log

Overview ¶

Package log provides a structured logging base on slog.

Sampling ¶

It supports sampling Info logs to reduce the log volume using sampler provided by WithSampler. However, if there exists an Error log, it records buffered Info logs for same request event they are not sampled. It provides context for root cause analysis while Error happens.

Trace Integration ¶

It supports recording log records as trace span's events if it's enabled by WithLogAsTraceEvent. It could significantly reduce the log volume then cost as trace is priced by number of span.

Rate limiting ¶

Applications often experience runs of errors, either because of a bug or because of a misbehaving user. Logging errors is usually a good idea, but it can easily make this bad situation worse: not only is your application coping with a flood of errors, it's also spending extra CPU cycles and I/O logging those errors. Since writes are typically serialized, logging limits throughput when you need it most.

Rate limiting fixes this problem by dropping repetitive log entries. Under normal conditions, your application writes out every entry. When similar entries are logged hundreds or thousands of times each second, though, it begins dropping duplicates to preserve throughput.