c06615137b
We consult ZooKeeper to determine the most recent image upload when we decide whether we should accept or decline a request. If we accept the request, we also consult it again for the same information when we start building the node. In both cases, we can use the cache to avoid what may potentially be (especially in the case of a large number of images or uploads) quite a lot of ZK requests. Our cache should be almost up to date (typically milliseconds, or at the worst, seconds behind), and the worst case is equivalent to what would happen if an image build took just a few seconds longer. The tradeoff is worth it. Similarly, when we create min-ready requests, we can also consult the cache. With those 3 changes, all references to getMostRecentImageUpload in Nodepool use the cache. The original un-cached method is kept as well, because there are an enormous number of references to it in the unit tests and they don't have caching enabled. In order to reduce the chances of races in many tests, the startup sequence is normalized to: 1) start the builder 2) wait for an image to be available 3) start the launcher 4) check that the image cache in the launcher matches what is actually in ZK This sequence (apart from #4) was already used by a minority of tests (mostly newer tests). Older tests have been updated. A helper method, startPool, implements #4 and additionally includes the wait_for_config method which was used by a random assortment of tests. Change-Id: Iac1ff8adfbdb8eb9a286929a59cf07cd0b4ac7ad
Nodepool
Nodepool is a system for managing test node resources. It supports launching single-use test nodes from cloud providers as well as managing access to pre-defined pre-existing nodes. Nodepool is part of a suite of tools that form a comprehensive test system, including Zuul.
The latest documentation for Nodepool is published at: https://zuul-ci.org/docs/nodepool/
The latest documentation for Zuul is published at: https://zuul-ci.org/docs/zuul/
Getting Help
There are two Zuul-related mailing lists:
- zuul-announce
-
A low-traffic announcement-only list to which every Zuul operator or power-user should subscribe.
- zuul-discuss
-
General discussion about Zuul, including questions about how to use it, and future development.
You will also find Zuul developers in the #zuul channel on Freenode IRC.
Contributing
To browse the latest code, see: https://opendev.org/zuul/nodepool To clone the latest code, use git clone https://opendev.org/zuul/nodepool
Bugs are handled at: https://storyboard.openstack.org/#!/project/zuul/nodepool
Code reviews are handled by gerrit at https://review.opendev.org
After creating a Gerrit account, use git review to submit patches. Example:
# Do your commits
$ git review
# Enter your username if promptedJoin #zuul on Freenode to discuss development or usage.
License
Nodepool is free software, licensed under the Apache License, version 2.0.
Python Version Support
Nodepool requires Python 3. It does not support Python 2.