Ejemplo n.º 1
0
func TestQueryShard(t *testing.T) {
	reflected, err := bson.Marshal(&reflectQueryShard{
		Sql:           "query",
		BindVariables: map[string]interface{}{"val": int64(1)},
		Keyspace:      "keyspace",
		Shards:        []string{"shard1", "shard2"},
		TabletType:    topo.TabletType("replica"),
		Session:       &commonSession,
	})
	if err != nil {
		t.Error(err)
	}
	want := string(reflected)

	custom := QueryShard{
		Sql:           "query",
		BindVariables: map[string]interface{}{"val": int64(1)},
		Keyspace:      "keyspace",
		Shards:        []string{"shard1", "shard2"},
		TabletType:    topo.TabletType("replica"),
		Session:       &commonSession,
	}
	encoded, err := bson.Marshal(&custom)
	if err != nil {
		t.Error(err)
	}
	got := string(encoded)
	if want != got {
		t.Errorf("want\n%+v, got\n%+v", want, got)
	}

	var unmarshalled QueryShard
	err = bson.Unmarshal(encoded, &unmarshalled)
	if err != nil {
		t.Error(err)
	}
	if !reflect.DeepEqual(custom, unmarshalled) {
		t.Errorf("want \n%+v, got \n%+v", custom, unmarshalled)
	}

	extra, err := bson.Marshal(&extraQueryShard{})
	if err != nil {
		t.Error(err)
	}
	err = bson.Unmarshal(extra, &unmarshalled)
	if err != nil {
		t.Error(err)
	}
}
Ejemplo n.º 2
0
func TestSession(t *testing.T) {
	reflected, err := bson.Marshal(&reflectSession{
		InTransaction: true,
		ShardSessions: []*ShardSession{{
			Keyspace:      "a",
			Shard:         "0",
			TabletType:    topo.TabletType("replica"),
			TransactionId: 1,
		}, {
			Keyspace:      "b",
			Shard:         "1",
			TabletType:    topo.TabletType("master"),
			TransactionId: 2,
		}},
	})
	if err != nil {
		t.Error(err)
	}
	want := string(reflected)

	custom := commonSession
	encoded, err := bson.Marshal(&custom)
	if err != nil {
		t.Error(err)
	}
	got := string(encoded)
	if want != got {
		t.Errorf("want\n%+v, got\n%+v", want, got)
	}

	var unmarshalled Session
	err = bson.Unmarshal(encoded, &unmarshalled)
	if err != nil {
		t.Error(err)
	}
	if !reflect.DeepEqual(custom, unmarshalled) {
		t.Errorf("want \n%+v, got \n%+v", custom, unmarshalled)
	}

	extra, err := bson.Marshal(&extraSession{})
	if err != nil {
		t.Fatal(err)
	}
	err = bson.Unmarshal(extra, &unmarshalled)
	if err != nil {
		t.Error(err)
	}
}
Ejemplo n.º 3
0
func getSrvKeyspace(rpcClient *rpcplus.Client, cell, keyspace string, verbose bool) {
	req := &topo.GetSrvKeyspaceArgs{
		Cell:     cell,
		Keyspace: keyspace,
	}
	reply := &topo.SrvKeyspace{}
	if err := rpcClient.Call(context.TODO(), "TopoReader.GetSrvKeyspace", req, reply); err != nil {
		log.Fatalf("TopoReader.GetSrvKeyspace error: %v", err)
	}
	if verbose {
		tabletTypes := make([]string, 0, len(reply.Partitions))
		for t, _ := range reply.Partitions {
			tabletTypes = append(tabletTypes, string(t))
		}
		sort.Strings(tabletTypes)
		for _, t := range tabletTypes {
			println(fmt.Sprintf("Partitions[%v] =", t))
			for i, s := range reply.Partitions[topo.TabletType(t)].Shards {
				println(fmt.Sprintf("  Shards[%v]=%v", i, s.KeyRange.String()))
			}
		}
		for i, s := range reply.Shards {
			println(fmt.Sprintf("Shards[%v]=%v", i, s.KeyRange.String()))
		}
		for i, t := range reply.TabletTypes {
			println(fmt.Sprintf("TabletTypes[%v] = %v", i, t))
		}
	}
}
Ejemplo n.º 4
0
func (agent *ActionAgent) initHeathCheck() {
	if !agent.IsRunningHealthCheck() {
		log.Infof("No target_tablet_type specified, disabling any health check")
		return
	}

	log.Infof("Starting periodic health check every %v with target_tablet_type=%v", *healthCheckInterval, *targetTabletType)
	t := timer.NewTimer(*healthCheckInterval)
	servenv.OnTermSync(func() {
		// When we enter lameduck mode, we want to not call
		// the health check any more. After this returns, we
		// are guaranteed to not call it.
		log.Info("Stopping periodic health check timer")
		t.Stop()

		// Now we can finish up and force ourselves to not healthy.
		agent.terminateHealthChecks(topo.TabletType(*targetTabletType))
	})
	t.Start(func() {
		agent.runHealthCheck(topo.TabletType(*targetTabletType))
	})
}
Ejemplo n.º 5
0
func getEndPoints(rpcClient *rpcplus.Client, cell, keyspace, shard, tabletType string, verbose bool) {
	req := &topo.GetEndPointsArgs{
		Cell:       cell,
		Keyspace:   keyspace,
		Shard:      shard,
		TabletType: topo.TabletType(tabletType),
	}
	reply := &topo.EndPoints{}
	if err := rpcClient.Call(context.TODO(), "TopoReader.GetEndPoints", req, reply); err != nil {
		log.Fatalf("TopoReader.GetEndPoints error: %v", err)
	}
	if verbose {
		for i, e := range reply.Entries {
			println(fmt.Sprintf("Entries[%v] = %v %v", i, e.Uid, e.Host))
		}
	}
}
Ejemplo n.º 6
0
// for direct zk connection: vtzk://host:port/cell/keyspace/tabletType
// we always use a MetaConn, host and port are ignored.
// the driver name dictates if we use zk or zkocc, and streaming or not
func (driver *sDriver) Open(name string) (sc db.Conn, err error) {
	if !strings.HasPrefix(name, "vtzk://") {
		// add a default protocol talking to zk
		name = "vtzk://" + name
	}
	u, err := url.Parse(name)
	if err != nil {
		return nil, err
	}

	dbi, tabletType := path.Split(u.Path)
	dbi = strings.Trim(dbi, "/")
	tabletType = strings.Trim(tabletType, "/")
	cell, keyspace := path.Split(dbi)
	cell = strings.Trim(cell, "/")
	keyspace = strings.Trim(keyspace, "/")
	return Dial(driver.ts, cell, keyspace, topo.TabletType(tabletType), driver.stream, tablet.DefaultTimeout)
}
Ejemplo n.º 7
0
func (zkts *Server) GetSrvTabletTypesPerShard(cell, keyspace, shard string) ([]topo.TabletType, error) {
	zkSgShardPath := zkPathForVtShard(cell, keyspace, shard)
	children, _, err := zkts.zconn.Children(zkSgShardPath)
	if err != nil {
		if zookeeper.IsError(err, zookeeper.ZNONODE) {
			err = topo.ErrNoNode
		}
		return nil, err
	}
	result := make([]topo.TabletType, 0, len(children))
	for _, tt := range children {
		// these two are used for locking
		if tt == "action" || tt == "actionlog" {
			continue
		}
		result = append(result, topo.TabletType(tt))
	}
	return result, nil
}
Ejemplo n.º 8
0
func TestKeyspaceIdBatchQuery(t *testing.T) {
	reflected, err := bson.Marshal(&reflectKeyspaceIdBatchQuery{
		Queries: []reflectBoundQuery{{
			Sql:           "query",
			BindVariables: map[string]interface{}{"val": int64(1)},
		}},
		Keyspace:    "keyspace",
		KeyspaceIds: []kproto.KeyspaceId{kproto.KeyspaceId("10"), kproto.KeyspaceId("20")},
		Session: &Session{InTransaction: true,
			ShardSessions: []*ShardSession{{
				Keyspace:      "a",
				Shard:         "0",
				TabletType:    topo.TabletType("replica"),
				TransactionId: 1,
			}, {
				Keyspace:      "b",
				Shard:         "1",
				TabletType:    topo.TabletType("master"),
				TransactionId: 2,
			}},
		},
	})
	if err != nil {
		t.Error(err)
	}
	want := string(reflected)

	custom := KeyspaceIdBatchQuery{
		Queries: []tproto.BoundQuery{{
			Sql:           "query",
			BindVariables: map[string]interface{}{"val": int64(1)},
		}},
		Keyspace:    "keyspace",
		KeyspaceIds: []kproto.KeyspaceId{kproto.KeyspaceId("10"), kproto.KeyspaceId("20")},
		Session:     &commonSession,
	}
	encoded, err := bson.Marshal(&custom)
	if err != nil {
		t.Error(err)
	}
	got := string(encoded)
	if want != got {
		t.Errorf("want\n%+v, got\n%+v", want, got)
	}

	var unmarshalled KeyspaceIdBatchQuery
	err = bson.Unmarshal(encoded, &unmarshalled)
	if err != nil {
		t.Error(err)
	}
	if !reflect.DeepEqual(custom, unmarshalled) {
		t.Errorf("want \n%+v, got \n%+v", custom, unmarshalled)
	}

	extra, err := bson.Marshal(&extraKeyspaceIdBatchQuery{})
	if err != nil {
		t.Error(err)
	}
	err = bson.Unmarshal(extra, &unmarshalled)
	if err != nil {
		t.Error(err)
	}
}
Ejemplo n.º 9
0
	"testing"

	"github.com/henryanand/vitess/go/bson"
	mproto "github.com/henryanand/vitess/go/mysql/proto"
	"github.com/henryanand/vitess/go/sqltypes"
	kproto "github.com/henryanand/vitess/go/vt/key"
	tproto "github.com/henryanand/vitess/go/vt/tabletserver/proto"
	"github.com/henryanand/vitess/go/vt/topo"
)

var commonSession = Session{
	InTransaction: true,
	ShardSessions: []*ShardSession{{
		Keyspace:      "a",
		Shard:         "0",
		TabletType:    topo.TabletType("replica"),
		TransactionId: 1,
	}, {
		Keyspace:      "b",
		Shard:         "1",
		TabletType:    topo.TabletType("master"),
		TransactionId: 2,
	}},
}

type reflectSession struct {
	InTransaction bool
	ShardSessions []*ShardSession
}

type extraSession struct {
Ejemplo n.º 10
0
func (wr *Wrangler) exportVtnsToZkns(zconn zk.Conn, vtnsAddrPath, zknsAddrPath string) ([]string, error) {
	zknsPaths := make([]string, 0, 32)
	parts := strings.Split(vtnsAddrPath, "/")
	if len(parts) != 8 && len(parts) != 9 {
		return nil, fmt.Errorf("Invalid leaf zk path: %v", vtnsAddrPath)
	}
	cell := parts[2]
	keyspace := parts[5]
	shard := parts[6]
	tabletType := topo.TabletType(parts[7])
	if tabletType == "action" || tabletType == "actionlog" {
		return nil, nil
	}
	addrs, err := wr.ts.GetEndPoints(cell, keyspace, shard, tabletType)
	if err != nil {
		return nil, err
	}

	// Write the individual endpoints and compute the SRV entries.
	vtoccAddrs := LegacyZknsAddrs{make([]string, 0, 8)}
	defaultAddrs := LegacyZknsAddrs{make([]string, 0, 8)}
	for i, entry := range addrs.Entries {
		zknsAddrPath := fmt.Sprintf("%v/%v", zknsAddrPath, i)
		zknsPaths = append(zknsPaths, zknsAddrPath)
		zknsAddr := zkns.ZknsAddr{Host: entry.Host, Port: entry.NamedPortMap["_mysql"], NamedPortMap: entry.NamedPortMap}
		err := WriteAddr(zconn, zknsAddrPath, &zknsAddr)
		if err != nil {
			return nil, err
		}
		defaultAddrs.Endpoints = append(defaultAddrs.Endpoints, zknsAddrPath)
		vtoccAddrs.Endpoints = append(vtoccAddrs.Endpoints, zknsAddrPath+":_vtocc")
	}

	// Prune any zkns entries that are no longer referenced by the
	// shard graph.
	deleteIdx := len(addrs.Entries)
	for {
		zknsStaleAddrPath := fmt.Sprintf("%v/%v", zknsAddrPath, deleteIdx)
		// A "delete" is a write of sorts - just communicate up that nothing
		// needs to be done to this node.
		zknsPaths = append(zknsPaths, zknsStaleAddrPath)
		err := zconn.Delete(zknsStaleAddrPath, -1)
		if zookeeper.IsError(err, zookeeper.ZNONODE) {
			break
		}
		if err != nil {
			return nil, err
		}
		deleteIdx++
	}

	// Write the VDNS entries for both vtocc and mysql
	vtoccVdnsPath := fmt.Sprintf("%v/_vtocc.vdns", zknsAddrPath)
	zknsPaths = append(zknsPaths, vtoccVdnsPath)
	if err = WriteAddrs(zconn, vtoccVdnsPath, &vtoccAddrs); err != nil {
		return nil, err
	}

	defaultVdnsPath := fmt.Sprintf("%v.vdns", zknsAddrPath)
	zknsPaths = append(zknsPaths, defaultVdnsPath)
	if err = WriteAddrs(zconn, defaultVdnsPath, &defaultAddrs); err != nil {
		return nil, err
	}
	return zknsPaths, nil
}
Ejemplo n.º 11
0
func main() {
	flag.Parse()
	servenv.Init()
	defer servenv.Close()
	templateLoader = NewTemplateLoader(*templateDir, dummyTemplate, *debug)

	ts = topo.GetServer()
	defer topo.CloseServers()

	wr := wrangler.New(logutil.NewConsoleLogger(), ts, 30*time.Second, 30*time.Second)

	actionRepo = NewActionRepository(ts)

	// keyspace actions
	actionRepo.RegisterKeyspaceAction("ValidateKeyspace",
		func(wr *wrangler.Wrangler, keyspace string, r *http.Request) (string, error) {
			return "", wr.ValidateKeyspace(keyspace, false)
		})

	actionRepo.RegisterKeyspaceAction("ValidateSchemaKeyspace",
		func(wr *wrangler.Wrangler, keyspace string, r *http.Request) (string, error) {
			return "", wr.ValidateSchemaKeyspace(keyspace, nil, false)
		})

	actionRepo.RegisterKeyspaceAction("ValidateVersionKeyspace",
		func(wr *wrangler.Wrangler, keyspace string, r *http.Request) (string, error) {
			return "", wr.ValidateVersionKeyspace(keyspace)
		})

	actionRepo.RegisterKeyspaceAction("ValidatePermissionsKeyspace",
		func(wr *wrangler.Wrangler, keyspace string, r *http.Request) (string, error) {
			return "", wr.ValidatePermissionsKeyspace(keyspace)
		})

	// shard actions
	actionRepo.RegisterShardAction("ValidateShard",
		func(wr *wrangler.Wrangler, keyspace, shard string, r *http.Request) (string, error) {
			return "", wr.ValidateShard(keyspace, shard, false)
		})

	actionRepo.RegisterShardAction("ValidateSchemaShard",
		func(wr *wrangler.Wrangler, keyspace, shard string, r *http.Request) (string, error) {
			return "", wr.ValidateSchemaShard(keyspace, shard, nil, false)
		})

	actionRepo.RegisterShardAction("ValidateVersionShard",
		func(wr *wrangler.Wrangler, keyspace, shard string, r *http.Request) (string, error) {
			return "", wr.ValidateVersionShard(keyspace, shard)
		})

	actionRepo.RegisterShardAction("ValidatePermissionsShard",
		func(wr *wrangler.Wrangler, keyspace, shard string, r *http.Request) (string, error) {
			return "", wr.ValidatePermissionsShard(keyspace, shard)
		})

	// tablet actions
	actionRepo.RegisterTabletAction("Ping", "",
		func(wr *wrangler.Wrangler, tabletAlias topo.TabletAlias, r *http.Request) (string, error) {
			ti, err := wr.TopoServer().GetTablet(tabletAlias)
			if err != nil {
				return "", err
			}
			return "", wr.TabletManagerClient().Ping(wr.Context(), ti)
		})

	actionRepo.RegisterTabletAction("ScrapTablet", acl.ADMIN,
		func(wr *wrangler.Wrangler, tabletAlias topo.TabletAlias, r *http.Request) (string, error) {
			// refuse to scrap tablets that are not spare
			ti, err := wr.TopoServer().GetTablet(tabletAlias)
			if err != nil {
				return "", err
			}
			if ti.Type != topo.TYPE_SPARE {
				return "", fmt.Errorf("Can only scrap spare tablets")
			}
			return "", wr.Scrap(tabletAlias, false, false)
		})

	actionRepo.RegisterTabletAction("ScrapTabletForce", acl.ADMIN,
		func(wr *wrangler.Wrangler, tabletAlias topo.TabletAlias, r *http.Request) (string, error) {
			// refuse to scrap tablets that are not spare
			ti, err := wr.TopoServer().GetTablet(tabletAlias)
			if err != nil {
				return "", err
			}
			if ti.Type != topo.TYPE_SPARE {
				return "", fmt.Errorf("Can only scrap spare tablets")
			}
			return "", wr.Scrap(tabletAlias, true, false)
		})

	actionRepo.RegisterTabletAction("DeleteTablet", acl.ADMIN,
		func(wr *wrangler.Wrangler, tabletAlias topo.TabletAlias, r *http.Request) (string, error) {
			return "", wr.DeleteTablet(tabletAlias)
		})

	// toplevel index
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		templateLoader.ServeTemplate("index.html", indexContent, w, r)
	})

	// keyspace actions
	http.HandleFunc("/keyspace_actions", func(w http.ResponseWriter, r *http.Request) {
		if err := r.ParseForm(); err != nil {
			httpError(w, "cannot parse form: %s", err)
			return
		}
		action := r.FormValue("action")
		if action == "" {
			http.Error(w, "no action provided", http.StatusBadRequest)
			return
		}

		keyspace := r.FormValue("keyspace")
		if keyspace == "" {
			http.Error(w, "no keyspace provided", http.StatusBadRequest)
			return
		}
		result := actionRepo.ApplyKeyspaceAction(action, keyspace, r)

		templateLoader.ServeTemplate("action.html", result, w, r)
	})

	// shard actions
	http.HandleFunc("/shard_actions", func(w http.ResponseWriter, r *http.Request) {
		if err := r.ParseForm(); err != nil {
			httpError(w, "cannot parse form: %s", err)
			return
		}
		action := r.FormValue("action")
		if action == "" {
			http.Error(w, "no action provided", http.StatusBadRequest)
			return
		}

		keyspace := r.FormValue("keyspace")
		if keyspace == "" {
			http.Error(w, "no keyspace provided", http.StatusBadRequest)
			return
		}
		shard := r.FormValue("shard")
		if shard == "" {
			http.Error(w, "no shard provided", http.StatusBadRequest)
			return
		}
		result := actionRepo.ApplyShardAction(action, keyspace, shard, r)

		templateLoader.ServeTemplate("action.html", result, w, r)
	})

	// tablet actions
	http.HandleFunc("/tablet_actions", func(w http.ResponseWriter, r *http.Request) {
		if err := r.ParseForm(); err != nil {
			httpError(w, "cannot parse form: %s", err)
			return
		}
		action := r.FormValue("action")
		if action == "" {
			http.Error(w, "no action provided", http.StatusBadRequest)
			return
		}

		alias := r.FormValue("alias")
		if alias == "" {
			http.Error(w, "no alias provided", http.StatusBadRequest)
			return
		}
		tabletAlias, err := topo.ParseTabletAliasString(alias)
		if err != nil {
			http.Error(w, "bad alias provided", http.StatusBadRequest)
			return
		}
		result := actionRepo.ApplyTabletAction(action, tabletAlias, r)

		templateLoader.ServeTemplate("action.html", result, w, r)
	})

	// topology server
	http.HandleFunc("/dbtopo", func(w http.ResponseWriter, r *http.Request) {
		if err := r.ParseForm(); err != nil {
			httpError(w, "cannot parse form: %s", err)
			return
		}
		result := DbTopologyResult{}
		topology, err := topotools.DbTopology(context.TODO(), wr.TopoServer())
		if err != nil {
			result.Error = err.Error()
		} else {
			result.Topology = topology
		}
		templateLoader.ServeTemplate("dbtopo.html", result, w, r)
	})

	// serving graph
	http.HandleFunc("/serving_graph/", func(w http.ResponseWriter, r *http.Request) {
		parts := strings.Split(r.URL.Path, "/")

		cell := parts[len(parts)-1]
		if cell == "" {
			cells, err := ts.GetKnownCells()
			if err != nil {
				httpError(w, "cannot get known cells: %v", err)
				return
			} else {
				templateLoader.ServeTemplate("serving_graph_cells.html", cells, w, r)
			}
			return
		}

		servingGraph := topotools.DbServingGraph(wr.TopoServer(), cell)
		templateLoader.ServeTemplate("serving_graph.html", servingGraph, w, r)
	})

	// redirects for explorers
	http.HandleFunc("/explorers/redirect", func(w http.ResponseWriter, r *http.Request) {
		if err := r.ParseForm(); err != nil {
			httpError(w, "cannot parse form: %s", err)
			return
		}

		var explorer Explorer
		switch len(explorers) {
		case 0:
			http.Error(w, "no explorer configured", http.StatusInternalServerError)
			return
		case 1:
			for _, ex := range explorers {
				explorer = ex
			}
		default:
			explorerName := r.FormValue("explorer")
			var ok bool
			explorer, ok = explorers[explorerName]
			if !ok {
				http.Error(w, "bad explorer name", http.StatusBadRequest)
				return
			}
		}

		var target string
		switch r.FormValue("type") {
		case "keyspace":
			keyspace := r.FormValue("keyspace")
			if keyspace == "" {
				http.Error(w, "keyspace is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			target = explorer.GetKeyspacePath(keyspace)

		case "shard":
			keyspace, shard := r.FormValue("keyspace"), r.FormValue("shard")
			if keyspace == "" || shard == "" {
				http.Error(w, "keyspace and shard are obligatory for this redirect", http.StatusBadRequest)
				return
			}
			target = explorer.GetShardPath(keyspace, shard)

		case "srv_keyspace":
			cell := r.FormValue("cell")
			if cell == "" {
				http.Error(w, "cell is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			keyspace := r.FormValue("keyspace")
			if keyspace == "" {
				http.Error(w, "keyspace is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			target = explorer.GetSrvKeyspacePath(cell, keyspace)

		case "srv_shard":
			cell := r.FormValue("cell")
			if cell == "" {
				http.Error(w, "cell is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			keyspace := r.FormValue("keyspace")
			if keyspace == "" {
				http.Error(w, "keyspace is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			shard := r.FormValue("shard")
			if shard == "" {
				http.Error(w, "shard is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			target = explorer.GetSrvShardPath(cell, keyspace, shard)

		case "srv_type":
			cell := r.FormValue("cell")
			if cell == "" {
				http.Error(w, "cell is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			keyspace := r.FormValue("keyspace")
			if keyspace == "" {
				http.Error(w, "keyspace is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			shard := r.FormValue("shard")
			if shard == "" {
				http.Error(w, "shard is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			tabletType := r.FormValue("tablet_type")
			if tabletType == "" {
				http.Error(w, "tablet_type is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			target = explorer.GetSrvTypePath(cell, keyspace, shard, topo.TabletType(tabletType))

		case "tablet":
			aliasName := r.FormValue("alias")
			if aliasName == "" {
				http.Error(w, "keyspace is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			alias, err := topo.ParseTabletAliasString(aliasName)
			if err != nil {
				http.Error(w, "bad tablet alias", http.StatusBadRequest)
				return
			}
			target = explorer.GetTabletPath(alias)

		case "replication":
			cell := r.FormValue("cell")
			if cell == "" {
				http.Error(w, "cell is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			keyspace := r.FormValue("keyspace")
			if keyspace == "" {
				http.Error(w, "keyspace is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			shard := r.FormValue("shard")
			if shard == "" {
				http.Error(w, "shard is obligatory for this redirect", http.StatusBadRequest)
				return
			}
			target = explorer.GetReplicationSlaves(cell, keyspace, shard)

		default:
			http.Error(w, "bad redirect type", http.StatusBadRequest)
			return
		}
		http.Redirect(w, r, target, http.StatusFound)
	})
	servenv.RunDefault()
}