I'm not sure I want to weigh in on "log" vs "metric"... but I did want to add some thoughts on logs in general.
If you need to "log" something to give users feedback as the system is running, it may be less of a log and more of a progress or status output.
Logs to me are things which happen and I want to be able to trace later, so summarizing or otherwise dropping logs that come in quickly in succession would be a problem. If I need to filter I pipe to grep, otherwise I can just save it all and read through it later.
Status messaging, which may be informative about your process is useful, and if its goal is to be observed real-time, then yea. A message or two a second seems like a good goal for consistency.
These are just two very different use cases to me. And generally I find the former critical to get right, while the later may be nice to have and may lead to discovery by nature of making it more accessible.
If you need to "log" something to give users feedback as the system is running, it may be less of a log and more of a progress or status output.
Logs to me are things which happen and I want to be able to trace later, so summarizing or otherwise dropping logs that come in quickly in succession would be a problem. If I need to filter I pipe to grep, otherwise I can just save it all and read through it later.
Status messaging, which may be informative about your process is useful, and if its goal is to be observed real-time, then yea. A message or two a second seems like a good goal for consistency.
These are just two very different use cases to me. And generally I find the former critical to get right, while the later may be nice to have and may lead to discovery by nature of making it more accessible.