[BugFix] Emit valid Prometheus # TYPE lines for BE/CN JVM metrics#75240
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alvin-phoenix-ai merged 1 commit intoJun 25, 2026
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JVM gauges were registered with the label baked into the metric-name
string, e.g. register_metric("jvm_heap_size_bytes{type=\"used\"}", ...).
The Prometheus exposition then printed that string verbatim after
"# TYPE ", producing illegal comment lines such as:
# TYPE starrocks_be_jvm_heap_size_bytes{type="committed"} gauge
A "# TYPE" metric name must not contain a label set, so a strict parser
rejects it. Prometheus aborts the whole scrape on the first text-format
error, so enabling enable_jvm_metrics took the node's entire metric set
offline (up=0), not just the JVM series.
Register each gauge under a bare name plus a real "type" label via
MetricLabels, mirroring stream_load_metrics. This yields one valid
"# TYPE <name>" line followed by the labelled samples. The sample lines
(name + labels) are byte-identical to before, so existing dashboards and
alerts are unaffected.
Update jvm_metrics_test to look metrics up by name + label, and add a
regression guard asserting the braced names no longer resolve.
Fixes StarRocks#75159
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Srihith Garlapati <srihith.garlapati@gmail.com>
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Codex Review: Didn't find any major issues. Chef's kiss. Reviewed commit: ℹ️ About Codex in GitHubYour team has set up Codex to review pull requests in this repo. Reviews are triggered when you
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[Java-Extensions Incremental Coverage Report]✅ pass : 0 / 0 (0%) |
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[FE Incremental Coverage Report]✅ pass : 0 / 0 (0%) |
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[BE Incremental Coverage Report]✅ pass : 0 / 0 (0%) |
kevincai
approved these changes
Jun 24, 2026
alvin-phoenix-ai
approved these changes
Jun 25, 2026
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@Mergifyio backport branch-4.0 |
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@Mergifyio backport branch-4.1 |
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✅ Backports have been createdDetails
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✅ Backports have been createdDetails
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This was referenced Jun 25, 2026
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Why I'm doing:
enable_jvm_metrics = truemakes the BE/CN/metricsendpoint emit invalidPrometheus text. Each JVM gauge is registered with its label baked into the
metric-name string, e.g.:
so the exposition prints that string verbatim after
# TYPE:A
# TYPEmetric name must not contain a label set. Prometheus aborts theentire scrape on the first text-format error, so flipping this flag on
takes the node's whole metric set offline (
up == 0) — not just the JVMseries.
promtool check metricsrejects it withinvalid metric name in comment. Reproduced on 4.0.10/4.0.11 andmain; the feature shipped in 4.0.0(#62210).
What I'm doing:
Register each JVM gauge under a bare metric name plus a real
typelabel viaMetricLabels, mirroring the existingstream_load_metricspattern. Themetrics framework then emits one valid
# TYPE <name>line followed by thelabelled samples:
The sample lines (name + labels) are byte-identical to before, so the
time-series identity is unchanged and existing dashboards/alerts keep working;
only the previously-malformed
# TYPEcomment is corrected. No metric isrenamed, so no docs change is required.
jvm_metrics_testis updated to look metrics up by name + label, plus aregression guard asserting the old braced names no longer resolve (which would
mean the label was still baked into the name).
Fixes #75159
What type of PR is this:
Does this PR entail a change in behavior?
If yes, please specify the type of change:
Checklist:
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