Plugin Health Checks

fapilog plugins can expose an async health_check() method to report readiness. Base protocols return True by default, so existing plugins stay compatible.

Checking health from code

from fapilog import get_logger

logger = get_logger()
health = await logger.check_health()

if health.all_healthy:
    print("All plugins healthy")
else:
    for plugin in health.plugins:
        if not plugin.healthy:
            print(f"{plugin.plugin_type}:{plugin.name} unhealthy: {plugin.last_error}")

Implementing in a custom plugin

class MySink:
    async def write(self, entry: dict) -> None:
        ...

    async def health_check(self) -> bool:
        try:
            return await self._client.ping() == 200
        except Exception:
            return False

Built-ins now provide sensible checks:

• StdoutJsonSink: verifies stdout is writable

• RotatingFileSink: verifies directory exists/writable and file handle open

• MemoryMappedPersistence: ensures mmap/file is open