Unexpected closed connections

Question

We are running Weblogic 5.1 sp10 on SUN OS 5.8 with JDK 1.3/SYBASE JConnect 5.2.
After we changed the program to use connection pooling from regular JDBC connection,
the connection could randomly be closed even within the scope. Here is the snippet
of the code
db = new Database(poolName);
con = db.getConnection();
stmt = con.createStatement();
stmt.execute(q1);
rs = stmt.executeQuery(query);
if (!rs.next()) {
return null;
MOSdeal mosDeal = new MOSdeal(rs);
return (mosDeal);
} catch (SQLException e) {
log.write("SQLException in DealEntity - " + e.getMessage() +"\n"
throw e;
} catch (MOSException e) {
throw e;
} finally {
try {
rs.close();

Answer 1

Frank,
Using connection pools is much faster then using regular connections,
so it does affect object concurrency characteristics.
So the only thing I could offer is to declare method where you get the
exception
as synchronized.
Regards,
Slava Imeshev
"Frank Lin" <[email protected]> wrote in message
news:[email protected]...
>
Due to the requirement of the apps., this program is designed to besingleton with
guaranteed only one thread. It ran in production for 2 years withoutproblem until
we change it from regular JDBC connection to connection pooling.
"Slava Imeshev" <[email protected]> wrote:
Frank,
I would guess there is something wrong with concurrent
processing of your code. A different thread could close the
connection. Make sure your code is thread-safe.
Also you could try to use our newsgroup search engine
at http://search.beasys.com/weblogic/gonews/
using JConnect as a keyword.
Regards,
Slava Imeshev
"Frank Lin" <[email protected]> wrote in message
news:[email protected]...
Hi, Slava, thank you for your reply. Here is the info you were
requesting.
>>>
What I meant the connection randomly closed is that the try block ofrs.close(),st.close(),con.close()
occationally throws a exception. And here is the JDBC connection pooldef.
in
weblogic.properties file(IP and user name/password are pseudo).
weblogic.jdbc.connectionPool.MOSpool=\
url=jdbc:sybase:Tds:XXX.XXX.XX.XX:9999,\
driver=com.sybase.jdbc2.jdbc.SybDriver,\
loginDelaySecs=1,\
initialCapacity=20,\
maxCapacity=50,\
capacityIncrement=2,\
allowShrinking=true,\
shrinkPeriodMins=5,\
testTable=sysobjects,\
refreshMinutes=30,\
testConnsOnReserve=true,\
testConnsOnRelease=true,\
props=user=XXXX;password=XXXX,\
allow=XXXX
"Slava Imeshev" <[email protected]> wrote:
Hi Frank,
o What do you mean saying "connection could randomly be closed"?
o Could you also post the definition of the connection pool?
o Could you post text of the exception, if any?
Regards,
Slava Imeshev
"Frank Lin" <[email protected]> wrote in message
news:[email protected]...
We are running Weblogic 5.1 sp10 on SUN OS 5.8 with JDK 1.3/SYBASEJConnect 5.2.
After we changed the program to use connection pooling from regularJDBC
connection,
the connection could randomly be closed even within the scope. Hereis the
snippet
of the code
db = new Database(poolName);
con = db.getConnection();
stmt = con.createStatement();
stmt.execute(q1);
rs = stmt.executeQuery(query);
if (!rs.next()) {
return null;
MOSdeal mosDeal = new MOSdeal(rs);
return (mosDeal);
} catch (SQLException e) {
log.write("SQLException in DealEntity - " +
e.getMessage()
+"\n"
throw e;
} catch (MOSException e) {
throw e;
} finally {
try {
rs.close();