[JUJU-1868] Prevent replacement of nil request body on retry #98
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
non-nil empty buffer when the body is nil. This should prevent observed "net/http: cannot rewind body after connection loss" errors.
SimonRichardson
approved these changes
Jan 19, 2023
|
/merge |
jujubot
added a commit
to juju/juju
that referenced
this pull request
Jan 26, 2023
#15096 The linked issue is being encountered when we saturate the provisioner worker pool and make many concurrent calls to the `ProvisioningInfo` API method for each machine pending provisioning. Within this method, we create an `environ`, which for MAAS makes calls to the provider API. Our API for MAAS had issues with its own retry logic that should be fixed under juju/gomaasapi#98. The new version of that library is recruited in this patch. In addition, we eschew here multiple calls to `ProvisioningInfo` for each machine. Instead, we get all provisioning info for pending machines in a single bulk call, and pass the appropriate info to each pooled job. The testing suite is improved by removal of some custom mock/stub logic in favour of a new generated mock. ## QA steps We don't have a MAAS with sufficient resources to provision many machines in parallel, but behaviour can be verified by repeatedly: - Adding a LXD model. - Running `juju add-machine -n 10` and waiting for quiescence. - Destroying the model. For regression, I also set my MAAS up for access via TLS and verified that provisioning still works. ## Documentation changes None. ## Bug reference https://bugs.launchpad.net/juju/+bug/1987009
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When operating a MAAS controller via TLS, Juju can observe the following error during (sufficiently concurrent) provisioning:
Based on pouring over the
httpstandard library, this appears to happen for GET requests without a body, where the retry logic incorrectly replaces anilbody with a (non-nil) empty buffer.Here we avoid doing the body reset when it is
nil.I was not able to recreate the exact failure scenario, but there is a new test that verifies that this change behaves correctly.