Match collation between VTGate and VTTablet

go/cmd/vttablet/vttablet.go

@@ -90,7 +90,7 @@ func main() {
 	if servenv.GRPCPort != nil {
 		gRPCPort = int32(*servenv.GRPCPort)
 	}
-	tablet, err := tabletmanager.BuildTabletFromInput(tabletAlias, int32(*servenv.Port), gRPCPort, mysqld.GetVersionString())
+	tablet, err := tabletmanager.BuildTabletFromInput(tabletAlias, int32(*servenv.Port), gRPCPort, mysqld.GetVersionString(), config.DB)
 	if err != nil {
 		log.Exitf("failed to parse -tablet-path: %v", err)
 	}

go/mysql/client.go

@@ -223,26 +223,9 @@ func setCollationForConnection(c *Conn, params *ConnParams) error {
 	// Certain MySQL or MariaDB versions might have different default collations for some
 	// charsets, so it is important to use a database-version-aware collation system/API.
 	env := collations.NewEnvironment(c.ServerVersion)
-
-	// if there is no collation or charset, we default to utf8mb4
-	charset := params.Charset
-	if params.Collation == "" && charset == "" {
-		charset = "utf8mb4"
-	}
-
-	var coll collations.Collation
-	if params.Collation == "" {
-		// If there is no collation we will just use the charset's default collation
-		// otherwise we directly use the given collation.
-		coll = env.DefaultCollationForCharset(charset)
-	} else {
-		// Here we call the collations API to ensure the collation/charset exist
-		// and is supported by Vitess.
-		coll = env.LookupByName(params.Collation)
-	}
-	if coll == nil {
-		// The given collation is most likely unknown or unsupported, we need to fail.
-		return vterrors.Errorf(vtrpcpb.Code_INTERNAL, "cannot resolve collation: '%s'", params.Collation)
+	coll, err := env.ResolveCollation(params.Charset, params.Collation)
+	if err != nil {
+		return err
 	}
 
 	// We send a query to MySQL to set the connection's collation.
@@ -252,10 +235,6 @@ func setCollationForConnection(c *Conn, params *ConnParams) error {
 		return err
 	}
 
-	// The collation environment is stored inside the connection parameters struct.
-	// We will use it to verify that execution requests issued by VTGate match the
-	// same collation as the one used to communicate with MySQL.
-	c.CollationEnvironment = env
 	c.Collation = coll.ID()
 	return nil
 }

go/mysql/collations/env.go

@@ -17,6 +17,7 @@ limitations under the License.
 package collations
 
 import (
+	"fmt"
 	"strings"
 	"sync"
 )
@@ -120,6 +121,32 @@ func fetchCacheEnvironment(version collver) *Environment {
 	return env
 }
 
+// ResolveCollation returns the default collation that will be used for the given charset and collation.
+// Both charset and collation can be empty strings, in which case utf8mb4 will be used as a charset and its
+// default collation will be returned.
+func (env *Environment) ResolveCollation(charset, collation string) (Collation, error) {
+	// if there is no collation or charset, we default to utf8mb4
+	if collation == "" && charset == "" {
+		charset = "utf8mb4"
+	}
+
+	var coll Collation
+	if collation == "" {
+		// If there is no collation we will just use the charset's default collation
+		// otherwise we directly use the given collation.
+		coll = env.DefaultCollationForCharset(charset)
+	} else {
+		// Here we call the collations API to ensure the collation/charset exist
+		// and is supported by Vitess.
+		coll = env.LookupByName(collation)
+	}
+	if coll == nil {
+		// The given collation is most likely unknown or unsupported, we need to fail.
+		return nil, fmt.Errorf("cannot resolve collation: '%s'", collation)
+	}
+	return coll, nil
+}
+
 // NewEnvironment creates a collation Environment for the given MySQL version string.
 // The version string must be in the format that is sent by the server as the version packet
 // when opening a new MySQL connection

go/mysql/conn.go

@@ -194,11 +194,6 @@ type Conn struct {
 	// query to MySQL after the handshake is done.
 	Collation collations.ID
 
-	// CollationEnvironment defines the collation environment used by this
-	// connection. We set its value using the ServerVersion we receive from
-	// MySQL after the handshake.
-	CollationEnvironment *collations.Environment
-
 	// Packet encoding variables.
 	sequence uint8
 }
@@ -1524,22 +1519,3 @@ func (c *Conn) IsUnixSocket() bool {
 func (c *Conn) GetRawConn() net.Conn {
 	return c.conn
 }
-
-// MatchCollation returns nil if the given collations.ID matches with the connection's
-// collation, otherwise it returns an error explaining why it does not match.
-func (c *Conn) MatchCollation(collationID collations.ID) error {
-	// The collation environment of a connection parameter should never be nil, if we fail
-	// to create it we already errored out when initializing the connection with MySQL.
-	if c.CollationEnvironment == nil {
-		return vterrors.New(vtrpcpb.Code_INTERNAL, "No collation environment for this connection")
-	}
-
-	coll := c.CollationEnvironment.LookupByID(collationID)
-	if coll == nil {
-		return vterrors.Errorf(vtrpcpb.Code_INTERNAL, "QueryOption's Collation is unknown (collation ID: %d)", collationID)
-	}
-	if coll.ID() != c.Collation {
-		return vterrors.Errorf(vtrpcpb.Code_INTERNAL, "QueryOption ('%v') and VTTablet ('%v') charsets do not match", coll.Name(), c.CollationEnvironment.LookupByID(c.Collation).Name())
-	}
-	return nil
-}

go/test/endtoend/recovery/unshardedrecovery/recovery.go

@@ -25,9 +25,6 @@ import (
 	"path"
 	"testing"
 
-	"vitess.io/vitess/go/mysql/collations"
-	"vitess.io/vitess/go/vt/proto/query"
-
 	"vitess.io/vitess/go/test/endtoend/recovery"
 	"vitess.io/vitess/go/test/endtoend/sharding/initialsharding"
 
@@ -292,7 +289,7 @@ func TestRecoveryImpl(t *testing.T) {
 	vtgateConn, err := vtgateconn.Dial(context.Background(), grpcAddress)
 	assert.NoError(t, err)
 	defer vtgateConn.Close()
-	session := vtgateConn.Session("@replica", &query.ExecuteOptions{Collation: int32(collations.Default().LookupByName("utf8mb4_general_ci").ID())})
+	session := vtgateConn.Session("@replica", nil)
 
 	//check that vtgate doesn't route queries to new tablet
 	recovery.VerifyQueriesUsingVtgate(t, session, "select count(*) from vt_insert_test", "INT64(3)")

go/vt/dbconfigs/dbconfigs.go

@@ -444,7 +444,7 @@ func NewTestDBConfigs(genParams, appDebugParams mysql.ConnParams, dbname string)
 		replParams:         genParams,
 		externalReplParams: genParams,
 		DBName:             dbname,
-		Collation:          genParams.Collation,
-		Charset:            genParams.Charset,
+		Collation:          "utf8mb4_general_ci",
+		Charset:            "utf8mb4",
 	}
 }