Java (JVM)

Collect JVM runtime and HTTP metrics from any JVM application and get curated dashboards and alerts for them with a single import.

JVM apps instrumented with the OpenTelemetry Java agent export their metrics over OTLP to your LeanSignal agent gateway (one per cluster or environment) — never to a remote or third-party endpoint. The gateway keeps full fidelity locally and forwards only the demanded subset to your central dataplane. This integration covers JVM runtime health (heap/non-heap memory, GC duration, threads, classes, CPU) plus HTTP server request metrics.

Metric names follow the standard OTLP → Prometheus normalization (dots become underscores, unit/_total suffixes are added), so jvm.memory.used becomes jvm_memory_used_bytes and http.server.request.duration becomes http_server_request_duration_seconds. The demands below are built against those names.

Prerequisites

• A LeanSignal agent gateway deployed and connected — one per cluster or environment. If you haven’t deployed it yet, follow Install the agent (source: LeanSignal/leansignal-agent). It should show as Connected under Agents in the LeanSignal app.
• Network reachability to the gateway’s OTLP port — 4317 (gRPC) or 4318 (HTTP). See Agent configuration.
• Your Java (JVM) app instrumented with the OpenTelemetry SDK, exporting metrics over OTLP to the gateway — configured in Setup.
• Editor or admin role in the LeanSignal app (importing a demand creates dashboards and alert rules).

Setup

Attach the OpenTelemetry Java agent and point it at your LeanSignal agent gateway (OTLP gRPC :4317 / HTTP :4318) — not a SaaS endpoint. No code changes are required; JVM runtime and HTTP server metrics are on by default.

# 1. Download the agent (pin a version in production)
curl -Lo opentelemetry-javaagent.jar \
  https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/latest/download/opentelemetry-javaagent.jar

# 2. Configure export to the gateway
export OTEL_SERVICE_NAME=orders-service
export OTEL_EXPORTER_OTLP_ENDPOINT=http://<gateway-host>:4317
export OTEL_EXPORTER_OTLP_PROTOCOL=grpc      # or http/protobuf against :4318
export OTEL_METRICS_EXPORTER=otlp            # default; keep metrics enabled

# 3. Run with the agent attached
java -javaagent:/path/opentelemetry-javaagent.jar -jar app.jar

The equivalent as JVM system properties: -Dotel.service.name=orders-service -Dotel.exporter.otlp.endpoint=http://<gateway-host>:4317.

Agent version and metric names

The stable jvm.* runtime metrics and the seconds-based http.server.request.duration require a current Java agent. Older agents emitted the experimental process.runtime.jvm.* names and http.server.duration in milliseconds — use a recent agent so the imported demand’s queries match. HTTP server metrics need a supported server/framework (Servlet, Spring MVC/WebFlux, Tomcat, Jetty, …); a pure batch/CLI JVM app emits only the jvm.* runtime metrics.

Where to send this

You have two options:

• Straight to the LeanSignal agent gateway. Point the app’s OTEL_EXPORTER_OTLP_ENDPOINT at it — nothing else in between.
• Via an OpenTelemetry Collector in agent mode. Point the app at a local collector and give that collector an otlp exporter to the gateway (leansignal-agent:4317).

Both are supported — pick whichever suits your topology. A local collector tends to fit when the app has no route to the gateway (a different network or cluster), or when you want local buffering, batching, or extra processing; exporting directly means one less process to operate.

Multiple instances

Give each running instance a stable identity so replicas stay distinct: set service.instance.id, exported as the instance label — for example OTEL_RESOURCE_ATTRIBUTES=service.instance.id=$(hostname), or your orchestrator’s pod name. The imported dashboard has an Instance filter — view all instances at once or focus on one.

Logs and traces

The Java agent from Setup already exports all three signals: with OTEL_EXPORTER_OTLP_ENDPOINT set, traces and logs flow to the gateway by default alongside metrics — Logback and Log4j output is captured automatically, and every supported framework is traced with no code changes. To turn a signal off, set OTEL_TRACES_EXPORTER=none or OTEL_LOGS_EXPORTER=none. See the Java zero-code instrumentation docs.

Demand-driven, like metrics

Logs and traces land in the gateway’s edge stores (a roughly one-hour full-fidelity window) and are queryable immediately in the LeanSignal app under Logs and Traces with the source set to Available. Nothing is stored centrally until a dashboard demands it — the ready-made demands on this page stay metrics-only. See Logs and Traces.

Demands

Java (JVM) ships as a ready-made demand in three variants. You don’t copy any JSON — in the LeanSignal app go to Demands, press the ˅ arrow on the Add Demand button (the arrow opens the import menu), choose Import from catalog…, and pick the variant. Each variant below lists the slug that identifies its published bundle. See Integrations for the full import flow.

The variants are nested — Standard is a superset of Essential, Extended a superset of Standard. Pick whichever is closest to what you need and treat it as a starting point: after import everything is a normal, editable copy, so retune thresholds, add or drop panels, and adjust queries for your environment — your edits reshape the demand automatically. Start small and re-import a larger variant later if you outgrow it.

Essential

The golden signals. 1 dashboard · 4 panels · 3 alerts — traffic, errors, latency, and heap headroom at a glance.

Import this variant from the catalog. Its demand slug:

Demand slug

java-otel-demand-essential

Dashboard — HTTP request rate, HTTP 5xx error rate, HTTP request duration p95, and Heap utilization vs limit.

Alerts (3)

Alert	Severity	Fires when
High HTTP 5xx error rate	critical	5xx ratio > 5% for 5m
High HTTP p95 latency	warning	p95 latency > 1s for 5m
Heap memory near limit	critical	post-GC heap floor > 90% of limit for 5m

Review the bundle JSON →

Standard

Well-rounded runtime coverage. 1 dashboard · 7 panels · 5 alerts — adds heap usage, GC pauses, and thread health. The recommended default.

Import this variant from the catalog. Its demand slug:

Demand slug

java-otel-demand-standard

Dashboard — everything in Essential, plus Heap memory used, GC pause duration p95, and Live thread count.

Alerts (5)

Alert	Severity	Fires when
High HTTP 5xx error rate	critical	5xx ratio > 5% for 5m
High HTTP p95 latency	warning	p95 latency > 1s for 5m
Heap memory near limit	critical	post-GC heap floor > 90% of limit for 5m
Elevated GC pause p95	warning	GC pause p95 > 0.5s for 5m
High heap utilization	warning	post-GC heap floor > 80% of limit for 10m

Review the bundle JSON →

Extended

Deep JVM visibility. 1 dashboard · 14 panels · 9 alerts — CPU, memory pools, GC behavior, and leak indicators for services you need to diagnose, not just watch.

Import this variant from the catalog. Its demand slug:

Demand slug

java-otel-demand-extended

Dashboard — everything in Standard, plus JVM CPU utilization, Heap used after last GC, Heap memory used by pool, Non-heap memory used, GC collection rate, Time spent in GC, and Threads by state.

Alerts (9)

Alert	Severity	Fires when
High HTTP 5xx error rate	critical	5xx ratio > 5% for 5m
High HTTP p95 latency	warning	p95 latency > 1s for 5m
Heap memory near limit	critical	post-GC heap floor > 90% of limit for 5m
Elevated GC pause p95	warning	GC pause p95 > 0.5s for 5m
High heap utilization	warning	post-GC heap floor > 80% of limit for 10m
Excessive time in GC	warning	GC time fraction > 10% for 10m
Very high HTTP p99 latency	warning	p99 latency > 2.5s for 5m
High thread count	warning	> 300 threads for 10m
Live heap high after GC (possible leak)	critical	post-GC heap > 90% for 15m

Review the bundle JSON →

Dashboards

Each variant imports one Java (JVM) dashboard, its panels grouped into collapsible sections. Every dashboard carries an Instance filter (on the instance label), so one import covers the whole fleet — view every instance at once, or focus on one. Legends are sortable tables showing last/mean/max per series, so the outlier instance stands out. Dashboards are demand-driven: importing one tells your agents to forward exactly the timeseries its panels query, and nothing else. Panels are ordinary Perses panels — edit queries, add panels, or retune them after import, and your changes reshape the demand automatically.

Alerts

Thresholds are conservative starting points — tune them to your workload.

Caution

Imported alert rules arrive without a notification channel and start out paused — with nowhere to deliver, they do not evaluate. After importing, create or pick a channel under Alerts → Manage Channels, attach it to each rule, and resume. Rules without a channel are marked with a warning icon in the alerts list.

Next steps

• Demand-driven observability — why importing a demand also shapes what your agents collect.
• Agent configuration — the full agent config surface.