OnChange trigger should not handle first reading

When OnChange trigger register for updates, it gets current sensor value
as an update. This reading fires trigger actions and is undesirable.

This change skips handling of first reading update for OnChange trigger.

Testing done:
- UTs updated and are passing,
- OnChange trigger is not doing an action on first reading update.

Signed-off-by: Szymon Dompke <szymon.dompke@intel.com>
Change-Id: Ief2d1edd5923fd332f3ea3234a9988e1967d972f
3 files changed
tree: 9d42dfdc45cf6c671015f2c5ab7832e4085f83b2
  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