iopsystems/rezolus v5.19.1

on GitHub

Added

• Agent: block IO latency is now split into its three phases, each a histogram
  broken down by op (read, write, flush, discard). blockio_queue_latency is
  the time a request waited before the device began servicing it — the
  component that grows under saturation, where device latency alone stays flat.
  blockio_total_latency is the end-to-end span the issuing workload actually
  experiences, measured directly rather than summed (two histograms cannot be
  added). The sampler already traced block_rq_insert, but insert and issue
  shared one timestamp and issue overwrote it, discarding the interval — so
  this needs no new probe attach. A request that goes straight to the driver
  has no queue phase and records no queue sample. (#1054, #1124)

Changed

• Agent: blockio_latency is renamed blockio_device_latency. It is the
  same measurement — the pre-split metric always reported the issue-to-complete
  span — but the bare name became ambiguous once the queue and end-to-end
  phases were split out alongside it. Readers treat the two names as one
  metric: the viewer, dashboard, and TUI resolve whichever name a recording
  carries (blockio_device_latency_metric), so existing recordings keep
  rendering unchanged. External consumers that query blockio_latency by name
  — Prometheus rules, Grafana dashboards, saved PromQL — need updating.
  (#1054, #1124)

Fixed

• Exporter: /metrics/binary served zero bytes when the agent could not be
  reached. To a scraper that only reads the body that is the same as an empty
  snapshot, but not to a consumer that probes the endpoint to decide what it
  speaks: zero bytes are not a msgpack document, so the probe concluded the
  endpoint was Prometheus and fell through to the text route. rezolus record
  probes exactly that way, so pointed at an exporter whose source had not come
  up yet it reported detected Prometheus, refused with .rez requires a rezolus (msgpack) endpoint, and recorded nothing for the whole run — even
  when the source appeared seconds later. It now serves a valid msgpack
  document carrying no metrics, which is both true and recoverable: the
  consumer keeps its connection and picks up real data the moment the agent
  appears. An empty body from the agent is normalized the same way. (#1176)

Removed

• Debian 11 (bullseye) packages are no longer published. Debian 11 has
  reached end of life: bullseye-security was last signed on 2026-08-31 and
  its Release file expired on 2026-09-07. apt refuses an expired Release,
  so apt-get update fails inside the build container and cannot be made to
  succeed without disabling the freshness check — which would mean shipping
  packages built against an archive that receives no further security updates.
  Debian 11 users should stay on 5.19.0 or upgrade to bookworm or trixie. The
  install script and the supported-distribution list are updated to match, so
  it reports the release as unsupported rather than adding a repository that
  has no packages for it.