Hi fellow monks,

I work on a web based hotel reservation system. My web application sometime lose the content of the cart, which is stored in a session (that wraps around Apache::Session, which use MySQL as the storage). It loses its content when it goes to the checkout page.

Whenever it happens, it sends an email to us and redirects the user to the start page to redo her booking. So we know when it happens, but it definitely will annoy users.

I and the other programmer have been trying to figure out why that happen for months and we have never been able to point the finger on any part of the code. This error happen intermittently and randomly. We could never see any pattern from the emails sent to us. It happens around 10-20 times a day.

I can not reproduce it in the test system, but it sometimes happen there as well, randomly. But I am worried to trace the error on the production system because it is heavily used 24/7.

Do you guys have any suggestion on how to debug this and find the cause?

UPDATE: more description about my environment.

My webapp runs under mod_perl 1.27 with a home grown application framework on a debian sarge box. Our application runs on multiple hostnames, each client gets its own hostname. But, we only have one secure hostname. The checkout page runs under this hostname. However, both secure and unsecure sites executes the same set of code.

Our session class wraps Apache::Session::MySQL (version 1.01 - Apache::Session's version is 1.6) with OO interface suited for the framework. When a user selects a room, it puts the room in the cart (which theoritically will store the session back to the database storage between requests). I suspect the error comes from the failure of Apache::Session to store/retrieve the data to/from database. But that is impossible, because A::S should throw an error instead.

The database server is shared by two internet facing web servers. It runs MySQL 4.1.1 and the session table type is MyISAM.

Anyway, does anyone know good perl consultants around Gold Coast, Australia?

Thanks

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badaiaqrandista

In reply to Debugging intermittent web application bug by badaiaqrandista

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