98
Traffic Server generates log files that contain information about every request it receives and every error it
detects.
This chapter discusses the following topics:
•
Understanding Traffic Server log files‚ on page 98
•
Understanding event log files‚ on page 98
•
Managing event log files‚ on page 99
•
Choosing event log file formats‚ on page 101
•
Rolling event log files‚ on page 109
•
Splitting event log files‚ on page 112
•
Collating event log files‚ on page 115
•
Viewing logging statistics‚ on page 119
Understanding Traffic Server log files
Traffic Server records information about each transaction (or request) that it processes and every error that it
detects in log files. Traffic Server keeps three types of log files:
•
System log files record system information, which includes messages about the state of Traffic Server and
any errors or warnings that it produces. This kind of information might include a note that event log files
were rolled, a warning that cluster communication timed out, or an error indicating that Traffic Server was
restarted. (Traffic Server posts alarms signifying error conditions on Traffic Server’s Dashboard; see
The
Dashboard page‚ on page 120
for details.)
All system information messages are logged with the system-wide logging facility message under the
daemon facility. The
syslog.conf
configuration file (stored in the
/etc
directory) specifies where
these messages are logged. A typical location is
/var/log/messages
.
Since the messages process works on a system-wide basis, it serves as the single repository for messages
from all Traffic Server processes, including
traffic_server
,
traffic_manager
, and
traffic_cop
.
System information logs observe a static format. Each log entry in the log contains information about the
date and time the error was logged, the hostname of the Traffic Server that reported the error, and a
description of the error or warning.
See
Appendix F‚ Traffic Server Error Messages
for a list of the system information messages that Traffic
Server logs.
•
Error log files record information about why a particular transaction was in error.
•
Event log files record information about the state of each transaction that Traffic Server processes.
Understanding event log files
Event log files record information about every request that Traffic Server processes. By analyzing the log files,
you can determine how many people use the Traffic Server cache, how much information each person
requested, what pages are most popular, and so on.
12 Working with Log Files
