CLDSRV-980: Make stopRefillJob actually stop the refill job

[anurag4DSB]

Intent: why does this change exist?

stopRefillJob() did not stop the rate limit refill job. Found while investigating RD-2240; unrelated to that memory leak beyond sharing the module.

System impact: what's affected, including downstream?

lib/api/apiUtils/rateLimit/refillJob.js only. startRefillJob gains an optional options argument ({ skipUnref }), mirroring startCleanupJob; the single production caller in lib/server.js is unchanged and takes the new default. The refill timer is now unref()'d, so it no longer holds the event loop open — the HTTP servers keep the process alive, as they already did for the cleanup job.

Preserved behavior: what explicitly stays the same?

Refill cadence, cleanup cadence, and everything the job does per tick. Start, stop, repeated stop and restart-after-stop all behave as before.

Intended change: what's different after this PR?

A running flag gates the re-arm at the end of tick, so a tick that was mid-await when stop ran no longer replaces the timer stop just cleared. startRefillJob also refuses a second concurrent start instead of orphaning the first timer, and warns.

Production impact was limited before this, because cleanUp() ends in process.exit(0) and overrides a live handle. What it did mean is that the job kept hitting Redis and mutating token buckets through the shutdown window, and leaked a live timer into any test that started it.

Verification: how do we know this worked, or how would we know if it didn't?

Two regression tests, written first and confirmed failing against stock. The mid-tick one uses a refill slower than the tick interval so a tick is guaranteed to be in flight at stop; on stock it reports the job still running, and the double-start one measured 12 refills in 450ms where a single loop gives about 4 — roughly three overlapping loops.

Rate limit suite 183 passing, 0 failing. Lint clean apart from two pre-existing prefer-await-to-then warnings on untouched lines.

[bert-e]

Hello anurag4dsb,

My role is to assist you with the merge of this
pull request. Please type @bert-e help to get information
on this process, or consult the user documentation.

Available options

name	description	privileged	authored
/after_pull_request	Wait for the given pull request id to be merged before continuing with the current one.
/bypass_author_approval	Bypass the pull request author's approval	⭐
/bypass_build_status	Bypass the build and test status	⭐
/bypass_commit_size	Bypass the check on the size of the changeset TBA	⭐
/bypass_incompatible_branch	Bypass the check on the source branch prefix	⭐
/bypass_jira_check	Bypass the Jira issue check	⭐
/bypass_peer_approval	Bypass the pull request peers' approval	⭐
/bypass_leader_approval	Bypass the pull request leaders' approval	⭐
/approve	Instruct Bert-E that the author has approved the pull request.		✍️
/create_pull_requests	Allow the creation of integration pull requests.
/create_integration_branches	Allow the creation of integration branches.
/no_octopus	Prevent Wall-E from doing any octopus merge and use multiple consecutive merge instead
/unanimity	Change review acceptance criteria from one reviewer at least to all reviewers
/wait	Instruct Bert-E not to run until further notice.

Available commands

name	description	privileged
/help	Print Bert-E's manual in the pull request.
/status	Print Bert-E's current status in the pull request.
/clear	Remove all comments from Bert-E from the history TBA
/retry	Re-start a fresh build TBA
/build	Re-start a fresh build TBA
/force_reset	Delete integration branches & pull requests, and restart merge process from the beginning.
/reset	Try to remove integration branches unless there are commits on them which do not appear on the source branch.

Status report is not available.

[bert-e]

Incorrect fix version

The Fix Version/s in issue CLDSRV-980 contains:

• None

Considering where you are trying to merge, I ignored possible hotfix versions and I expected to find:

• 9.3.17

• 9.4.2

Please check the Fix Version/s of CLDSRV-980, or the target
branch of this pull request.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.19%. Comparing base (24fb6b3) to head (36120ee).
✅ All tests successful. No failed tests found.

Additional details and impacted files

Files with missing lines	Coverage Δ
lib/api/apiUtils/rateLimit/refillJob.js	92.30% <100.00%> (+2.83%)	⬆️

@@                 Coverage Diff                 @@
##           development/9.3    #6260      +/-   ##
===================================================
+ Coverage            85.17%   85.19%   +0.01%     
===================================================
  Files                  206      206              
  Lines                13424    13438      +14     
===================================================
+ Hits                 11434    11448      +14     
  Misses                1990     1990              

Flag	Coverage Δ
file-ft-tests-null-compat	62.97% <81.25%> (-5.93%)	⬇️
kmip-ft-tests	28.41% <81.25%> (+0.05%)	⬆️
mongo-v0-ft-tests	69.56% <81.25%> (+<0.01%)	⬆️
mongo-v1-ft-tests	69.54% <81.25%> (-0.07%)	⬇️
multiple-backend	36.88% <81.25%> (+0.04%)	⬆️
s3c-ft-tests-v1	63.99% <6.25%> (-0.06%)	⬇️
sur-tests	36.02% <81.25%> (+0.04%)	⬆️
sur-tests-inflights	37.85% <81.25%> (+0.01%)	⬆️
unit	71.16% <100.00%> (+0.07%)	⬆️
utapi-v2-tests	34.67% <81.25%> (+0.04%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[bert-e]

Request integration branches

Waiting for integration branch creation to be requested by the user.

To request integration branches, please comment on this pull request with the following command:

/create_integration_branches

Alternatively, the /approve and /create_pull_requests commands will automatically
create the integration branches.