Feature #17854
closedmds: only evict an unresponsive client when another client wants its caps
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Description
Instead of immediately evicting a client when it has not responded within the timeout, set a flag to mark the client as laggy. Then in Locker, when another client tries to do something that would be blocked by the laggy client, evict the laggy client.
Test this by having two clients, accessing separate directories. Have client A go unresponsive, and see that it is not evicted while client B continues to do work in its own directory. Then, have Client B try and touch the files in client A's directory, and see that client A gets evicted at that point.
Updated by Patrick Donnelly about 6 years ago
- Subject changed from Only evict an unresponsive client when another client wants its caps to mds: only evict an unresponsive client when another client wants its caps
- Target version changed from v12.0.0 to v14.0.0
- Source changed from other to Development
- Tags set to intern
- Component(FS) MDS added
Updated by Rishabh Dave almost 6 years ago
I am planning to start working on this feature. How can I get a client to be unresponsive without evicting it?
Updated by Patrick Donnelly almost 6 years ago
- Status changed from New to In Progress
- Assignee set to Rishabh Dave
- Tags deleted (
intern) - Labels (FS) task(intern) added
Updated by Zheng Yan almost 6 years ago
Rishabh Dave wrote:
I am planning to start working on this feature. How can I get a client to be unresponsive without evicting it?
check Server::find_idle_sessions(). the function checks if clients have renewed their sessions recently. A client is unresponsive if it hasn't renewed its session for session_timeout seconds. Once found unresponsive client, you can check Locker::revoking_caps_by_client to find if mds wants to revoke caps from the unresponsive client.
Updated by Patrick Donnelly almost 6 years ago
- Status changed from In Progress to Fix Under Review
Updated by Rishabh Dave almost 6 years ago
Unresponsive/stale clients do not hold any caps1. Therefore, deferring their eviction would mean keeping them infinitely. Instead, Zheng suggested to avoid marking open sessions holding no caps stale and evict them directly at session_autoclose1.
[1] https://github.com/ceph/ceph/pull/22645#discussion_r197319784
Updated by Patrick Donnelly about 5 years ago
- Target version changed from v14.0.0 to v15.0.0
Updated by Patrick Donnelly about 5 years ago
- Start date deleted (
11/10/2016) - Pull request ID set to 22645
Updated by Patrick Donnelly almost 5 years ago
- Status changed from Fix Under Review to Pending Backport
- Backport set to nautilus,mimic
Updated by Nathan Cutler almost 5 years ago
- Copied to Backport #40899: mimic: mds: only evict an unresponsive client when another client wants its caps added
Updated by Nathan Cutler almost 5 years ago
- Copied to Backport #40900: nautilus: mds: only evict an unresponsive client when another client wants its caps added
Updated by Nathan Cutler over 4 years ago
- Status changed from Pending Backport to Resolved
While running with --resolve-parent, the script "backport-create-issue" noticed that all backports of this issue are in status "Resolved" or "Rejected".