[jira] [Created] (FLINK-6380) BlobService concurrency issues between delete and put/get methods

["Nico Kruber (JIRA)" <ji...@apache.org>]

Nico Kruber created FLINK-6380:
----------------------------------

             Summary: BlobService concurrency issues between delete and put/get methods
                 Key: FLINK-6380
                 URL: https://issues.apache.org/jira/browse/FLINK-6380
             Project: Flink
          Issue Type: Bug
          Components: Network
    Affects Versions: 1.3.0
            Reporter: Nico Kruber


{{BlobCache#deleteAll(JobID)}} deletes the job directory which is only created at the start of {{BlobCache#getURL(BlobKey)}} which then relies on the directory being present.

This is not restricted to the {{BlobCache}}, though, but also affects the {{BlobServer}} in two ways:
1) its own local storage and
2) its backing {{BlobStore}}

For the latter, i.e. in {{FileSystemBlobStore}}, there is no guarantee that a directory will not be deleted concurrently (from a {{delete}} method) between its creation and writing a file (in a {{get}} method):

* the {{delete}} method for name-addressable blobs always deletes the job-specific storage directory if there is no further blob for this job
* the content-addressable blobs do that similarly but are shared among jobs and thus only delete directories if there is no other blob.

Since name-addressable blobs have not been used so far and the latter case typically does not occur concurrently with get/put requests, this has not been a problem so far but is more relevant after applying FLINK-6046.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)