(WIP) add cluster meta executor

cluster/internal/data.proto

@@ -23,3 +23,13 @@ message MapShardResponse {
     repeated string TagSets = 4;
     repeated string Fields = 5;
 }
+
+message ExecuteStatementRequest {
+    required string Statement = 1;
+    required string Database = 2;
+}
+
+message ExecuteStatementResponse {
+    required int32 Code = 1;
+    optional string Message = 2;
+}

cluster/meta_executor.go

@@ -0,0 +1,154 @@
+package cluster
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/influxdata/influxdb"
+	"github.com/influxdata/influxdb/influxql"
+	"github.com/influxdata/influxdb/services/meta"
+)
+
+// MetaExecutor executes meta queries on all data nodes.
+type MetaExecutor struct {
+	mu             sync.RWMutex
+	timeout        time.Duration
+	pool           *clientPool
+	maxConnections int
+	Logger         *log.Logger
+	Node           *influxdb.Node
+
+	MetaClient interface {
+		DataNode(id uint64) (ni *meta.NodeInfo, err error)
+		DataNodes() ([]meta.NodeInfo, error)
+	}
+}
+
+// NewMetaExecutor returns a new initialized *MetaExecutor.
+func NewMetaExecutor() *MetaExecutor {
+	return &MetaExecutor{
+		timeout:        DefaultWriteTimeout,
+		pool:           newClientPool(),
+		maxConnections: 1000,
+		Logger:         log.New(os.Stderr, "[meta-executor] ", log.LstdFlags),
+	}
+}
+
+// ExecuteStatement executes a single InfluxQL statement on all nodes in the cluster concurrently.
+func (m *MetaExecutor) ExecuteStatement(stmt influxql.Statement, database string) error {
+	println("MetaExecutor.ExecuteStatement start")
+	defer println("MetaExecutor.ExecuteStatement end")
+	// Get a list of all nodes the query needs to be executed on.
+	nodes, err := m.MetaClient.DataNodes()
+	if err != nil {
+		return err
+	}
+
+	// Start a goroutine to execute the statement on each of the remote nodes.
+	var wg sync.WaitGroup
+	wg.Add(len(nodes))
+	errs := make(chan error)
+	defer close(errs)
+
+	for _, node := range nodes {
+		go func(node meta.NodeInfo) {
+			defer wg.Done()
+			if err := m.executeOnNode(stmt, database, &node); err != nil {
+				errs <- err
+			}
+		}(node)
+	}
+
+	// Wait on all nodes to execute the statement and respond.
+	wg.Wait()
+
+	select {
+	case err = <-errs:
+		return err
+	default:
+		return nil
+	}
+}
+
+// executeOnNode executes a single InfluxQL statement on a single node.
+func (m *MetaExecutor) executeOnNode(stmt influxql.Statement, database string, node *meta.NodeInfo) error {
+	println("MetaExecutor.executeOnNode start")
+	defer println("MetaExecutor.executeOnNode end")
+	// Executing statement on the local node?
+	//if node.ID == m.Node.ID {
+	//	panic("fix me !!!!!!!!!!!!!!!!!!!")
+	//}
+
+	// We're executing on a remote node so establish a connection.
+	fmt.Printf("dialing: %v\n", node)
+	c, err := m.dial(node.ID)
+	if err != nil {
+		return err
+	}
+
+	conn, ok := c.(*pooledConn)
+	if !ok {
+		panic("wrong connection type in MetaExecutor")
+	}
+	// Return connection to pool by "closing" it.
+	defer func(conn net.Conn) { conn.Close() }(conn)
+
+	// Build RPC request.
+	var request ExecuteStatementRequest
+	request.SetStatement(stmt.String())
+	request.SetDatabase(database)
+
+	// Marshal into protocol buffer.
+	buf, err := request.MarshalBinary()
+	if err != nil {
+		return err
+	}
+
+	// Send request.
+	conn.SetWriteDeadline(time.Now().Add(m.timeout))
+	if err := WriteTLV(conn, executeStatementRequestMessage, buf); err != nil {
+		conn.MarkUnusable()
+		return err
+	}
+
+	// Read the response.
+	conn.SetReadDeadline(time.Now().Add(m.timeout))
+	_, buf, err = ReadTLV(conn)
+	if err != nil {
+		conn.MarkUnusable()
+		return err
+	}
+
+	// Unmarshal response.
+	var response ExecuteStatementResponse
+	if err := response.UnmarshalBinary(buf); err != nil {
+		return err
+	}
+
+	if response.Code() != 0 {
+		return fmt.Errorf("error code %d: %s", response.Code(), response.Message())
+	}
+
+	return nil
+}
+
+// dial returns a connection to a single node in the cluster.
+func (m *MetaExecutor) dial(nodeID uint64) (net.Conn, error) {
+	// If we don't have a connection pool for that addr yet, create one
+	_, ok := m.pool.getPool(nodeID)
+	if !ok {
+		factory := &connFactory{nodeID: nodeID, clientPool: m.pool, timeout: m.timeout}
+		factory.metaClient = m.MetaClient
+
+		p, err := NewBoundedPool(1, m.maxConnections, m.timeout, factory.dial)
+		if err != nil {
+			return nil, err
+		}
+		m.pool.setPool(nodeID, p)
+	}
+	return m.pool.conn(nodeID)
+}

cluster/meta_writer.go

@@ -0,0 +1,33 @@
+package cluster
+
+import (
+	"log"
+	"os"
+
+	"github.com/influxdata/influxdb/services/meta"
+	"github.com/influxdata/influxdb/tsdb"
+)
+
+// MetaWriter writes meta query changes to the local tsdb store.
+type MetaWriter struct {
+	TSDBStore *tsdb.Store
+	Logger    *log.Logger
+
+	MetaClient interface {
+		Database(name string) (*meta.DatabaseInfo, error)
+	}
+}
+
+// NewMetaWriter returns a new initialized *MetaWriter.
+func NewMetaWriter() *MetaWriter {
+	return &MetaWriter{
+		Logger: log.New(os.Stderr, "[meta-writer] ", log.LstdFlags),
+	}
+}
+
+// DropDatabase closes and deletes all local files for the database.
+func (m *MetaWriter) DropDatabase(name string) error {
+	println("MetaWriter.DropDatabase start")
+	defer println("MetaWriter.DropDatabase end")
+	return m.TSDBStore.DeleteDatabase(name)
+}

cluster/query_executor.go

@@ -33,6 +33,9 @@ type QueryExecutor struct {
 	// Used for rewriting points back into system for SELECT INTO statements.
 	PointsWriter *PointsWriter
 
+	// Used for executing meta statements on all data nodes.
+	MetaExecutor *MetaExecutor
+
 	// Output of all logging.
 	// Defaults to discarding all log output.
 	LogOutput io.Writer
@@ -277,6 +280,8 @@ func (e *QueryExecutor) executeDropContinuousQueryStatement(q *influxql.DropCont
 }
 
 func (e *QueryExecutor) executeDropDatabaseStatement(stmt *influxql.DropDatabaseStatement) error {
+	println("cluster.QueryExecutor.executeDropDatabaseStatement start")
+	defer println("cluster.QueryExecutor.executeDropDatabaseStatement end")
 	dbi, err := e.MetaClient.Database(stmt.Name)
 	if err != nil {
 		return err
@@ -293,12 +298,9 @@ func (e *QueryExecutor) executeDropDatabaseStatement(stmt *influxql.DropDatabase
 		return err
 	}
 
-	// Remove the database from the local store
-	if err := e.TSDBStore.DeleteDatabase(stmt.Name); err != nil {
-		return err
-	}
-
-	return nil
+	// Tell all data nodes in the cluster to
+	// delete their local files for this database.
+	return e.MetaExecutor.ExecuteStatement(stmt, "")
 }
 
 // executeDropRetentionPolicy closes all local shards for the retention

cluster/rpc.go

@@ -219,3 +219,65 @@ func (w *WriteShardResponse) UnmarshalBinary(buf []byte) error {
 	}
 	return nil
 }
+
+// ExecuteStatementRequest represents the a request to execute a statement on a node.
+type ExecuteStatementRequest struct {
+	pb internal.ExecuteStatementRequest
+}
+
+// Statement returns the InfluxQL statement.
+func (r *ExecuteStatementRequest) Statement() string { return r.pb.GetStatement() }
+
+// SetStatement sets the InfluxQL statement.
+func (r *ExecuteStatementRequest) SetStatement(statement string) {
+	r.pb.Statement = proto.String(statement)
+}
+
+// Database returns the database name.
+func (r *ExecuteStatementRequest) Database() string { return r.pb.GetDatabase() }
+
+// SetDatabase sets the database name.
+func (r *ExecuteStatementRequest) SetDatabase(database string) { r.pb.Database = proto.String(database) }
+
+// MarshalBinary encodes the object to a binary format.
+func (m *ExecuteStatementRequest) MarshalBinary() ([]byte, error) {
+	return proto.Marshal(&m.pb)
+}
+
+// UnmarshalBinary populates ExecuteStatementRequest from a binary format.
+func (m *ExecuteStatementRequest) UnmarshalBinary(buf []byte) error {
+	if err := proto.Unmarshal(buf, &m.pb); err != nil {
+		return err
+	}
+	return nil
+}
+
+// ExecuteStatementResponse represents the response returned from a remote ExecuteStatementRequest call.
+type ExecuteStatementResponse struct {
+	pb internal.WriteShardResponse
+}
+
+// Code returns the response code.
+func (w *ExecuteStatementResponse) Code() int { return int(w.pb.GetCode()) }
+
+// SetCode sets the Code
+func (w *ExecuteStatementResponse) SetCode(code int) { w.pb.Code = proto.Int32(int32(code)) }
+
+// Message returns the repsonse message.
+func (w *ExecuteStatementResponse) Message() string { return w.pb.GetMessage() }
+
+// SetMessage sets the Message
+func (w *ExecuteStatementResponse) SetMessage(message string) { w.pb.Message = &message }
+
+// MarshalBinary encodes the object to a binary format.
+func (m *ExecuteStatementResponse) MarshalBinary() ([]byte, error) {
+	return proto.Marshal(&m.pb)
+}
+
+// UnmarshalBinary populates ExecuteStatementResponse from a binary format.
+func (m *ExecuteStatementResponse) UnmarshalBinary(buf []byte) error {
+	if err := proto.Unmarshal(buf, &m.pb); err != nil {
+		return err
+	}
+	return nil
+}