[HDFS-13665] Move RPC response serialization into Server.doResponse

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: HDFS-12943
• Fix Version/s: HDFS-12943, 3.3.0
• Hadoop Flags: Reviewed
• Assignee: Plamen Jeliazkov
• Reporter: Plamen Jeliazkov
• Created: 08/Jun/18 16:04
• Updated: 24/Dec/18 18:22
• Resolved: 11/Jul/18 23:13

Description

In HDFS-13399 we addressed a race condition in AlignmentContext processing where the RPC response would assign a transactionId independently of the transactions own processing, resulting in a stateId response that was lower than expected. However this caused us to serialize the RpcResponse twice in order to address the header field change.

See here:
https://issues.apache.org/jira/browse/HDFS-13399?focusedCommentId=16464279&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16464279

And here:
https://issues.apache.org/jira/browse/HDFS-13399?focusedCommentId=16498660&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16498660

At the end it was agreed upon to move the logic of Server.setupResponse into Server.doResponse directly.