Opentelemetry vs. Prometheus

Observability tools, like OpenTelemetry and Prometheus, are critical for ensuring optimal performance and reliability in cloud-native applications. While OpenTelemetry provides comprehensive telemetry data collection, supporting traces, logs, and metrics for whole-system observability, Prometheus excels in monitoring and analyzing time-series data. 

While you can use Prometheus and OpenTelemetry together, they have distinctly different capabilities that set each apart. Prometheus is ideal for dynamic systems and focused monitoring of individual components, and OpenTelementry offers a unified view across distributed systems. Both OpenTelemetry and Prometheus provide options for data collection but are significantly different from one another. 

This comprehensive overview of OpenTelemetry and Prometheus covers key features and capabilities, as well as advantages and disadvantages, of both tools.

What is OpenTelemetry (OTel)?

For cloud-native applications, OpenTelemetry is the future of instrumentation. It’s the first critical step that allows companies to monitor and improve application performance. OpenTelemetry also supports multiple programming languages and technologies.

Key features and capabilities

In addition to collecting telemetry data across applications, OpenTelemetry provides services and supporting infrastructures for those applications. It is a vendor-neutral telemetry standard used throughout the industry. OTel combines cloud technologies, orchestration engines, and containers to facilitate faster digital innovation.

Of course, OpenTelemetry also provides enterprises with flexibility by allowing them to standardize the way they collect data with less vendor lock-in and greater interoperability. The best way for companies to move forward is by understanding their customers’ needs and how they interact with their online experiences.

Supported programming languages and technologies

OpenTelemetry’s vendor-neutral open-source tools, APIs, and SDKs support multiple programming languages, including Go, Java, and Python. These tools work together to execute the measurement by specifying what needs to be measured, collecting relevant data, cleaning and organizing information, and exporting data to a monitoring backend.

What is Prometheus?

Prometheus is a metrics monitoring tool used for monitoring time-series data that changes over time. Initially developed at SoundCloud in 2012, the CloudNative Computing Foundation accepted Prometheus in 2016 as the second project slated to graduate from the foundation after the open-source system Kubernetes.

Key features and capabilities

Prometheus prioritizes reliability over accuracy, making it an ideal solution for cloud-based dynamic systems, such as microservices. The system also works with billing applications that require accuracy and may provide the best solution for relative monitoring applications and infrastructures.

Historical background and community support

SoundCloud originally developed Prometheus as a toolkit for alerting and monitoring systems. It’s a free, open-source software application, so it’s easy to integrate natively. Since its launch, many organizations and companies have adopted Prometheus, and the project has an active user and developer community.

Performance and scalability

OTel is becoming the industry standard in telemetry data generation. Distributed systems rely heavily on observability to gauge their health, and telemetry data makes observability possible. Using OpenTelemetry, companies can generate telemetry data without depending on multiple vendors.

OpenTelemetry allows companies to collect telemetry data regardless of the provider. Distributed systems rely heavily on telemetry data for monitoring their states. Therefore, a global standard is required for microservices and polyglot architectures. As of now, OTel is well positioned to fill this void.

Furthermore, OpenTelemetry’s components are loosely coupled to provide integration options. The main OpenTelemetry components are:

• Application programming interfaces (APIs): Instrument code and coordinate data collection across entire systems.
• Data specifications: The data specifications define the OpenTelemetry Protocol (OTLP) and relevant semantic conventions used by applications.
• Software development kits (SDKs): Using libraries, SDKs implement and support APIs for data gathering, processing, and exporting. The SDKs are also language-specific, similar to APIs.
• OpenTelemetry Collector: Can be used across a wide range of systems, whether open-source or commercial.

In short, OpenTelemetry APIs, SDKs, libraries, and integrations can collect and manage telemetry data (traces, metrics, and logs). The OpenTelemetry project was created through a merger between OpenCensus and OpenTracing. The Cloud Native Computing Foundation (CNCF) also incubated Kubernetes.

How is Prometheus built?

Prometheus stores data locally on disk so that it can be accessed and queried quickly. It also allows metrics to be stored remotely. Prometheus servers are stand-alone and do not rely on remote services or network storage.

How does Prometheus monitoring work?

In Prometheus, data is collected as a time series generated by an underlying pull model. At specific intervals of time, Prometheus queries a list of data sources or exporters. For reference and querying, Prometheus data is stored in metrics. 

Prometheus stores data locally on disk so it can be accessed and queried quickly. It also allows metrics to be stored remotely. In addition, the Prometheus servers are stand-alone and do not rely on remote services or network storage.

As a multidimensional data model, Prometheus supports PromQL*, a language that allows companies to query the metrics data collected. Not only can companies pull model data collection over HTTP with Prometheus, but it also supports a basic visualization layer and offers an alert manager to handle alerts.

What is PromQL? 

Prometheus Query Language, or PromQL, is the query language provided by Prometheus for selecting and aggregating data. It is precisely adjusted to work in convention with a time-series database and offers time-related query functionalities.

What are the features of Prometheus? 

Prometheus’s main features are:

• Autonomous, dedicated server nodes that do not rely on distributed storage
• A data model that identifies time series data by metric name and key/value pairs
• Integrated dashboards that support internal graphic displays
• Choice of static configuration or service discovery for the discovery of targets
• Use of a pull model over an HTTP connection for time series collection
• Time series pushed through an intermediary gateway 
• Flexible querying with PromQL to leverage dimensionality

How does OTel work?

OpenTelemetry works with three major forms of telemetry data: tracing, metrics, and logging. OTel can help track requests within a system to identify performance issues and failures. In terms of metrics, the system tracks and reports on processes through histograms, gauges, and other graphical reports that are easy to understand. Finally, the last way to analyze logging messages is to analyze those specific to a given application.

Tracing, metrics, and logging have always been crucial to observing a system across its entire lifecycle. However, the complexity of modern applications and resource layers makes it difficult to implement tracing across all services. For example, a single incident can be tracked for hours when paired with vague log data because the information needs to be siloed consistently. 

OpenTelemetry (and other similar products) seeks to correct this problem through its consolidated system for metrics, tracing, and logging. GitHub provides a platform for those interested in participating in a community to influence and improve OpenTelemetry as an open-source project. Analyzing telemetry data can help create a multi-layered ecosystem. As a result, your company may be able to address performance issues more efficiently.

What are the features of OTel? 

OpenTelemetry’s main features include the following:

• Support for telemetry data in consistent formats across all major programming
• Exports telemetry data in multiple formats to a backend of choice
• Allows logging, monitoring of metrics, and telemetry data tracing
• Supports multi-language and technology-agnostic instrumentation

Key differences between OpenTelemetry vs. Prometheus

Data collection and metrics

• OpenTelemetry: Provides unified data collection, handling metrics, traces, and logs.
• Prometheus: Focused primarily on metrics and time-series data.

Flexibility and integration

• OpenTelemetry: Vendor-neutral with high flexibility and broad ecosystem integration.
• Prometheus: Integrates well with other CNCF projects but is metrics-centric.

Visualization and storage

• OpenTelemetry: Lacks a built-in visualization layer and relies on external tools.
• Prometheus: Includes basic visualization capabilities with built-in storage.

OpenTelemetry advantages

• Better performance: Manages and generates telemetry efficiently.
• Collector: Allows companies to receive, process, and export telemetry data in various formats.
• Easy to use: Business-friendly, with documentation for troubleshooting and repairing bugs.
• Language support: Supports C++, Go, Java, Javascript, Python, and more.
• Libraries: Offers auto-instrument frameworks and libraries to reduce codebase change requirements.
• Observability: Integration points allow collected data to be ingested by observability platforms.
• Partners and backers: Includes Google, Microsoft, and other prominent cloud vendors.
• Flexibility: Vendor-neutral, which allows companies to switch tools.

OpenTelemetry disadvantages

• Lack of storage: Does not provide a visualization layer or backend storage.
• Poor support: Room for improvement with support and documentation. 

Prometheus advantages

• Pull-built: Actively scrapes targets to retrieve metrics; server initiates HTTP call to fetch system/app metrics from endpoints to exporter.
• Control: Pull-based system enables rate control for flexibility in multiple scrap configurations; multiple rates for different targets allow better server control.

Prometheus disadvantages

• Limited use cases: Great tool for metrics monitoring but doesn’t go further than that.
• Full-stack: Not a full-stack application monitoring tool.
• Logs: Only tracks metrics, so users need to rely on other tools for logging.
• Static: Designed for a single machine; lacks flexibility and cannot scale horizontally.
• Time: Requires effort and time to effectively set up exporters for valuable visualization.
• Traces: Does not support traces or root cause analysis.

Best practices for integration with existing systems

Integrating OpenTelemetry

By following these practices, you can help ensure a smooth and effective OTel integration.

• Compatibility: Ensure that OpenTelemetry can work with your existing monitoring tools and backends.
• Collaboration: Work closely with development and operations teams to ensure agreement on observability goals.
• Gradual adoption: Start by instrumenting critical paths in your application, gradually expanding coverage as you need it.
• Custom instrumentation: Use manual instrumentation where automatic options aren’t feasible. 
• Version management: Keep OpenTelemetry libraries updated to benefit from the most current improvements.

Integrating Prometheus

By following these practices, you can effectively integrate Prometheus into your existing systems.

• Start with core services: Ensure high availability and performance by monitoring the most critical services.
• Use exporters: Take advantage of official and community exporters to monitor various systems such as databases, caches, and hardware.
• Adjust scrape intervals: Dial in scrape intervals based on the criticality and nature of the data to balance performance and resource usage.
• Alerting: Configure alerting thresholds in Prometheus to receive notifications before any issues can impact users. 
• Data retention: Manage data retention policies to balance storage costs with the need for historical data.
• Utilize service discovery: Use service discovery to dynamically manage targets as your infrastructure scales or changes.
• Documentation: Document your Prometheus configuration thoroughly, including tracked metrics, alerting rules, and dashboard setup.
• Security: Employ authentication access and network restrictions to secure Prometheus instances, preventing unauthorized access to sensitive metrics.

Setting up OpenTelemetry

This step-by-step guide provides an example of OpenTelemetry setup using Go.

1. Check Go installation: Make sure Go is installed on your system. You can confirm this by running ‘go version‘ in your terminal.
2. Set up a Go project: Navigate to your project directory or create a new one using ‘go mod init <module_name>‘ to initialize a Go module to manage dependencies.
3. Install dependencies: Run ‘go get go.opentelemetry.io/otel‘ to install OpenTelemetry packages.
4. Set up tracer: Initialize a tracer provider and configure it to export traces.
5. Instrument code: Use the tracer to create spans around the code you want to monitor.
6. Run your application: Execute your Go application; the telemetry data will be collected and exported.
7. Analyze Data: Review the exported data using your chosen backend.

For more details on setting up OTel, visit the OpenTelemetry Go guide.

Setting up Prometheus

Getting started with Prometheus is fairly simple and straightforward. These steps will help you get your Prometheus setup underway.

1. Download Prometheus: Get the latest version from the Prometheus website.
2. Extract and configure: Unzip the file, navigate to the folder, and edit prometheus.yml to define scrape targets.
3. Run Prometheus: Start Prometheus with ‘./prometheus –config.file=prometheus.yml‘.
4. Access Web UI: Open http://localhost:9090 in your browser to access the Prometheus dashboard.
5. Start monitoring: Use the UI to query and monitor your systems.

The Prometheus getting started guide offers more in-depth details for setting up Prometheus.

Why is OpenTelemetry important? 

To collect and transmit telemetry data to backend platforms, OpenTelemetry is essential. The common instrumentation format overcomes visibility gaps across all services. In addition, engineers can install a new proprietary agent whenever a backend platform is changed. 

OpenTelemetry also handles new technologies, unlike commercial solutions, which must be integrated to make products work together. Aside from simplifying alerting, troubleshooting, and debugging, OTel data is helpful for monitoring, too.

Collecting and analyzing telemetry data has always been used to understand system behavior. However, recent network complexity has made this more challenging. Tracing the cause of an individual incident in these labyrinthine systems can take hours or days.

OpenTelemetry can help correlate traces, logs, and metrics from across applications and services, improving observability. The open-source project also enables APM (application performance monitoring) and other vital functions by removing roadblocks to instrumentation. Ultimately, this results in better service reliability, reduced downtime, and efficiency in identifying and resolving incidents.

OpenTelemetry use cases

Distributed tracing

Organizations widely use OpenTelemetry to trace requests across complex microservice architectures. This helps developers identify performance bottlenecks and track the flow of requests. Shopify uses OTel for tracing in its distributed systems.

Monitoring cloud-native applications

OpenTelemetry provides unified observability across cloud-native environments, enabling effective monitoring of applications running on many kinds of modern infrastructures. Google integrates OpenTelemetry into its cloud-native services to give customers superior cloud monitoring capabilities.

Enhancing observability with metrics and logs 

By collecting and correlating metrics, traces, and logs, OpenTelemetry gives teams a comprehensive view of their systems and provides root cause analysis. Microsoft employs OpenTelemetry in Azure services to standardize observability across its cloud platform.

Why is Prometheus important?

Prometheus is popular due to its powerful features for monitoring metrics, providing alerts, and automating responses to changing conditions with orchestration systems. In addition to collecting metrics—or concise descriptions of events, such as dates, times, and descriptive values—about applications and infrastructure, Prometheus can monitor performance. The Prometheus software gathers only a little bit of data about many things rather than collecting a lot of data about one thing.

Prometheus use cases

Infrastructure monitoring

Users rely on Prometheus to monitor servers, containers, and networking equipment and offer real-time data on system health and performance. Reddit relies on Prometheus to monitor its large-scale infrastructure, monitor the environment, and quickly identify issues.

Application performance monitoring (APM)

Prometheus collects metrics from applications to track performance and ensure reliable operation across connected environments. GitLab employs Prometheus to monitor their CI/CD pipeline performance and monitor application services to help maintain high availability and optimize application performance.

Alerting

Prometheus can integrate with alerting tools like Alertmanager to notify teams of issues based on custom thresholds, ensuring rapid response to incidents. SoundCloud, the pioneer of Prometheus, takes advantage of its alert functions to quickly notify them of issues in its streaming service infrastructure.

What the future holds

The future of OpenTelemetry

OpenTelemetry expects to focus on enhancing its capabilities across the board, particularly focusing on improving support for logs, metrics, and traces. OTel will likely emphasize better integration with various backends and increased automation capabilities. Users can expect advancements in community collaboration, a broader toolset for simplifying implementation, and OpenTelemetry’s use in complex cloud ecosystems. OTel also expects to provide enhanced observability in mobile environments and bring deeper integration with mobile platforms. 

The future of Prometheus

Prometheus has prepared a roadmap that outlines developer ambitions for the platform. Plans include improving scalability and enhanced availability features, as well as smoother integration with other cloud-native systems. Prometheus will likely continue developing long-term storage solutions, strive for better support for service discovery, and seek to boost query performance. The Prometheus community is also focused on refining the user experience, including the development of more robust visualization and alerting functions. 

Conclusion

Organizations with higher levels of observability have a much easier time tracking down and resolving issues, resulting in more reliable operations and fewer downtimes. Tools like OpenTelemetry and Prometheus can aid organizations in meeting observability goals in different ways. While Prometheus supports rich queries, metrics, and interoperability as part of the cloud-native ecosystem, OpenTelemetry collects metrics, traces, metadata, and logs and scales with organizational growth.

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