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From Filip Hanik - Dev Lists <devli...@hanik.com>
Subject Re: JDBC Pool Disconnections
Date Wed, 06 Apr 2011 20:03:43 GMT
On 4/6/2011 1:54 PM, הילה wrote:
> I wanted to add the last string as well, but they said to forget about it..
>
> :] and they should know best
> however, if disconnections will continue (there are some right now) I'll try
> it anyway
>
> as for the connection validation = you said that if the DB closes a
> connection (why does it happen? can I prevent it?)
most common is that the DB times out an idle connection. A pool holds a connection open, the
connection is not being used and the DB times 
it out. there are many examples, same thing if there is a network glitch, or the db is restarted.


> than the pool is checking
> if the connection is open and working. and if not? i the DB closed the
> connection and it's not usable.. then what does the pool do?
if the pool doesn't check, then it doesn't do anything.
if the pool check (testOnBorrow=true) and the test fails, it closes the old connection and
opens a new one.

Filip
>
> 2011/4/6 Filip Hanik - Dev Lists<devlists@hanik.com>
>
>> validate == connection is open and working
>>
>> if they are worried about performance, there is a compromise that gets you
>> best of both worlds
>>
>>
>> testOnBorrow="true"
>> validationQuery="select 1"
>> validationInterval="30000"
>>
>> this ensures that in a high concurrency environment, the number of
>> validations are limited
>>
>> Filip****
>>
>>
>>
>>
>> On 4/6/2011 1:36 PM, הילה wrote:
>>
>>> I wanted to add it, bu the company that developed the application that
>>> runs
>>>
>>> on the tomcat, says that it affect performance and has issues.
>>>
>>> what do you mean "validates it"? what does it do, exactly?
>>>
>>> Thanks
>>> Hila
>>>
>>>
>>> 2011/4/6 Filip Hanik - Dev Lists<devlists@hanik.com>
>>>
>>>   On 4/5/2011 7:31 AM, הילה wrote:
>>>>   name="jdbc/com/vstechnology/appname
>>>>> scope="Shareable"
>>>>> type="javax.sql.Datasource"
>>>>>
>>>>>
>>>>> url="jdbc:jtds:sqlserver://SQLServerName:1433/DBname;useCursors=false;sendStringParametersAsUnicode=false"
>>>>> factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
>>>>> maxActive="200"
>>>>> minIdle="0"
>>>>> maxIdle="10"
>>>>> maxWait="10000"
>>>>> initialSize="20"
>>>>> driverClassName="net.sourceforge.jtds.jdbc.Driver"
>>>>>
>>>>>   Add in
>>>> testOnBorrow="true"
>>>> validationQuery="select 1"
>>>>
>>>> this ensures that if the DB closes a connection, the pool validates it
>>>>
>>>> best
>>>> Filip
>>>>
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