Monitoring Apache Logs
Ultimate Guide to Logging - Your open-source resource for understanding, analyzing, and troubleshooting system logs
Monitoring Apache Logs
Apache logs provide a significant amount of information about your web operations including server performance metrics, traffic volume, and errors. Monitoring these logs can help you optimize your web server and web applications, troubleshoot problems faster, and identify unusual events such as surges in traffic. This can lead to better website performance and a better experience for your users.
This section shows different methods of monitoring and analyzing Apache logs.
Top Alerts
Alerts are immediate notifications that give you a chance to proactively fix issues before too many customers are impacted or report support issues. Unfortunately, most Unix distributions don’t have convenient alerting tools, but you can try to build your own using cron jobs or postfix. Even better, log management services like SolarWinds® Loggly® will continuously check your logs to see if an alert should fire, and can notify you right away.
Here are some great alerts to consider for Apache. The search examples use the Loggly syntax, and you can find good thresholds by looking at trends during your peak site usage periods.
| Description | Search | Threshold |
| Your error rate is too high | apache.status:>400 | >100 in the last 15 minutes |
| Your traffic is much higher than normal | logtype:apache | >1000 in the last 15 minutes |
| Your site is much slower than desired | apache.requestTimeMillis:>1000 | >200 in the last 15 minutes |
Here are some tips on setting up Apache alerts.
- Check every 15 minutes over a 15-minute window. If you select less, you may have issues when there is an outage or a burst of data that gets queued.
- Set the email to go to a mailing list owned by your ops team, or use a service like PagerDuty to alert your on-call person or send an SMS.
Top Dashboards
Dashboards are a great way to stay on top of what’s happening on your site, as told by your Apache logs. Unix command line tools don’t offer good graphical dashboards, but log management systems have great capabilities built in. Here are some dashboards to set up for Apache, with an example screenshot showing each below.
Apache status over time tells you if there is an unexpected increase in traffic or error rate.
Line chart showing HTTP request status over time. © 2019 SolarWinds, Inc. All rights reserved.
Apache response time tells you if response times are slow due to servers getting overloaded or new code deployments. In the trend view, select timeline chart, a numeric field of apache.requestTimeMillis and the operator is Average or Max.
Line chart showing the maximum and average request time for Apache requests. © 2019 SolarWinds, Inc. All rights reserved.
Apache traffic by IP tells you if traffic issues are overwhelmingly caused by one or a small number of clients.
Pie chart of requests according to the source IP address. © 2019 SolarWinds, Inc. All rights reserved.
Top error URIs tells you which URIs have the most errors.
Bar chart of error requests according to the URI. © 2019 SolarWinds, Inc. All rights reserved.