[HDFS-17027] RBF: Add supports for observer.auto-msync-period when using routers

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: rbf
• Labels: pull-request-available
• Target Version/s: 3.4.0
• Hadoop Flags: Reviewed
• Assignee: Simbarashe Dzinamarira
• Reporter: Simbarashe Dzinamarira
• Created: 26/May/23 19:54
• Updated: 28/Jan/24 02:14
• Resolved: 31/May/23 17:20

Description

None-RBF clients that use observer reads have the option to set dfs.client.failover.observer.auto-msync-period.<nameservice> . This config makes the client automatically do an msync, allowing clients to use the observer reads feature without any code change.

To use observer reads with RBF, clients set dfs.client.rbf.observer.read.enable. The way this flag is implemented does not allow clients to use the auto-msync-period config. So with RBF, clients either have to

1. Not use observer reads
2. Use observer reads with the risk of stale reads
3. Make code changes to explicitly call msync.

We should add support for dfs.client.failover.observer.auto-msync-period.<nameservice>. This can be done by adding a ProxyProvider, in a similar manner to the ObserverReadProxyProvider.

Issue Links

• links to: GitHub Pull Request #5693