Analyzing individual requests is often a useful way of gaining a better understanding of detected errors. In the image below, you can see that requests to
Redis started to fail around the
10:45 mark on the timeline. To find the Failure rate tab, go to the service’s details page and select View (View requests, View dynamic web requests, or View resources).
Select View backtrace to see where these requests came from. We can now see that all of these requests originate in the
weather-express service. We also see that nearly all failed
Redis calls have the same Exception—an
AbortError caused by a closed connection.
We can go one step further, down to the affected
Node.js PurePath traces. With the
weather-express service selected, select the Analyze tab in the bottom-right corner of the page and then select View PurePaths in the left column. You can see such a
Node.js PurePath trace and its code-level execution tree below. Note that the
Redis method call leads to an error. You can see where this error occurs in the flow of the
We can also analyze the exception that occurs at this point in the request—select the Exceptions tab.
Each PurePath trace shows a unique set of parameters leading up to the error. With this approach to analysis, the PurePath view can be very useful in helping you understand why certain exceptions occurred.