Datadog APM: A Comprehensive Guide

Is your application performance feeling a bit sluggish? Are you spending too much time putting out fires instead of building great software? You’re not alone. Many developers and DevOps teams struggle with these challenges. But what if I told you there was a tool that could help you pinpoint performance issues, trace requests, and get a bird’s-eye view of your entire system? Enter Datadog APM. This Datadog APM guide will show you how to use this powerful tool to gain deep insights into your application and improve its speed, efficiency, and reliability.

Table of Contents

What is Datadog APM?

Datadog Application Performance Monitoring (APM) is a service that helps you monitor the performance of your applications. It does this by collecting data about how your application is behaving and presenting it in a way that is easy to understand. This lets you quickly identify and solve performance problems. APM tracks requests as they move through your system, giving you a full view of the journey of a user request. It allows you to observe how different components interact with each other.

Datadog APM is not a standalone product; rather, it is one of the many powerful tools within the Datadog observability platform. If you’re not familiar with Datadog, it’s a SaaS platform that offers a wide range of monitoring tools. In short, Datadog brings together logs, metrics, and traces. This allows you to correlate events in your system with their root cause.

With Datadog APM, you can:

Identify bottlenecks: Quickly find out which parts of your application are slow or causing issues.
Trace requests: Follow a request as it moves through your system, seeing which services are involved and how much time each one takes.
Monitor key metrics: Track important performance data, like response time, error rates, and resource usage.
Set alerts: Get notified when your application’s performance drops below acceptable levels.
Visualize performance data: Use graphs and dashboards to see trends and patterns in your application’s behavior.
Get a full view of your application’s health: See how all of your services and components are performing, all in one place.

Key Components of Datadog APM

Datadog APM comprises a few main parts that work together to give you the full picture of your application’s performance:

APM Agents

These are the bits of software you need to install on your servers, containers, or functions. The agent is the workhorse for collecting trace data. It picks up on incoming requests and tracks them as they move through your code. It sends this data back to Datadog, which then puts it together. Datadog APM agents have an auto-instrumentation feature. It can detect a variety of frameworks, libraries, and databases, then add hooks so it can trace calls.

Traces

Traces represent a single request that passes through your application. Each trace is made up of spans. Think of a trace as the full journey of a single request, like a user loading a web page. Traces allow you to follow how a request moves between services, databases, and other parts of your system. They also show you the time spent at each step along the way.

Spans

These are the building blocks of a trace. Each span represents a single unit of work within the request. For example, a span could be a call to a database, an API request, or a piece of code. Spans contain specific information. They show details of what occurred, and how long it took.

Service Maps

Service maps give you a visual view of how your services are connected. They show how requests flow between services, and the relationship between different parts of your system. This is a great way to see the big picture and understand how all the pieces fit together.

Dashboards

Dashboards are tools for viewing and analyzing your performance data. You can see metrics, traces, service maps, and other data on a single screen. You can create dashboards to monitor the overall health of your application. Or, you can make custom dashboards to track specific metrics or services.

Alerts

Alerts help you know when there is a problem with your application. You can set up alerts to notify you if performance drops, errors increase, or any other metric goes outside of acceptable bounds. This way, you can fix problems before they impact your users.

Why Should You Use Datadog APM?

Why should you consider Datadog APM for your application monitoring? Here are some of the main benefits you’ll see:

Improved Performance

With Datadog APM, you can identify slow parts of your application. This helps you focus on the areas that need work and helps you fix those issues. You can reduce response times and make your application run more efficiently. It helps your users have a better experience.

Faster Problem Solving

When problems happen, you can quickly find the cause with trace-level visibility. You can look at specific requests and see where things go wrong. This saves time and lets you fix issues much more quickly.

Better Collaboration

Service maps give you a view of how your services are connected and how they interact. You can use this to communicate clearly with your team. This aids in cross-team collaboration because everyone has a view of how the system works.

Proactive Monitoring

Setting alerts for key metrics lets you know about problems before they impact your users. You can spot performance drops or errors, which allows you to take action early on.

Full Observability

Datadog APM is just one part of the larger Datadog platform. By putting traces, metrics, and logs together, you get a complete look at your system. This helps you better understand how everything is working and find complex issues that might not be obvious.

Setting Up Datadog APM

Let’s dive into setting up Datadog APM. Here’s a step-by-step guide to get you up and running:

1. Sign Up for Datadog

If you do not have a Datadog account, you must sign up for one. Datadog offers a free trial, so you can test out the platform before committing to a paid plan. Sign up on the Datadog website and follow the steps to create your account.

2. Install the APM Agent

After setting up your account, download and install the APM agent on your servers, containers, or functions. Datadog provides agents for all the most used operating systems and environments. Follow the specific instructions for your set up in the Datadog documentation.

The exact process will differ. For instance, here is an example for installing an APM agent on a Linux server:

Download the agent: Download the proper agent for your Linux distribution using the Datadog website.
Install the agent: Install the agent using the package manager (e.g., apt or yum).
Configure the agent: Edit the Datadog agent configuration file. Then, put your Datadog API key and any other settings that are needed.
Start the agent: Start the Datadog agent. Then, make sure it is running.

3. Instrument Your Application

To get trace data from your application, you need to add some code (called instrumentation). Datadog has libraries for all major programming languages that help make this easy.

Here is an example for Python:

Install the library: Use pip to install the ddtrace library in your Python environment.
Import and initialize the library: In your main application code, import ddtrace and initialize it with the API key you’ll find in the Datadog settings.
Run your application: Run your application like you would usually. The agent will now start collecting trace data.

For other programming languages, the process is quite similar. You’ll need to install the right Datadog library. You’ll also need to import and initialize it in your application’s start up code. This step tells Datadog that a service that you want to monitor is starting up.

4. Configure your services

When Datadog collects traces, it needs to know how to associate those traces to services you own. In your Datadog environment, create services. You can do this via the UI or by tagging your traces with the service name you wish to use. This will help you better understand how data flows through your system.

5. Verify Your Setup

After you set up the agent and instrument your application, you must make sure that data is being correctly sent to Datadog. Go to the Datadog APM section in the web interface. If everything is set up well, you will begin to see traces, spans, and service maps in your Datadog account.

Using Datadog APM

Once everything is up and running, you can use Datadog APM to view your application performance. Here’s how to use the main parts of the tool:

Viewing Traces

Traces show you the path a request takes through your system. Here is how you can use traces in Datadog APM:

Navigate to the APM section: In your Datadog account, go to the APM section from the main navigation menu.
Explore traces: Find the “Traces” view, and filter by service, time, or other options to locate specific traces.
Inspect trace details: Click on a trace to see each span and the time spent at each step.

You can use this to find the points where a request spends the most time. This indicates areas that might need more optimization.

Examining Spans

Spans are pieces of a trace that give specific details about each step in the application. Here is how to use spans:

Locate a trace: In the “Traces” view, click on any trace you want to examine.
Analyze individual spans: Click on a span to view further details, like start and end time, tags, and logs associated with the span.
Compare spans: Compare spans within the same trace. Use this data to see which operations take longer, and which are quick.

Spans can give you information for individual operations. This can tell you how a single database query impacts performance.

Using Service Maps

Service maps give you a clear picture of how your services connect to each other. Here is how to use service maps:

Navigate to Service Maps: Find the service maps view in the APM section of the Datadog user interface.
View your services: See how your services relate to each other, including the flow of requests and their dependencies.
Analyze service health: See metrics and error rates on each service. Use this to understand their health, and the overall system performance.

Service maps are great for identifying problems in your whole system at a high level. You can quickly spot service that’s not performing as it should.

Creating Dashboards

Dashboards show metrics and other key information in a way that is easy to understand. They can be used to track your system’s performance over time. Here is how to set up and use a dashboard:

Go to the Dashboards section: Navigate to the “Dashboards” section of your Datadog account.
Create a new dashboard: Create a new dashboard by clicking the relevant button.
Add widgets: Add widgets to the dashboard. This can include graphs, metrics, and service maps. Configure the widgets so they show you the data that you want to track.
Customize your dashboard: Change the layout, add titles, and share your dashboard with your team.

Dashboards are great for checking the health of your applications. You can set them up for overall performance or focus on certain services or operations.

Setting up Alerts

Alerts are key to knowing when problems happen in your system. Here is how to set up an alert in Datadog:

Navigate to Monitors: In Datadog, find the “Monitors” section, then click to add a new monitor.
Define the monitor conditions: Pick the metric you want to track, the alert trigger conditions (such as a certain threshold or a sudden error increase), and other key data.
Set notifications: Set how you want to be alerted when the monitor is triggered (like email, Slack, or other integrations).
Test and activate the monitor: Review and activate the monitor to begin getting notifications when the conditions are met.

Alerts help you find problems before they affect your users, so they’re a critical part of any monitoring system.

Advanced Datadog APM Techniques

Now that you have the basic ideas down, let’s go over a few advanced methods to get even more from Datadog APM:

Custom Instrumentation

Sometimes the automatic instrumentation is not enough. You need to add custom spans to specific areas of your code. This helps get very detailed data for key operations in your app.

Most APM agents will have a way to create custom spans. Here’s a Python example:

from ddtrace import tracer

with tracer.trace('custom.operation'):
    # Your custom code here
    do_some_work()

Using these custom spans gives you better control over what data you gather.

Distributed Tracing

In systems with many services, it’s important to keep track of requests as they move from one service to another. Distributed tracing does this by passing trace context from service to service. This lets you see the complete path of a request in a complex system.

Datadog APM has support for distributed tracing, and will handle propagation of trace context automatically in most cases.

Log Correlation

Linking logs with traces lets you understand what was happening inside your app when a problem happened. Datadog lets you link logs directly with specific spans. Use this for better context when troubleshooting.

Here’s an example using Python logging:

import logging
from ddtrace import tracer

logger = logging.getLogger(__name__)

with tracer.trace('my.operation') as span:
    logger.info("Starting operation", extra={'dd.trace_id': span.trace_id, 'dd.span_id': span.span_id})
    do_some_work()

By adding the trace and span IDs to the log message, you can see logs right within your traces.

Error Tracking

Datadog APM can track errors in your application. It can show you when errors occur, and give you details about the error. This information is invaluable for identifying and fixing bugs.

When errors happen in a traced operation, Datadog will gather this information and add it to the span. You can view and track your errors within the Datadog UI.

Using Tags

Tags let you add custom metadata to your spans. You can use tags to add details about the operation, the type of request, the user, etc. Tags are useful when filtering and grouping data.

Here’s how to add tags to a span in Python:

from ddtrace import tracer

with tracer.trace('my.operation') as span:
    span.set_tag('environment', 'production')
    span.set_tag('user_id', '12345')
    do_some_work()

These tags make it easier to search, filter, and get better insights from your data.

Best Practices for Using Datadog APM

To make the most of Datadog APM, follow these best practices:

Instrument all critical parts of your application

Make sure you instrument all the key parts of your application. These areas should include API endpoints, database calls, and service interactions. This lets you get a complete view of the path of a request.

Use meaningful span names

Give each span a name that’s meaningful, and easy to understand. This helps you quickly grasp what the span represents and where it fits in the trace.

Add relevant tags

Use tags to add helpful context to your traces. This lets you filter and group data in dashboards. It also helps you locate particular operations or conditions in your code.

Regularly review your dashboards and alerts

Look over your dashboards and alerts to make sure they’re showing the proper data. It will help you react to changes in your system’s behavior.

Set realistic alert thresholds

Be sure to set alert thresholds that make sense for your application. Set thresholds that are sensitive enough to warn you about real issues. Be sure your thresholds are not so sensitive that you get too many false positives.

Continuously monitor and optimize

Datadog APM is not something to just set up and then forget. Use this data to find opportunities to optimize your application and improve its performance over time. Always monitor and react to changes in your application or code.

Integrations with other Datadog Products

Datadog APM doesn’t work in a vacuum. It’s designed to work with other products within the Datadog suite. This gives you more insights into your application and infrastructure.

Metrics

Datadog’s metrics system will track performance metrics, such as CPU and memory use. They are correlated with your traces. This helps you get a complete view of your system’s health.

Logs

Datadog’s log management lets you see your application logs within the context of your traces. This can help you troubleshoot errors. It helps you gain more context when debugging.

Infrastructure Monitoring

Datadog can monitor your infrastructure. It can provide data about the resources that your application uses. Correlating APM data with infrastructure metrics helps you find the root cause of performance problems.

Synthetic Monitoring

Synthetic monitoring simulates user actions on your application. This lets you see how it behaves from an end-user viewpoint. Synthetic tests can be combined with APM data to track performance and user experience.

Real User Monitoring (RUM)

RUM tracks the real-world performance of your application as experienced by actual users. Combining RUM data with APM data gives you an end-to-end view of your application’s performance. You can see how both the front-end and back-end are working.

Datadog APM Use Cases

Datadog APM is useful in a variety of situations. Here are a few cases where it can be especially helpful:

Microservices architecture

In a microservices-based system, requests often travel between many services. Datadog APM lets you see how requests move through your microservices. You can find performance bottlenecks and errors that might be hard to see with other means.

Complex APIs

APIs can involve calls to other APIs and databases. It can sometimes be tricky to see how those pieces work together. APM lets you look at the full journey of an API request, to see where the time is spent.

Databases

Databases are often a major cause of performance problems. Datadog APM lets you see how much time is spent making database calls and to see slow queries. You can use this information to make optimizations, to boost performance.

Cloud environments

In cloud environments, application components can be spread across many instances. This adds extra complexity when trying to understand how the system works. Datadog APM lets you keep track of requests in the cloud and get a good view of your performance.

Mobile applications

APM is not just for server-side applications. You can use it to track performance for your mobile apps as well. By monitoring the calls that your mobile apps make to the back end, you can better know what your end users are experiencing.

Is Datadog APM Right for You?

Datadog APM is an amazing tool, but it might not be the proper fit for everyone. Here are a few things to think about when choosing whether to use it:

Pros

Full Observability: Datadog brings together metrics, logs, and traces to give a complete view of your system.
Easy to use: The platform is user friendly. It has a good interface for visualizing and interacting with your data.
Lots of integrations: Datadog connects to a wide variety of services and tools. It can be tailored to many kinds of environments.
Good support: Datadog has solid documentation and support. This can help you get up and running quickly.
Scalable: Datadog is designed to handle large-scale systems and complex applications, allowing it to grow as your needs grow.

Cons

Cost: Datadog is a SaaS platform, which has a cost that may be a concern. It might be pricey for smaller projects or organizations.
Complexity: Datadog is a powerful, but also complex tool. You might have to spend some time learning how to use it effectively.
Setup: There might be some work to do to install agents and instrument your application. You will also need a deep understanding of your stack to correctly setup.
Vendor lock-in: Because Datadog is a platform, and not a simple tool, you may have to deal with some vendor lock-in, if you get used to the Datadog way of doing things.

When to Choose Datadog APM?

Datadog APM is great if:

You have complex applications with multiple services or databases.
You need to understand the full path of a request through your system.
You need a single platform for monitoring metrics, logs, and traces.
You want a tool that is simple to use and integrates with many other services.
You can pay for the service.

When to consider alternatives

You might want to consider other options if:

You only need very basic monitoring capabilities.
You prefer an open-source system to a commercial solution.
You have budgetary constraints and are not willing to pay a premium.

Datadog APM vs. Other APM Tools

Datadog APM is not the only APM system available. Here are some popular alternatives, and how they compare:

New Relic

New Relic is another well-known APM platform. It has many features, and a wide range of integrations.
Pros: New Relic has a solid set of features, mature integrations, and good community support.
Cons: New Relic can be more expensive than Datadog. Its user interface can feel less simple or intuitive for some.

Dynatrace

Dynatrace offers a full monitoring system. It uses AI to automate issue detection and root cause analysis.
Pros: Dynatrace has a powerful AI engine, automatic discovery of dependencies, and is designed for large and complex systems.
Cons: Dynatrace can be pricey and complex to set up, and it’s best for companies that need enterprise grade features and support.

Prometheus

Prometheus is an open-source system for metrics monitoring. You can combine it with other tools for tracing and log management.
Pros: Prometheus is a free tool that is very customizable and flexible.
Cons: Prometheus requires a certain level of know how to set up and manage. It also lacks some of the built-in features that a platform like Datadog offers.

Jaeger

Jaeger is an open-source tracing tool that is suitable for cloud-native architectures. It is also often used with Kubernetes.
Pros: Jaeger is a free and powerful tracing tool that is used often in Kubernetes environments.
Cons: Jaeger has more of a learning curve to set up. It may not be as easy to use as a full platform like Datadog.

Choosing the Right Tool

Your choice will depend on your needs, budget, and technical skills. Think about these:

Budget: How much can you spend?
Features: What features are most important to you?
Ease of use: How easy is the tool to learn and use?
Integration: Does it connect well with your existing systems?
Scalability: Can it handle the size and complexity of your application?

If you want the power of a full observability platform, with an easy to use interface, and a large ecosystem of integrations, then Datadog APM is hard to beat.

Stepping up your Observability game

Datadog APM is a powerful tool that helps you see how your applications perform, find performance problems quickly, and optimize your system. By following the steps in this guide, and thinking through the pros and cons, you can decide if Datadog APM is a good fit for you, and start using it to make your applications faster and more reliable. Don’t wait until performance issues cause problems, try it today and see how Datadog APM can improve your development workflow.