[ https://issues.jboss.org/browse/WFCORE-3948?page=com.atlassian.jira.plugi... ] Brian Stansberry commented on WFCORE-3948: ------------------------------------------ The following is just information, no solution. Here are the uses of ADDITIONAL_MODULES, per IDEA, annotated by me with the Phase n which each DUP runs: {code} Field ADDITIONAL_MODULES Found usages (10 usages found) Value read (10 usages found) wildfly-server (10 usages found) org.jboss.as.server.deployment.annotation (1 usage found) PARSE CompositeIndexProcessor (1 usage found) deploy(DeploymentPhaseContext) (1 usage found) 79 for(AdditionalModuleSpecification i : top.getAttachmentList(Attachments.ADDITIONAL_MODULES)) { org.jboss.as.server.deployment.module (7 usages found) STRUCTURE ManifestClassPathProcessor (2 usages found) deploy(DeploymentPhaseContext) (1 usage found) 132 for (AdditionalModuleSpecification module : topLevelDeployment.getAttachmentList(Attachments.ADDITIONAL_MODULES)) { createAdditionalModule(ResourceRoot, DeploymentUnit, VirtualFile, Map<VirtualFile, AdditionalModuleSpecification>, VirtualFile, ArrayDeque<RootEntry>) (1 usage found) 228 topLevelDeployment.addToAttachmentList(Attachments.ADDITIONAL_MODULES, module); STRUCTURE ManifestDependencyProcessor (1 usage found) deploy(DeploymentPhaseContext) (1 usage found) 73 for(AdditionalModuleSpecification i : top.getAttachmentList(Attachments.ADDITIONAL_MODULES)) { DEPENDENCIES ModuleClassPathProcessor (1 usage found) deploy(DeploymentPhaseContext) (1 usage found) 57 final List<AdditionalModuleSpecification> additionalModules = deploymentUnit.getAttachment(Attachments.ADDITIONAL_MODULES); DEPENDENCIES ModuleExtensionListProcessor (1 usage found) deploy(DeploymentPhaseContext) (1 usage found) 112 final List<AdditionalModuleSpecification> additionalModules = deploymentUnit.getAttachment(Attachments.ADDITIONAL_MODULES); CONFIGURE_MODULE ModuleSpecProcessor (1 usage found) deployModuleSpec(DeploymentPhaseContext) (1 usage found) 143 final List<AdditionalModuleSpecification> additionalModules = deploymentUnit.getAttachmentList(Attachments.ADDITIONAL_MODULES); DEPENDENCIES SubDeploymentDependencyProcessor (1 usage found) deploy(DeploymentPhaseContext) (1 usage found) 66 for (AdditionalModuleSpecification module : deploymentUnit.getAttachmentList(Attachments.ADDITIONAL_MODULES)) { org.jboss.as.server.deployment.module.descriptor (2 usages found) STRUCTURE DeploymentStructureDescriptorParser (2 usages found) deploy(DeploymentPhaseContext) (2 usages found) 134 for(AdditionalModuleSpecification i : deploymentUnit.getParent().getAttachmentList(Attachments.ADDITIONAL_MODULES)) { 188 deploymentUnit.addToAttachmentList(Attachments.ADDITIONAL_MODULES, additional); {code} So, ManifestClassPathProcessor, ManifestDependencyProcessor and DeploymentStructureDescriptorParser are relevant as they execute in the STRUCTURE phase where writes occur. Here's the relevant bit from ServerService that shows their relative execution order: {code} DeployerChainAddHandler.addDeploymentProcessor(SERVER_NAME, Phase.STRUCTURE, Phase.STRUCTURE_SUB_DEPLOYMENT, new SubDeploymentProcessor()); ... DeployerChainAddHandler.addDeploymentProcessor(SERVER_NAME, Phase.STRUCTURE, Phase.STRUCTURE_JBOSS_DEPLOYMENT_STRUCTURE, new DeploymentStructureDescriptorParser()); DeployerChainAddHandler.addDeploymentProcessor(SERVER_NAME, Phase.STRUCTURE, Phase.STRUCTURE_CLASS_PATH, new ManifestClassPathProcessor()); ... DeployerChainAddHandler.addDeploymentProcessor(SERVER_NAME, Phase.STRUCTURE, Phase.STRUCTURE_DEPENDENCIES_MANIFEST, new ManifestDependencyProcessor()); {code} I start with SubDeploymentProcessor because it's the one that creates the SubDeploymentUnitService instances for the subdeployments, which in turn starts and create the parallel DUP execution. So this seems problematic, e.g. DeploymentStructureDescriptorParser is reading ADDITIONAL_MODULES on behalf of subdeployments, assuming it's correctly populated, but that may not have occurred, even for the top level deployment. The DeploymentStructureDescriptorParser may not have run yet for the root deployment, or it may have *and* ManifestClassPathProcessor may have run for the root and one or more sibling subdeployments. Or not. And then the execution of ManifestDependencyProcessor is just a race amongst them all. -- This message was sent by Atlassian Jira (v7.13.8#713008)