}
return nil
}
func getActions(wr *wrangler.Wrangler, zconn zk.Conn, actionPath string) ([]*actionnode.ActionNode, error) {
actions, _, err := zconn.Children(actionPath)
if err != nil {
return nil, fmt.Errorf("getActions failed: %v %v", actionPath, err)
}
sort.Strings(actions)
wg := sync.WaitGroup{}
mu := sync.Mutex{}
nodes := make([]*actionnode.ActionNode, 0, len(actions))
for _, action := range actions {
wg.Add(1)
go func(action string) {
defer wg.Done()
actionNodePath := path.Join(actionPath, action)
data, _, err := zconn.Get(actionNodePath)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
wr.Logger().Warningf("getActions: %v %v", actionNodePath, err)
return
}
actionNode, err := actionnode.ActionNodeFromJson(data, actionNodePath)
if err != nil {
wr.Logger().Warningf("getActions: %v %v", actionNodePath, err)
return
}
mu.Lock()
nodes = append(nodes, actionNode)
mu.Unlock()
}(action)
}
wg.Wait()
return nodes, nil
}
// Create a path and any pieces required, think mkdir -p.
// Intermediate znodes are always created empty.
func CreateRecursive(zconn Conn, zkPath, value string, flags int, aclv []zookeeper.ACL) (pathCreated string, err error) {
parts := strings.Split(zkPath, "/")
if parts[1] != "zk" {
return "", fmt.Errorf("zkutil: non zk path: %v", zkPath)
}
pathCreated, err = zconn.Create(zkPath, value, flags, aclv)
if zookeeper.IsError(err, zookeeper.ZNONODE) {
_, err = CreateRecursive(zconn, path.Dir(zkPath), "", flags, aclv)
if err != nil && !zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
return "", err
}
pathCreated, err = zconn.Create(zkPath, value, flags, aclv)
}
return
}
func (zkts *Server) CreateKeyspace(keyspace string, value *topo.Keyspace) error {
keyspacePath := path.Join(globalKeyspacesPath, keyspace)
pathList := []string{
keyspacePath,
path.Join(keyspacePath, "action"),
path.Join(keyspacePath, "actionlog"),
path.Join(keyspacePath, "shards"),
}
alreadyExists := false
for i, zkPath := range pathList {
c := ""
if i == 0 {
c = jscfg.ToJson(value)
}
_, err := zk.CreateRecursive(zkts.zconn, zkPath, c, 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
alreadyExists = true
} else {
return fmt.Errorf("error creating keyspace: %v %v", zkPath, err)
}
}
}
if alreadyExists {
return topo.ErrNodeExists
}
event.Dispatch(&events.KeyspaceChange{
KeyspaceInfo: *topo.NewKeyspaceInfo(keyspace, value),
Status: "created",
})
return nil
}
// UpdateTabletFields is part of the topo.Server interface
func (zkts *Server) UpdateTabletFields(ctx context.Context, tabletAlias *topodatapb.TabletAlias, update func(*topodatapb.Tablet) error) (*topodatapb.Tablet, error) {
// Store the last tablet value so we can log it if the change succeeds.
var lastTablet *topodatapb.Tablet
zkTabletPath := TabletPathForAlias(tabletAlias)
f := func(oldValue string, oldStat zk.Stat) (string, error) {
if oldValue == "" {
return "", fmt.Errorf("no data for tablet addr update: %v", tabletAlias)
}
tablet := &topodatapb.Tablet{}
if err := json.Unmarshal([]byte(oldValue), tablet); err != nil {
return "", err
}
if err := update(tablet); err != nil {
return "", err
}
lastTablet = tablet
data, err := json.MarshalIndent(tablet, "", " ")
if err != nil {
return "", err
}
return string(data), nil
}
err := zkts.zconn.RetryChange(zkTabletPath, 0, zookeeper.WorldACL(zookeeper.PERM_ALL), f)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return nil, err
}
return lastTablet, nil
}
// NewConnFromFile returns a fake zk.Conn implementation, that is seeded
// with the json data extracted from the input file.
func NewConnFromFile(filename string) zk.Conn {
result := &zconn{
root: &node{
_stat: _stat{name: "/"},
children: make(map[string]*node),
},
existWatches: make(map[string][]chan zookeeper.Event)}
data, err := ioutil.ReadFile(filename)
if err != nil {
panic(fmt.Errorf("NewConnFromFile failed to read file %v: %v", filename, err))
}
values := make(map[string]interface{})
if err := json.Unmarshal(data, &values); err != nil {
panic(fmt.Errorf("NewConnFromFile failed to json.Unmarshal file %v: %v", filename, err))
}
for k, v := range values {
jv, err := json.Marshal(v)
if err != nil {
panic(fmt.Errorf("NewConnFromFile failed to json.Marshal value %v: %v", k, err))
}
// CreateRecursive will work for a leaf node where the parent
// doesn't exist, but not for a node in the middle of a tree
// that already exists. So have to use 'Set' as a backup.
if _, err := zk.CreateRecursive(result, k, string(jv), 0, nil); err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
_, err = result.Set(k, string(jv), -1)
}
if err != nil {
panic(fmt.Errorf("NewConnFromFile failed to zk.CreateRecursive value %v: %v", k, err))
}
}
}
return result
}
// CreateShard is part of the topo.Server interface
func (zkts *Server) CreateShard(ctx context.Context, keyspace, shard string, value *topodatapb.Shard) error {
shardPath := path.Join(globalKeyspacesPath, keyspace, "shards", shard)
pathList := []string{
shardPath,
path.Join(shardPath, "action"),
path.Join(shardPath, "actionlog"),
}
data, err := json.MarshalIndent(value, "", " ")
if err != nil {
return err
}
alreadyExists := false
for i, zkPath := range pathList {
c := ""
if i == 0 {
c = string(data)
}
_, err := zk.CreateRecursive(zkts.zconn, zkPath, c, 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
alreadyExists = true
} else {
return fmt.Errorf("error creating shard: %v %v", zkPath, err)
}
}
}
if alreadyExists {
return topo.ErrNodeExists
}
return nil
}
func cmdWait(args []string) {
if len(args) != 1 {
log.Fatalf("wait: can only wait for one path")
}
zkPath := args[0]
isDir := zkPath[len(zkPath)-1] == '/'
zkPath = fixZkPath(zkPath)
var wait <-chan zookeeper.Event
var err error
if isDir {
_, _, wait, err = zconn.ChildrenW(zkPath)
} else {
_, _, wait, err = zconn.GetW(zkPath)
}
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
_, wait, err = zconn.ExistsW(zkPath)
} else {
log.Fatalf("wait: error %v: %v", zkPath, err)
}
} else {
if *exitIfExists {
fmt.Printf("already exists: %v\n", zkPath)
return
}
}
event := <-wait
fmt.Printf("event: %v\n", event)
}
// PubMIDLock public message mid lock, make sure that get the unique mid
func PubMIDLock() (bool, string, error) {
prefix := "p"
splitSign := "@"
pathCreated, err := zk.Create(fmt.Sprintf("%s/%s%s", Conf.ZKPIDPath, prefix, splitSign),
"0", zookeeper.EPHEMERAL|zookeeper.SEQUENCE, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
return false, pathCreated, fmt.Errorf("zk.Create(%s/%s%s) error(%v)", Conf.ZKPIDPath, prefix, splitSign, err)
}
for {
childrens, stat, err := zk.Children(Conf.ZKPIDPath)
if err != nil {
return false, pathCreated, fmt.Errorf("zk.Children(%s) error(%v)", Conf.ZKPIDPath, err)
}
// If node isn`t exist
if childrens == nil || stat == nil {
return false, pathCreated, fmt.Errorf("node(%s) is not existent", Conf.ZKPIDPath)
}
var realQueue []string
for _, children := range childrens {
tmp := strings.Split(children, splitSign)
if prefix == tmp[0] {
realQueue = append(realQueue, children)
}
}
// Sort sequence nodes
sort.Strings(realQueue)
tmp := strings.Split(pathCreated, "/")
posReal := sort.StringSlice(realQueue).Search(tmp[len(tmp)-1])
// If does not get lock
if posReal > 0 {
// Watch the last one
watchPath := fmt.Sprintf("%s/%s", Conf.ZKPIDPath, realQueue[posReal-1])
_, watch, err := zk.ExistsW(watchPath)
if err != nil || zookeeper.IsError(err, zookeeper.ZNONODE) {
return false, pathCreated, fmt.Errorf("zk.ExistsW(%s) error(%v) or no node", watchPath, err)
}
// Watch the lower node
watchNode := <-watch
switch watchNode.Type {
case zookeeper.EVENT_DELETED:
default:
return false, pathCreated, fmt.Errorf("zookeeper watch errCode:%d", watchNode.Type)
}
return false, pathCreated, nil
} else {
return true, pathCreated, nil
}
}
// Never get here
return false, pathCreated, fmt.Errorf("never get here")
}
func (zkts *Server) CreateTablet(tablet *topo.Tablet) error {
zkTabletPath := TabletPathForAlias(tablet.Alias())
// Create /zk/<cell>/vt/tablets/<uid>
_, err := zk.CreateRecursive(zkts.zconn, zkTabletPath, tablet.Json(), 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
err = topo.ErrNodeExists
}
return err
}
// Create /zk/<cell>/vt/tablets/<uid>/action
tap := path.Join(zkTabletPath, "action")
_, err = zkts.zconn.Create(tap, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
return err
}
// Create /zk/<cell>/vt/tablets/<uid>/actionlog
talp := path.Join(zkTabletPath, "actionlog")
_, err = zkts.zconn.Create(talp, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
return err
}
return nil
}
// CreateShard is part of the topo.Server interface
func (zkts *Server) CreateShard(ctx context.Context, keyspace, shard string, value *pb.Shard) error {
shardPath := path.Join(globalKeyspacesPath, keyspace, "shards", shard)
pathList := []string{
shardPath,
path.Join(shardPath, "action"),
path.Join(shardPath, "actionlog"),
}
alreadyExists := false
for i, zkPath := range pathList {
c := ""
if i == 0 {
c = jscfg.ToJSON(value)
}
_, err := zk.CreateRecursive(zkts.zconn, zkPath, c, 0, zookeeper.WorldACL(zookeeper.PERM_ALL))
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
alreadyExists = true
} else {
return fmt.Errorf("error creating shard: %v %v", zkPath, err)
}
}
}
if alreadyExists {
return topo.ErrNodeExists
}
event.Dispatch(&events.ShardChange{
ShardInfo: *topo.NewShardInfo(keyspace, shard, value, -1),
Status: "created",
})
return nil
}
// UpdateShardReplicationFields is part of the topo.Server interface
func (zkts *Server) UpdateShardReplicationFields(ctx context.Context, cell, keyspace, shard string, update func(*pb.ShardReplication) error) error {
// create the parent directory to be sure it's here
zkDir := path.Join("/zk", cell, "vt", "replication", keyspace)
if _, err := zk.CreateRecursive(zkts.zconn, zkDir, "", 0, zookeeper.WorldACL(zookeeper.PERM_ALL)); err != nil && !zookeeper.IsError(err, zookeeper.ZNODEEXISTS) {
return err
}
// now update the data
zkPath := shardReplicationPath(cell, keyspace, shard)
f := func(oldValue string, oldStat zk.Stat) (string, error) {
sr := &pb.ShardReplication{}
if oldValue != "" {
if err := json.Unmarshal([]byte(oldValue), sr); err != nil {
return "", err
}
}
if err := update(sr); err != nil {
return "", err
}
data, err := json.MarshalIndent(sr, "", " ")
if err != nil {
return "", err
}
return string(data), nil
}
err := zkts.zconn.RetryChange(zkPath, 0, zookeeper.WorldACL(zookeeper.PERM_ALL), f)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return err
}
return nil
}
