ORA-03106: Fatal Duplex Communication Protocol Error

Problem description:

1. received a call from O & M colleagues, said that the execution of the stored procedure on database a error: ORA-3113 communication channel file end also reported this error, the stored procedure is to access database B through link;

2. There are three tables in the remote database in the stored procedure, one of which is in the SELECT statement and hung. No error is reported;

3. query the table in database B and report the ORA-03106: Fatal duplex communication protocol error, but the limit returns a small number of rows, it is normal;

4. Database B fails to deliver data, and the error "ORA-12569: TNS: Packet Checksum Failure" is reported. However, during the test, it is okay to set up a test machine in another data center and issue data.

 

Analysis:

1. The day before the problem occurred, the network was faulty and adjusted.

2. In the same environment, there is no problem in other zones. Only this zone has a problem, and data in this zone can be stored in other data centers for operation.

3. If the network access to data center B is faulty, an error is reported if the data volume exceeds a certain value.

4. Metalink analysis may be due to network reasons

=== ODM research ===
KM search
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Keyword = ORA-12569
1. Getting ORA-12569: TNS: Packet Checksum Failure while trying to connect through client. (Doc ID 257793.1)
Cause
+ There is a mismatch in the header of the TCP packet between the client and the server.

+ Header leaving the server and by the time the client gets the packet on the other end the header has changed.

2. connections via firewall fail and report ORA-12569 TNS packet Checksum Failure in trace (Doc ID 976703.1)
Cause
Firewall setting (s) is changing/altering packets. any change to Oracle Net packets will stop Oracle Net from working. inside each packet is packet header, which contains information regarding the packet when it was sent. upon grouping packet, if the header information does not match the packet details, then connection will fail.

 

Solution:

The switch has a firewall function and has enabled the firewall option. When each packet passes through, the packet header is checked. As a result, a large amount of data is easily timed out and disconnected, and the front end is hung. If the firewall function is disabled, everything becomes normal.

The user reported a problem for one week. When the analysis points to the network cause, the network still says that the network is okay. The network will not be changed until the DBA finds a specific network problem. Thanks to the network. If this happens several times, DBA will become a network expert.