[STORM-3104] Delayed worker launch due to accidental transitioning in state machine

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.0.0
• Component/s: storm-server
• Assignee: Unassigned
• Reporter: Zhengdai Hu
• Created: 14/Jun/18 00:38
• Updated: 21/Sep/18 17:27

Description

In Slot.java, there is a comparison in

handleWaitingForBlobUpdate()

between dynamic state's current assignment and new assignment, which accidentally route back state machine just transitioned from WAIT_FOR_BLOB_LOCALIZATION back to WAIT_FOR_BLOB_LOCALIZATION, because the current assignment in this case is highly likely to be null and different from new assignment (I'm not sure if it's guaranteed). This causes delay for a worker to start/restart.

The symptom can be reproduced by launching an empty storm server and submit any topology. Here's the log sample (relevant transition starting from 2018-06-13 16:57:12.274 o.a.s.d.s.Slot SLOT_6700 [DEBUG]):

2018-06-13 16:57:10.254 o.a.s.d.s.Slot SLOT_6700 [INFO] STATE EMPTY msInState: 6024 -> EMPTY msInState: 6024
2018-06-13 16:57:10.255 o.a.s.d.s.Slot SLOT_6700 [DEBUG] STATE EMPTY
2018-06-13 16:57:10.257 o.a.s.d.s.Slot SLOT_6700 [DEBUG] Transition from EMPTY to WAITING_FOR_BLOB_LOCALIZATION
2018-06-13 16:57:10.257 o.a.s.d.s.Slot SLOT_6700 [INFO] STATE EMPTY msInState: 6027 -> WAITING_FOR_BLOB_LOCALIZATION msInState: 0
2018-06-13 16:57:10.258 o.a.s.d.s.Slot SLOT_6700 [DEBUG] STATE WAITING_FOR_BLOB_LOCALIZATION
2018-06-13 16:57:10.258 o.a.s.d.s.Slot SLOT_6700 [DEBUG] pendingChangingBlobs are []
2018-06-13 16:57:11.259 o.a.s.d.s.Slot SLOT_6700 [INFO] STATE WAITING_FOR_BLOB_LOCALIZATION msInState: 1003 -> WAITING_FOR_BLOB_LOCALIZATION msInState: 1003
2018-06-13 16:57:11.260 o.a.s.d.s.Slot SLOT_6700 [DEBUG] STATE WAITING_FOR_BLOB_LOCALIZATION
2018-06-13 16:57:11.260 o.a.s.d.s.Slot SLOT_6700 [DEBUG] found changing blobs [BLOB CHANGING LOCAL TOPO BLOB TOPO_CONF test-1-1528927024 LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02), BLOB CHANGING LOCAL TOPO BLOB TOPO_CODE test-1-1528927024 LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02)] moving them to pending...
2018-06-13 16:57:12.262 o.a.s.d.s.Slot SLOT_6700 [INFO] STATE WAITING_FOR_BLOB_LOCALIZATION msInState: 2005 -> WAITING_FOR_BLOB_LOCALIZATION msInState: 2005
2018-06-13 16:57:12.263 o.a.s.d.s.Slot SLOT_6700 [DEBUG] STATE WAITING_FOR_BLOB_LOCALIZATION
2018-06-13 16:57:12.263 o.a.s.d.s.Slot SLOT_6700 [DEBUG] found changing blobs [BLOB CHANGING LOCAL TOPO BLOB TOPO_JAR test-1-1528927024 LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02)] moving them to pending...
2018-06-13 16:57:12.274 o.a.s.d.s.Slot SLOT_6700 [DEBUG] pendingLocalization LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02) == current null ? false
2018-06-13 16:57:12.274 o.a.s.d.s.Slot SLOT_6700 [INFO] There are pending changes, waiting for them to finish before launching container...
2018-06-13 16:57:12.275 o.a.s.d.s.Slot SLOT_6700 [DEBUG] Transition from WAITING_FOR_BLOB_LOCALIZATION to WAITING_FOR_BLOB_UPDATE
2018-06-13 16:57:12.275 o.a.s.d.s.Slot SLOT_6700 [INFO] STATE WAITING_FOR_BLOB_LOCALIZATION msInState: 2018 -> WAITING_FOR_BLOB_UPDATE msInState: 1
2018-06-13 16:57:12.275 o.a.s.d.s.Slot SLOT_6700 [DEBUG] STATE WAITING_FOR_BLOB_UPDATE
2018-06-13 16:57:12.275 o.a.s.d.s.Slot SLOT_6700 [DEBUG] pendingLocalization: null, new: LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02), current: null, pdchanging: LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02)
2018-06-13 16:57:12.276 o.a.s.d.s.Slot SLOT_6700 [INFO] SLOT 6700: Assignment Changed from null to LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02)
2018-06-13 16:57:12.278 o.a.s.d.s.Slot SLOT_6700 [DEBUG] Transition from WAITING_FOR_BLOB_UPDATE to WAITING_FOR_BLOB_LOCALIZATION
2018-06-13 16:57:12.278 o.a.s.d.s.Slot SLOT_6700 [INFO] STATE WAITING_FOR_BLOB_UPDATE msInState: 4 -> WAITING_FOR_BLOB_LOCALIZATION msInState: 0
2018-06-13 16:57:12.279 o.a.s.d.s.Slot SLOT_6700 [DEBUG] STATE WAITING_FOR_BLOB_LOCALIZATION
2018-06-13 16:57:12.279 o.a.s.d.s.Slot SLOT_6700 [DEBUG] pendingChangingBlobs are []
2018-06-13 16:57:12.279 o.a.s.d.s.Slot SLOT_6700 [DEBUG] pendingLocalization LocalAssignment(topology_id:test-1-1528927024, executors:[ExecutorInfo(task_start:10, task_end:10), ExecutorInfo(task_start:16, task_end:16), ExecutorInfo(task_start:4, task_end:4), ExecutorInfo(task_start:7, task_end:7), ExecutorInfo(task_start:1, task_end:1), ExecutorInfo(task_start:13, task_end:13)], resources:WorkerResources(mem_on_heap:768.0, mem_off_heap:0.0, cpu:60.0, shared_mem_on_heap:0.0, shared_mem_off_heap:0.0, resources:{offheap.memory.mb=0.0, onheap.memory.mb=768.0, cpu.pcore.percent=60.0}, shared_resources:{}), owner:zhu02) == current null ? false
2018-06-13 16:57:12.280 o.a.s.d.s.Slot SLOT_6700 [DEBUG] launch container for the first time
2018-06-13 16:57:12.284 o.a.s.d.s.BasicContainer SLOT_6700 [INFO] Created Worker ID 4155b2bb-ebd1-431d-907f-d8a4ff1e1da4

I would like to know if this is actually the desired behavior of the state machine, or I can help fix the bug. The implementation would be to redesign the if statement.