I assume based on all the "wonderful experiences" the states have experienced 
in last dozen years that Canada has wised up and stopped Americans from 
sneaking across the border without a passport?

better pack you snowshoes..they have about 6 feet of snow (last time i checked)

 

Keep me apprised,
M-

  



> Date: Tue, 25 Feb 2014 11:50:30 -0400
> Subject: Re: Tomcat/Java Spring MVC 2.0/c3p0 - Consultant needed
> From: charle...@thelearningbar.com
> To: users@tomcat.apache.org
> 
> On Tue, Feb 25, 2014 at 11:37 AM, Daniel Mikusa <dmik...@gopivotal.com>wrote:
> 
> > On Feb 25, 2014, at 10:14 AM, Charles Richard <
> > charle...@thelearningbar.com> wrote:
> >
> > > Hi,
> > >
> > > On Tue, Feb 25, 2014 at 1:26 AM, Christopher Schultz <
> > > ch...@christopherschultz.net> wrote:
> > >
> > >> -----BEGIN PGP SIGNED MESSAGE-----
> > >> Hash: SHA256
> > >>
> > >> Charles,
> > >>
> > >> On 2/24/14, 10:15 AM, Charles Richard wrote:
> > >>> Sorry if this is not the right forum for this kind of inquiry. I
> > >>> figure the best candidates would be in this forum from personal
> > >>> experience.
> > >>>
> > >>> Our company is having production issues which I believe are either
> > >>> due to application inefficiencies or a bug somewhere in our
> > >>> software stack.
> > >>>
> > >>> We are having production issues with our Tomcat connection pool
> > >>> using c3p0 and while my knowledge in this area has improved, I lack
> > >>> the Java developer background that might help in this area and we
> > >>> are at a point where we need this solved quickly.
> > >>
> > >> I've never gotten the sense that c3p0 was production-ready. What made
> > >> you deploy with c2p0 instead of either of the two connection pools
> > >> that ship with Tomcat? (Note that c3p0 has nothing to do with Tomcat,
> > >> other than that Tomcat can be configured to use c3p0 as its
> > >> connection-pool).
> > >>
> > >>
> > > That is good to know that c3p0 might not be commonly used in production
> > by
> > > companies using tomcats. I was under the impression it was the most
> > > commonly used.
> > >
> > >
> > >> The problems could be related to leaked connections which I'm quite
> > >>> sure we have. I have turned on c3p0 debugging and identified this
> > >>> in the past and the ideal consultant could identify in our code
> > >>> where those are happening and fix them.
> > >>
> > >> Both pools Tomcat provides can help you track-down so-called
> > >> "abandoned" connections by providing stack traces that point to the
> > >> line of code that obtained the connection (or even Statement or
> > >> ResultSet).
> > >>
> > >> C3P0 also allows you to track down abandoned connections and my gut
> > > feeling tells me how problem is not tied down exclusively to this as our
> > > Tomcat connection pools go from 1 used connection to 150 in a minute and
> > I
> > > know we are not losing that many leaked connections in a minute.
> > > Regardless, I will check with the manager here to see if this has been
> > > tried in the past before I started this job and potentially try this as
> > > unfortunately, the problem is not happening in our staging environment.
> >
> > When you are experiencing the problem next, take some thread dumps. Try
> > to get two or three, with 10 to 15 seconds between each one. You can then
> > look at the thread dumps to see what's going on here.
> >
> >
> > https://wiki.apache.org/tomcat/HowTo#How_do_I_obtain_a_thread_dump_of_my_running_webapp_.3F
> >
> 
> It's not easy to get good thread dumps as one minute things are fine and
> the next minute, the site is going downhill. I have bash scripts that
> monitor c3p0 connections and take an automatic thread dump as soon as the
> number exceeds what's normal.
> 
> >
> > There is information about interpreting them here or if you need help with
> > it, you could post it to the list.
> >
> >
> > https://wiki.apache.org/tomcat/HowTo#How_do_I_read_a_Java_thread_dump_.3F
> >
> > I have tried to analyze the thread dumps I have gotten so far without much
> luck but this could just be that I don't understand enough what I'm looking
> for. I will look at the link provided.
> 
> Thanks for taking the time to write this!
> 
> Dan
> >
> > Cheers,
> Charles
> 
> > >
> > >
> > >> I would highly recommend that you read this blog post I wrote several
> > >> years ago that can help you look for obvious errors by providing
> > >> examples for what JDBC code should look like -- if you are managing
> > >> your own JDBC calls of course:
> > >>
> > >>
> > http://blog.christopherschultz.net/index.php/2009/03/16/properly-handling-pooled-jdbc-connections/
> > >>
> > >>> We are looking to hire a consultant that would come to Fredericton,
> > >>> NB, Canada to work with us on this problem. Serious inquiries only.
> > >>> I will be looking for proof that you have extensive experience with
> > >>> Tomcat, Java Spring and c3p0.
> > >>>
> > >>> If you are interested, send me your resume (through your company
> > >>> or individually) and send me as much proof as possible of your
> > >>> experience with the specific technologies mentioned.
> > >>
> > >> While there is certainly no prohibition against doing so, this isn't
> > >> really a "help wanted" message board. We are happy to help you -- for
> > >> free! -- via email to solve your own problems. If you find this free
> > >> forum helpful, please consider staying to be a part of the community.
> > >> You may help others or learn things yourself.
> > >>
> > >> I find this forum for the most part helpful and I've posted a few times
> > > before. In general though, I haven't felt that comfortable to post here.
> > >
> > > Before you hire anyone, you might want to try the following:
> > >>
> > >> 1. Swap c3p0 for something more reliable such as Tomcat's default pool
> > >> (based upon commons-dbcp) or the newer, higher-performance
> > >> tomcat-pool. You can find documentation for both of those online in
> > >> the Users' Guide. If the pool is performing okay, this may not be
> > >> necessary, but it's nearly free to try so it may be a good first-step.
> > >>
> > >
> > > I might have to wait a month to try this so our peak traffic subsides as
> > I
> > > could test the config on our staging environment but since the problem is
> > > only happening on production, I would be nervous of not having the
> > optimal
> > > configuration and make things worse.
> > >
> > >>
> > >> 2. Check your own code for resource-handling errors. Take some time to
> > >> read my blog post, or have your engineers do it (better yet, have
> > >> everyone read it).
> > >>
> > >> Will do.
> > >
> > >
> > >> 3. Run a static-analysis tool such as FindBugs (which is free) against
> > >> your code. It can detect resource leaks you may not have known you
> > >> had. Running the tool takes almost no setup and/or skill, and you can
> > >> read the report entirely for free. If you have a million errors, it
> > >> might take you a lot of staff to identify and fix the problems, but
> > >> it's likely to point-out some problem areas -- and point you to the
> > >> exact line numbers where problems are likely to be.
> > >>
> > >> Thanks for the recommendation, I've never heard of this tool.
> > >
> > >
> > >> You might get a lot of mileage (kilometerage?) out of the above
> > >> without having to hire anyone.
> > >>
> > >> Thanks for taking the time to write this and trying to help!
> > >
> > >> - -chris
> > >>
> > >
> > > Cheers!
> > > Charles
> > >
> > >
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> > >> -----END PGP SIGNATURE-----
> > >>
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