Number of connections in JSP with pool cache connection

I'm using a Bean from examples, its name: "ods", this is Pool Connection Cache, when a user start connection, this open 10 connections. In my project works 20 users, the DBA prefers don't use too many connections. The version of DB is 8.1.7 and web server 9iAS.
How do I do?
Can I use other number of connections by session?
What is the most rapid connection for work?
The instruction used is:
<jsp:useBean id="ods" class="oracle.jdbc.pool.OracleConnectionCacheImpl" scope="session" />
Thanks
MIGUEL ANGEL CARO
[email protected]

Hi,
Please repost your question in the J2EE forum. This forum is for Web Cache issues only. Sorry about the confusion.
We'll be changing the title of this forum soon to avoid mispostings.

Similar Messages

Number of connections with JSP pool cache

I'm using a Bean from examples, its name: "ods", this is Pool Connection Cache, when a user start connection, this open 10 connections. In my project works 20 users, the DBA prefers don't use too many connections. The version of DB is 8.1.7 and web server 9iAS.
How do I do?
Can I use other number of connections by session?
What is the most rapid connection for work?
The instruction used is:
<jsp:useBean id="ods" class="oracle.jdbc.pool.OracleConnectionCacheImpl" scope="session" />
Thanks
MIGUEL ANGEL CARO
[email protected]

Hi,
Please repost your question in the J2EE forum. This forum is for Web Cache issues only. Sorry about the confusion.
We'll be changing the title of this forum soon to avoid mispostings.

Number of connections with JSP

I'm using a Bean from examples, its name: "ods", this is Pool Connection Cache, when a user start connection, this open 10 connections. In my project works 20 users, the DBA prefers don't use too many connections. The version of DB is 8.1.7 and web server 9iAS.
How do I do?
Can I use other number of connections by session?
What is the most rapid connection for work?
The instruction used is:
<jsp:useBean id="ods" class="oracle.jdbc.pool.OracleConnectionCacheImpl" scope="session" />
Thanks
MIGUEL ANGEL CARO
[email protected]

Hi,
Please repost your question in the J2EE forum. This forum is for Web Cache issues only. Sorry about the confusion.
We'll be changing the title of this forum soon to avoid mispostings.

Number of connections unused in a weblogic pool ?

Here is my question :
Do you know a way to know the number of connections unused (or the number of connections in use) at a particular moment in a weblogic connection pool ?
Thanks a lot !
And sorry for my poor english...
Jerome.

Presumably this is for server monitoring rather than because you are going to do anything with it in the server itself.
If it was mea I would look in the management interface. You might have to drill down a bit and just plain guess.

Number of connections in a JDBC pool

Hi,
I am running Sun One Webserver 6.1SP4 on Solaris 8 on sparc machines. My web app interacts with Oracle 9.2 using the web server's jdbc pooling mechanism. Everything works fine, but what worries me is the number of connections always goes up even during nights when the traffic is considerably low compared to day time. Here is part of my server.xml relevant to the pool.
<JDBCCONNECTIONPOOL name="spfc-dbp1" datasourceclassname="oracle.jdbc.pool.OracleDataSource" steadypoolsize="8" maxpoo
lsize="80" poolresizequantity="8" idletimeout="300" maxwaittime="10000" connectionvalidationrequired="on" connectionvalidati
onmethod="auto-commit" validationtablename="" failallconnections="off" transactionisolationlevel="read-committed" isolationl
evelguaranteed="on">
I checked all my code to make sure I am calling close() on result sets, statements and the connection itself both immediately after completing work as well as in the finally blocks.
The only mechanism I have to bring down the number of connections is to restart the web server. I played around with the poolresizequantity, idletimeout properties, but it didn't help much.
I thank all of you in advance for any insights.
-Sharma

Hi Sharma,
I have a similar problem.
Starting my portal and it works for about ten minutes. Then it is unreachable, because of an ProfileException error. I guess it is too many DB Connections.
I can do 2 things:
- wait for about 20minutes and it works again for ten minutes, or
- restart tomcat.
Currently I am setting up a new Connection Pool, Jdbc2Pool.
Did you find a solution to your problem?
Ciao,
Axel

Problems with JSP-ApplicationModule pooling in runtime

Hello!
I have an urgent Problem with the ApplicationModule Pooling in Runtime. The Application uses JSP with BC4J and is deployed on Tomcat 3.1 and MS IIS 4.0 (The Client want to use this MS-Product). We use JDev 3.1.1.2 for development.
Now my Problem:
A user start the IE4 and log on to the application and it works fine. They log off and log in again a second time and then the user gets a NullPointerException at the point when the Application wants to checkout a new instance from the ApplicationModule Pool. The next time he logs on it works fine again and the next time not and so on. Every second time the user logs on he gets a NullPointerException.
But there are three AdminUsers and with these users are no Problems.
Can anyone help me or has someone the same problems?
Greetings
Thorsten

There are a number of pooling problems fixed in JDeveloper 3.2. You can also step into the pooling code by using remote debugging to figure out why you are encountering this problem.

Problem with reached maximum number of connections to database

Dear Experts,
Our Production system was not responding properly last week.
The below was the reply from the Basis team.
"It seems that we have again problem with reached maximum number of connections to database. We have extended this number to 100 this year and now it seems that it’s not enough again. It seems that something is running on Production, which takes over too many connections."
They have increased the number to 200 as a work around.
Do we have any means to find out, which component or application is causing the issue.
Please advise me if any better way is available to correct the issue.
Please see the below trace.
From default trace:
======
Caused by: com.sap.engine.services.dbpool.exceptions.BaseSQLException: ResourceException occurred in method ConnectionFactoryImpl.getConnection(): javax.resource.R
esourceException: (Failed in component: dbpool, BC-JAS-TRH) Cannot create connection. Possible reasons: 1)Maximum allowed connections to DB or EIS is reached. You
can apply CSN Note 719778 in order to check and resolve connection leaks. 2) Configuration to DB/EIS is wrong or DB/EIS is temporary unreachable. 3) Connections ar
e not enough for current load.
        at com.sap.engine.services.dbpool.cci.ConnectionFactoryImpl.getConnection(ConnectionFactoryImpl.java:60)
        at com.sap.security.core.persistence.datasource.imp.J2EEConnectionPool.getConnection(J2EEConnectionPool.java:205)
        ... 61 more
Caused by: javax.resource.ResourceException: (Failed in component: dbpool, BC-JAS-TRH) Cannot create connection. Possible reasons: 1)Maximum allowed connections to
DB or EIS is reached. You can apply CSN Note 719778 in order to check and resolve connection leaks. 2) Configuration to DB/EIS is wrong or DB/EIS is temporary unr
eachable. 3) Connections are not enough for current load.
        at com.sap.engine.services.connector.jca.ConnectionHashSet.match(ConnectionHashSet.java:230)
        at com.sap.engine.services.connector.jca.ConnectionManagerImpl.allocateConnection(ConnectionManagerImpl.java:343)
        at com.sap.engine.services.connector.jca.ShareableConnectionManager.allocateConnection(ShareableConnectionManager.java:54)
        at com.sap.engine.services.dbpool.cci.ConnectionFactoryImpl.getConnection(ConnectionFactoryImpl.java:52)
        ... 62 more
Caused by: com.sap.engine.services.dbpool.exceptions.BaseResourceException: SQLException is thrown by the pooled connection: com.sap.sql.log.OpenSQLException: No c
onnection to data source SAPEPPDB available. All 100 pooled connections are in use and 70 connection requests are currently waiting. The connection pool size might
need to be adjusted.
        at com.sap.engine.services.dbpool.spi.ManagedConnectionFactoryImpl.createManagedConnection(ManagedConnectionFactoryImpl.java:192)
        at com.sap.engine.services.connector.jca.ConnectionHashSet.match(ConnectionHashSet.java:221)
        ... 65 more
Caused by: com.sap.sql.log.OpenSQLException: No connection to data source SAPEPPDB available. All 100 pooled connections are in use and 70 connection requests are
currently waiting. The connection pool size might need to be adjusted.
======
Thanks and Kind Regards,
Jelbin

Stop all instances(including DB) and start again, Hope it should work.
It may happened that jar has not been synchronized with the database and may be version mismatch with the java.
719778 - Data Source fails to return connection
1650472 - Transactions are interrupted due to database connection periodically failing to establish
1138877 - How to Deploy External Drivers JDBC/JMS Adapters
Change the connection pool so that it can connect to DB as per the note 719778
Regards
Vijay Kalluri

A significant number of connection failures have occurred with a remote server (Event ID 14502)

I see a number of these events on my Lync 2010 Server. NSlookup shows that 75.0.230.1 is an sbcglobal.net server. (See bolded text.) I have no federation or other connections to sbcglobal.net or AT&T, so why is my Lync server attempting to contact this
server (and others) at all?
Log Name:      Lync Server
Source:        LS Protocol Stack
Date:          3/14/2014 11:34:30 AM
Event ID:      14502
Task Category: (1001)
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      EdgeServer.mydomain.com
Description:
A significant number of connection failures have occurred with remote server IP 75.0.230.1. There have been 75 failures in the last 184 minutes. There have been a total of 75 failures.
The specific failure types and their counts are identified below.
Instance count   - Failure Type
75                 0x80072746(WSAECONNRESET)
This can be due to credential issues, DNS, firewalls or proxies. The specific failure types above should identify the problem.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
    <Provider Name="LS Protocol Stack" />
    <EventID Qualifiers="50153">14502</EventID>
    <Level>2</Level>
    <Task>1001</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2014-03-14T16:34:30.000000000Z" />
    <EventRecordID>32141</EventRecordID>
    <Channel>Lync Server</Channel>
    <Computer>EdgeServer.mydomain.com</Computer>
    <Security />
</System>
<EventData>
    <Data>75.0.230.1</Data>
    <Data>
    </Data>
    <Data>75</Data>
    <Data>184</Data>
    <Data>75</Data>
    <Data>75</Data>
    <Data>0x80072746(WSAECONNRESET)</Data>
    <Data>
    </Data>
    <Data>
    </Data>
    <Data>
    </Data>
    <Data>
    </Data>
</EventData>
</Event>
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To combat the issue, enable an HLB port on your FE servers (or any other pool you are using HLB on) and configure the health checks for the load balancer to use that port instead of the port used for TLS traffic.
Start by configuring the pool in Topology Builder, right click the pool, and choose Edit Properties>General. Place a check in the “Enable Hardware Load Balancer monitoring port” and specify a port.
Also you can refer below link
http://ocsguy.com/2011/11/02/lync-hardware-load-balancer-monitoring-port/
Please remember, if you see a post that helped you please click "Vote As Helpful" and if it answered your question, please click "Mark As Answer"

Maximum number of connection pools?

Hello,
I'm running WL 5.1, sp11 on Solaris with Oracle 8.1.7. I was
wondering, is there a maximum number of connection pools allowed by
weblogic? Or does it not matter so long as the sum of all the max
connections in each pool is less than the max connections oracle will
let you make simultaneously?
Thanks, Dave

Hi. There is no limit to the number of pools weblogic will let you
make. The number of connections Oracle will let you have is
between them and you. :-)
Joe
"D. Alvarado" wrote:
Hello,
I'm running WL 5.1, sp11 on Solaris with Oracle 8.1.7. I was
wondering, is there a maximum number of connection pools allowed by
weblogic? Or does it not matter so long as the sum of all the max
connections in each pool is less than the max connections oracle will
let you make simultaneously?
Thanks, Dave

Problem in connecting JSP with Oracle 9i.

Hi,
I am having problem in connecting JSP with Oracle 9i.
I am using windows XP and my JDK version is 1.4. For executing JSP I am using
"jakarta-tomcat-5.5.4-preconfigured". My database name is global.
I have set java_home, j2ee_home, oracle_home, path, classpath as follows:
j2ee_home=c:\sun\appserver
java_home=c:\sun\appserver\jdk
oracle_home=C:\oracle\ora92
path=C:\Sun\AppServer\bin;C:\Sun\AppServer\jdk\bin;C:\oracle\ora92\bin
classpath=C:\Sun\AppServer\lib\j2ee.jar;C:\oracle\ora92\jdbc\lib\ojdbc14.jar;C:\oracle\ora92\jdbc\lib\nls_charse
t12.zip
My code is as follows:
<%@ page language="java" %>
<%@ page import ="java.sql.*"%>
<%
try
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
Connection conn = DriverManager.getConnection ("jdbc:oracle:oci8:@global", "scott", "tiger");
catch(SQLException e)
out.println(""+e);
out.println("Connected");
%>
I tried other program:
<%@ page language="java" %>
<%@ page import ="java.sql.*"%>
<%
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:global","scott","tiger");
out.println("Connected");
%>
I am getting following error:
exception
org.apache.jasper.JasperException: Unable to compile class for JSP
An error occurred at line: 5 in the jsp file: /jsp/oracle.jsp
Generated servlet error:
oracle.jdbc.OracleDriver cannot be resolved or is not a type
     org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:84)
     org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:328)
     org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:389)
     org.apache.jasper.compiler.Compiler.compile(Compiler.java:288)
     org.apache.jasper.compiler.Compiler.compile(Compiler.java:267)
     org.apache.jasper.compiler.Compiler.compile(Compiler.java:255)
     org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:556)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:296)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:245)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
Thanking you in advance,
Anurag

maneesh108 wrote:
hi this is maneesh1) Read the thread it has been answered.
2) The thread is very old. Don't resurrect old threads.
I'm locking this zombie thread.
Kaj

How do I configure the number of connection in the pool for webservice axis

Hi
How do I configure the number of connection in the pool using xml.
We are using axis 1.4 and commons-httpclient-3.0.1Is there any way we can do it using the client-config.wsdd file.
We do not want to do any modification in the code for this.
Is it possible to set socket timeout also in the wsdd file.
Your resolution will be really helpful for us.
Thank You
Ottran

Export them at a smaller size:
File -> Export - not the options at 'Size'
Regards
TD

Formula to count Number of Connection Pools

Hello Folks,
1. i heard that there is a formula for selecting number of connection pools, what is it please
2. how can we implement user security in connection pools based on users
3. what other users exists in presentation services other than users in repository services, and if we need to give the control to users for presentation services, where shall we give it.
thank you
kumar

1. i heard that there is a formula for selecting number of connection pools, what is it pleaseI don't know about a formula as such, but you can get this kind of data via the Systems Management function of OBIEE
http://rnm1978.wordpress.com/2009/07/22/oracle-bi-management-systems-management-mbeans/
Maybe there's an undocumented ODBC call that BI Server supports to reveal this kind of information??

Connection of jsp with sql for retreval of input data

Sir,
i am a beginner.
i want to know how to connect jsp with the sql, and retrieve the values from the database.
could u please help me.
its urgent..
thank you

This has been asked many times so try using the search bar to the left of this page
If you are using Tomcat, there is a tutorial within the documentation
http://tomcat.apache.org/tomcat-5.5-doc/jndi-datasource-examples-howto.html

Problem with the cache hit ratio

Hello,
I ma having a problem with the cache hit ratio I am geting. I am sure, 100% sure, that something has got to be wrong with the cache hit ratio I am fetching!
1) I will post the code that I am using to retrieve the cache hit ratio. I've seen about a thousand different equations, all equivalent in the end.
In oracle cache hit ratio seems to be:
cache hits / cache lookups,
where cache hits <=> logica IO - physical reads
cache lookups <=> logical IO
Now some people use the session logical Reads stat, from teh view v$sysstat; others use db block gets + db consistent gets; whatever. At the end of the day its all the same, and this is what i Use:
SELECT (P1.value + P2.value - P3.value) AS CACHE_HITS, (P1.value + P2.value) AS CACHE_LOOKUPS, P4.value AS MAX_BUFFS_SIZEB
FROM v$sysstat P1, v$sysstat P2, v$sysstat P3, V$PARAMETER P4
WHERE
P1.name = 'db block gets' AND
P2.name = 'consistent gets' AND
P3.name = 'physical reads' AND
P4.name = 'sga_max_size'
2) The problem:
The cache hit ratio I am retrieving cannot be correct. In this case i was benchamarking a HUGELY inneficient query, consisting of the Union of 5 Projections over the same source table, and Oracle is configured with a relatively small SGA of 300 MB. They query plan is awful, the database will read the source database table 5 times.
And I can see in the physical data statistics of the source tablespace, that total Bytes read is aproximatly 5 times the size of the text file that I used to bulk load data into the databse.
Some of the relevant stats, wait events:
db file scattered read     1129,93 seconds
Elapsed time: 1311,9 seconds
CPU time: 179,84
SGA max Size: 314572800 Bytes
And total bytes read: 77771964416 B (aproximatly 72 Gga bytes)
the source txt loaded to the database was aprox 16 G
Number of reads was like 4.5 times the source datafile.
I would say this, given the difference between CPU time and Elapsed Time, it is clear that the query spent almost all of its time doin DB file scattered reads. How is it possible that i get the following cache hit ratio:
Cache hit Ratio: 0,92
Cache hits: 109680186
Cache lookups: 119173819
I mean only 8% of that Logical I/O corresponded to physical I/O? It is just not possible.
3) Procedure of taking stats:
Now to retrieve these stats I snapshot the system 2 times. One before the query, one after the query.
But: this is not done in a single session. In total 3 sessions are created. One session two retrieve the stats before the query, one session to run the query, a last session to snapshot after the query.
Could the problem, assuming there is one, be related to this:
"The V$SESSTAT view contains statistics on a per-session basis and is only valid for the session currently connected. When a session disconnects all statistics for the session are updated in V$SYSSTAT. The values for the statistics are cleared until the next session uses them."
What does this paragraph mean. Does it mean that the v$sysstat only shows you the stats of the last session that closed? Or does it mean thtat v$sysstat is increamented with the statistics of each v$sessionstat once a session terminates? If so, then my procedure for gathering those stats should be correct.
Can anyone help me sort out the origin of such a high cache hit ratio, with so much I/O being done?

sono99 wrote:
Hi,s
first of, let me start by saying that there were many things in your post that you mentioned that I could no understand. 1. Because i am not an Oracle Expert, i use whatever RDBMS whenever i need to. 2. Because another problem has come up and, right now, i cannot inform myself to be able to comprehend it all.Well, could it be that you need to understand the database you are working on in order to comprehend it? That is why we strongly advise you to read the concepts manual first, you need to understand the architecture that Oracle uses, as well as the basic concepts of how oracle does locking and maintains read consistency. It does these different than other database engines, and some things become nonsense if looked at from the viewpoint of a single user.
>
quote:
It would be useful to see the execution plan jhust in case you have simplified the problem so much that a critical detail is missing.
First, the query code:
2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:>SQL> CREATE TABLE FAVFRIEND
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 2 NOLOGGING TABLESPACE TARGET
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 3 AS
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 4 SELECT ID as USRID, FAVF1 as FAVF FROM PROFILE
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 5 UNION ALL
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 6 SELECT ID as USRID, FAVF2 AS FAVF FROM PROFILE
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 7 UNION ALL
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 8 SELECT ID as USRID, FAVF3 AS FAVF FROM PROFILE
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 9 UNION ALL
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 10 SELECT ID as USRID, FAVF4 AS FAVF FROM PROFILE
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 11 UNION ALL
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 12 SELECT ID as USRID, FAVF5 AS FAVF FROM PROFILE
[2009-10-20 15:11:59,141 INFO]: OUTPUT_GOBLER:> 13 ;
Now, Althought it is clear from the query that the statement is executed with the NOLOGGiNG, i have disabled the logging entirely for the tablespace.There are certain rules about nologging that may not be obvious. Again, this derives from the basic Oracle architecture, and if you use the wrong definitions of things like logging, you will be led down the primrose path to confusion.
>
Futhermore, yes, the RDBMS is a test RDBMS... I have droped the database a few times... And I am constantly deleting an re-inserting data into the source database table named PROFILE.>
I also make sure do check all the datafile statistics, and for this query the amount of RedoLog, Undo "Log", Templife used is negligible, practically zero.Create table is DDL, which has implied commits before and afterwards. There is a lot going on, some of it dependent on the volume of data returned. The Oracle database writer writes things out when it feels like it, there are situations where it might just leave it in memory for a while. With nologging, Oracle may not care that you can't perform recovery if it is interrupted. So you might want to look into statspack or EM to tell you what is going on, the datafile statistics may not be all that informative for this case.
>
Most of the I/O is reading, a few of the I/O is writing.
My idea is not to optimize this query, it is to understand how it performs. Well, have you read the Concepts manual?
I have other implementations to test, namely I having trouble with one of them.
Furthermore, I doubt the query Plan Oracle is using actually involves tablescans (as I I'd like it to do); because in the Wait Events, most of the wait time for this query is spent doing "db file scattered read". And I think this is different from a tablescan.Please look up the definition of [db file scattered read|http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/instance_tune.htm#sthref703].
>
Do you really have to use sessions external to the query session ? Can you query v$mystat joined to v$statname from the session itself.
No, I don't want to that!
I avoid as much as possible having the code I execute being implemented in java. Why do you think java has anything to do with this? In your session, desc v$mystat and v$statname, these are views you can look at.
When i can avoid it I don't query the database directly through JDBC, i use the RDBMS command line client, which is supposed to be very robust. Er, is that sqlplus?
So yes, I only connect to the database with JDBC... in very last session.
Of course, I Could Have put both the gather stats before query and gathers stats after query a single script: the script that would be also runing the query.
But that would cause me a number of problems, namely some of the SQL i build has to be implemented dynamically. And I don't want to be replicating the snapshoting code into every query script I make. This way I have one sql with the snapshoting scripts; and multiple scripts for running each query. I avoid code replication in this manner.Instrumentation is a large subject; dynamic sql generation is something to be avoided if possible. Remember, Oracle is written with the idea that many people are going to be sharing code and the database, so it is optimized in that way. For SQL parsing in particular, if every SQL is different, you get a performance problem called "hard parsing." You can (and generally should, and sometimes can't avoid) use bind variables so that Oracle doesn't need to hard parse every SQL. In fact, this is one of those things that applies to other engines besides Oracle. I would recommend you read Tom Kyte's books, he explains what is going on in detail, including in some places the non-Oracle viewpoint.
>
Furthermore, Since the database is not a production database, it is there so I can do my tests. I don't have to be concerned with what other sessions may be doing to my system. There are only the sessions I control.No, there are sessions Oracle controls. If you are on unix, you can easily see this, but there are ways to see it on Windows, too. In some cases, your own sessions can affect themselves.
>
then what it the array fetch size ? If the array fetch size is large enough the number of block visits would be similar to the number of physical block reads.
I don't know what the arraysize you mention is. i have not touched that parameter. So whatever it is, it's the default.You should find out! You can go to http://tahiti.oracle.com and type array fetch size into the search box. You can also go to http://asktom.oracle.com and do the same thing, with some more interesting detail.
>
By the way, I don't get the query results into my client, the query results are dumped into a target output table.
So, if the arraysize has something to do with the number of rows that Oracle is returning the client in each step... I think it doesn't matter.You may hear this phrase a lot:
"It depends."
>
As for the query plan, If i am not mistaken you can't get get query plans for queries that are: create table as select.What?
JG@TTST> explain plan for create table jjj as select * from product_master;
Explained.
JG@TTST> select count(*) from plan_table;
COUNT(*)
         3
I can however commit the create table part and just call for the evalution of the Select part of the query; i believe it should be same.
"Optimizer"     "Cost"     "Cardinality"     "Bytes"     "Partition Start"     "Partition Stop"     "Partition Id"     "ACCESS PREDICATES"     "FILTER PREDICATES"
"SELECT STATEMENT"     "ALL_ROWS"     "2563"     "586110"     "15238860"     ""     ""     ""     ""     ""
"UNION-ALL"     ""     ""     ""     ""     ""     ""     ""     ""     ""
"TABLE ACCESS(FULL) SONO99.PROFILE"     ""     "512"     "117222"     "3047772"     ""     ""     ""     ""     ""
"TABLE ACCESS(FULL) SONO99.PROFILE"     ""     "513"     "117222"     "3047772"     ""     ""     ""     ""     ""
"TABLE ACCESS(FULL) SONO99.PROFILE"     ""     "513"     "117222"     "3047772"     ""     ""     ""     ""     ""
"TABLE ACCESS(FULL) SONO99.PROFILE"     ""     "513"     "117222"     "3047772"     ""     ""     ""     ""     ""
"TABLE ACCESS(FULL) SONO99.PROFILE"     ""     "513"     "117222"     "3047772"     ""     ""     ""     ""     ""
This query plan was taken from sql developer, exported to txt, and the PROFILE table here has only 100k tuples.
Right now I am more concerned with testing the MODEL query. Which Oracle doesn't seem to be able any more... but that is a matter for another thread.
Regarding this plan. The Union ALL seems to be more than just a binary Operator... IT seems to be Neray.
The union all on that execution plan seems to be taking as leaf tables 5 99sono.Profile tables, and be making a table scan to them all. So I'd say that the RDBMS should only scan each database block once and not 5 times.
But: It doesn't seem to be so. IT seems like what oracle is doing is scanning completly each the table, and then moving on to next select statement in the UNION ALL. Because given the amount of source table that was read, 5 times greater than the size of the source table. Oracle didn't reuse read blocks.
But this is just my feeling.Your feeling is uninteresting. Telling us what you really hope to accomplish might be more interesting.
Anyway, in terms of consistent gets, how many consistent gets should the RDBMS be doing? 5
One for each table block?It depends.
>
My best regards,
Nuno (99sono xp).

Submit submit a large number of task to a thread pool (more than 10,000)

i want to submit a large number of task to a thread pool (more than 10,000).
Since a thread pool take runnable as input i have to create as many objects of Runnable as the number of task, but since the number of task is very large it causes the memory overflow and my application crashes.
Can you suggest me some way to overcome this problem?

Ravi_Gupta wrote:
I have to serve them infinitely depending upon the choice of the user.
Take a look at my code (code of MyCustomRunnable is already posted)
public void start(Vector<String> addresses)
searching = true;What is this for? Is it a kind of comment?
>
Vector<MyCustomRunnable> runnables = new Vector<MyCustomRunnable>(1,1);
for (String address : addresses)
try
runnables.addElement(new MyCustomRunnable(address));
catch (IOException ex)
ex.printStackTrace();
}Why does MyCustomRunnable throw an IOException? Why is using up resources when it hasn't started. Why build this vector at all?
>
//ThreadPoolExecutor pool = new ThreadPoolExecutor(100,100,50000L,TimeUnit.MILLISECONDS,new LinkedBlockingQueue());
ExecutorService pool = Executors.newFixedThreadPool(100);You have 100 CPUs wow! I can only assume your operations are blocking on a Socket connection most of the time.
>
boolean interrupted = false;
Vector<Future<String>> futures = new Vector<Future<String>>(1,1);You don't save much by reusing your vector here.
for(int i=1; !interrupted; i++)You are looping here until the thread is interrupted, why are you doing this? Are you trying to generate loading on a remote server?
System.out.println("Cycle: " + i);
for(MyCustomRunnable runnable : runnables)Change the name of you Runnable as it clearly does much more than that. Typically a Runnable is executed once and does not create resources in its constructor nor have a cleanup method.
futures.addElement((Future<String>) pool.submit(runnable));Again, it unclear why you would use a vector rather than a list here.
>
for(Future<String> future : futures)
try
future.get();
catch (InterruptedException ex)
interrupted = true;If you want this to break the loop put the try/catch outside the loop.
ex.printStackTrace();
catch (ExecutionException ex)
ex.printStackTrace();If you are generating a load test you may want to record this kind of failure. e.g. count them.
futures.clear();
try
Thread.sleep(60000);Why do you sleep even if you have been interrupted? For better timing, you should sleep, before check if you futures have finished.
catch(InterruptedException e)
searching = false;again does nothing.
System.out.println("Thread pool terminated..................");
//return;remove this comment. its dangerous.
break;why do you have two way of breaking the loop. why not interrupted = true here.
searching = false;
System.out.println("Shut downing pool");
pool.shutdownNow();
try
for(MyCustomRunnable runnable : runnables)
runnable.close(); //release resources associated with it.
catch(IOException e)put the try/catch inside the loop. You may want to ignore the exception but if one fails, the rest of the resources won't get cleaned up.
The above code serve the task infinitely untill it is terminated by user.
i had created a large number of runnables and future objects and they remain in memory until
user terminates the operation might be the cause of the memory overflow.It could be the size of the resources each runnable holds. Have you tried increasing your maximum memory? e.g. -Xmx512m

Number of connections in JSP with pool cache connection

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