[HDDS-4403] Update the container replica history to the Recon DB lazily instead of for every report.

• Type: Task
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.1.0
• Component/s: Ozone Recon
• Labels: pull-request-available
• Target Version/s: 1.1.0
• Assignee: Siyao Meng
• Reporter: Aravindan Vijayan
• Created: 28/Oct/20 13:52
• Updated: 13/Jan/21 18:00
• Resolved: 13/Jan/21 18:00

Description

Recon tracks the history for every container replica on the Ozone cluster in its SQL DB (By default, this is Derby). To track this, it keeps track of the last timestamp of a replica on a DN through reports. This becomes a SQL DB scan + write operation for every container report received. Even though there is async hand off from the report to EventQueue, the event queue handler itself by default uses 1 thread per event type (report type). Hence, there is implicit blocking behavior here which is pushed down to DNs.

This has to be changed into a lazy update of DB to support better scalability. Details on how to achieve this will be added to the JIRA later.

Issue Links

• links to: GitHub Pull Request #1670