From: Ken Bloom <kbloom@...>
Date: 2009-02-13T09:08:46+09:00
Subject: Re: SQLite as a Log?

On Thu, 12 Feb 2009 18:17:34 -0500, Joel VanderWerf wrote:

> James Gray wrote:
>> In a current project we're discussing using SQLite for all application
>> logging.
>> 
>> This is a heavy multiprocessing environment, which was one of our
>> reasons for considering it.  We also love the idea of structured
>> queries helping us debug issues:  show me any logged errors between
>> these times.
>> 
>> The minus of course is a slight loss in transparency.  For example, you
>> can't just tail a log file when you want.
>> 
>> Anyway, I would love to hear from anyone who has done this.  Did you
>> like it?  What were the downsides I am missing?
>> 
>> Thanks in advance for any information you can provide.
>> 
>> James Edward Gray II
> 
> IIRC one writer blocks the entire sqlite db. You could avoid this using
> a gatekeeper server for writing to the log.
> 
> Re tailing log files: I avoid that anyway, even with file logging,
> because it doesn't know about log rotation. The alternative I've found
> helpful is to set up a drb service that lets a process listen for log
> entries.

tail -F is useful following a log across log rotations. It follows the 
file by filename, not by file descriptor. (I learned this trick debugging 
an embedded system that rotated its logs every 5 minutes or so.)

--Ken

-- 
Chanoch (Ken) Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/