看了下mysql-connector-5.1.40版本中，如果设置failoverReadOnly=true (即默认值，参考链接)，当mysql连接failover时，会根据jdbc连接串将当前连接的readOnly值设置为true (第8行代码)
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
private synchronized void switchCurrentConnectionTo(int hostIndex, MySQLConnection connection) throws SQLException {
invalidateCurrentConnection();
boolean readOnly;
if (isPrimaryHostIndex(hostIndex)) {
readOnly = this.explicitlyReadOnly == null ? false : this.explicitlyReadOnly;
} else if (this.failoverReadOnly) {
readOnly = true;
} else if (this.explicitlyReadOnly != null) {
readOnly = this.explicitlyReadOnly;
} else if (this.currentConnection != null) {
readOnly = this.currentConnection.isReadOnly();
} else {
readOnly = false;
}
syncSessionState(this.currentConnection, connection, readOnly);
this.currentConnection = connection;
this.currentHostIndex = hostIndex;
} |
当执行update操作时，如果检测到readonly，就会跑出createSQLException （第8-9行代码）
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
protected int executeUpdate(byte[][] batchedParameterStrings, InputStream[] batchedParameterStreams, boolean[] batchedIsStream, int[] batchedStreamLengths,
boolean[] batchedIsNull, boolean isReallyBatch) throws SQLException {
synchronized (checkClosed().getConnectionMutex()) {
MySQLConnection locallyScopedConn = this.connection;
if (locallyScopedConn.isReadOnly()) {
throw SQLError.createSQLException(Messages.getString("PreparedStatement.34") + Messages.getString("PreparedStatement.35"),
SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
}
....
}
} |
上述报错信息是PreparedStatement.34和PreparedStatement.35，查mysql connector的LocalizedErrorMessages.properties
|
1
2
|
PreparedStatement.34=Connection is read-only.
PreparedStatement.35=Queries leading to data modification are not allowed
|
报错信息一致。
因此， 如果是使用的主备mysql，需要手动切换master和slave，如果使用的是多主的mysql(例如，phxsql)，需要设置failoverReadOnly=false