Searching back through some old mail I see something similar has
surfaced before in this bug report:
https://bugs.launchpad.net/dhis2/+bug/534567
Also there was an issue with one of the servers in India which also
used mysql where I had a look at the log file and found an
inexplicably large number of threads blocked in a write operation
which I now suspect is also related.
It seems that some care needs to be taken to manage the mysql
connection pool over time. And as I suggested above I believe
(suspect!) the way to do that might be to proactively manage the
connection threads using c3p0's idleTestperiod property. Note I am no
hibernate or c3p0 expert.
I do recall from the "old days" perhaps around 2.01 we were commonly
setting c3p0 related properties in the hibernate.properties file. I
also remember (but can't find a reference) some suggestion of dropping
this. Lars, do you remember why we don't have these parameters set in
the hibernate.properties any more? I have a funny feeling that they
are required to keep long running mysql installations alive and
kicking.
Regards
Bob
···
On 5 July 2010 17:39, Orvalho Augusto <orvaquim@gmail.com> wrote:
Thanks for help.
Postgres I will use if I do not have a solution.
I will try things on the connection pool.
One very important note:
I have used DHIS 2.01 for almost a year and never happened to have these
errors on the same Fedora Server as described before. I have tried some
snapshot versions and again never had this.
I jumped from 2.01 to 2.04 and I start with MySQL troubles.Caveman
On Mon, Jul 5, 2010 at 10:20 AM, Bob Jolliffe <bobjolliffe@gmail.com> wrote:
Hi Orvalho
Whereas I do agree postgres might solve your problems it does seem
like a drastic solution to this problem. The fact is mysql does
actually work and apparently work well so it should be possible to
solve this.Trying to think logically here ... you have another similar setup
where everything seems ok. I suppose the load could be quite
different on the two servers, but lets discount that for a bit. If
you are reusing old stale and broken connections then the only three
places i can think to look are:
(i) the jdbc driver (version compatibility). I think you checked that.
(ii) tcp/ip problems
(iii) the connection poolRegarding (ii) can you check the value of bind-address in
/etc/mysql/my.cnf (or whatever config file you are using). This
should be set to 127.0.0.1 unless you are connecting to the db from a
different host. At least this interface will always be up so you
shouldnt get intermittent network errors on it.Regarding (iii) I suggest (as above) that you look at setting up c3p0
parameters to periodically test and discard stale connections. Does
anybody (maybe Indian team) have a good sample config?Regards
BobOn 4 July 2010 13:09, Orvalho Augusto <orvaquim@gmail.com> wrote:
> It will give some job because we developed a tool to convert data from
> one
> database to MySQL.
>
> It is the only thing I can try to do to solve.
>
> Caveman
>
>
>
> On Sun, Jul 4, 2010 at 8:16 AM, Knut Staring <knutst@gmail.com> wrote:
>>
>> Is postgres out of the question?
>>
>> On Jul 4, 2010 5:59 AM, "Orvalho Augusto" <orvaquim@gmail.com> wrote:
>>
>> I do not know what to do. I have found this:
>>
>>
>> http://dev.mysql.com/doc/refman/5.1/en/connector-j-usagenotes-troubleshooting.html
>>
>> And what makes me feel really bad is:
>> "22.3.5.3.4: I have a servlet/application that works fine for a day,
>> and
>> then stops working overnight MySQL closes connections after 8 hours of
>> inactivity. You either need to use a connection pool that handles stale
>> connections or use the "autoReconnect" parameter"
>>
>> and
>> "The autoReconnect facility is deprecated, and may be removed in a
>> future
>> release. "
>>
>>
>> So what we do?
>>
>> Caveman
>>
>> On Mon, Jun 28, 2010 at 12:59 PM, Bob Jolliffe <bobjolliffe@gmail.com>
>> wrote: > > Hi > > It looks...
>>
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>
>
>
>