Maarten,
If you have a class that make the connection to the database and
process the sql query. Is recommended to has a class instance for each
IOSession? How you associated the class instance with the ioseccion?
Do you have an example that describe the use to the basicdatasource with
mina.
Angel Figueroa
Maarten Bosteels wrote:
>
> Angel,
>
> The example uses a DataSource, which essentialy IS a connection pool.
> Have a look at
> http://commons.apache.org/dbcp/apidocs/org/apache/commons/dbcp/BasicDataSource.html
>
> Suppose you configure mina with a thread-pool that uses maximum 10
> threads,
> and you configure
> a BasicDataSource to have a fixed size of 10.
> Then only 10 connections will be made to the database during the entire
> lifecycle of your server,
> and a thread should never have to wait for a db-connection to become
> available.
>
> One of our servers has constantly 300 tcp connections or more, but uses
> only
> 15 db connections.
>
> Maarten
>
> On 11/2/07, Angel.Figueroa <[EMAIL PROTECTED]> wrote:
>>
>>
>> Maarten,
>>
>> In you example. Every time messageReceived is called for a IoSession,
>> you make a new connection. The cost for the connection will be high,
>> particular for a database connection.
>>
>> But Suppose the example is change to use a Connection Pool. In that way
>> every time a new client is connected to the server, a new connection is
>> added to the db connection pool, or reuse a connection that is not
>> associated to a IOSession.
>>
>> How this can me implemented in mina.?
>>
>> Angel Figueroa
>>
>>
>>
>> Maarten Bosteels wrote:
>> >
>> > On 11/2/07, Angel.Figueroa <[EMAIL PROTECTED]> wrote:
>> >>
>> >>
>> >> Maarten,
>> >>
>> >> I understand that the messageReceived will never be called
>> >> simultaneously
>> >> for the same session. But it can be called concurrently for different
>> >> IoSession's.
>> >>
>> >> Let put a real example. A Server Application that received SQL
>> Query
>> >> from
>> >> different client connected to it.
>> >> Each client sent a SQL query to the Server. The Server has 10
>> >> connections
>> >> to the database.
>> >>
>> >> How the messageReceived can process each client request (SQL
>> Query)
>> >> simultaneously, using the 10 connections ?
>> >
>> >
>> >
>> > The fact that messageReceived can be called simultaneously (by multiple
>> > threads)
>> > just means that you have to be careful with using shared resources, but
>> > other than that, you don't need to worry.
>> >
>> > Since it's reasonable that any DataSource implementation is
>> thread-safe,
>> > you
>> > could implement your example like this:
>> >
>> > public class QuickMina extends IoHandlerAdapter {
>> >
>> > DataSource dataSource;
>> >
>> > public void setDataSource(DataSource dataSource) {
>> > this.dataSource = dataSource;
>> > }
>> >
>> > public void messageReceived(IoSession session, Object message) throws
>> > Exception {
>> > // a TextLineDecoder will ensure that passed in message is a string
>> > String sql = (String) message;
>> > Connection connection = dataSource.getConnection();
>> > try {
>> > Statement stmt = connection.createStatement();
>> > try {
>> > int rowsUpdated = stmt.executeUpdate(sql);
>> > session.write("rows updated: " + rowsUpdated);
>> > } catch(SQLException e) {
>> > session.write("failed: " + e.getMessage());
>> > } finally {
>> > stmt.close();
>> > }
>> > } finally {
>> > connection.close();
>> > }
>> >
>> > }
>> > }
>> >
>> > Disclaimer:
>> > I haven't tested this code, it's just an example. I wouldn't advise you
>> to
>> > allow clients to send db updates this way :-)
>> >
>> > Maarten
>> >
>> >
>> >
>> >>
>> >>
>> >>
>> >> Maarten Bosteels wrote:
>> >> >
>> >> > Angel,
>> >> >
>> >> > Your question is not really clear to me.
>> >> > What exactly are you worried about ?
>> >> > Note that, by default, messageReceived will never be called
>> >> simultaneously
>> >> > for the same session.
>> >> > But it can be called concurrently for different IoSession's, this
>> does
>> >> not
>> >> > pose a problem by itself.
>> >> > You just have to make sure your implementation is thread-safe: don't
>> >> store
>> >> > conversattional state in instance fields of your IoHandler and
>> properly
>> >> > synchronize access to shared data.
>> >> > This is all very analogous to servlet programming.
>> >> >
>> >> > Maarten
>> >> >
>> >> > On 11/1/07, Angel.Figueroa <[EMAIL PROTECTED]> wrote:
>> >> >>
>> >> >>
>> >> >> If more that one message is received at the same time. How to
>> control
>> >> the
>> >> >> execution of the business logic method.
>> >> >>
>> >> >> public void messageReceived(IoSession session, Object message)
>> >> throws
>> >> >> Exception
>> >> >> {
>> >> >>
>> >> >>
>> >> >>
>> >>
>> //----------------------------------------------------------------------
>> >> >> // received the Request Transaction
>> >> >>
>> >> >>
>> >>
>> //----------------------------------------------------------------------
>> >> >> String theMessage = ( String ) message;
>> >> >>
>> >> >>
>> >> //--------------------------------------------------------------
>> >> >> // Process Transaction Code business logic method
>> >> >>
>> >> //--------------------------------------------------------------
>> >> >> theMessage = transaction.ProcessTransaction
>> >> (theMessage,arclient);
>> >> >>
>> >> >>
>> >> >>
>> >>
>> //----------------------------------------------------------------------
>> >> >> // send the response Transaction Back
>> >> >>
>> >> >>
>> >>
>> //----------------------------------------------------------------------
>> >> >> session.write(theMessage);
>> >> >> }
>> >> >>
>> >> >> --
>> >> >> View this message in context:
>> >> >>
>> >>
>> http://www.nabble.com/messageReceived-and-bussiness-logic-tf4729241s16868.html#a13522950
>> >> >> Sent from the Apache MINA Support Forum mailing list archive at
>> >> >> Nabble.com
>> >> >> .
>> >> >>
>> >> >>
>> >> >
>> >> >
>> >>
>> >> --
>> >> View this message in context:
>> >>
>> http://www.nabble.com/messageReceived-and-bussiness-logic-tf4729241s16868.html#a13541041
>> >> Sent from the Apache MINA Support Forum mailing list archive at
>> >> Nabble.com
>> >> .
>> >>
>> >>
>> >
>> >
>>
>> --
>> View this message in context:
>> http://www.nabble.com/messageReceived-and-bussiness-logic-tf4729241s16868.html#a13546644
>> Sent from the Apache MINA Support Forum mailing list archive at
>> Nabble.com
>> .
>>
>>
>
>
--
View this message in context:
http://www.nabble.com/messageReceived-and-bussiness-logic-tf4729241s16868.html#a13547580
Sent from the Apache MINA Support Forum mailing list archive at Nabble.com.
