Red Hat DIRECTORY SERVER 2.0 - GATEWAY Bedienungsanleitung PDF herunterladen (Seite 61)

Chapter 7. Logging

Finding bad links

Most browsers also include a query header Referer: which contains the URL of the

page that contain the link the user queried to bring them here. This can be particularly

useful to ﬁnd remote pages that have bad links onto your site.

CustomLog "%{Referer}i %U %>s" referer_log

Figure 7-14. Logging referers

Those pages which have bad links pointing into your site will generate status

code 404 and can be tracked down.

Log rotation

It is one thing to create logs; it is quite another to cope with them. A log ﬁle grows

without bound unless action is taken and this can cause problems.

Problems with growing log ﬁles

• Larger ﬁles are harder to manipulate.

• File systems run out of space.

• The information you log may constitute personal data.

A solution to this generic problem of log ﬁle growth is log rotation. This involves the

regular (nightly or weekly, typically) moving of an existing log ﬁle to some other ﬁle

name and starting fresh with an empty log ﬁle. After a period the old log ﬁles get

thrown away.

Because this is a general issue, Red Hat Linux provides a general solution that can be

applied to any set of log ﬁles, not just the web server’s. There is an Apache-speciﬁc

solution (which is provided by the rotatelogs command) but we will use Red Hat

Linux’s generic solution, provided in the logrotate package.

Once each night the logrotate program reads in its conﬁguration ﬁles telling it which

logs to rotate and how to do it. One of these instructions tells it to rotate any ﬁle in

/var/log/httpd whose name ends with log.

# rotate log files weekly

weekly

# keep 4 weeks worth of backlogs

rotate 4

# create new (empty) log files after rotating old ones

create

# RPM packages drop log rotation information into this directory

include /etc/logrotate.d

Figure 7-15. /etc/logrotate.conf: The main log rotation ﬁle

The main conﬁguration ﬁle sets up the defaults and then reads in a directory of in-

structions for speciﬁc sets of log ﬁles from the /etc/logrotate.d directory.

/etc/logrotate.conf: commands

weekly

Each ﬁle should be rotated weekly. The log rotation job runs nightly, though, so

this can be changed to daily for a speciﬁc log ﬁle if desired.

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 95 96

Keine Kommentare

Red Hat DIRECTORY SERVER 2.0 - GATEWAY Bedienungsanleitung Seite 61