Re: string character corruption problem and broken connection problem

Could a sniffing program help to clarify this issue?
I mean, by capturing data right from the tcp/ip stack,
maybe it would be possible to identify what caused the
server back end to crash, even if there wasn't anything
sent to log files or syslog.



> On Tue, Dec 02, 2003 at 01:57:37PM -0500, Ethan Perry wrote:
>> I'm using a user-defined function that refers to a shared library that
>> I've built out of a third party C++ application.
>>
>> The function returns a string of values and works fine in the psql
>> command line environment. When I call this function over JDBC,
>> however, the string of values sometimes has garbage characters
>> interspersed in:  for instance, "???B???B??????)??????)???g)Affect
>> 1.85" instead of just "Affect 1.85"
>>
>> After these characters are in the resulting string from the ResultSet
>> multiple times, the postgreqsql server eventually sometimes goes down,
>> and JDBC reports the following error:
>>
>> The backend has broken the connection. Possibly the action you have
>> attempted has caused it to close. Exception in updateMsg msgId9106The
>> backend has broken the connection. Possibly the action you have
>> attempted has caused it to close.
>>  at org.postgresql.PG_Stream.ReceiveChar(PG_Stream.java:143)
>>  at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:68)
>> at org.postgresql.Connection.ExecSQL(Connection.java:398)
>>  at org.postgresql.jdbc2.Statement.execute(Statement.java:130)
>>  at org.postgresql.jdbc2.Statement.executeQuery(Statement.java:54) at
>> anthroViz.model.MessageReader.updateMsg(MessageReader.java:72)
>>
>> Any suggestions on what to look for that could be causing this would
>> be very appreciated.
>
> It seems unlikely this is a problem with the JDBC driver. I'd point the
> finger at the shared library code -- the postmaster should not go down
> as a result of a normal query from a client. Have you investigated the
> cause of the backend crashes (examining coredumps etc)? What is logged
> by the postmaster when it goes down?
>
> -O
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings