[micrometer] Fix interference with user-configured request logger by Copilot · Pull Request #2533 · javalin/javalin

Copilot · 2026-02-24T09:54:16Z

MicrometerPlugin.onInitialize() registered its metrics collection via state.requestLogger.http { ... }, which overwrote any user-configured request logger. This meant users had to choose between metrics and request logging — they couldn't have both.

Changes

MicrometerPlugin.kt: Before registering its own logger, the plugin now captures the existing httpRequestLogger. The new logger composites both: metrics are recorded first, then the user's logger is invoked. The user's logger is never lost regardless of registration order.
MicrometerPluginTest.kt: Added a test asserting the user-configured request logger is still called when the plugin is registered.

// Both of these now work together — no longer mutually exclusive
config.requestLogger.http { ctx, ms -> println("${ctx.method()} ${ctx.path()} ${ms}ms") }
config.registerPlugin(MicrometerPlugin { it.registry = registry })

Original prompt

This section details on the original issue you should resolve

<issue_title>javalin-micrometer interferance with request logger</issue_title>
<issue_description>Actual behavior (the bug)
When register the micrometer after setting the request logger, then the request logger in not called on fulfilled requests.

Expected behavior
Request logger should be triggered regardless of metrics plugin.

To Reproduce

set the request logger

register micrometer plugin

create an http endpoint

do a http request to that endpoint

Example Java code:
    public static void main(String[] args) {
    var micrometerPlugin = new MicrometerPlugin();
    var javalin =
        Javalin.create(
                config -> {
                  config.registerPlugin(micrometerPlugin);
                  config.requestLogger.http(
                      (ctx, ms) -> {
                        var format = "Request: %s %s took %s ms";
                        System.out.printf(format + "%n", ctx.method(), ctx.path(), ms);
                      });

                  config.routes.get("/hello", ctx -> ctx.result("Hello World"));
                })
            .start(8089);
  }
Additional context

I believe this is the issue:
// Register HTTP request logger to collect metrics
state.requestLogger.http { ctx, executionTimeMs ->
    recordHttpMetrics(ctx, executionTimeMs, state)
}
Based on this, it looks like we have to choose between a request logger and metrics, not both.</issue_description>

<agent_instructions>Please ensure that micrometer does not interfere with user config. </agent_instructions>

Comments on the Issue (you are @copilot in this section)

Fixes javalin-micrometer interferance with request logger #2531

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

Co-authored-by: tipsy <[email protected]>

tipsy · 2026-02-24T10:36:37Z

@copilot I think we should avoid touching the request logger, can you use an after and grab the time manually?

codecov · 2026-02-24T10:45:21Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.26%. Comparing base (9c3461f) to head (587d292).
⚠️ Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #2533   +/-   ##
=========================================
  Coverage     86.26%   86.26%           
  Complexity     1505     1505           
=========================================
  Files           155      155           
  Lines          4338     4338           
  Branches        522      522           
=========================================
  Hits           3742     3742           
  Misses          363      363           
  Partials        233      233

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

…metrics Co-authored-by: tipsy <[email protected]>

Copilot · 2026-02-24T10:46:49Z

@copilot I think we should avoid touching the request logger, can you use an after and grab the time manually?

Done in 161997a. The plugin now uses before/after handlers to capture timing and record metrics without touching requestLogger at all.

One trade-off with the after handler approach: auto-generated ETag 304s aren't visible since the 304 status is set during response writing (after our after handler runs). The etags test is updated to reflect this — metrics record the handler's status (200), not the ETag transport optimization (304). Explicit ETags set by the handler would still work correctly.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

www.google.com
- Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=5757 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.79vxVn --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,5491375344045772556,12134624301296659610,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
- Triggering command: /opt/google/chrome/chrome /opt/google/chrome/chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-client-side-phishing-detection --disable-default-apps --disable-dev-shm-usage --disable-features=IgnoreDuplicateNavs,Prewarm --disable-gpu --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-automation --enable-logging --headless=new --log-level=0 --no-first-run --no-sandbox (dns block)
- Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=9128 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.53Dp3K --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,11119842164605674254,4817581800876992358,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

tipsy · 2026-02-24T14:43:04Z

@copilot good point, let's go back to your original proposal.

…metrics Co-authored-by: tipsy <[email protected]>

Copilot · 2026-02-24T14:47:53Z

@copilot good point, let's go back to your original proposal.

Reverted in 587d292. Back to capturing the existing logger and chaining it after metrics recording.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

optimizationguide-pa.googleapis.com
- Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=8977 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.eR20v7 --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,17441623299415734598,13366108916326324218,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
- Triggering command: /opt/google/chrome/chrome /opt/google/chrome/chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-client-side-phishing-detection --disable-default-apps --disable-dev-shm-usage --disable-features=IgnoreDuplicateNavs,Prewarm --disable-gpu --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-automation --enable-logging --headless=new --log-level=0 --no-first-run --no-sandbox (dns block)
www.google.com
- Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=8977 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.eR20v7 --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,17441623299415734598,13366108916326324218,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)
- Triggering command: /opt/google/chrome/chrome /opt/google/chrome/chrome --allow-pre-commit-input --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-client-side-phishing-detection --disable-default-apps --disable-dev-shm-usage --disable-features=IgnoreDuplicateNavs,Prewarm --disable-gpu --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --enable-automation --enable-logging --headless=new --log-level=0 --no-first-run --no-sandbox (dns block)
- Triggering command: /proc/self/exe /proc/self/exe --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --no-sandbox --disable-dev-shm-usage --use-angle=swiftshader-webgl --crashpad-handler-pid=9111 --enable-crash-reporter=, --noerrdialogs --user-data-dir=/tmp/org.chromium.Chromium.scoped_dir.yTjVhr --change-stack-guard-on-fork=enable --shared-files=v8_context_snapshot_data:100 --field-trial-handle=3,i,3741048064751700057,16289580944237695656,262144 --disable-features=IgnoreDuplicateNavs,PaintHolding,Prewarm --variations-seed-version --trace-process-track-uuid=3190708989122997041 --enable-logging --log-level=0 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Initial plan

7bda330

Copilot AI assigned Copilot and tipsy Feb 24, 2026

Copilot started work on behalf of tipsy February 24, 2026 09:54 View session

[micrometer] fix request logger interference with user config

4f8237d

Co-authored-by: tipsy <[email protected]>

Copilot AI changed the title ~~[WIP] Fix request logger interference with micrometer plugin~~ Fix MicrometerPlugin overwriting user-configured HTTP request logger Feb 24, 2026

Copilot AI requested a review from tipsy February 24, 2026 10:00

Copilot finished work on behalf of tipsy February 24, 2026 10:00

Copilot started work on behalf of tipsy February 24, 2026 10:37 View session

[micrometer] use before/after handlers instead of request logger for …

161997a

…metrics Co-authored-by: tipsy <[email protected]>

Copilot AI changed the title ~~Fix MicrometerPlugin overwriting user-configured HTTP request logger~~ Fix MicrometerPlugin interference with user-configured HTTP request logger Feb 24, 2026

Copilot finished work on behalf of tipsy February 24, 2026 10:47

Copilot started work on behalf of tipsy February 24, 2026 14:43 View session

[micrometer] revert to logger-chaining approach to preserve ETag 304 …

587d292

…metrics Co-authored-by: tipsy <[email protected]>

Copilot finished work on behalf of tipsy February 24, 2026 14:48

tipsy marked this pull request as ready for review February 24, 2026 14:50

tipsy changed the title ~~Fix MicrometerPlugin interference with user-configured HTTP request logger~~ [micrometer] Fix interference with user-configured request logger Feb 24, 2026

tipsy merged commit e134377 into master Feb 25, 2026
16 checks passed

tipsy deleted the copilot/fix-request-logger-issue branch February 25, 2026 23:25

geir-morten-larsen mentioned this pull request Feb 26, 2026

javalin-micrometer interferance with request logger #2531

Closed

tipsy mentioned this pull request Feb 26, 2026

Support multiple RequestLoggers #2538

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[micrometer] Fix interference with user-configured request logger#2533

[micrometer] Fix interference with user-configured request logger#2533
tipsy merged 4 commits intomasterfrom
copilot/fix-request-logger-issue

Copilot AI commented Feb 24, 2026 •

edited

Loading

Uh oh!

tipsy commented Feb 24, 2026

Uh oh!

codecov bot commented Feb 24, 2026 •

edited

Loading

Uh oh!

Copilot AI commented Feb 24, 2026 •

edited

Loading

I tried to connect to the following addresses, but was blocked by firewall rules:

Uh oh!

tipsy commented Feb 24, 2026

Uh oh!

Copilot AI commented Feb 24, 2026 •

edited

Loading

I tried to connect to the following addresses, but was blocked by firewall rules:

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Uh oh!

Conversation

Copilot AI commented Feb 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Changes

Comments on the Issue (you are @copilot in this section)

Uh oh!

tipsy commented Feb 24, 2026

Uh oh!

codecov bot commented Feb 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

Copilot AI commented Feb 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

I tried to connect to the following addresses, but was blocked by firewall rules:

Uh oh!

tipsy commented Feb 24, 2026

Uh oh!

Copilot AI commented Feb 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

I tried to connect to the following addresses, but was blocked by firewall rules:

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Copilot AI commented Feb 24, 2026 •

edited

Loading

codecov bot commented Feb 24, 2026 •

edited

Loading

Copilot AI commented Feb 24, 2026 •

edited

Loading

Copilot AI commented Feb 24, 2026 •

edited

Loading