What Are Semantic Conventions in OTEL?

What Are Semantic Conventions in OTEL?

OpenTelemetry (OTEL) is a big data platform that enables the collection and analysis of large-scale telemetry data. Many companies have adopted it for use in their products. In this post, we’ll discuss semantic conventions in OpenTelemetry and how they are used to make data processing easier. We’ll also discuss the different types of semantic conventions and their importance.

What Is OpenTelemetry (OTEL)?

OpenTelemetry is an initiative created to provide a standard for collecting and processing telemetry data from distributed systems. It consists of a set of APIs, SDKs, and integrations that allow developers to instrument their code and send data to any monitoring system. The goal of OpenTelemetry is to make it easier for developers to instrument their code and collect data from their applications.

Telemetry data is helpful in understanding the performance of distributed systems and diagnosing issues. However, collecting telemetry data can be difficult because many different types of data need to be collected, and every kind of data has its own format. OpenTelemetry addresses this problem by providing a standard way to collect telemetry data. This means developers can instrument their code once and send the data to any monitoring system supporting the OpenTelemetry standard.

What Are Semantic Conventions?

Semantic conventions are the agreed-upon meaning of words and phrases within a particular language or culture. They help us communicate with each other by providing a shared understanding of our symbols.

For example, the convention in English is that the word “dog” refers to a four-legged furry animal that barks, while in Spanish, the word “perro” has the same meaning. This allows speakers of both languages to communicate effectively about dogs, even though they may never have met before.

Without these conventions, communication would be much more difficult; they would constantly have to explain the meaning of every single word they use. Semantic conventions make communication more efficient by allowing them to take shortcuts in their speech and writing.

There are conventions for all sorts of symbols, not just words. For example, the “thumbs up” gesture is a convention that means “good job” or “I agree” in many cultures.

Conventions can be specific to a particular language or culture or be more general. For example, the convention in English is that adjectives go before nouns (“the red car”), while in French, this order is reversed (“la Voiture rouge”). This rule is a specific linguistic convention needed to learn if one wants to speak French correctly.

What Do Semantic Conventions Mean In OTEL?

Semantic conventions are essential in OpenTelemetry because they provide a way to define how data should be structured and exchanged between different components in a system. Data can be consistently interpreted and processed by various tools and services by using semantic conventions.

Semantic conventions can be used to describe the structure of data and the relationships between different data elements. For example, a convention can specify that all data items related to a particular resource should be grouped together. This would allow an analysis tool to automatically identify all of the data items of a specific resource without manually inspecting each individual data item.

In addition to specifying the structure of data, semantic conventions can also be used to define the meaning of data. For example, a convention can determine that a certain data item represents the temperature of a resource. This would allow an analysis tool to automatically interpret the meaning of the data item without relying on human experts.

Semantic conventions ensure that data is consistently interpreted and processed by different tools and services. Without semantic conventions, it would be very difficult to exchange data between different components in a system.

What Are Metric Semantic Conventions?

Semantic conventions provide a way to standardize the meaning of metrics across different software implementations. Using common definitions for metrics makes it easier to compare and contrast results from various tools. The OpenTelemetry project has published a set of metric semantic conventions that can be used by any software that collects or displays metrics data.

The metric semantic conventions define a set of core dimensions that should be used when recording metric data. These dimensions include name, description, unit, and type. In addition, the conventions define a set of recommended labels that can be used to further describe the data. By adhering to these standards, it is possible to create easily understood metrics that can be effectively compared.

The metric semantic conventions are just one part of the OpenTelemetry initiative, which is working to standardize how telemetry data is collected and stored. The project’s goal is to make it easier for developers to work with telemetry data from a variety of sources.

In addition to the metric semantic conventions, the OpenTelemetry team has also published standards for logging and tracing data. By using these standards, it is possible to create software that can generate consistent results regardless of the underlying implementation.

The OpenTelemetry project has already seen a great deal of adoption from major companies in the tech industry. As more developers begin to use the standards, it is likely that the OpenTelemetry initiative will continue to gain momentum.

What Are Resource Semantic Conventions?

The resource semantic conventions are the set of agreed-upon rules for how information about monitored resources should be represented in telemetry data. By following these conventions, vendors can ensure that their monitoring data is compatible with various systems and tools.

The Resource Semantic Conventions cover four main areas:

  • Attributes: Information about the physical or logical characteristics of a resource. Examples include CPU utilization, memory usage, and network bandwidth.
  • Events: A record of something that has happened to a resource. Events can be useful for troubleshooting or giving context to other telemetry data. Examples include a service being started or stopped, a disk error, or a user logging in.
  • Logs: A record of events that have happened to a resource, organized in chronological order. Logs can be useful for auditing or debugging purposes.
  • Metrics: Information about the performance of a resource. Examples include response time, throughput, and error rate.


Attributes are often used to describe the dimensions of the data. For example, when dealing with network data, attributes might describe the source and destination IP address, the port numbers, etc. Attributes can also be used to describe metadata about the data itself. For example, when dealing with log data, attributes might describe the timestamp, the logging level, etc.

Attributes are stored in so-called AttributeMaps. An AttributeMap is a map from attribute keys to attribute values. The keys are typically strings, but they can also be other data types. The values can be any data type that can be represented as a JSON value.

One of the benefits of using attributes is that they provide a way to add additional information to the data without changing the data itself. This is especially useful when dealing with legacy systems that cannot be modified.

Another benefit of attributes is that they can be used to filter and group data. For example, if one has a log file that contains messages from multiple sources, they can use attributes to filter out messages from certain sources. Or, if they want to group all messages with the same logging level, they can use attributes.


Events are one of the core concepts in OpenTelemetry, providing a way to record significant moments or states in the system that can be used for monitoring and analysis. They can be generated manually by operators or automatically by the system itself. OpenTelemetry events contain metadata about the event and any relevant data that was collected at the time of the event.

Events can be used to track the progress of a system through its lifecycle or to identify changes in state that may indicate an issue. They can also be used to record performance data, such as response times or resource utilization. By analyzing events, it is possible to understand how a system is functioning and where potential problems may lie.

OpenTelemetry provides a set of APIs and libraries that make it easy to generate and collect events from applications and services. It also includes several tools for processing and analyzing event data. The OpenTelemetry Collector is one such tool that can be used to aggregate events from multiple sources and export them to a variety of storage backends.

Resource Semantic Conventions in Use Today

There are many different resource semantic conventions in use today, each with its own strengths and weaknesses. More popular conventions include the Resource Description Framework (RDF), Web Ontology Language (OWL), and Schema.org.

The RDF is a widely used standard for representing information about resources on the Internet. It is based on the idea of representing data as a set of triples, consisting of a subject, predicate, and object.

The OWL is another popular standard for representing resource information. It is based on the idea of representing data as a set of axioms, which are logical statements about the relationships between resources.

Schema.org is a relatively new standard gaining popularity due to its simplicity and ease of use. It uses a simple syntax to represent data about resources, making it easy for developers to add support for it to their systems.

While there are many different resource semantic conventions in use today, the RDF, OWL, and Schema.org are three of the most popular. Each has its own strengths and weaknesses, so choosing the right one for one’s needs is important.

Why Are These Constants Important?

The constants are important in OpenTelemetry as they provide a set of agreed-upon definitions and resource types that help ensure interoperability between different software implementations. The metric and resource semantic conventions define a consistent way to label metrics and resources, essential for aggregating data from multiple sources. By using these constants, developers can be confident that their data will be compatible with other systems that use the same conventions.

OpenTelemetry aims to provide a vendor-neutral way to instrument cloud-native software. Achieving this goal relies on a set of common building blocks that are shared by all implementations. The constants are one of these building blocks, and they play a crucial role in ensuring that data from different sources can be aggregated and analyzed in a consistent way.

It would be very difficult to exchange data between different telemetry systems without these constants. The metric and resource semantic conventions provide a common language that everyone can use to label and describe their data. 

Simplifying the Interpretation of Data

Semantic conventions are important in OTEL because they help to define the meaning of resources and metrics. Semantic conventions provide a common language for all users of the system. This allows for a more accurate interpretation of data and helps to ensure that everyone is on the same page when it comes to resource usage and performance. If you’d like to learn more about semantic conventions or other features of LogicMonitor, check out the LogicMonitor platform demo.