[CURATOR-544] Implement SessionFailedRetryPolicy

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.3.0
• Fix Version/s: 5.0.0
• Component/s: Client
• Assignee: Unassigned
• Reporter: Zili Chen
• Created: 29/Sep/19 09:24
• Updated: 08/May/20 07:21
• Resolved: 07/May/20 22:41

Description

https://lists.apache.org/x/thread.html/2549c310c1e3232d2f746bf1cf7110c094ea2ca9d1e54b34b75a508f@%3Cuser.curator.apache.org%3E

Currently Curator will always reset on session expire and instance a new ZK client as well as recover state.

Because on session expire ephemeral znodes get deleted, some of user cases possibly want to manually handle session expire before automatically reset o.a.c.ConnectionState.

I propose implement a SessionConnectionHandlingPolicy whose callWithRetry use SessionFailRetryLoop so that o.a.c.ConnectionState fails on session expired.

BTW, it would be a user-friendly way to make user of SessionFailRetryLoop.

I volunteer to work on an implementation.

What do you think?

CC randgalt

As time goes by, we change a bit what API looks like. For implement the same functionality, we change code of RetryPolicy instead. To be brief, we (1) move RetryLook.isRetriableException to RetryPolicy#allowRetry(Exception) and existing impls have a default impl that keeps the manner (2) impl a SessionFailedRetryPolicy that throws when SessionExipredException tested, while the other examination delegated to another policy.