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Re: Problem after problem... (Re: [JBoss-user] http session clustering)

Stephen Davidson

2003-07-05

Replies:

Hi Sacha.

Umm, I should point out that Petstore & xPetstore have been found to have
a number of issues with them.

One of the ones we ran accross was that it uses PASSWORD as a field name
for a couple of Entity Beans. Many databases refuse that as a column
name, as they consider it a reserved word.

A few other compatability issues were found with it as well for
JBoss 3.x, which I am still working on.

To our panicked friend, the bad news is this;
No Appserver does everything properly. I know this, as I have actually
worked with most of the others in a production (or near production)
environment. By near production, I mean this;
The appserver worked in single node mode, but when attempts were made
to scale, load test and/or cluster, the appserver failed miserably,
and the product's support department failed to support their product.
No, JBoss does not yet do everything for everybody, but it is by
far the most complete solution out there.

That said, I do have the following comments;
Why do you not take the problems you are having and;
1) post them to the developer list;
2) Since you seem to have many details, and what sounds like
"golden" testcases, start opening bug reports on SourceForge?
The bug reports, they need the following;
A) Sample Code that causes the bug to occur
B) Platform the bug occurs on (OS/Java Version/Jboss version, etc)
C) Where necessary, the configuration that causes the bug to
occur.

I found when I supplied that info for the last major project
I was working on, bug fixes where issued within a week (usually
within a couple of days). Patches where possible was also
appreciated.

And JBoss Group, especially Ben Sabrin, it sounds like it would
be good publicity if this gent's thesis would succeed. So how
about lending him a technical hand to get his thesis done?

Joao, there are Java Users Groups in every city now, as well
as J2EE Groups in most. (Btw, anybody in Dallas, the DFW J2EE
SIG meets the third Tuesday of the month - This month the topic
is a Joint Presentation with another User Group on the Keel
Meta-Framework, a project that uses JBoss as one of its core
modules). You might be able to find somebody in one of these
groups to give you hand with some of the issues with your
project. It would speed things up for you a little if you could
get some help from people that have been doing this for a while.

If you are having specific issues with your Thesies Application,
go ahead and query me offline. I will have a quick look, and
will let you know where (and usually what) your problem is.
(I have been dealing with Massive Scale J2EE Applications for
nearly 4 years now).

Regards,
Steve


Sacha Labourey wrote:
> Well, if this application is buggy, it is buggy. Either you fix it, or you
> use another one. Take xPetstore: Sun says it contains the best j2EE
> patterns. Take a subset of this app, cluster it, and you end-up with a
> clustered j2eE app.
>
> Good luck,
>
>
>      Sacha
>
>
>>-----Original Message-----
>>From: Joao Clemente [mailto:jpcl@(protected)]
>>Sent: vendredi, 4. juillet 2003 01:41
>>To: jboss-user@(protected)
>>Cc: sacha.labourey@(protected)
>>Subject: Problem after problem... (Re: [JBoss-user] http
>>session clustering)
>>
>>
>>
>>sorry for replying so late, but here goes:
>>No, my problems are still not solved... And I almost gave up
>>on this...
>>This is my university thesis, and I'm already almost a year
>>late (it should
>>take a year and I've started my research almost two years
>>ago). If this is
>>not finished in the 2 year-time, the thesis will be cancelled by the
>>university.
>>
>>I'm suposed to use JBoss to provide a "scalable, fault-tolerant and
>>high-available middleware" infra-structure for a j2ee app
>>that is being
>>developed by another person.. another thesis that is being
>>developed at the
>>same time, a kind of a webmail on steroids..
>>This j2ee application is build on top of a already developed
>>open source
>>webapplication (servlet+jsp). It was "redesigned" to use
>>EJB's aswell. Then
>>it was expanded with the help of a couple of more external
>>libraries of
>>other independent open-source projects..
>>So we're talking about a webapp that was redisegned to be a
>>j2ee app, and
>>then glued to some other libs and projects and with some extra code
>>developed here... Put a Ldap connection here, a jabber server there, a
>>mailserver somewhere else and with a bit of luck you get
>>something like
>>this...
>>
>>About 10 months ago, I should had delivered tested results on
>>how the jboss
>>cluster can improve the scalability and fault-tolerance of
>>this application.
>>I'm failing miserably every test I make... day after day I crash into
>>another problem, and I'm unable to get those test results...
>>
>>I'm not saying this is JBoss's fault... No. I've found a
>>couple of bugs that
>>were JBoss and Javagroups related, as you (sacha) can
>>certainly remember.
>>But those were not the reasons I'm failing every time I try...
>>
>>This app sucks. Thats the truth I'm already seeing for a long
>>time ago and
>>it's exactly that that my thesis advisor (togheter with the
>>other theses
>>developer and advisor) is refusing to see..
>>Sure.. "but the app works fine", they say.
>>"It's a problem on your side", they say...
>>"It's your work to get that thing usable under load, it's
>>what your research
>>is suposed to do", they say..
>>
>>And, actually, if we use 1 (ONE!!!) client (wich, btw, must be
>>InterntExplorer) , with 1 (A SINGLE ONE!!!) jboss server, and
>>you test it
>>manually... it works..
>>
>>But, for instance,
>> - The app uses non-serializable objects all over the http
>>session. This
>>ceartainly gives us a hard time getting fault-tolerance (or
>>failover) to
>>work, besides the problems with the load-balancing...
>> - The owner of the original project (the one that was
>>redesigned here to
>>have ejb's besides servlets and jsp's) admitted that it never
>>tought of it
>>to be clustered, and had no ideia of what was to be done for it to be
>>runnable in a cluster...
>>
>>About three or four months ago I started writing java test
>>programs using
>>httpunit to load the app.. I've designed a simple client
>>model that would
>>just do four or five steps in the web app... Simple, right?
>>Then added a
>>threading model so I could have n similar clients accessing
>>the webapp...
>>Again, simple...
>>I decided to test WITHOUT a cluster. So, there as been at
>>least 3 months
>>that I do NOT have a load balancer, i DO NOT have a clustered
>>jboss setup,
>>there is just 1 jboss server and my client application...
>>
>>Results? I'm almost willing to wait 'till the 2 years of my
>>thesis end, my
>>university cancels it, so that I can start something new from
>>the scratch...
>>With NO cluster involved:
>>
>> - with 1 client ,if I run my test case (get hompage, login,
>>check mail,
>>logout) for 6 times, I would get locked. End of story.
>> - with 2 clients, would get about the same results..
>> - with 4 clients, I would get little more than exceptions...
>>
>> oh, btw, in most of these cenarios, I' would not even be
>>able to use the
>>application manually, as it would enter a cicle redirecting
>>me for the start
>>page (it's a "feature" of this app: if something goes wrong
>>then redirect to
>>start page)... until I shutted down jboss and started it over
>>(trying to
>>undeploy the app would lock jboss)
>>
>> and no, it does not stop here...
>> after some time, we found out that a singleton object of
>>that j2ee app was
>>unable to be runned concurrently and would cause the exception...
>> gimme some more headaches, and we find out that the locking
>>was due to one
>>of the external libs that were being used that, by some
>>reason, locks under
>>yet to be understood circuntances.. oh, and that lib was now
>>deprecated..
>>
>> ok, now what?
>> sending mail would work fine if used with InternetExplorer,
>>but would give
>>my java test client a error 500 page... Now what? Is it my
>>client's code
>>fault? Whose fault is it? Once again, one more week goes by
>>and we find that
>>there is another lib that was badly written..
>>
>> At what point am I now? This app finally runs with 4
>>(FOUR!?!) concurrent
>>clients... More than that and I get exceptions all over
>>again... Gimme a
>>break... I know JBoss is useable with hundrends of clients. I
>>know it! I see
>>it with my own short j2ee apps that I wrote for testing with
>>my clustered
>>setup!
>> This app, with a "no-cluster" environment breaks with 5
>>clients! It's
>>impossible to but this in a cluster and make it work
>>better... it sucks,
>>period!
>>
>>
>>But time keeps running and my thesis, my "scalable and fault-tolerant
>>middleware for a j2e appp" is going down the drain... no way
>>this app is
>>going to be useable under load... and I keep banging my head
>>on the wall
>>each time I run my tests, see the exceptions, and think to my
>>self... "ok...
>>where is it now? is it my test code? is it the app? is is the
>>xyz lib that
>>the app uses? maybe it's the foo lib... maybe the mail server
>>fault? maybe
>>jboss this time? maybe this java vm implementation has a bug... maybe
>>the..."
>>
>>
>>sometimes I'm over a week or two without doing progress... I
>>wake up in the
>>morning, I just feel like crying and I think "why tha hell
>>didn't I went for
>>medicine school? what 'tha heck... maybe I can still be a plumber or
>>something... maybe I should just be in bed..."
>>
>>


--
Java/J2EE Developer/Integrator
214-724-7741





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