Start errors with lowercase letter

Error messages shouldn't be capitalized.

https://github.com/golang/go/wiki/CodeReviewComments#error-strings

control.go

@@ -125,7 +125,7 @@ func hostInfo(addr string, defaultPort int) ([]*HostInfo, error) {
 	if err != nil {
 		return nil, err
 	} else if len(ips) == 0 {
-		return nil, fmt.Errorf("No IP's returned from DNS lookup for %q", addr)
+		return nil, fmt.Errorf("no IP's returned from DNS lookup for %q", addr)
 	}
 
 	// Filter to v4 addresses if any present

frame.go

@@ -854,7 +854,7 @@ func (w *writePrepareFrame) writeFrame(f *framer, streamID int) error {
 		if f.proto > protoVersion4 {
 			flags |= flagWithPreparedKeyspace
 		} else {
-			panic(fmt.Errorf("The keyspace can only be set with protocol 5 or higher"))
+			panic(fmt.Errorf("the keyspace can only be set with protocol 5 or higher"))
 		}
 	}
 	if f.proto > protoVersion4 {
@@ -1502,7 +1502,7 @@ func (f *framer) writeQueryParams(opts *queryParams) {
 		if f.proto > protoVersion4 {
 			flags |= flagWithKeyspace
 		} else {
-			panic(fmt.Errorf("The keyspace can only be set with protocol 5 or higher"))
+			panic(fmt.Errorf("the keyspace can only be set with protocol 5 or higher"))
 		}
 	}
 

integration_test.go

@@ -72,7 +72,7 @@ func TestRingDiscovery(t *testing.T) {
 			t.Logf("p=%q host=%v ips=%s", p, pool.host, pool.host.ConnectAddress().String())
 
 		}
-		t.Errorf("Expected a cluster size of %d, but actual size was %d", *clusterSize, size)
+		t.Errorf("expected a cluster size of %d, but actual size was %d", *clusterSize, size)
 	}
 }
 

marshal.go

@@ -1728,7 +1728,7 @@ func unmarshalUUID(info TypeInfo, data []byte, value interface{}) error {
 
 	u, err := UUIDFromBytes(data)
 	if err != nil {
-		return unmarshalErrorf("Unable to parse UUID: %s", err)
+		return unmarshalErrorf("unable to parse UUID: %s", err)
 	}
 
 	switch v := value.(type) {
@@ -2050,7 +2050,7 @@ func marshalUDT(info TypeInfo, value interface{}) ([]byte, error) {
 	case Marshaler:
 		return v.MarshalCQL(info)
 	case unsetColumn:
-		return nil, unmarshalErrorf("Invalid request: UnsetValue is unsupported for user defined types")
+		return nil, unmarshalErrorf("invalid request: UnsetValue is unsupported for user defined types")
 	case UDTMarshaler:
 		var buf []byte
 		for _, e := range udt.Elements {

metadata.go

@@ -559,7 +559,7 @@ func getKeyspaceMetadata(session *Session, keyspaceName string) (*KeyspaceMetada
 		iter.Scan(&keyspace.DurableWrites, &replication)
 		err := iter.Close()
 		if err != nil {
-			return nil, fmt.Errorf("Error querying keyspace schema: %v", err)
+			return nil, fmt.Errorf("error querying keyspace schema: %v", err)
 		}
 
 		keyspace.StrategyClass = replication["class"]
@@ -585,13 +585,13 @@ func getKeyspaceMetadata(session *Session, keyspaceName string) (*KeyspaceMetada
 		iter.Scan(&keyspace.DurableWrites, &keyspace.StrategyClass, &strategyOptionsJSON)
 		err := iter.Close()
 		if err != nil {
-			return nil, fmt.Errorf("Error querying keyspace schema: %v", err)
+			return nil, fmt.Errorf("error querying keyspace schema: %v", err)
 		}
 
 		err = json.Unmarshal(strategyOptionsJSON, &keyspace.StrategyOptions)
 		if err != nil {
 			return nil, fmt.Errorf(
-				"Invalid JSON value '%s' as strategy_options for in keyspace '%s': %v",
+				"invalid JSON value '%s' as strategy_options for in keyspace '%s': %v",
 				strategyOptionsJSON, keyspace.Name, err,
 			)
 		}
@@ -703,7 +703,7 @@ func getTableMetadata(session *Session, keyspaceName string) ([]TableMetadata, e
 			if err != nil {
 				iter.Close()
 				return nil, fmt.Errorf(
-					"Invalid JSON value '%s' as key_aliases for in table '%s': %v",
+					"invalid JSON value '%s' as key_aliases for in table '%s': %v",
 					keyAliasesJSON, table.Name, err,
 				)
 			}
@@ -716,7 +716,7 @@ func getTableMetadata(session *Session, keyspaceName string) ([]TableMetadata, e
 			if err != nil {
 				iter.Close()
 				return nil, fmt.Errorf(
-					"Invalid JSON value '%s' as column_aliases for in table '%s': %v",
+					"invalid JSON value '%s' as column_aliases for in table '%s': %v",
 					columnAliasesJSON, table.Name, err,
 				)
 			}
@@ -728,7 +728,7 @@ func getTableMetadata(session *Session, keyspaceName string) ([]TableMetadata, e
 
 	err := iter.Close()
 	if err != nil && err != ErrNotFound {
-		return nil, fmt.Errorf("Error querying table schema: %v", err)
+		return nil, fmt.Errorf("error querying table schema: %v", err)
 	}
 
 	return tables, nil
@@ -777,7 +777,7 @@ func (s *Session) scanColumnMetadataV1(keyspace string) ([]ColumnMetadata, error
 			err := json.Unmarshal(indexOptionsJSON, &column.Index.Options)
 			if err != nil {
 				return nil, fmt.Errorf(
-					"Invalid JSON value '%s' as index_options for column '%s' in table '%s': %v",
+					"invalid JSON value '%s' as index_options for column '%s' in table '%s': %v",
 					indexOptionsJSON,
 					column.Name,
 					column.Table,
@@ -837,7 +837,7 @@ func (s *Session) scanColumnMetadataV2(keyspace string) ([]ColumnMetadata, error
 			err := json.Unmarshal(indexOptionsJSON, &column.Index.Options)
 			if err != nil {
 				return nil, fmt.Errorf(
-					"Invalid JSON value '%s' as index_options for column '%s' in table '%s': %v",
+					"invalid JSON value '%s' as index_options for column '%s' in table '%s': %v",
 					indexOptionsJSON,
 					column.Name,
 					column.Table,
@@ -915,7 +915,7 @@ func getColumnMetadata(session *Session, keyspaceName string) ([]ColumnMetadata,
 	}
 
 	if err != nil && err != ErrNotFound {
-		return nil, fmt.Errorf("Error querying column schema: %v", err)
+		return nil, fmt.Errorf("error querying column schema: %v", err)
 	}
 
 	return columns, nil

token.go

@@ -153,7 +153,7 @@ func newTokenRing(partitioner string, hosts []*HostInfo) (*tokenRing, error) {
 	} else if strings.HasSuffix(partitioner, "RandomPartitioner") {
 		tokenRing.partitioner = randomPartitioner{}
 	} else {
-		return nil, fmt.Errorf("Unsupported partitioner '%s'", partitioner)
+		return nil, fmt.Errorf("unsupported partitioner '%s'", partitioner)
 	}
 
 	for _, host := range hosts {