Change local_metadata.value to MEDIUMBLOB to accomodate long replication positions.

Signed-off-by: deepthi <deepthi@planetscale.com>

go/vt/mysqlctl/backup.go

@@ -26,6 +26,7 @@ import (
 
 	"golang.org/x/net/context"
 
+	"vitess.io/vitess/go/mysql"
 	"vitess.io/vitess/go/sqlescape"
 	"vitess.io/vitess/go/vt/log"
 	"vitess.io/vitess/go/vt/mysqlctl/backupstorage"
@@ -318,8 +319,7 @@ func Restore(ctx context.Context, params RestoreParams) (*BackupManifest, error)
 
 	// Add backupTime and restorePosition to LocalMetadata
 	params.LocalMetadata["RestoredBackupTime"] = manifest.BackupTime
-	// TODO(deepthi): Uncomment this when the table is fixed to fit replication positions.
-	//params.LocalMetadata["RestorePosition"] = mysql.EncodePosition(manifest.Position)
+	params.LocalMetadata["RestorePosition"] = mysql.EncodePosition(manifest.Position)
 
 	// Populate local_metadata before starting without --skip-networking,
 	// so it's there before we start announcing ourselves.

go/vt/mysqlctl/metadata_tables.go

@@ -30,7 +30,7 @@ import (
 const (
 	sqlCreateLocalMetadataTable = `CREATE TABLE IF NOT EXISTS _vt.local_metadata (
   name VARCHAR(255) NOT NULL,
-  value VARCHAR(255) NOT NULL,
+  value MEDIUMBLOB NOT NULL,
   PRIMARY KEY (name)
   ) ENGINE=InnoDB`
 	sqlCreateShardMetadataTable = `CREATE TABLE IF NOT EXISTS _vt.shard_metadata (
@@ -46,6 +46,9 @@ var (
 	sqlAlterLocalMetadataTable = []string{
 		`ALTER TABLE _vt.local_metadata ADD COLUMN db_name VARBINARY(255) NOT NULL DEFAULT ''`,
 		`ALTER TABLE _vt.local_metadata DROP PRIMARY KEY, ADD PRIMARY KEY(name, db_name)`,
+		// VARCHAR(255) is not long enough to hold replication positions, hence changing to
+		// MEDIUMBLOB.
+		`ALTER TABLE _vt.local_metadata CHANGE value value MEDIUMBLOB NOT NULL`,
 	}
 	sqlAlterShardMetadataTable = []string{
 		`ALTER TABLE _vt.shard_metadata ADD COLUMN db_name VARBINARY(255) NOT NULL DEFAULT ''`,

test/recovery.py

@@ -263,8 +263,7 @@ class TestRecovery(unittest.TestCase):
     self.assertEqual(metadata['Alias'], 'test_nj-0000062346')
     self.assertEqual(metadata['ClusterAlias'], 'recovery_keyspace.0')
     self.assertEqual(metadata['DataCenter'], 'test_nj')
-    # TODO(deepthi): Uncomment this when RestorePosition is fixed.
-    #self.assertEqual(metadata['RestorePosition'], master_pos)
+    self.assertEqual(metadata['RestorePosition'], master_pos)
     logging.debug('RestoredBackupTime: %s', str(metadata['RestoredBackupTime']))
     gotTime = datetime.strptime(metadata['RestoredBackupTime'], '%Y-%m-%dT%H:%M:%SZ')
     self.assertEqual(gotTime, expectedTime)