Hi everyone,
I just started to work for jboss application server. In
my environment I have jboss application server configured with Apache web
server. When first time I checked my apache server log I found that size of my
access.log file is more than 1GB and I was unable to open it. When I was
looking for the solution I came across the term log rotation.
For managing logs in apache you need to rotate the logs
either on time or size basis. In my case I decide to rotate my error and access
logs after every 20MB so I can easily read and analyze it. Let's look at how to
make logging more easily manageable in Apache.
Before we start let us take a look at some of the Apache
logging directives that are commonly used. These can be used to change the way
logging works in Apache.
Logging Directives
- CustomLog: The
CustomLog directive is used to set the log file name and its format. This
directive is used to configure the access_log logs.
- LogFormat: This
directive is used when you want to set the format for the access logs.
- LogLevel: This
directive used to set the level of verbosity in the error logs.
Configure Logging
Configuring Apache logging to make it easier to manage can
be done in several ways. The Apache configuration file, usually located at
/etc/httpd/conf/httpd.conf, has a section that defines some basic logging in
the default configuration file that ships with an Apache installation.
Set the LogLevel:
This should generally be set to warn. You can set this to a
higher level of verbosity on a development machine as you might want more
information from the server. However, if you are running a production server
you want to avoid creating too many logs as that will slow down the server.
LogLevel warn
Some of the other useful options for setting the level of
logging are Emerg for emergencies, Crit for critical issues, Error to set it to
error level, which is a little less verbose than warning level. The two most
verbose options are Info and Debug. These write a lot of data, and can eat up
space very quickly.
Set the LogFormat
parameter:
This is the directive used to set the format of the logs
that are generated. You can set the user agent and other details of the log
files. Note that you should avoid tweaking this unless you know what you are
doing. This is especially the case if you plan to use a standard log file
parsing tool to analyze your web server logs.
LogFormat "%h %l %u %t \"%r\" %>s %b"
common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent
Configure Error Logs:
As discussed earlier, there are two important logs created
by default. The error log is one of them. This is the file where your web
server writes all of the issues it encounters. This log can be a lifesaver when
troubleshooting an issue with the server. The simplest way to configure the
error log's parameter is to set it to something like this:
ErrorLog /etc/httpd/logs/error_log
However, if you want to manage your logs in a smarter way,
there are two things that you might want to use. The first is log rotation, and
the other is setting up log file names to change on an hourly basis. The log
rotation can be handled by a tool that ships with most Apache installations,
called rotatelogs.
Setting up the logs to create 20MB size file is a simple
hack. For those familiar with the date command in Linux, the Apache
configuration file understand and translate some of the date commands. It
interprets %Y as year, %m as month, %d as date, and %H as the hour of the day,
%M as minutes and %S as seconds. We use this parameter together like
%Y-%m-%d-%H_%M_%S to set naming convention and track the exact timing. And for
the file rotate after every 20M simply write it after the naming conventions.
The final error log's configuration would look something like this.
ErrorLog "|bin/rotatelogs
logs/error.log.%Y-%m-%d-%H_%M_%S 20M"
This configuration will rotate the error logfile whenever it
reaches a size of 20 megabytes, and the suffix to the logfile name will be
created of the form errorlog.YYYY-mm-dd-HH_MM_SS.
Access Logs:
The other important log generated by Apache is the access
log. This is the file where Apache logs information on every visitor and visit
to the web server. This is extremely useful to track and monitor usage
patterns, track malicious users, and basically keep an eye on proceedings. As
your usage increases, so will the size of this file. So again, like the error
file, it is a good idea to set the rotation policy we used for the error logs
for the access logs as well. We use the same rotation policy and setup the
access logs to look something like this.
CustomLog "|bin/rotatelogs
logs/access.log.%Y-%m-%d-%H_%M_%S 20M" combined
This configuration will rotate the access logfile whenever
it reaches a size of 20 megabytes, and the suffix to the logfile name will be
created of the form errorlog.YYYY-mm-dd-HH_MM_SS.
After making changes in httpd.conf file it is good to take a
restart of apache server to activate those changes. And now your access and
error logs are rotating after every 20MB and will create a new file.
You can find more information on its usage of rotatelogs
at link http://httpd.apache.org/docs/2.0/programs/rotatelogs.html
It works in my case hope this will help you.
“Effort only fully releases its reward after a person refuses to quit.”
Regards,
Akhilesh B. Humbe
