Tag Archives: OpenStack

MQTT in the Cloud: Firehose

This is the first post in what’s going to be a multi post series exploring how MQTT can be leveraged in the cloud. The series will look at several different models for deploying applications in the cloud and how you can leverage MQTT as an event based protocol for those applications. This first post will be looking at using MQTT as unified event bus for heterogeneous service deployed using more traditional configuration managed services by looking at the OpenStack community infrastructure’s firehose effort.

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Python Test Runners

For the past year and half I’ve been working on a parallel test runner for python tests, stestr. I started this project to fit a need in the OpenStack community and it since has been adopted as the test runner used in the OpenStack project. But, it is generally a useful tool and something I think would provide general value for people writing python tests. I thought it would be valuable to explain two things in this post, first the testing stack underlying stestr and the history behind the project. The second aspect is how it compares to other popular python test runners are out there, and the purpose it fills.

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Gate Bug Triage Conclusion

A few months ago I made the post about debugging a gate failure. It has been linked around and copied to quite a few places and seems to be a very popular post. (definitely the most popular so far on this blog) I figured since the bug I opened from that was closed as invalid a while ago that I should write an update about the conclusion to the triage efforts for the OOM failures on neutron jobs. It turns out that my suppositions in the earlier post were only partially correct. The cause of the failures was running out of memory but what was leading to the OOM failures wasn’t just limited to neutron. It was just that the neutron jobs ran with more services which used more memory which made failures there more common.

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Triaging and classifying a gate failure

Recently I was helping someone debug a gate failure they had hit on one of their patches. After going through the logs with them and finding the cause of the failures, I was asked to go through how I debug gate failures. To help people understand how to get from a failure to a fix.

I figured I would go through what I did and why on that particular failure and use it as an example to explain my initial debug process. I do want to preface this by saying that I wasted a great deal of time debugging this failure, because I missed certain details at first, but I’m leaving all of those steps in here on purpose.

The log url for this failure is:


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QA Program: From Juno into the Future

Based on some of the comments that were posted on the recent “Which Program for Rally” ML thread I feel that there’s been some continued confusion around exactly how all the  projects work together in the QA program. So after discussing it with a wise council of my elders, I decided to start a blog so that I had a place to post more details and I could give a high level overview and clarify how everything works. I’m not really sure how much I’ll be using this blog in the future, as having one is something I’ve resisted for quite some time. But, I felt that making this post warranted me giving in to peer pressure.

Today’s the QA program :

So today in the QA program we have 3 projects, here is a high level over:

  • Tempest: The OpenStack Integrated test suite, it’s concerned with just  with having tests and running them
  • devstack: A documented shell script to build complete OpenStack development environments.
  • grenade: Upgrade testing using 2 versions of devstack to test an offline upgrade. Tempest can optionally be used after each version is deployed to verify the cloud.

Each of these projects is independent and is useful by itself. They have  defined scope (which admittedly gets blurred and constantly evolves) and  when used together along with external tools they can be used in different pipelines for certain goals.
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