forked from vitessio/vitess
/
replication_graph.go
112 lines (97 loc) · 3.25 KB
/
replication_graph.go
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// Copyright 2013, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package zktopo
import (
"encoding/json"
"fmt"
"path"
"github.com/youtube/vitess/go/vt/topo"
"github.com/youtube/vitess/go/zk"
"golang.org/x/net/context"
"launchpad.net/gozk/zookeeper"
pb "github.com/youtube/vitess/go/vt/proto/topodata"
)
/*
This file contains the replication graph management code for zktopo.Server
*/
func keyspaceReplicationPath(cell, keyspace string) string {
return path.Join("/zk", cell, "vt", "replication", keyspace)
}
func shardReplicationPath(cell, keyspace, shard string) string {
return path.Join("/zk", cell, "vt", "replication", keyspace, shard)
}
// 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
}
// GetShardReplication is part of the topo.Server interface
func (zkts *Server) GetShardReplication(ctx context.Context, cell, keyspace, shard string) (*topo.ShardReplicationInfo, error) {
zkPath := shardReplicationPath(cell, keyspace, shard)
data, _, err := zkts.zconn.Get(zkPath)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return nil, err
}
sr := &pb.ShardReplication{}
if err = json.Unmarshal([]byte(data), sr); err != nil {
return nil, fmt.Errorf("bad ShardReplication data %v", err)
}
return topo.NewShardReplicationInfo(sr, cell, keyspace, shard), nil
}
// DeleteShardReplication is part of the topo.Server interface
func (zkts *Server) DeleteShardReplication(ctx context.Context, cell, keyspace, shard string) error {
zkPath := shardReplicationPath(cell, keyspace, shard)
err := zkts.zconn.Delete(zkPath, -1)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return err
}
return nil
}
// DeleteKeyspaceReplication is part of the topo.Server interface
func (zkts *Server) DeleteKeyspaceReplication(ctx context.Context, cell, keyspace string) error {
zkPath := keyspaceReplicationPath(cell, keyspace)
err := zkts.zconn.Delete(zkPath, -1)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return err
}
return nil
}