Monitoring Traffic
Traffic Server provides several options for monitoring system performance and analyzing network traffic.
This chapter discusses the following topics:
- Traffic Server Monitoring Tools
- Working with Traffic Manager Alarms
- Viewing Statistics from Traffic Line
Traffic Server Monitoring Tools
Traffic Server provides the following tools to monitor system performance and analyze network traffic:
- Traffic Server can send email that's triggered by alarms that signal any detected failure conditions; refer to Working with Traffic Manager Alarms.
- The Traffic Line command-line interface provides an alternative method of viewing Traffic Server performance and network traffic information; refer to Viewing Statistics from Traffic Line.
- The Traffic Shell command-line tool provides yet another alternative method of viewing Traffic Server performance and network traffic information; refer to Starting Traffic Shell.
Working with Traffic Manager Alarms
Traffic Server signals an alarm when it detects a problem. For example, the space allocated to event logs could be full or Traffic Server may not be able to write to a configuration file.
Configuring Traffic Server to Email Alarms
To configure Traffic Server to send an email to a specific address whenever an alarm occurs, follow the steps below:
- In a text editor, open the
records.configfile located in the Traffic Serverconfigdirectory. - Set the
proxy.config.alarm_emailvariable to the email address alarms will be routed to. - Save and close the
records.configfile. - Navigate to the Traffic Server
bindirectory.
- Run the command
traffic_line -xto apply the configuration changes.
Using a Script File for Alarms
Alarm messages are built into Traffic Server - you cannot change them. However, you can write a script file to execute certain actions when an alarm is signaled. Traffic Server provides a sample script file named example_alarm_bin.sh in the bin directory; simply modify the file to suit your needs.
Viewing Statistics from Traffic Line
You can use the Traffic Line command-line interface to view statistics about Traffic Server performance and web traffic. In addition to viewing statistics, you can also configure, stop, and restart the Traffic Server system. For additional information, refer to Configuring Traffic Server Using Traffic Line and Traffic Line Commands. You can view specific information about a Traffic Server node or cluster by specifying the variable that corresponds to the statistic you want to see.
To view a statistic:
- Log on to a Traffic Server node as the Traffic Server administrator; navigate to the Traffic Server
bindirectory.
- Enter the following command:
traffic_line -r variable
wherevariableis the variable representing the information you want to view. For a list of variables you can specify, refer to Traffic Line Variables.
For example, the following command displays the document hit rate for the Traffic Server node:
traffic_line -r proxy.node.http.cache_hit_ratio
If the Traffic Serverbindirectory is not in your path, then prepend the Traffic Line command with./(for example:./traffic_line -r variable).