rotate logtype=buffer services

[q66]

Right now filling the buffer just truncates and it will not log anything past that. This makes it generally of limited use except for stuff that only prints a small amount of output and then stops. IMO it would be much more useful if the log scrolled; i.e. truncate from the top as more output comes in, rather than cutting off the bottom.

[notramo]

This would be a very useful change. When a service crashes, I'm mostly not interested in the messages at service startup, I want to see the messages just before the crash. With a truncated log buffer, it's not possible.

[iacore]

I think the program will fail to write to stderr/stdout and crash.

I found this weird problem here: monero-project/monero#9964

[davmac314]

I think the program will fail to write to stderr/stdout and crash.

If you mean "... when the buffer is full", then no, it won't. The output will continue to be consumed by dinit, but will no longer be buffered.

FWIW the intention of "buffered" logging was:

• primarily for services that had to start before any other logging was available
• primarily for services that aren't expected to generate much output.