flowable/flowable-engine · warning

Exception while autodeploying CMMN definitions. This excepti

Error message

Exception while autodeploying CMMN definitions. This exception can be ignored if the root cause indicates a unique constraint violation, which is typically caused by two (or more) servers booting up at the exact same time and deploying the same definitions. 

What it means

DefaultAutoDeploymentStrategy.deployResourcesInternal builds a CMMN deployment and calls deploymentBuilder.deploy(). If that throws a RuntimeException and isThrowExceptionOnDeploymentFailure() is false, the exception is swallowed with this warning; if true, it is rethrown. It exists so concurrent server startups hitting a unique-constraint on the same auto-deployment do not crash every node.

Source

Thrown at modules/flowable-cmmn-spring/src/main/java/org/flowable/cmmn/spring/autodeployment/DefaultAutoDeploymentStrategy.java:72

    protected void deployResourcesInternal(String deploymentNameHint, Resource[] resources, CmmnEngine engine) {
        CmmnRepositoryService repositoryService = engine.getCmmnRepositoryService();

        // Create a single deployment for all resources using the name hint as the literal name
        final CmmnDeploymentBuilder deploymentBuilder = repositoryService.createDeployment().enableDuplicateFiltering().name(deploymentNameHint);

        for (final Resource resource : resources) {
            addResource(resource, deploymentBuilder);
        }

        try {

            deploymentBuilder.deploy();

        } catch (RuntimeException e) {
            if (isThrowExceptionOnDeploymentFailure()) {
                throw e;
            } else {
                LOGGER.warn("Exception while autodeploying CMMN definitions. "
                    + "This exception can be ignored if the root cause indicates a unique constraint violation, "
                    + "which is typically caused by two (or more) servers booting up at the exact same time and deploying the same definitions. ", e);
            }
        }

    }

}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Read the wrapped root cause in the log to see the actual failure (unique constraint vs XML parse error).
2. If you want failures to surface, set cmmn.deployment.throwExceptionOnDeploymentFailure (CmmnEngineConfiguration.setThrowExceptionOnDeploymentFailure) to true.
3. Serialize/avoid concurrent auto-deploys: deploy once during image build or use shared deployment (deploymentMode: single-resource/startup with tenant checks).
4. If it is the unique-constraint race, it is benign — the other node's deployment wins; verify definitions are present in ACT_CMMN_DEPLOYMENT.
5. Fix the invalid CMMN resource if the cause is schema/validation failure.

Example fix

// before
@Bean
public EngineConfigurationConfigurer<SpringProcessEngineConfiguration> config() { ... } // silent swallow
cmmnEngineConfiguration.setThrowExceptionOnDeploymentFailure(false);
// after
cmmnEngineConfiguration.setThrowExceptionOnDeploymentFailure(true); // fail fast on bad deployments

// pre-flight: ensure only one node auto-deploys or definitions already exist
long count = managementService.executeCommand(ctx ->
    ctx.getProcessEngineConfiguration().getDeploymentEntityManager()
       .findDeploymentsByQueryCriteria(new DeploymentQueryImpl().deploymentName(deploymentName))).size();
if (count > 0) { /* skip auto-deploy */ }

try {
    cmmnEngine.run();
} catch (FlowableException e) {
    if (e.getCause() instanceof SQLException && e.getMessage().contains("unique")) {
        LOGGER.info("Concurrent auto-deploy detected; continuing");
    } else {
        throw e;
    }
}

When it happens

Trigger: Spring boot auto-deployment of CMMN resources (default strategy) when the database insert fails — most often a unique constraint (ACT_CMMN_DEPLOYMENT) violation from two nodes deploying identical resources simultaneously, or invalid CMMN XML.

Common situations: Multiple application instances starting simultaneously against a shared Flowable database; a restart racing with a previous deployment; malformed .cmmn/.cmmn10.xml resources when throwExceptionOnDeploymentFailure is false (error hidden in logs).

Related errors

• Exception while autodeploying CMMN definitions. This excepti
• Exception while autodeploying CMMN definitions for resource
• Exception while autodeploying DMN definitions. This exceptio
• Task '
• Can only enable a plan item instance which is in state ENABL

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/5fd14df3173616af. Report an issue: GitHub.