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From "TomohitoNakayama" <tomon...@basil.ocn.ne.jp>
Subject Re: [jira] Updated: (DERBY-478) Function to force closing connection (and session)
Date Mon, 01 Aug 2005 14:21:12 GMT
Hello.

Talking with others , I have come to think the code in DERBY-273 was special ,
because ordinary application program does not shutdown database.

I might stand on that basis ....

How others think about ?

Best regards.

/*

         Tomohito Nakayama
         tomonaka@basil.ocn.ne.jp
         tomohito@rose.zero.ad.jp
         tmnk@apache.org

         Naka
         http://www5.ocn.ne.jp/~tomohito/TopPage.html

*/
----- Original Message ----- 
From: "TomohitoNakayama" <tomonaka@basil.ocn.ne.jp>
To: "Derby Development" <derby-dev@db.apache.org>
Sent: Monday, August 01, 2005 11:17 PM
Subject: Re: [jira] Updated: (DERBY-478) Function to force closing connection (and session)


> Hello.
>
> I have overviewed jdbc-4_0-edr-spec.pdf , and found next description for new feature
of JDBC4.0 , chapter 3.1 Overview of changes 
> in
> page 12.
>
>>Connection Management
>>Additional enhancements to Connection and improved connection state tracking, and
greater
>>Statement objects in pool environments.
>
> However, improved connection state tracking seems to mean just be able to track the state
and
> does not mean ability to change state of connection.
>
> In the same page 12 , specification describe new method added to Connection interface.
>
>>■ Connection
>>Added the methods createBlob, createClob, createNClob,createQueryObject, isValid,
createXML, getClientInfo,setClientInfo.
>
> There exists "isValid" but not "setValid".
>
> Then, I think it is impossible for JDBC 4.0 to force closing connection.
> Just be able to diagnose connection.
>
> Best regards.
>
> /*
>
>         Tomohito Nakayama
>         tomonaka@basil.ocn.ne.jp
>         tomohito@rose.zero.ad.jp
>         tmnk@apache.org
>
>         Naka
>         http://www5.ocn.ne.jp/~tomohito/TopPage.html
>
> */
> ----- Original Message ----- 
> From: "TomohitoNakayama" <tomonaka@basil.ocn.ne.jp>
> To: "Derby Development" <derby-dev@db.apache.org>
> Sent: Saturday, July 30, 2005 4:06 PM
> Subject: Re: [jira] Updated: (DERBY-478) Function to force closing connection (and session)
>
>
>> Hello.
>>
>> Can you give me time to see JDBC extensions ?
>> I have surveyed JDBC3.0 , jdbc-3_0-fr-spec.pdf, but have not surveyed JDBC4.0 .
>>
>> I think I need to survey JDBC4.0 too.
>> //And it would be wise to wait discussing about this for the survey of JDBC 4.0 :)
>>
>> Best regards.
>>
>> /*
>>
>>         Tomohito Nakayama
>>         tomonaka@basil.ocn.ne.jp
>>         tomohito@rose.zero.ad.jp
>>         tmnk@apache.org
>>
>>         Naka
>>         http://www5.ocn.ne.jp/~tomohito/TopPage.html
>>
>> */
>> ----- Original Message ----- 
>> From: "David Van Couvering" <David.Vancouvering@Sun.COM>
>> To: "Derby Development" <derby-dev@db.apache.org>
>> Sent: Saturday, July 30, 2005 3:38 AM
>> Subject: Re: [jira] Updated: (DERBY-478) Function to force closing connection (and
session)
>>
>>
>>> Sorry if I'm missing something, but if we end up agreeing that this is needed,
doesn't this require a non-standard extension to
>>> the JDBC API?
>>>
>>> Thanks,
>>>
>>> David
>>>
>>> TomohitoNakayama wrote:
>>>
>>>> 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
>>>>         tomonaka@basil.ocn.ne.jp
>>>>         tomohito@rose.zero.ad.jp
>>>>         tmnk@apache.org
>>>>
>>>>         Naka
>>>>         http://www5.ocn.ne.jp/~tomohito/TopPage.html
>>>>
>>>> */
>>>> ----- Original Message ----- From: "Rick Hillegas" <Richard.Hillegas@Sun.COM>
>>>> To: "Derby Development" <derby-dev@db.apache.org>
>>>> 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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>>>>> Checked by AVG Anti-Virus.
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>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>
>>
>> --------------------------------------------------------------------------------
>>
>>
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>>
>>
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>>
>>
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>>
>
>
>
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> Checked by AVG Anti-Virus.
> Version: 7.0.338 / Virus Database: 267.9.7/60 - Release Date: 2005/07/28
>
>
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> Checked by AVG Anti-Virus.
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> 



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