You are previewing #20: Running the Numbers: System, Network, and Environment Monitoring.
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#20: Running the Numbers: System, Network, and Environment Monitoring

Book Description

This booklet is about one aspect of system and network monitoring: collecting, storing, reviewing, and acting on numbers (or, more formally, data points) that tell us something relevant about our environment. We are concentrating on instrumenting our systems and networks rather than on examining or monitoring the services we provide. We focus on monitoring our environment and less on controlling the equipment that controls it.

But with any monitoring process comes the ability to influence the thing being monitored, either automatically or through conscious action on the part of the person(s) doing the monitoring. As Lord Kelvin1 said, "If you cannot measure it, you cannot improve it," and we seek to improve our processes by monitoring what is going on in them."

Table of Contents

  1. Copyright
  2. Preface
  3. 1. Introduction
    1. 1.1. What Is Monitoring?
    2. 1.2. Why Monitor?
    3. 1.3. Service Level Agreements
    4. 1.4. What Types of Data Can We Collect?
    5. 1.5. Contents of This Booklet
  4. 2. Data Collection
    1. 2.1. What You Can Collect
      1. 2.1.1. Baselines: What Is Normal?
      2. 2.1.2. Values Over Time
      3. 2.1.3. Variations
    2. 2.2. Types of Sensor Information
      1. 2.2.1. SNMP
      2. 2.2.2. Environmental Sensors
      3. 2.2.3. CPU Sensors
      4. 2.2.4. Disk Sensors (SMART)
      5. 2.2.5. UPS Sensors
      6. 2.2.6. Custom Sensors
      7. 2.2.7. A Warning on Environmental Sensor Readings
      8. 2.2.8. A Warning on Monitoring System Load
    3. 2.3. Underlying Sensor Hardware
    4. 2.4. Types of Interfaces
      1. 2.4.1. SNMP
      2. 2.4.2. HTTP
      3. 2.4.3. OWFS—1-Wire File System
      4. 2.4.4. MODBUS
      5. 2.4.5. ASCII Serial
      6. 2.4.6. Telnet
      7. 2.4.7. USB
      8. 2.4.8. XML, XML-RPC
      9. 2.4.9. Command Line
  5. 3. Data Storage and Logging
    1. 3.1. What to Keep, What to Toss
    2. 3.2. A Place for Everything
      1. 3.2.1. Flat Text Files
      2. 3.2.2. The Miracle of RRDtool
      3. 3.2.3. Traditional Database
      4. 3.2.4. Non-Traditional Database
    3. 3.3. Here a Point, There a Point
      1. 3.3.1. Everything Gets Old
    4. 3.4. Out with the Old
  6. 4. Visualization
    1. 4.1. Visualization vs. Numbers
    2. 4.2. Visual Acuity
      1. 4.2.1. What Goes Together?
      2. 4.2.2. One of These Things Is Not Like the Others
      3. 4.2.3. What Sort of Visualization?
      4. 4.2.4. Time Is on Your Side
      5. 4.2.5. Consistency
    3. 4.3. Creating Visuals
      1. 4.3.1. Visuals with Gnuplot
      2. 4.3.2. Perl Visuals with GD::Graph
      3. 4.3.3. Visuals with PHP
      4. 4.3.4. Graphing with RRDtool
        1. 4.3.4.1. Drraw—Ad Hoc Web Interface to RRDtool
        2. 4.3.4.2. Orca: Using RRDtool with Other Data
      5. 4.3.5. Other Visualization Tools
  7. 5. Alerting
    1. 5.1. Thresholds and Problem Detection
    2. 5.2. Alerts, Methods, and Notifications
  8. 6. Analysis
    1. 6.1. Web Site Security Flaw
    2. 6.2. HVAC Problems
    3. 6.3. DNS Server Failover
  9. 7. Software and Hardware Sources
    1. 7.1. Software
      1. 7.1.1. MRTG—The Multi Router Traffic Grapher
      2. 7.1.2. Cricket
      3. 7.1.3. Cacti
      4. 7.1.4. Torrus: Data Series Processing
      5. 7.1.5. Thermd
      6. 7.1.6. Time Series Data Through Other Tools
    2. 7.2. Hardware
      1. 7.2.1. Hardware Vendors and Recommendations
    3. 7.3. External Monitoring of Utilities
  10. 8. Advice
    1. 8.1. General Advice on Monitoring
    2. 8.2. Advice on Environmental Monitoring
    3. 8.3. Tell 'em What You Told 'em
    4. 8.4. In Closing
  11. A. Sample Scripts
    1. A.1. Smcount—Count Sendmail Events from Syslog
    2. A.2. Mailstats—Sample Smcount Output
    3. A.3. Smcricket—Sendmail Stats Into Cricket
    4. A.4. Querycount—Log BIND 9 Statistics
    5. A.5. Querycountlog—Sample Querycount Output
    6. A.6. Gather BIND 9 Statistics via Snmpd
    7. A.7. Ntpcricket—NTP Statistics Into Cricket
  12. Glossary
  13. References
  14. About the Authors