Adopt Oslo Guru Meditation Reports

https://blueprints.launchpad.net/ceilometer/+spec/guru-meditation-report

This spec adopts Oslo Guru Meditation Reports in Ceilometer. The feature will enhance debugging capabilities of all Ceilometer services, by providing an easy and convenient way to collect debug data about current threads and configuration, among other things, to developers, operators, and tech support in production deployments.

Problem description

Currently, Ceilometer doesn’t provide a way to collect state data from active service processes. The only information that is available to deployers, developers, and tech support is what was actually logged by the service. Additional data could be usefully used to debug and solve problems that occur during Ceilometer operation. We could be interested in stack traces of green and real threads, pid/ppid info, package version, configuration as seen by the service, etc.

Oslo Guru Meditation Reports provide an easy way to add support for collecting the live state info from any service. Report generation is triggered by sending a special(USR1) signal to a service. Reports are generated on stderr, and can be piped into system log based on need.

Nova has supported Oslo Guru Meditation Reports.

Proposed change

First, a new oslo-incubator module (reports.*) should be synchronized into Ceilometer tree. Then, each service process needs to initialize the error report system before the process executes launch method in the main function.

Alternatives

None

Data model impact

None

REST API impact

None

Security impact

This feature could expose service internals to someone who is able to send the needed signal to a service. That said, we can probably assume that the operator is already authorized to achieve a lot more than just having an access to stack traces and configuration used. Of course, if deployers are afraid of the information leak for some reason, they could also make sure their stderr output is channeled into safe place.

Pipeline impact

None

Other end user impact

None

Performance/Scalability Impacts

The feature does not require any additional resources until it’s triggered by the user and reports are not expected to be generated too often, so it has little impact on performance and scalability.

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:
zhangtralon

Work Items

  • sync reports.* module from oslo-incubator
  • adopt it in all ceilometer services under ceilometer/cmd/
  • add some developer docs on how to use this feature

Future lifecycle

None

Dependencies

Currently, the reports.* module from oslo-incubator is graduating into oslo.reports in Library. In case it’s graduated into oslo.reports before Ceilometer switches to it, we will not need to synchronize the reports.* module.

Testing

None

Documentation Impact

Documentation should be extended to describe the new feature.