Maarten,
Suppose you want to use more that one instance. How you assign an
instance to a IOSession?
Angel Figueroa
Maarten Bosteels wrote:
>
> On 11/2/07, Angel.Figueroa <[EMAIL PROTECTED]> wrote:
>>
>>
>> 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?
>
>
> No, I would use a stateless singleton: one instance that is used by all
> IoSession's.
> In fact, I would use Spring's JdbcTemplate.
>
> Do you have an example that describe the use to the basicdatasource
> with
>> mina.
>
>
> Just look at the docs of DBCP. The fact that you use it from an MINA app
> really doesn't matter.
>
> Maarten
>
> 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
>> .
>>
>>
>
>
--
View this message in context:
http://www.nabble.com/messageReceived-and-bussiness-logic-tf4729241s16868.html#a13549176
Sent from the Apache MINA Support Forum mailing list archive at Nabble.com.
