AWS X-Ray | Core Concepts Flashcards
What can I do with X-Ray?
Core Concepts
AWS X-Ray | Developer Tools
X-Ray makes it easy for you to:
Create a service map – By tracking requests made to your applications, X-Ray can create a map of services used by your application. This provides you with a view of connections among services in your application, and enables you to create a dependency tree, detect latency or errors when working across AWS Availability Zones or Regions, zero in on services not operating as expected, and so on.
Identify errors and bugs – X-Ray can automatically highlight bugs or errors in your application code by analyzing the response code for each request made to your application. This enables easy debugging of application code without requiring you to reproduce the bug or error.
Build your own analysis and visualization apps – X-Ray provides a set of query APIs you can use to build your own analysis and visualizations apps that use the data that X-Ray records.
What is a trace?
Core Concepts
AWS X-Ray | Developer Tools
An X-Ray trace is a set of data points that share the same trace ID. For example, when a client makes a request to your application, it is assigned a unique trace ID. As the request makes its way through services in your application, the services relay information regarding the request back to X-Ray using this unique trace ID. The piece of information relayed by each service in your application to X-Ray is a segment, and a trace is a collection of segments.
What is a segment?
Core Concepts
AWS X-Ray | Developer Tools
An X-Ray segment encapsulates all the data points for a single component (for example, authorization service) of the distributed application. Segments include system-defined and user-defined data in the form of annotations and are composed of one or more sub-segments that represent remote calls made from the service. For example, when your application makes a call to a database in response to a request, it creates a segment for that request with a sub-segment representing the database call and its result. The sub-segment can contain data such as the query, table used, timestamp, and error status.
What is an annotation?
Core Concepts
AWS X-Ray | Developer Tools
An X-Ray annotation is system-defined or user-defined data associated with a segment. A segment can contain multiple annotations. System-defined annotations include data added to the segment by AWS services, whereas user-defined annotations are metadata added to a segment by a developer. For example, a segment created by your application can automatically be injected with region data for AWS service calls, whereas you might choose to add region data yourself for calls made to non-AWS services.
What are errors?
Core Concepts
AWS X-Ray | Developer Tools
X-Ray errors are system annotations associated with a segment for a call that results in an error response. The error includes the error message, stack trace, and any additional information (for example, version or commit ID) to associate the error with a source file.
What is sampling?
Core Concepts
AWS X-Ray | Developer Tools
To provide a performant and cost-effective experience, X-Ray does not collect data for every request that is sent to an application. Instead, it collects data for a statistically significant number of requests. X-Ray should not be used as an audit or compliance tool because it does not guarantee data completeness.
