[FLINK-6020] Blob Server cannot handle multiple job submits (with same content) parallelly

• Type: Sub-task
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.3.0, 1.4.0
• Component/s: Runtime / Coordination
• Assignee: Till Rohrmann
• Reporter: Tao Wang
• Created: 10/Mar/17 08:32
• Updated: 17/Aug/17 10:03
• Resolved: 17/May/17 06:21

Description

In yarn-cluster mode, if we submit one same job multiple times parallelly, the task will encounter class load problem and lease occuputation.

Because blob server stores user jars in name with generated sha1sum of those, first writes a temp file and move it to finalialize. For recovery it also will put them to HDFS with same file name.

In same time, when multiple clients sumit same job with same jar, the local jar files in blob server and those file on hdfs will be handled in multiple threads(BlobServerConnection), and impact each other.

It's better to have a way to handle this, now two ideas comes up to my head:
1. lock the write operation, or
2. use some unique identifier as file name instead of ( or added up to) sha1sum of the file contents.

Issue Links

• breaks: FLINK-7467 a slow client on the BlobServer may block writing operations
• links to: GitHub Pull Request #3525
• links to: GitHub Pull Request #3888