Hello.
I respond myself (and make a new question).
For example, if application close database by itself , that application should
ensure to close physical connection too.
However , if connection exists in ConnectionPool, there are no way to ensure
to close physical connection.
(This was problem found in DERBY-273. )
This problem to ensure closing physical connection when closing database is
considered as next.
Application programs , which uses connection pool , do not close database and
middleware programs such as application server , which will close database, should manage connection pool using JDBC interface for
ConnectionPooling and
ensure to close connection.
In this meaning, code of DERBY-273 is special because it closes database though
not being middleware program .
// Well , it was not application program but test program , and does not apply
our program to anything :)
Another example,even if application does not close database,it is not out of imagine that connection falls into illegal state and
database administrator wants to kill unhealthy connection .
//This would be incompatible to the charter of derby , "zero administration for end
users" .... :(
If the application server that serve the ConnectionPool supports to kill
Connection by administrator, we can leave it.
But if the application server does not support, it can be emergency exit to
force closing connection using function of dbms.
This problem is not clear yet, because I don't know what is unhealthy state of
connection yet.
//Sorry for talking what I don't know exactly ....
If there exists such state and it is unavoidable , function to force closing
connection would be needed.
Does anyone know such a state of connection in Derby ....?
I have experienced such states, using other rdbms softwares in situation of
rough treatment .......
Best regards.
/*
Tomohito Nakayama
[EMAIL PROTECTED]
[EMAIL PROTECTED]
[EMAIL PROTECTED]
Naka
http://www5.ocn.ne.jp/~tomohito/TopPage.html
*/
----- Original Message -----
From: "TomohitoNakayama" <[EMAIL PROTECTED]>
To: "Derby Development" <[email protected]>
Sent: Friday, July 29, 2005 10:01 PM
Subject: Re: [jira] Updated: (DERBY-478) Function to force closing connection
(and session)
Hello.
It would be interesting to understand the problem that this enhancement is
wrestling with.
Nakayama-san, can you shed some more light on your reasons for logging this bug?
As Dan and Rick says, it is not recommended to close physical Connection
directly when ConnectionPool was used.
However ,I think there are cases user reluctantly close physical Connection.
For example, if application close database by itself , that application should
ensure to close physical connection too.
However , if connection exists in ConnectionPool, there are no way to ensure
to close physical connection.
(This was problem found in DERBY-273. )
Another example,even if application does not close database,it is not out of imagine that connection falls into illegal state and
database administrator wants to kill unhealthy connection .
//This would be incompatible to the charter of derby , "zero administration for end
users" .... :(
If the application server that serve the ConnectionPool supports to kill
Connection by administrator, we can leave it.
But if the application server does not support, it can be emergency exit to
force closing connection using function of dbms.
Best regards.
/*
Tomohito Nakayama
[EMAIL PROTECTED]
[EMAIL PROTECTED]
[EMAIL PROTECTED]
Naka
http://www5.ocn.ne.jp/~tomohito/TopPage.html
*/
----- Original Message -----
From: "Rick Hillegas" <[EMAIL PROTECTED]>
To: "Derby Development" <[email protected]>
Sent: Friday, July 29, 2005 2:33 AM
Subject: Re: [jira] Updated: (DERBY-478) Function to force closing connection
(and session)
I agree with Dan.
PooledConnection exposes a getConnection() method which returns its wrapped
Connection object. I suspect the intention is that that Connection is itself a
wrapper whose close()
method deliberately does not close the underlying physical Connection. Being
able to
close the underlying Connection would work at cross-purposes to the whole idea
of Connection pooling.
It would be interesting to understand the problem that this enhancement is
wrestling with.
Nakayama-san, can you shed some more light on your reasons for logging this bug?
Thanks,
-Rick
Daniel John Debrunner wrote:
Rick Hillegas wrote:
Hi David,
Where in the JDBC 4 spec would this be? I seem to have missed it.
There's a fairly long section on Connection Pooling, but I didn't see
this issue addressed.
I'm not sure it should be. Applications should not have the ability to
close the underlying physical connection from their logical connection
object. An api exists to close the physical connection, the close method
on PooledConnection. But applications do not (and should not) have
access to PooledConnection.
Dan.
Thanks,
-Rick
David Van Couvering wrote:
Isn't this part of the proposed interfaces for the JDBC 4 spec?
Tomohito Nakayama (JIRA) wrote:
[ http://issues.apache.org/jira/browse/DERBY-478?page=all ]
Tomohito Nakayama updated DERBY-478:
------------------------------------
Summary: Function to force closing connection (and session) (was: Force
to close connection and session)
Description: When connection exists in ConnectionPool , there are
no way to ensure closing connection inside the ConnectionPool from
application program just using jdbc interface.
I think there exists needs to force closing connection when it is
needed to ensure closing of connection. was:When connection exists
in ConnectionPool , there are no way to ensure
Function to force closing connection (and session)
--------------------------------------------------
Key: DERBY-478
URL: http://issues.apache.org/jira/browse/DERBY-478
Project: Derby
Type: Improvement
Components: Network Server
Reporter: Tomohito Nakayama
When connection exists in ConnectionPool , there are no way to
ensure closing connection inside the ConnectionPool from application
program just using jdbc interface.
I think there exists needs to force closing connection when it is
needed to ensure closing of connection.
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