# SyslogBackend `SyslogBackend` implements `mw::log::detail::Backend` for Linux. `SyslogRecorderFactory` selects it when the log mode contains `kSystem`. `TextRecorder` uses it in the same way as `SlogBackend` on QNX. `SyslogBackend` stores `LogRecord` objects in a `CircularAllocator`. `ReserveSlot()` acquires a slot and `FlushSlot()` sends its contents to syslog. No log data leaves the process before `FlushSlot()` runs. `FlushSlot()` maps `LogLevel` to a syslog(3) priority. It sends the application ID, context ID, and payload in one formatted call. `kOff` and out-of-range levels are ignored. `Syslog::openlog()` runs once during construction. The `Syslog` object seam enables host tests without a running syslog daemon. The sequence diagram shows a log call from stream construction to syslog(3). The sequence below shows a single log call from `LogStream` construction through to the `syslog(3)` call made when the stream is destroyed and the slot is flushed: