Maximum number of cursors excedeed

Question

We have an application that runs Weblogic Server 6.1sp1 with Oracle
Thin Driver on Oracle8.1.7. There's a stateless session bean that calls
a stored procedure which returns a cursor, than fetches the rows using
the cursor and then cleanly closes everything ( statements, results
sets, connection ). After restarting the application server for the
first 5 calls it appears that the cursor is not closed. Everything works
fine then for almost 7500 calls, the same input data, everything is
allocated and realeased cleanly. After 7500 calls when the memory
becomes a little scarce, all of a sudden the cursors are not closed, the
same method that has worked perfectly so far, now it fails to close the
cursors. The number of cursors constantly goes up until it reaches the
maximum number of opened cursors when, sadly, it crashes miserably with
ExceptionsUsingSP--:Exception:ORA-01000: maximum open cursors exceeded.
Does anybody have any idea about how I could fix this ?
Thank you,
Horea
PS I'm using the following statement to get the number of opened
cursors:
select a.value, b.name from v$mystat a, v$statname b
where a.statistic# = b.statistic# and a.statistic#= 3

Answer 1

You are right that you are retriving and closing the cursor ! I can't tell
you the exact cause of this.
We ran into similar issue when we did the same thing . And the only
conclusion I came across is that I was ceating a new CallableStatment in the
loop everytime.
So, what we did is that we created the CallableStatement object only
once. And than we did the looping to set its value and execute it.
Also this gave us a very significant performance improvement.
try it ,
thanks,
Prashant
but the callable statement is released in the end, right ? cs.close()
should
do this !!! And if you read the whole story it is closed for the first
thousand calls, then it happens not to be closed.
"Jeetendra Talreja" <[email protected]> wrote in message
news:[email protected]...
You are creating a new callable statement object with every call to this
method. That is what I think causes the MAXIMUM NO OF CURSORS EXCEEDED.
Create the callable statement ONLY once and then you can execute the
statement by supplying different parameters.
Follow these steps:
1. create callable statement once.
2. set parameters, execute, got the resultset.
3. set parameters, execute, got the resultset.
and you can go on and on.
Thanks
public List _getAllResourceOptionsUsingSP(RGQueryData qd, boolean
onlyFirstOne) throws RGException
Connection conn = null;
CallableStatement cs = null;
ResultSet cursor = null;
RGData rgData = null;
RGCarrierData rgCarrierData = null;
ArrayList list = new ArrayList();
ArrayList carrierDataList = null;
int laneId = NullDef.NULL_INT, laneHierarchy = NullDef.NULL_INT;
Vector idVector = new Vector();
List excludedIdList = qd.getLaneIdList();
RGDebugLog.logLow("RGRetrievalJDBCAccessor:getAllResourceOptionsUsingSP\n"
+ "qd:" + qd);
try
conn = OFRDef.CONNECTION_CREATOR.createConnection();
RGDebugLog.logLow("RGRetrievalJDBCAccessor:getAllResourceOptionsUsingSP\n"+
>
"query data: " + qd);
cs = conn.prepareCall( GET_RESOURCE_OPTION_SP );
cs.setInt(1, qd.getTcCompanyId()); //coid IN
rg_lane.tc_company_id%TYPE,
cs.setString(2, qd.getBusinessUnit()); //buid IN
rg_lane.business_unit%TYPE,
cs.setInt(3, qd.getOFacilityId()); //ofacid IN
rg_lane.o_facility_id%TYPE,
cs.setString(4, qd.getOCity()); //ocity IN rg_lane.o_city%TYPE,
cs.setString(5, qd.getOCounty()); //ocnty IN rg_lane.o_county%TYPE,
cs.setString(6, qd.getOStateProv()); //ost IN
rg_lane.o_state_prov%TYPE,
cs.setString(7, qd.getOPostalCode()); //ozip IN
rg_lane.o_postal_code%TYPE,
cs.setString(8, qd.getOCountryCode()); //ocountry IN
rg_lane.o_country_code%TYPE,
cs.setInt(9, qd.getDFacilityId()); //dfacid IN
rg_lane.d_facility_id%TYPE,
cs.setString(10, qd.getDCity()); //dcity IN rg_lane.d_city%TYPE,
cs.setString(11, qd.getDCounty()); //dcnty IN rg_lane.d_county%TYPE,
cs.setString(12, qd.getDStateProv()); //dst IN
rg_lane.d_state_prov%TYPE,
cs.setString(13, qd.getDPostalCode()); //dzip IN
rg_lane.d_postal_code%TYPE,
cs.setString(14, qd.getDCountryCode()); //dcountry IN
rg_lane.d_country_code%TYPE,
cs.setDate(15, new java.sql.Date(qd.getKeyDTTM().getTime())); //idttm
IN DATE,
cs.setString(16, qd.getRgQualifer()); //rgq IN
rg_lane.rg_qualifier%TYPE,
cs.setString(17, qd.getCarrierCode()); //ccode IN
rg_lane_dtl.carrier_code%TYPE,
cs.setString(18, qd.getMot()); //mot IN rg_lane_dtl.mot%TYPE,
cs.setString(19, qd.getEquipmentCode()); //equip IN
rg_lane_dtl.equipment_code%TYPE,
cs.setString(20, qd.getServiceLevel()); //sl IN
rg_lane_dtl.carrier_code%TYPE,
cs.setString(21, qd.getProtectionLevel()); //pl IN
rg_lane_dtl.carrier_code%TYPE,
cs.registerOutParameter(22, OracleTypes.CURSOR); //rs_option_refcur
OUT rs_option_curtype
boolean b = cs.execute();
cursor = (ResultSet)cs.getObject(22);
if(cursor!=null)
while (cursor.next())
laneId = cursor.getInt("lane_id");//rl.lane_id,
laneHierarchy = cursor.getInt("lane_hierarchy");//lane hierarchy
rgCarrierData = new RGCarrierData();
rgData.setLaneId(laneId);//rl.lane_id,
rgData.setLaneHierarchy(laneHierarchy);//lane_hierarchy,
catch(Exception e)
RGDebugLog.logException( e );
throw new
RGException("RGRetrievalJDBCAccessor:getAllResourceOptionsUsingSP--:Exceptio
>
n:" + e.getMessage());
finally
try
if (cursor != null)
cursor.close();
if (cs != null)
cs.close();
if (conn != null)
conn.close();
catch(Exception e)
throw new
RGException("RGRetrievalJDBCAccessor:getAllResourceOptionsUsingSP--:Exceptio
>
n:" + e.getMessage());
return list;
----- Original Message -----
From: "Jeetendra Talreja" <[email protected]>
To: <[email protected]>
Sent: Monday, January 21, 2002 10:10 AM
Subject: Re: Maximum number of cursors excedeed
>
Can You send the block of code that is executing the callable statement.We
had similar problems with Prepared Statements, It used to fail after
exceuting about 100 statements with the same error. And we realised
there
>
was a problem in the code.
Thanks
Jeetendra
"Horea Raducan" <[email protected]> wrote in message
news:<[email protected]>...
We have an application that runs Weblogic Server 6.1sp1 with Oracle
Thin Driver on Oracle8.1.7. There's a stateless session bean that
calls
>
a stored procedure which returns a cursor, than fetches the rows using
the cursor and then cleanly closes everything ( statements, results
sets, connection ). After restarting the application server for the
first 5 calls it appears that the cursor is not closed. Everything
works
>
fine then for almost 7500 calls, the same input data, everything is
allocated and realeased cleanly. After 7500 calls when the memory
becomes a little scarce, all of a sudden the cursors are not closed,
the
>
same method that has worked perfectly so far, now it fails to closethe
>
cursors. The number of cursors constantly goes up until it reaches the
maximum number of opened cursors when, sadly, it crashes miserably
with
>
ExceptionsUsingSP--:Exception:ORA-01000: maximum open cursorsexceeded.
>
Does anybody have any idea about how I could fix this ?
>
Thank you,
Horea
>
PS I'm using the following statement to get the number of opened
cursors:
select a.value, b.name from v$mystat a, v$statname b
where a.statistic# = b.statistic# and a.statistic#= 3
>
>
"Horea Raducan" <[email protected]> wrote in message
news:[email protected]...
How come the same code closes all the cursors for 7500 calls with the
same
input
data and then all of a sudden it doesn't. Thank you for your effort but
it
wasn't very helpful.
Slava Imeshev wrote:
So this mean you don't close objects properly. Check your code.
Regards,
Slava Imeshev
"Horea Raducan" <[email protected]> wrote in message
news:[email protected]...
It helps, it takes longer to crash ;))) but it doesn't solve the
problem.
Slava Imeshev wrote:
Hi Horea,
Did you try increasing this parameter, anyway?
Regards,
Slava Imeshev
"Horea Raducan" <[email protected]> wrote in message
news:[email protected]...
The OPNE_CURSORS is 300. In a normal run that should be enough (
there
no
more
that 13, 14 cursors opened ). The weird behaviour starts after I
stress
heavilly the application.
Slava Imeshev wrote:
Hi Horea,
If you're absolutely sure you don't loose
cursors due to improper closing of JDBC
objects, try increasing oracle parameter
OPEN_CURSORS.
Regards,
Slava Imeshev
"Horea Raducan" <[email protected]> wrote in message
news:[email protected]...
We have an application that runs Weblogic Server 6.1sp1
with
Oracle
Thin Driver on Oracle8.1.7. There's a stateless session bean
that
calls
a stored procedure which returns a cursor, than fetches the
rows
using
the cursor and then cleanly closes everything ( statements,results
sets, connection ). After restarting the application server
for
the
first 5 calls it appears that the cursor is not closed.
Everything
works
fine then for almost 7500 calls, the same input data,
everything
is
allocated and realeased cleanly. After 7500 calls when the
memory
becomes a little scarce, all of a sudden the cursors are notclosed,
the
same method that has worked perfectly so far, now it fails
to
close
the
cursors. The number of cursors constantly goes up until it
reaches
the
maximum number of opened cursors when, sadly, it crashes
miserably
with
ExceptionsUsingSP--:Exception:ORA-01000: maximum open
cursors
exceeded.
Does anybody have any idea about how I could fix this ?
Thank you,
Horea
PS I'm using the following statement to get the number of
opened
cursors:
select a.value, b.name from v$mystat a, v$statname b
where a.statistic# = b.statistic# and a.statistic#= 3