4 ms·
How would passing on the container ID help in mapping multiple log messages to the same request? If a request is going through multiple containers, you'll get m
by rdli 10y ago
How would passing on the container ID help in mapping multiple log messages to the same request? If a request is going through multiple containers, you'll get multiple container IDs.
To solve this problem, you need a unique trace ID and vector clock, and this actually needs to propagated through your logging system, not through container tags.
- ktamura 10y agoAh, I completely misunderstood. Yes, you are right: Threading data together across multiple containers belonging to a single logical request is hard (and AFAIK, none of the container orchestration tools deal with it well).
- bogomipz 10y agoHow is the unique trace ID implemented? Vector clocks would be in use by your distributed data store for conflict resolution such as Riak does. Could you elaborate on how you've implemented such a system?
- rdli 10y agoIt's not about conflict resolution, it's about ordering. Imagine you have 3 services. A calls B calls C. A request goes into A. The request fails. Since there are 3 services involved, you want to be able to see the log statements of all 3 services, in order. To do this, you need a UUID that is passed from A to B to C and a vector clock that is incremented from A to B to C so you get perfect ordering. Passing the data around is not super hard (you can use HTTP headers, for example). The tricky bit is having a library that does the right thing in A and B and C. And if A is written in Java and B is written in NodeJS, that library better work on both!
- bogomipz 10y agoYes, this makes total sense. I think I completely misunderstood you post earlier. Thanks for the clarification.