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Tracking down problems with Jaeger

Hunter

Article from ADMIN 70/2022

By Martin Loschwitz

The various components of cloud-native applications are always exchanging information, which makes troubleshooting difficult. The Jaeger tracing framework helps hunt down the perpetrators.

Administrators facing a container-based setup with distributed applications for the first time in their career might hark back to the past and secretly think the old ways were better. From their perspective, at least, you might understand how this misconception comes about. People who used to be responsible for troubleshooting had a few fairly obvious starting points. Large monolithic programs such as MySQL simply output error messages. A look at the logfile was therefore often all it took to get at least a hint of where to look.

If nothing useful could be found in the logfile, you still had the level below it as the starting point. For example, if communication between server and client did not work as described in the documentation, many an admin would turn to tools such as Tcpdump (Figure 1), which lets you read data traffic down to the lowest levels of a network connection for subsequent visualization with Wireshark to check for potential issues. Also, the client could see potential errors and output appropriate messages on the terminal, if need be.