1.21.0

This release adds several new metrics for tracking flash wear, as well as a new
syslog log source. It also includes a config flag to enable legacy statsd metric
names, and a data retention check to the upload process. For more information on
the new metrics, check out the
docs.

Added

• Added metrics for tracking flash wear for mmc block devices like eMMC and SD
  cards
  • diskstats/<disk_name>/bytes_written
  • diskstats/<disk_name>/lifetime_pct
  • diskstats/<disk_name>/manufacturer_id
  • diskstats/<disk_name>/name
• Added syslog as a logs source. This adds support for messages in both RFC5424
  and RFC3164 format sent over UDP. This is enabled with the syslog feature
  which defaults to enabled.
• Added a config flag to enable legacy statsd metric names. This will generate
  metrics that follow the format generated by the collectd statsd server. This
  is a helpful option for people looking to remove collectd as a dependency,
  but keep the legacy format for metric keys. The config value can be found in
  metrics->statsd_server->legacy_key_names.
• Added time-based data filtering: When upgrading multiple devices' visibility
  levels, the Memfault backend now tells memfaultd to only upload data from
  the time of the change forward. This prevents unexpected large data uploads
  from device history.
• Added interface/<interface>/total_bytes/{tx,rx} metrics. These allow us to
  track the total bytes sent over an interface over the course of an hour.

Changed

• Added intelligent traffic distribution: Device initial connections now include
  a random delay (up to 25% of the configured upload interval). This prevents
  traffic spikes when many devices connect simultaneously, ensuring smoother
  backend performance.
• ram and loop disks are no longer tracked with diskstats in auto mode.
  These are virtual disks, and provide little value when tracking metrics.