Add initial support for observability with JFR

This commit introduces new JFR events to monitor and trace
job and step executions. The most important design decision
is to have a single event for each action, instead of two
separate events (like ChunkTransactionEvent instead of
ChunkTransactionStartEvent and ChunkTransactionStopEvent).

This design has two main advantages:
- Ability to time events and have a non-zero duration
- Avoid the need to correlate events on the consumer side

Further improvements ideas:
- Create an observability template to time actions
- Use AOP for observability aspects

Resolves #4972

Author: fmbenhassine

spring-batch-core/src/main/java/org/springframework/batch/core/job/AbstractJob.java

@@ -37,6 +37,7 @@
 import org.springframework.batch.core.job.parameters.JobParametersValidator;
 import org.springframework.batch.core.listener.JobExecutionListener;
 import org.springframework.batch.core.SpringBatchVersion;
+import org.springframework.batch.core.observability.jfr.events.job.JobExecutionEvent;
 import org.springframework.batch.core.step.Step;
 import org.springframework.batch.core.step.StepExecution;
 import org.springframework.batch.core.launch.NoSuchJobException;
@@ -277,6 +278,9 @@ public final void execute(JobExecution execution) {
 		}
 
 		JobSynchronizationManager.register(execution);
+		JobExecutionEvent jobExecutionEvent = new JobExecutionEvent(execution.getJobInstance().getJobName(),
+				execution.getJobInstance().getId(), execution.getId());
+		jobExecutionEvent.begin();
 		String activeJobMeterName = "job.active";
 		LongTaskTimer longTaskTimer = BatchMetrics.createLongTaskTimer(this.meterRegistry, activeJobMeterName,
 				"Active jobs", Tag.of(BatchMetrics.METRICS_PREFIX + activeJobMeterName + ".name",
@@ -349,6 +353,8 @@ public final void execute(JobExecution execution) {
 					execution.setExitStatus(exitStatus.and(newExitStatus));
 				}
 				stopObservation(execution, observation);
+				jobExecutionEvent.exitStatus = execution.getExitStatus().getExitCode();
+				jobExecutionEvent.commit();
 				longTaskTimerSample.stop();
 				execution.setEndTime(LocalDateTime.now());
 
@@ -364,6 +370,7 @@ public final void execute(JobExecution execution) {
 			finally {
 				JobSynchronizationManager.release();
 			}
+			System.out.println("execution = " + execution);
 
 		}
 

spring-batch-core/src/main/java/org/springframework/batch/core/launch/support/TaskExecutorJobOperator.java

@@ -27,6 +27,7 @@
 import org.springframework.batch.core.launch.JobOperator;
 import org.springframework.batch.core.launch.NoSuchJobException;
 import org.springframework.batch.core.launch.NoSuchJobExecutionException;
+import org.springframework.batch.core.observability.jfr.events.job.JobLaunchEvent;
 import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
 import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
 import org.springframework.batch.core.repository.JobRepository;
@@ -92,6 +93,7 @@ public JobExecution start(Job job, JobParameters jobParameters)
 			JobRestartException, JobParametersInvalidException {
 		Assert.notNull(job, "Job must not be null");
 		Assert.notNull(jobParameters, "JobParameters must not be null");
+		new JobLaunchEvent(job.getName(), jobParameters.toString()).commit();
 		return super.start(job, jobParameters);
 	}
 

spring-batch-core/src/main/java/org/springframework/batch/core/observability/BatchMetrics.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2023 the original author or authors.
+ * Copyright 2019-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,6 +55,10 @@ public final class BatchMetrics {
 
 	public static final String STATUS_FAILURE = "FAILURE";
 
+	public static final String STATUS_COMMITTED = "COMMITTED";
+
+	public static final String STATUS_ROLLED_BACK = "ROLLED_BACK";
+
 	private BatchMetrics() {
 	}
 

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/job/JobExecutionEvent.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.job;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Job Execution")
+@Description("Job Execution Event")
+@Category({ "Spring Batch", "Job" })
+public class JobExecutionEvent extends Event {
+
+	@Label("Job Name")
+	public String jobName;
+
+	@Label("Job Instance Id")
+	public long jobInstanceId;
+
+	@Label("Job Execution Id")
+	public long jobExecutionId;
+
+	@Label("Job Exit Status")
+	public String exitStatus;
+
+	public JobExecutionEvent(String jobName, long jobInstanceId, long jobExecutionId) {
+		this.jobName = jobName;
+		this.jobInstanceId = jobInstanceId;
+		this.jobExecutionId = jobExecutionId;
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/job/JobLaunchEvent.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.job;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Job Launch Request")
+@Description("Job Launch Request Event")
+@Category({ "Spring Batch", "Job" })
+public class JobLaunchEvent extends Event {
+
+	@Label("Job Name")
+	public String jobName;
+
+	@Label("Job Parameters")
+	public String jobParameters;
+
+	public JobLaunchEvent(String jobName, String jobParameters) {
+		this.jobParameters = jobParameters;
+		this.jobName = jobName;
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/step/StepExecutionEvent.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.step;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Step Execution")
+@Description("Step Execution Event")
+@Category({ "Spring Batch", "Step" })
+public class StepExecutionEvent extends Event {
+
+	@Label("Step Name")
+	public String stepName;
+
+	@Label("Job Name")
+	public String jobName;
+
+	@Label("Step Execution Id")
+	public long stepExecutionId;
+
+	@Label("Job Execution Id")
+	public long jobExecutionId;
+
+	@Label("Step Exit Status")
+	public String exitStatus;
+
+	public StepExecutionEvent(String stepName, String jobName, long stepExecutionId, long jobExecutionId) {
+		this.stepName = stepName;
+		this.jobName = jobName;
+		this.stepExecutionId = stepExecutionId;
+		this.jobExecutionId = jobExecutionId;
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/step/chunk/ChunkScanEvent.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.step.chunk;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Chunk Scan")
+@Description("Chunk Scan Event")
+@Category({ "Spring Batch", "Step", "Chunk" })
+public class ChunkScanEvent extends Event {
+
+	@Label("Step Name")
+	public String stepName;
+
+	@Label("Step Execution Id")
+	public long stepExecutionId;
+
+	@Label("Skip Count")
+	public long skipCount;
+
+	public ChunkScanEvent(String stepName, long stepExecutionId) {
+		this.stepName = stepName;
+		this.stepExecutionId = stepExecutionId;
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/step/chunk/ChunkTransactionEvent.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.step.chunk;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Chunk Transaction")
+@Description("Chunk Transaction Event")
+@Category({ "Spring Batch", "Step", "Chunk" })
+public class ChunkTransactionEvent extends Event {
+
+	@Label("Step Name")
+	public String stepName;
+
+	@Label("Step Execution Id")
+	public long stepExecutionId;
+
+	@Label("Transaction Status")
+	public String transactionStatus;
+
+	public ChunkTransactionEvent(String stepName, long stepExecutionId) {
+		this.stepName = stepName;
+		this.stepExecutionId = stepExecutionId;
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/step/chunk/ChunkWriteEvent.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.step.chunk;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Chunk Write")
+@Description("Chunk Write Event")
+@Category({ "Spring Batch", "Step", "Chunk" })
+public class ChunkWriteEvent extends Event {
+
+	@Label("Step Name")
+	public String stepName;
+
+	@Label("Step Execution Id")
+	public long stepExecutionId;
+
+	@Label("Chunk Write Status")
+	public String chunkWriteStatus;
+
+	@Label("Item Count")
+	public long itemCount;
+
+	public ChunkWriteEvent(String stepName, long stepExecutionId, long itemCount) {
+		this.itemCount = itemCount;
+		this.stepName = stepName;
+		this.stepExecutionId = stepExecutionId;
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/observability/jfr/events/step/chunk/ItemProcessEvent.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.observability.jfr.events.step.chunk;
+
+import jdk.jfr.Category;
+import jdk.jfr.Description;
+import jdk.jfr.Event;
+import jdk.jfr.Label;
+
+@Label("Item Process")
+@Description("Item Process Event")
+@Category({ "Spring Batch", "Step", "Chunk" })
+public class ItemProcessEvent extends Event {
+
+	@Label("Step Name")
+	public String stepName;
+
+	@Label("Step Execution Id")
+	public long stepExecutionId;
+
+	@Label("Item Process Status")
+	public String itemProcessStatus;
+
+	public ItemProcessEvent(String stepName, long stepExecutionId) {
+		this.stepName = stepName;
+		this.stepExecutionId = stepExecutionId;
+	}
+
+}