A Comprehensive Guide to Log Monitoring

Logs are like puzzle pieces gathered from your systems. Each one is a tiny clue to understanding the bigger picture, but without the right approach, those pieces will remain scattered and meaningless.

Log monitoring is about connecting the dots, identifying patterns, and clearly understanding how everything fits together.

This article explores key concepts and best practices in log monitoring to ultimately help you detect and resolve production issues faster.

What are logs?

Logs are timestamped records of everything happening within a computer system. They contain much of the data that makes a system observable, such as user inputs, system outputs, error messages, audit trails, and more.

These details are essential for understanding how applications, servers, and services are behaving, and they help engineers keep track of significant events, troubleshoot problems, and improve overall service reliability.

Log records come in different flavors, such as:

• Application logs that focus on what's happening inside a specific application,
• Infrastructure logs, which are records generated by the underlying system components such as servers, containers, virtual machines, or network devices,
• and security logs for keeping tabs on user activity and other related events.

These logs are often stored in text files, databases, and specialized log management systems. However, they're only valuable if you actively watch what they're saying.

This is where log monitoring comes in.

What is log monitoring?

Log monitoring is the practice of scrutinizing and acting on the log data collected from various components within your business environment, including web services, cloud platforms, databases, network hardware, and more.

Through the ongoing analysis and visualization of log data, you can quickly detect unusual activity, security risks, system failures, and performance bottlenecks, which contributes to observability and enables much faster incident response.

Why is log monitoring important?

Modern software systems are incredibly complex, with countless interconnected parts generating mountains of log data. Trying to make sense of this information without help is like searching for a needle in a haystack. That's why log monitoring is so critical.

Without this watchful eye, troubleshooting problems becomes a nightmare. Imagine a sudden system crash – without log monitoring, you'd be left scrambling through endless log files, desperately trying to find the cause.

But with a log monitoring system, you'll get a real-time view of what's happening. Automated alerts pinpoint issues instantly, allowing you to respond quickly and effectively.

But log monitoring isn't just about fixing problems after they occur; it's also about preventing them in the first place. By identifying early warning signs, you can proactively address issues and keep your systems running smoothly.

Now that you know what log monitoring is all about, let's look at what's involved in making it work for you.

What's involved in log monitoring?

Log monitoring is a multi-stage process that starts with identifying the relevant log sources. This is where you pinpoint the systems and applications that generate the relevant log data for your monitoring goals.

Next comes log aggregation. Instead of having logs scattered across different locations, you bring them together into a central repository through log shippers like Vector, Fluentd, or the OpenTelemetry Collector.

Log aggregation is often accompanied by log parsing where the raw log entries are normalized into a consistent structured format and enriched with relevant contextual information. This is an essential step in making the logs easier to analyze and compare.

With your logs parsed and normalized, you'll need a place to store them. A centralized log management solution is your best bet for efficiently and securely managing the growing volume of log data generated by your systems.

The heart of log monitoring lies in the analysis and visualization of log data. Your chosen log management platform should allow log exploration, perform complex queries, and uncover hidden patterns and anomalies. Visual dashboards bring this data to life, making it easy to identify trends and communicate insights.

Finally, no log monitoring system is complete without alerting. By setting up rules and thresholds, you can trigger real-time notifications when critical events occur or when unusual patterns emerge in your logs.

Such notifications ought to be managed through an incident management platform capable of directing alerts to the appropriate individual or team through the right channel (like Slack, email, SMS, or phone call), with options for further escalation if needed.

When to use log monitoring

While there are countless reasons to embrace log monitoring, here are some key scenarios where it truly shines:

1. Troubleshooting incidents

Fundamentally, log monitoring is used to find out what went wrong when errors or performance problems occur in the system.

It helps you pinpoint the root cause of problems, whether it's a bug in your code, a server overload, or something else that has to do with upstream services.

This leads to faster troubleshooting, less downtime, and quicker recovery from incidents.

2. Keeping the bad guys out

Continuously monitoring your logs for unauthorized access or other suspicious activity is a prerequisite to getting alerted to patterns that might raise red flags.

The Open Web Application Security Project (OWASP) even lists insufficient logging and monitoring as a top security risk. Without it, you'll be leaving the door wide open for attackers.

Logs also provide a crucial audit trail after a security incident, helping you understand what happened and prevent future breaches.

You can see an example of how to monitor Linux authentication logs here.

3. Ensuring regulatory compliance

For industries with strict regulatory requirements, such as finance or healthcare, logs provide a trail of system activity, which allows you to demonstrate adherence to legal and security standards during audits.

Continuous log monitoring ensures that potential violations are flagged early and resolved to reduce the risk of non-compliance.

Log monitoring best practices

To craft an effective log monitoring strategy, certain best practices must be followed such as the following:

1. Follow logging best practices

For log monitoring to be truly effective, ensure that the logs you're generating follow logging best practices. The most important one is for the logs to be in a structured format such as JSON. You also want to avoid sensitive data in your logs as this poses security risks and reduces their value for observability.

2. Integrate log monitoring with incident response

Log monitoring isn't just about collecting data; it's about taking action. To maximize its effectiveness, you must pair it with an appropriate incident response strategy that route alerts to the right people or teams through the appropriate channel.

3. Complement logs with metrics and tracing

While logs help you understand the "what" and "when" of discrete events within your system, they aren't enough for end-to-end observability in cloud-native environments.

To gain a more holistic view, ensure your services are instrumented to collect both metrics and distributed traces so that you can accurately track issue causation instead of relying on simple correlations, and quantify their impact on users and system performance.

You can use tools like Prometheus and OpenTelemetry to instrument and collect those signals from your services and infrastructure.

4. Prevent alert fatigue

Alerts are essential for catching problems quickly, but too many alerts can be just as bad as none at all.

Imagine a car alarm that goes off every time a bird lands on it – you'd quickly learn to ignore it, even if there's a real thief trying to break in.

This is alert fatigue, and it can cause you to miss critical issues.

You can avoid this by focusing on alerting for truly important events with customer impact, not minor hiccups.

5. Create log retention policies

Logs are valuable, but storing them indefinitely can become a costly burden. Establish clear log retention policies that balance the need for historical analysis with efficient storage management.

You can adopt strategies like moving older, less frequently accessed logs to cheaper storage options, maintain a separate policy for compliance logs according to regulatory requirements, and deleting logs when they are no longer needed.

How to choose a log monitoring tool

For log monitoring to be productive and efficient, you need to select a platform that supports your goals at the required scale. Below are some of the key aspects to consider:

• Integration with your tech stack: Ensure the tool easily integrates with your entire infrastructure, from applications and servers to cloud services.

• Scalability: It should also scale effortlessly as your systems grow by handling increasing log volumes without compromising performance.

• Analytical capabilities: Look for a tool that provides real-time dashboards and other features that help you identify trends in your system behavior.

• Incident management: The platform should offer customizable alerts and provide features that streamline incident management workflows.

Monitoring your log data with Better Stack

Better Stack's observability platform offers first-class log management and monitoring features that help you transform your log data into actionable insights without breaking the bank.

Beyond basic monitoring features like live tailing, customizable dashboards, and log querying, you can derive metrics directly from logs to enable anomaly monitoring even in scenarios with high cardinality or where direct metrics instrumentation is not feasible.

You'll also get comprehensive incident and on-call management tools to help you detect issues immediately they occur, route alerts to the right channels, and AI-based incident silencing that prevents alert fatigue.

To see all this and more in action, sign up for a free account here.

Final thoughts

It's clear that attaining adequate situational awareness of your application and its surrounding infrastructure relies heavily on log monitoring.

Dedicating time to implement and refine this process is a valuable investment that promises substantial returns in the long-term provided you select the right tooling and implement the best practices outlined above.

Thanks for reading, and happy logging!

Article by

Ayooluwa Isaiah

Ayo is a technical content manager at Better Stack. His passion is simplifying and communicating complex technical ideas effectively. His work was featured on several esteemed publications including LWN.net, Digital Ocean, and CSS-Tricks. When he's not writing or coding, he loves to travel, bike, and play tennis.

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