Remove key in tags to reduce metrics count

[xliuxu]

Issue: knative/serving#8609

Signed-off-by: Lance Liu xuliuxl@cn.ibm.com

[knative-prow-robot]

Welcome @lanceliuu! It looks like this is your first PR to knative/pkg 🎉

[knative-prow-robot]

Hi @lanceliuu. Thanks for your PR.

I'm waiting for a knative member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[vagababov]

LG in general.
Did you verify that this patch solves your memory issues?

[evankanderson]

You probably also want to remove keyTagKey from line 170 and 175 (which is where we instruct OpenCensus to aggregate divided by key), and the definition on line 49.

[evankanderson]

/ok-to-test

[xliuxu]

I removed the key tag accordingly. Thank you @evankanderson.
After apply this patch, the total metrics count for controller drops significantly.
Before:

~ wc -l metrics-controller.txt
   68628 metrics-controller.txt

After:

~ wc -l metrics-controller.txt
     570 metrics-controller.txt

Also the size of metrics drops from ~11M to ~66K
@vagababov

[xliuxu]

/test pull-knative-pkg-unit-tests

[evankanderson]

/retest

[evankanderson]

Wow, the cardinality for key must have been really high (which will cause problems with Stackdriver, at least, but many monitoring systems struggle with high-cardinality labels).

/lgtm
/approve

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: evankanderson, lanceliuu

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• controller/OWNERS [evankanderson]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[markusthoemmes]

/retest