[AMBARI-20440] Concurrent odification of HostComponentDesiredState entity results in Blueprint based deployment stuck in PENDING state

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 2.5.0
• Component/s: ambari-server
• Assignee: Magyari Sandor Szilard
• Reporter: Magyari Sandor Szilard
• Created: 14/Mar/17 08:52
• Updated: 16/Mar/17 15:26
• Resolved: 16/Mar/17 15:26

Description

If topology tasks are generated in parallel during Blueprint deployment (topology.task.creation.parallel=true) sometimes concurrent modification of HostComponentDesiredState entity might be modified concurrently which results in desiredState remaining in INIT state. As a result HostRoleCommand for START topology task is not generated and remains in PENDING state.
The problem appears when a component is set as restartRequiredAfterRackChange in stack definition. In this case when host components are created by PersistHostResourcesTask restartRequired is set to true on the same component on other hosts, meanwhile InstallHostTask is running which sets the desiredState for the same component. As both restartRequired and desiredState fields are stored in HostComponentDesiredState entity it could happen then when updating restartRequired field desiredState is reverted back to INIT state.