[HDFS-8189] ClientProtocol#createErasureCodingZone API was wrongly annotated as Idempotent

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: HDFS-7285
• Component/s: namenode
• Hadoop Flags: Reviewed
• Assignee: Vinayakumar B
• Reporter: Uma Maheswara Rao G
• Created: 20/Apr/15 19:09
• Updated: 30/Sep/15 19:38
• Resolved: 28/Apr/15 08:57

Description

Currently createErasureCodingZone was annotated as Idempotent
But it should be annotated as @AtMostOnce as we handle retries via retryCache.

 @Idempotent
  public void createErasureCodingZone(String src, ECSchema schema)
      throws IOException;

It will fail to create Zone if its already a zone. So, simply we can not retry by ignoring previous call success. So, we were using retryCache already for handling this situation.

 if (getECSchema(srcIIP) != null) {
      throw new IOException("Directory " + src + " is already in an " +
          "erasure coding zone.");
    }