Understand These Metrics in Server Monitoring (2025)
Understand These Metrics in Server Monitoring (2025)
Published on July 3, 2025 Last Updated on July 4, 2025
Written by
Morgan Frank - Specialist in Page Speed
Your website relies on a server, which is a powerful computer that stores your website’s files and delivers them to visitors. Just like any computer, a server can experience performance problems.
Server monitoring is the process of keeping a close eye on your server’s health and performance to identify and fix any issues before they slow down your website or cause it to become unavailable. It is a crucial part of the website.
It’s not about waiting for things to break. It’s about being proactive and catching small problems early, before they turn into big problems.
Before we look at specific tools and techniques, let’s summarize the key things to remember:
Key Takeaways
Monitoring is Proactive: We’re looking for potential problems, not just reacting to disasters.
Key Resources to Watch: We need to monitor the server’s CPU (its “brain”), memory (RAM), disk space and speed, and network connection. For databases, we need to check how quickly they can retrieve information.
Tools are Essential: We use specialized software to track these resources and alert us to problems.
Know What’s “Normal”: We need to understand what normal performance looks like for our server so we can spot anything unusual.
Get Alerts: We set up alerts to notify us (e.g., via email or text message) if something goes wrong.
Investigate and Fix: When we find a problem, we need to figure out the cause and then take steps to fix it.
Regular Checks: Monitoring isn’t a one-time thing; it’s an ongoing process.
Why Bother Monitoring?
Without monitoring, you’re flying blind. You won’t know if your server is struggling until your website slows down or crashes, which directly impacts your users and potentially your business. Here’s why monitoring is so important:
Catch Problems Early: Detect performance issues before they affect your visitors. A slow website leads to frustrated users, higher bounce rates, and lower search engine rankings.
Optimize Performance: Understand how your server resources are being used. This allows you to identify areas where you can improve efficiency and make your website faster.
Plan for Growth: See how your server handles increasing traffic. This helps you determine when you need to upgrade your server resources (more RAM, faster CPU, etc.) to accommodate future growth.
Troubleshoot Effectively: When something does go wrong, monitoring data gives you the information you need to quickly diagnose the cause and find a solution.
Improve Security: Some monitoring tools can also help detect unusual activity that might indicate a security breach.
Uptime: Detect downtime and bring it up.
What to Watch: Key Server Metrics
A server has several key components that we need to keep an eye on. Here are the most important metrics to monitor:
Let’s understand some of the important terms before we dive into the tools:
CPU Usage (Central Processing Unit): The CPU is the “brain” of the server. This metric shows how busy the CPU is. If the CPU is constantly running at or near 100%, it’s a sign that the server is overloaded and needs more processing power.
Memory Usage (RAM – Random Access Memory): RAM is the server’s short-term memory. It’s where the server stores data that it needs to access quickly. If the server runs out of RAM, it starts using the hard drive as temporary memory (called “swapping”), which is much slower.
Disk I/O (Input/Output): This measures how quickly the server can read and write data to its storage (hard drive or SSD). Slow disk I/O can be a major bottleneck, especially for websites that rely heavily on databases.
Network Traffic: This shows how much data is being sent and received by the server over the network. High network traffic can indicate a problem, such as a denial-of-service attack, or it might simply mean your website is very popular (which is good!).
Database Performance (If Applicable): Most websites use a database to store information (like user accounts, product details, or blog posts). We need to monitor how quickly the database can respond to requests for information (“queries”). Slow database queries can significantly slow down your website.
Tools of the Trade: Server Monitoring Software
To monitor these metrics, we use specialized software tools. There are many options available, ranging from simple command-line utilities to sophisticated monitoring platforms.
Here are some of the types of tools, along with some popular examples.
1. System Monitoring Tools (Comprehensive Overview): These tools provide a broad view of your server’s overall health and performance.
Nagios: A powerful and widely used open-source monitoring system. It can monitor a wide range of resources and send alerts when problems occur.
Zabbix: Another popular open-source option, similar to Nagios.
Prometheus: An open-source monitoring solution often used with Grafana (for visualization).
Grafana: A visualization tool that lets you create custom dashboards to display data from various sources (like Prometheus). Icinga: Open Source monitoring system.
Checkmk: Monitoring System.
Netdata: Get real-time insights.
2.Application Performance Monitoring (APM) Tools (Code-Level Insights): These tools focus on the performance of your application (your website’s code). They can help you identify bottlenecks within your code itself.
New Relic: A popular APM platform that provides detailed insights into your website’s performance.
Datadog: Another comprehensive APM and infrastructure monitoring tool.
AppDynamics: An APM platform often used for large, complex applications.
Dynatrace: Another APM platform.
3.Operating System Utilities (Built-in Tools): Your server’s operating system (like Linux or Windows) comes with built-in tools that you can use to quickly check performance.
top (Linux/macOS): Shows you which processes are using the most CPU and memory.
htop (Linux): A more user-friendly version of top.
iostat (Linux): Shows you how busy your hard drive is.
vmstat (Linux): Provides information about memory, CPU, and I/O usage.
Task Manager (Windows): Shows you which programs are running and how much CPU and memory they’re using.
Resource Monitor (Windows):
4. Log Monitoring:
5. Loggly:
6. Sematext Logs:
7. Papertrail:
8. Splunk:
Knowing What’s “Normal” and Setting Up Alerts
Just seeing the numbers isn’t enough. You need to know what’s normal for your server, and you need to be notified if something goes wrong.
Let’s discuss some of the best practices.
1.Establish Baselines: The first step is to understand what “normal” performance looks like for your server. Use your monitoring tools to track your server’s performance over time (e.g., a week or a month) during typical usage. This will give you a baseline against which to compare future performance.
2. Set Up Alerts: Once you know what’s normal, you can set up alerts to notify you if something deviates from that norm. For example, you might set up alerts for:
High CPU usage (e.g., above 90% for more than a few minutes)
High memory usage (e.g., consistently above 95%)
High disk I/O
Unusual network traffic spikes
Slow database queries
Errors in your server logs
3.Alerting Methods: Get notified via Email, SMS etc..
Troubleshooting: Finding and Fixing Problems
When you get an alert (or notice slow performance), you need to act like a detective and figure out what’s causing the problem.
Here are the steps you should take:
1. Identify the Bottleneck: Use your monitoring tools to pinpoint which resource is causing the problem (CPU, memory, disk I/O, network, or database).
2.Investigate the Cause: Once you know what is wrong, you need to figure out why. This often involves looking at your monitoring data in more detail and using operating system utilities. Some common causes include:
High CPU Usage: A specific program or website script might be using too much processing power.
High Memory Usage: A program might have a “memory leak” (it keeps using more and more memory without releasing it). Or, you might simply need more RAM.
High Disk I/O: A program might be reading or writing a lot of data to the hard drive. This is often related to database activity.
High Network Traffic: You might have a sudden surge in legitimate website visitors, or you might be experiencing a denial-of-service attack.
Database:
Use APM tools.
3.Fix the Problem: The solution will depend on the cause. It might involve.
Optimizing your website’s code.
Upgrading your server hardware.
Adding more servers (using load balancing).
Fixing bugs in your code.
4.Monitor After Fixing: After you’ve fixed the problem, keep a close eye on your monitoring tools to make sure the issue is resolved and doesn’t come back.
Conclusion
Monitoring your server’s performance is absolutely essential for keeping your website running quickly and reliably. It’s like preventative maintenance for your website. By using the right tools, understanding key metrics, and setting up alerts, you can catch problems early and ensure a smooth experience for your visitors. Don’t wait for your website to crash – start monitoring your server today!.
Determined to change that, he built RapidLoad — a smart, AI-driven tool that empowers site owners to dramatically improve speed scores, enhance user experience, and meet Google’s Core Web Vitals without needing to touch a single line of code.
