Socket unexpectedly closed by a frontend while communicating with the backend - Mailing list pgsql-bugs

Hello guys! I'm a little bit confused with the following case.

I've got a Postgressql server running on host A, and a java based client
running on host B. The client uses org.postgresql.Driver JDBC driver
(version 9.1-901.jdbc3).

sometimes while executing long running stored procedure I get exception
"java.net.SocketException: Socket closed". I'm using
org.apache.commons.dbcp.BasicDataSource for retrieving

connections. DBCP pool is configured with default options.



I got tcp dump in order to figure out on which side (client or server)
socket is being closed;



Here is what I've got:



1.   Client B sends a test query message when tries to borrow connection
from dbcp pool ("Select 1")

2.   Server A sends successful response back (Type: Command completion,
Ready for query)

3.   Client B sends ACK message in response on server A response (see the
item 2).

4.   Client B sends query message to the server A.

5.   Server A sends ACK message in response on client Query message (see
the item 4).

6.   Client B sends terminating message (Type : Termination) after some
time passed (from 3 to 10 or sometimes even more minutes).

7    Client B sends FIN ACK message to the server.

8.   Server A sends back ACK on termination message.

9.   Server A sends ACK on (FIN, ACK) message (item 7).

10.  Server A sends back a response on the client query (from item 4) Type:
Row description Columns: 40.

11.  Client B sends RST message (reset).

12.  Server A continues sending response on the query Type: Data row
Length: 438 Columns 40 and so on.

13   Client B sends RST message (reset) again.

14.  Server A continues sending response on the query Type: Data row
Length: 438 Columns 40 and so on.

15.  Client B sends RST message (reset).



After that communication seems to be finished.



After the item 6, in my client logs I got Exception like the following:



Caused by: java.net.SocketException: Socket closed

        at java.net.SocketInputStream.socketRead0(Native Method)

        at java.net.SocketInputStream.read(SocketInputStream.java:152)

        at java.net.SocketInputStream.read(SocketInputStream.java:122)

        at
org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:145)

        at
org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:114)

        at
org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:73)

        at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:274)

        at
org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1661)

        at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)



Could you please help me to figure out the reason of such a failure. (This
bug happens once per 10 successful cases.)



Thanks in advance!


Best regards, Mike Pryakhin.