Make MongoDB schema scripts idempotent

spring-batch-core/src/main/resources/org/springframework/batch/core/schema-mongodb.js

@@ -1,13 +1,22 @@
 // to execute in MongoShell after changing the database name `db.` as needed
-db.createCollection("BATCH_JOB_INSTANCE");
-db.createCollection("BATCH_JOB_EXECUTION");
-db.createCollection("BATCH_STEP_EXECUTION");
+// This script is idempotent and can be safely reapplied.
 
 // SEQUENCES
-db.createCollection("BATCH_SEQUENCES");
-db.getCollection("BATCH_SEQUENCES").insertOne({_id: "BATCH_JOB_INSTANCE_SEQ", count: Long(0)});
-db.getCollection("BATCH_SEQUENCES").insertOne({_id: "BATCH_JOB_EXECUTION_SEQ", count: Long(0)});
-db.getCollection("BATCH_SEQUENCES").insertOne({_id: "BATCH_STEP_EXECUTION_SEQ", count: Long(0)});
+db.getCollection("BATCH_SEQUENCES").updateOne(
+    {_id: "BATCH_JOB_INSTANCE_SEQ"},
+    {$setOnInsert: {count: NumberLong(0)}},
+    {upsert: true}
+);
+db.getCollection("BATCH_SEQUENCES").updateOne(
+    {_id: "BATCH_JOB_EXECUTION_SEQ"},
+    {$setOnInsert: {count: NumberLong(0)}},
+    {upsert: true}
+);
+db.getCollection("BATCH_SEQUENCES").updateOne(
+    {_id: "BATCH_STEP_EXECUTION_SEQ"},
+    {$setOnInsert: {count: NumberLong(0)}},
+    {upsert: true}
+);
 
 // INDICES
 db.getCollection("BATCH_JOB_INSTANCE").createIndex( {"jobName": 1}, {"name": "job_name_idx"});

spring-batch-core/src/main/resources/org/springframework/batch/core/schema-mongodb.jsonl

@@ -1,7 +1,9 @@
-{create:'BATCH_JOB_INSTANCE'}
-{create:'BATCH_JOB_EXECUTION'}
-{create:'BATCH_STEP_EXECUTION'}
-{create:'BATCH_SEQUENCES'}
-{insert: "BATCH_SEQUENCES", documents: [ { _id: 'BATCH_JOB_INSTANCE_SEQ', count: NumberLong(0) } ]}
-{insert: "BATCH_SEQUENCES", documents: [ { _id: 'BATCH_JOB_EXECUTION_SEQ', count: NumberLong(0) } ]}
-{insert: "BATCH_SEQUENCES", documents: [ { _id: 'BATCH_STEP_EXECUTION_SEQ', count: NumberLong(0) } ]}
+{update: "BATCH_SEQUENCES", updates: [ { q: { _id: "BATCH_JOB_INSTANCE_SEQ" }, u: { $setOnInsert: { count: NumberLong(0) } }, upsert: true } ]}
+{update: "BATCH_SEQUENCES", updates: [ { q: { _id: "BATCH_JOB_EXECUTION_SEQ" }, u: { $setOnInsert: { count: NumberLong(0) } }, upsert: true } ]}
+{update: "BATCH_SEQUENCES", updates: [ { q: { _id: "BATCH_STEP_EXECUTION_SEQ" }, u: { $setOnInsert: { count: NumberLong(0) } }, upsert: true } ]}
+{createIndexes: "BATCH_JOB_INSTANCE", indexes: [ { key: { jobName: 1 }, name: "job_name_idx" } ]}
+{createIndexes: "BATCH_JOB_INSTANCE", indexes: [ { key: { jobName: 1, jobKey: 1 }, name: "job_name_key_idx" } ]}
+{createIndexes: "BATCH_JOB_INSTANCE", indexes: [ { key: { jobInstanceId: -1 }, name: "job_instance_idx" } ]}
+{createIndexes: "BATCH_JOB_EXECUTION", indexes: [ { key: { jobInstanceId: 1 }, name: "job_instance_idx" } ]}
+{createIndexes: "BATCH_JOB_EXECUTION", indexes: [ { key: { jobInstanceId: 1, status: 1 }, name: "job_instance_status_idx" } ]}
+{createIndexes: "BATCH_STEP_EXECUTION", indexes: [ { key: { stepExecutionId: 1 }, name: "step_execution_idx" } ]}

spring-batch-core/src/test/java/org/springframework/batch/core/repository/support/MongoDBSchemaScriptsIntegrationTests.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2026-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.repository.support;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.time.LocalDateTime;
+import java.util.List;
+
+import com.mongodb.client.MongoCollection;
+import org.bson.Document;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import org.springframework.batch.core.job.Job;
+import org.springframework.batch.core.job.JobExecution;
+import org.springframework.batch.core.job.parameters.JobParameters;
+import org.springframework.batch.core.job.parameters.JobParametersBuilder;
+import org.springframework.batch.core.launch.JobOperator;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+@DirtiesContext
+@Testcontainers(disabledWithoutDocker = true)
+@SpringJUnitConfig(MongoDBIntegrationTestConfiguration.class)
+class MongoDBSchemaScriptsIntegrationTests {
+
+	private static final String CREATE_SCRIPT = "src/main/resources/org/springframework/batch/core/schema-mongodb.jsonl";
+
+	private static final String DROP_SCRIPT = "src/main/resources/org/springframework/batch/core/schema-drop-mongodb.jsonl";
+
+	@Autowired
+	private MongoTemplate mongoTemplate;
+
+	@BeforeEach
+	void setUp() throws IOException {
+		executeScript(DROP_SCRIPT);
+	}
+
+	@Test
+	void createScriptShouldBeIdempotent(@Autowired JobOperator jobOperator, @Autowired Job job) throws Exception {
+		executeScript(CREATE_SCRIPT);
+
+		JobExecution firstExecution = jobOperator.start(job, jobParameters("first"));
+		assertEquals(1L, firstExecution.getJobInstanceId());
+		assertEquals(1L, firstExecution.getId());
+		assertEquals(List.of(1L, 2L),
+				firstExecution.getStepExecutions()
+					.stream()
+					.map(stepExecution -> stepExecution.getId())
+					.sorted()
+					.toList());
+
+		executeScript(CREATE_SCRIPT);
+
+		JobExecution secondExecution = jobOperator.start(job, jobParameters("second"));
+		assertEquals(2L, secondExecution.getJobInstanceId());
+		assertEquals(2L, secondExecution.getId());
+		assertEquals(List.of(3L, 4L),
+				secondExecution.getStepExecutions()
+					.stream()
+					.map(stepExecution -> stepExecution.getId())
+					.sorted()
+					.toList());
+
+		assertSequenceValue("BATCH_JOB_INSTANCE_SEQ", 2L);
+		assertSequenceValue("BATCH_JOB_EXECUTION_SEQ", 2L);
+		assertSequenceValue("BATCH_STEP_EXECUTION_SEQ", 4L);
+	}
+
+	private JobParameters jobParameters(String name) {
+		return new JobParametersBuilder().addString("name", name)
+			.addLocalDateTime("runtime", LocalDateTime.now())
+			.toJobParameters();
+	}
+
+	private void executeScript(String path) throws IOException {
+		Files.lines(new FileSystemResource(path).getFilePath()).forEach(this.mongoTemplate::executeCommand);
+	}
+
+	private void assertSequenceValue(String sequenceName, long expectedValue) {
+		MongoCollection<Document> sequences = this.mongoTemplate.getCollection("BATCH_SEQUENCES");
+		Document sequence = sequences.find(new Document("_id", sequenceName)).first();
+		assertNotNull(sequence);
+		assertEquals(expectedValue, sequence.getLong("count"));
+	}
+
+}

spring-batch-docs/modules/ROOT/pages/job/configuring-repository.adoc

@@ -92,7 +92,8 @@ The `max-varchar-length` defaults to `2500`, which is the length of the long
 Similar to the JDBC-based `JobRepository`, the MongoDB-based `JobRepository` requires some collections
 to store the batch metadata. These collections are defined in the `org/springframework/batch/core/schema-mongodb.jsonl`
 of the `spring-batch-core` jar. As with the JDBC-based `JobRepository`, you need to create these collections
-in your MongoDB database before running any job.
+in your MongoDB database before running any job. The provided MongoDB schema scripts are idempotent and
+can be safely reapplied without resetting sequence values.
 
 Moreover, since it is https://www.mongodb.com/docs/manual/core/dot-dollar-considerations/[not recommended] to use `.` in
 field names in MongoDB documents, you need to customize the `MongoTemplate` used by the `MongoJobRepositoryFactoryBean`
@@ -319,4 +320,3 @@ If even that does not work or if you are not using an RDBMS, the
 only option may be to implement the various `Dao`
 interfaces that the `SimpleJobRepository` depends
 on and wire one up manually in the normal Spring way.
-