A circular buffer can keep the rotation logic in memory and avoid the overhead of spawning a cron job each time a log file rolls, so for a server that writes millions of lines per second it can reduce latency and CPU usage. However, you have to manage the buffer size carefully—if it overflows before the disk flushes you lose data. The classic cron approach is simple, auditable, and reliable because the rotation happens in a separate process with explicit timestamps; it’s also easier to configure retention policies in a deterministic way. If you go circular, make sure you back it up with a watchdog that writes to disk on a regular interval and logs any overflow. For most production workloads, sticking with cron or a dedicated logrotate daemon keeps things stable and predictable; a circular buffer is a useful optimization only if you can guarantee enough memory and a fail‑over path.