dhis2-devs team mailing list archive

[Neeraj Gupta <neeraj.hisp@xxxxxxxxx>]

Thanks Bob,

We will try the options and will let you know the results.

On Thu, Jan 26, 2017 at 3:53 PM, Bob Jolliffe <bobjolliffe@xxxxxxxxx> wrote:

> This seems to be a known problem between mysql, java and c3p0 (the
> database connection pool).  It seems that mysql resets connections which
> are not used for 8 hours (by default).  For some reason these stale
> connections then get served up from the connection pool giving rise to this
> error.
>
> You can kick the problem further down the tracks by increasing the timeout
> on the mysql side.  check the documentation for the configuration option.
>
> Or you can make c3p0 more robust, for example by checking connections on
> checkout (google 'c3p0 mysql reset' for lots of discussion, tips, advice
> etc).  This involves tweaking hibernate settings, possibly inside the war
> file.  I haven't tested myself on mysql for a long time.  I think HISP
> India folk probably have the best experience of supporting mysql on DHIS2
> over the years.
>
> On 25 January 2017 at 07:55, Neeraj Gupta <neeraj.hisp@xxxxxxxxx> wrote:
>
>> Dear team,
>>
>> For one of our client, we are using DHIS2.21 with MySQL 5.6. Application
>> server and database server are separate and can talk to each other.
>> Since last 3 weeks, they are facing issues and getting the below message
>> instead of login screen.
>>
>> *org.springframework.transaction.CannotCreateTransactionException: Could
>> not open Hibernate Session for transaction; nested exception is
>> org.hibernate.TransactionException: JDBC begin transaction failed*
>>
>> After refreshing the page twice or thrice login page gets loaded.
>>
>> I tried to check the log file and found below errors
>>
>>    - org.hibernate.TransactionException: JDBC begin transaction failed
>>    - com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:
>>    Communications link failure
>>    - java.net.SocketException: Connection reset
>>
>> Has anyone had any idea about these and how these can be rectified? Any
>> help is much appreciated.
>>
>> --
>> Thanks,
>> Neeraj Gupta
>>
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>


-- 
Thanks,
Neeraj Gupta