# Expection on child workflow execution

**URL:** <https://community.temporal.io/t/expection-on-child-workflow-execution/11416>\
**Category:** Community Support\
**Tags:** java-sdk\
**Created:** [March 18, 2024, 5:25pm UTC](https://community.temporal.io/t/expection-on-child-workflow-execution/11416 "2024-03-18T17:25:16Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Puneet\_Chaturvedi](https://avatars.discourse-cdn.com/v4/letter/p/eb9ed0/32.png) [@Puneet\_Chaturvedi](https://community.temporal.io/u/Puneet_Chaturvedi)\
**Post date:** [March 18, 2024, 5:25pm UTC](https://community.temporal.io/t/expection-on-child-workflow-execution/11416/1 "2024-03-18T17:25:16Z")

</div>

Using a ParentWorkflow → Child Workflow → SubchildWorkflow structure to process multiple list of records ~50K (list of UUIDs) concurrently, Child workflow are being submitted using async function. For batch of ids getting below exception from Child workflow, using java-sdk version 1.23.0

```auto
{
[info] "time" : "2024-03-18T13:11:19.610-04:00",
[info] "thread_name" : "Workflow Executor taskQueue=\"default\", namespace=\"default\": 112",
[info] "level" : "INFO",
[info] "ServiceName" : "Amos",
[info] "TaskQueue" : "default",
[info] "Namespace" : "default",
[info] "stackTrace" : "i.g.StatusRuntimeException: INVALID_ARGUMENT: UnhandledCommand
[info] at i.g.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:271)
[info] at i.g.stub.ClientCalls.getUnchecked(ClientCalls.java:252)
[info] at i.g.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:165)
[info] at i.t.a.w.v.WorkflowServiceGrpc$WorkflowServiceBlockingStub.respondWorkflowTaskCompleted(WorkflowServiceGrpc.java:3924)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.lambda$sendTaskCompleted$0(WorkflowWorker.java:468)
[info] at i.t.i.r.GrpcSyncRetryer.retry(GrpcSyncRetryer.java:69)
[info] at i.t.i.r.GrpcRetryer.retryWithResult(GrpcRetryer.java:60)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.sendTaskCompleted(WorkflowWorker.java:463)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:335)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:263)
[info] at i.t.i.w.PollTaskExecutor.lambda$process$0(PollTaskExecutor.java:105)
[info] ... 3 common frames omitted
[info] Wrapped by: j.l.RuntimeException: Failure processing workflow task. WorkflowId=34400051119699900893-1, RunId=accbcee6-7415-46fc-865e-a33c3ec99ead, Attempt=1
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.wrapFailure(WorkflowWorker.java:422)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.wrapFailure(WorkflowWorker.java:263)
[info] at i.t.i.w.PollTaskExecutor.lambda$process$0(PollTaskExecutor.java:110)
[info] at j.u.c.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[info] at j.u.c.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[info] at java.lang.Thread.run(Thread.java:748)
[info] "
[info] }
[info] Error during child workflow execution: workflowId='FCE14543-8017-497E-9BBA-606547919EE1-123', runId='', workflowType='MigrateBlobSubChildWorkflow', initiatedEventId=11, startedEventId=0, namespace='default', retryState=RETRY_STATE_NON_RETRYABLE_FAILURE
[info] {
[info] "time" : "2024-03-18T13:11:20.218-04:00",
[info] "thread_name" : "Workflow Executor taskQueue=\"default\", namespace=\"default\": 2",
[info] "level" : "WARN",
[info] "ServiceName" : "Amos",
[info] "WorkflowType" : "MigrationBlobChildWorkflow",
[info] "TaskQueue" : "default",
[info] "WorkflowId" : "25800051119699900893-1",
[info] "RunId" : "f689dfd1-229e-4b53-9cef-c8e7352adba1",
[info] "Namespace" : "default",
[info] "stackTrace" : "i.g.StatusRuntimeException: INVALID_ARGUMENT: UnhandledCommand
[info] at i.g.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:271)
[info] at i.g.stub.ClientCalls.getUnchecked(ClientCalls.java:252)
[info] at i.g.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:165)
[info] at i.t.a.w.v.WorkflowServiceGrpc$WorkflowServiceBlockingStub.respondWorkflowTaskCompleted(WorkflowServiceGrpc.java:3924)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.lambda$sendTaskCompleted$0(WorkflowWorker.java:468)
[info] at i.t.i.r.GrpcSyncRetryer.retry(GrpcSyncRetryer.java:69)
[info] at i.t.i.r.GrpcRetryer.retryWithResult(GrpcRetryer.java:60)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.sendTaskCompleted(WorkflowWorker.java:463)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:335)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:263)
[info] at i.t.i.w.PollTaskExecutor.lambda$process$0(PollTaskExecutor.java:105)
[info] at j.u.c.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[info] at j.u.c.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[info] at java.lang.Thread.run(Thread.java:748)
[info] "
[info] }
[info] {
[info] "time" : "2024-03-18T13:11:20.230-04:00",
[info] "thread_name" : "Workflow Executor taskQueue=\"default\", namespace=\"default\": 2",
[info] "level" : "INFO",
[info] "TaskQueue" : "default",
[info] "Namespace" : "default",
[info] "stackTrace" : "i.g.StatusRuntimeException: INVALID_ARGUMENT: UnhandledCommand
[info] at i.g.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:271)
[info] at i.g.stub.ClientCalls.getUnchecked(ClientCalls.java:252)
[info] at i.g.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:165)
[info] at i.t.a.w.v.WorkflowServiceGrpc$WorkflowServiceBlockingStub.respondWorkflowTaskCompleted(WorkflowServiceGrpc.java:3924)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.lambda$sendTaskCompleted$0(WorkflowWorker.java:468)
[info] at i.t.i.r.GrpcSyncRetryer.retry(GrpcSyncRetryer.java:69)
[info] at i.t.i.r.GrpcRetryer.retryWithResult(GrpcRetryer.java:60)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.sendTaskCompleted(WorkflowWorker.java:463)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:335)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:263)
[info] at i.t.i.w.PollTaskExecutor.lambda$process$0(PollTaskExecutor.java:105)
[info] ... 3 common frames omitted
[info] Wrapped by: j.l.RuntimeException: Failure processing workflow task. WorkflowId=25800051119699900893-1, RunId=f689dfd1-229e-4b53-9cef-c8e7352adba1, Attempt=1
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.wrapFailure(WorkflowWorker.java:422)
[info] at i.t.i.w.WorkflowWorker$TaskHandlerImpl.wrapFailure(WorkflowWorker.java:263)
[info] at i.t.i.w.PollTaskExecutor.lambda$process$0(PollTaskExecutor.java:110)
[info] at j.u.c.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[info] at j.u.c.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[info] at java.lang.Thread.run(Thread.java:748)
[info] "

```

---

<div class="post-metadata">

**Author:** ![antonio.perez](https://sea2.discourse-cdn.com/flex016/user_avatar/community.temporal.io/antonio.perez/32/2417_2.png) [@antonio.perez](https://community.temporal.io/u/antonio.perez)\
**Post date:** [March 20, 2024, 11:07am UTC](https://community.temporal.io/t/expection-on-child-workflow-execution/11416/2 "2024-03-20T11:07:38Z")

</div>

Hi @Puneet_Chaturvedi

[UnhandledCommand](https://docs.temporal.io/references/errors#unhandled-command) is benign most or the time, depending on the rate you see it.

In your current scenario, this can be caused by a child’s workflow completing at the same time the parent tries to close the workflow execution. Completing the child workflow will add an event to the parent workflow history, the server will reject closing the parent while there are buffered events.

Let me know if it helps,  
Antonio

---

<div class="post-metadata">

**Author:** ![Puneet\_Chaturvedi](https://avatars.discourse-cdn.com/v4/letter/p/eb9ed0/32.png) [@Puneet\_Chaturvedi](https://community.temporal.io/u/Puneet_Chaturvedi)\
**Post date:** [April 4, 2024, 7:43pm UTC](https://community.temporal.io/t/expection-on-child-workflow-execution/11416/3 "2024-04-04T19:43:05Z")

</div>

Thanks @antonio.perez this helps to understand whats going on here, what should be best way to avoid this issue and prevent from closing so that all child finishes first.