fixed issue with invalid readings being visible

Before this change readings for sensors that are not yet available were
displayed as value 0.0 with timestamp 1970-01-01 which was meant to
represent invalid readings. This behaviour is undesired in case of
periodic report with appendLimit set. After this change invalid readings
are no longer visible.

Tested:
- Readings for sensors that is currently not available are not present
  on redfish.
- Confirmed in new unit tests that sensor readings can appear in any
  order. And produce correct results.

Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
Change-Id: I340b85017530d120f2da2cc8ac4ae1840177e78c
7 files changed
tree: 3c6a685b5d09b912743aefde55780baedf4f0315
  1. redfish-tests/
  2. scripts/
  3. src/
  4. subprojects/
  5. tests/
  6. .clang-format
  7. .gitignore
  8. LICENSE
  9. MAINTAINERS
  10. meson.build
  11. meson_options.txt
  12. OWNERS
  13. README.md
  14. xyz.openbmc_project.Telemetry.service.in
README.md

Telemetry

This component implements middleware for sensors and metrics aggregation.

Capabilities

This application is implementation of Telemetry proposed in OpenBMC design docs [1].

It's responsible for:

  • on-demand creation of metric reports,
    • aggregated sets of sensor values available in system [2],
  • access to metric report in both pull and push model (triggers),
  • run-time monitoring of sensor[3] updates.

Use-cases

  • generic and centralized way to observe telemetry data inside system
  • back-end for Redfish TelemetryService[4]

How to build

There are two way to build telemetry service:

  • using bitbake in yocto environment
  • using meson as native build

To build it using bitbake follow the guide from OpenBMC docs[5]. To build it using meson follow the quick guide to install meson[6] and then run below commands

meson build
cd build
ninja

After successful build you should be able to run telemetry binary or start unit tests

./tests/telemetry-ut
./telemetry

In case if system is missing boost dependency, it is possible to build it locally and set BOOST_ROOT environment variable to location of built files for meson. After this change meson should be able to detect boost dependency. See [7] for more details.

Notes

More information can be found in OpenBMC docs repository [8].

References

  1. OpenBMC platform telemetry design
  2. Sensor support for OpenBMC
  3. dbus-sensors
  4. Redfish TelemetryService
  5. Yocto-development
  6. Meson-Quick-Guide
  7. Meson-Boost-dependency
  8. OpenBMC-docs-repository