5 ms·

Couldn't this be injected into the runtime so that no code changes are required? Perhaps really performance critical stuff could have a "notrace" annotation.

thinkharderdev 3y ago
Sure, and a lot of tools will do this in one way or another. Either instrument code directly or provide annotations/macros to trace a specific method (something like tokio-tracing in the Rust ecosystem). However, tracing literally every method call would probably be prohibitively expensive so typically you have either: 1. Instrumentation with "understands" common frameworks/libraries and knows what to instrument (eg request handlers in web frameworks) 2. Full opt-in. They make it easy to add a trace for a method invocation with a simple annotation but nothing gets instrumented by default
austinsharp 3y ago
Yes, OTel has autoinstrumentation libraries for some language that can pick up a fair amount by default. Though it's unlikely that that would ever be sufficient, it's a nice start. For Java: https://opentelemetry.io/docs/instrumentation/java/automatic/ https://opentelemetry.io/docs/instrumentation/java/automatic...
imiric 3y ago
There are several projects that leverage eBPF for automatic instrumentation[1]. How accurate and useful these are vs. doing this manually will depend on the use case, but I reckon the automatic approach gets you most of the way there, and you can add the missing traces yourself, so if nothing else it saves a lot of work. [1]: https://ebpf.io/applications/ https://ebpf.io/applications/
pondidum 3y ago
Yes, and itel has instrumentation libraries which do this. However, no automatic instrumentation can do everything for you; it can't know what are all the interesting properties or things to add as attributes. But adding tracing automatically to SQL clients, web frameworks etc is very valuable

thinkharderdev 3y ago

Sure, and a lot of tools will do this in one way or another. Either instrument code directly or provide annotations/macros to trace a specific method (something like tokio-tracing in the Rust ecosystem). However, tracing literally every method call would probably be prohibitively expensive so typically you have either: 1. Instrumentation with "understands" common frameworks/libraries and knows what to instrument (eg request handlers in web frameworks) 2. Full opt-in. They make it easy to add a trace for a method invocation with a simple annotation but nothing gets instrumented by default

austinsharp 3y ago

Yes, OTel has autoinstrumentation libraries for some language that can pick up a fair amount by default. Though it's unlikely that that would ever be sufficient, it's a nice start. For Java: https://opentelemetry.io/docs/instrumentation/java/automatic/ https://opentelemetry.io/docs/instrumentation/java/automatic...

imiric 3y ago

There are several projects that leverage eBPF for automatic instrumentation[1]. How accurate and useful these are vs. doing this manually will depend on the use case, but I reckon the automatic approach gets you most of the way there, and you can add the missing traces yourself, so if nothing else it saves a lot of work. [1]: https://ebpf.io/applications/ https://ebpf.io/applications/

pondidum 3y ago

Yes, and itel has instrumentation libraries which do this. However, no automatic instrumentation can do everything for you; it can't know what are all the interesting properties or things to add as attributes. But adding tracing automatically to SQL clients, web frameworks etc is very valuable