title: Azure Data Lake U-SQL parallel jobs failed
body: <p>we are running a u-sql job through ADF that reads a folder with a Avro file and converts the data to csv. Running simultaneous jobs, reading from different folders and outputting to different folders caused the following error</p>
  
  <pre><code>FinalMetadataOperationUserError: Failed to write job meta-data due to user error
  
  Component
  JobManager_User
  
  Message
  Failed to write job meta-data due to user error
  
  Description
  Version of object ddc1c212-b227-4b0b-8199-58bde69ce2e1.master.Avro doesn't exist
  
     at Scope.MetadataService.Client.Usql.WcfBasedMetadataClientForUsql.ExecuteMetadataJob(MetadataJob mdJob)
     at MetaDataExecutor.RealMetaDataExecutor.Execute(MetadataJob job)
     at MetaDataExecutor.Committer.Commit(MetadataJob job)
  
  Job URL
  https://***.azuredatalakeanalytics.net/jobLink/8b604ae4-179d-4375-a68a-c1b6771473ca
  </code></pre>
  
  <p>Upon checking the job resources, the 8b604ae4... folder indeeed has the Avro dll. Does anyone understand this error message or how can we setup ADF to run parallel u-sql jobs? Our pipeline is pretty straightforward as seen in the image below
                                     <a href="https://i.stack.imgur.com/oWrDh.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oWrDh.jpg" alt="enter image description here"></a> </p>
  
  <p>Thanks!</p>