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https://issues.apache.org/jira/browse/ZOOKEEPER-5069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18097483#comment-18097483
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dong he commented on ZOOKEEPER-5069:
------------------------------------
A pull request has been opened for this issue:
[PR #2426](https://github.com/apache/zookeeper/pull/2426)
The PR adds the watch_details AdminServer command and the wchd four-letter
command alias for querying detailed Watch registrations.
> Add AdminServer command to query watch registration details
> -----------------------------------------------------------
>
> Key: ZOOKEEPER-5069
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-5069
> Project: ZooKeeper
> Issue Type: New Feature
> Components: server
> Affects Versions: 3.10.0
> Reporter: dong he
> Priority: Major
> Labels: pull-request-available
> Attachments: watch_details_design_document_en.md
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Motivation
> ZooKeeper currently provides the watches, watches_by_path, and watch_summary
> AdminServer commands. They expose session IDs, paths, or aggregate data only;
> they do not provide a per-watch view that can be correlated with current
> client connection information, including client IP address, port, connection
> state, and Watch type.
> This makes it difficult to diagnose Watch registrations on a ZooKeeper Server.
> Proposed Change
> Add a read-only AdminServer command named watch_details, with the four-letter
> command alias wchd.
> Endpoints:
> - GET /commands/watch_details
> - GET /commands/wchd
> The command returns Watch registrations maintained by the current ZooKeeper
> Server only. It does not aggregate data across the ensemble, so results can
> differ when queried from a Leader, Follower, or Observer.
> Optional Query Parameters
> - path: exact znode path match
> - session_id: exact Session ID match; decimal and hexadecimal input are
> supported
> - client_ip: exact client IP match
> - limit: maximum number of returned entries; default 100, range 1 through 1000
> Multiple parameters use AND semantics.
> Response and Behavior
> Each returned entry contains the watched path, hexadecimal Session ID, client
> IP and port, watch kind (data or children), watch mode (standard, persistent,
> or persistent_recursive), current connection establishment time, session
> timeout, and whether the connection uses TLS.
> The command returns only Watches associated with active, non-stale ServerCnxn
> instances. It does not return total_count, does not guarantee ordering, and
> uses limit + 1 internally to determine whether the response is truncated.
> The command is intentionally exposed without an additional AdminServer
> authentication or ACL restriction.
> Compatibility
> This is an additive, read-only AdminServer command. The IWatchManager
> extension uses a default method to preserve binary compatibility for existing
> third-party IWatchManager implementations. A custom WatchManager that does
> not implement the detailed query returns HTTP 501.
> Performance
> The command applies filters while traversing Watch registrations, stops after
> limit + 1 matches, does not build a full Watcher-to-Path reverse index, does
> not calculate total_count, and does not modify the Watch registration or
> trigger hot path.
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