[Do not merge] Prototype for detection of zero copy locks

[MikhailBurdukov]

The prototype script that should detect dead zero copy locks. Probably will be never merged but lets keep it anyway, may be one day will be useful

Summary by Sourcery

Introduce a prototype tool to detect dead zero-copy locks in Zookeeper by adding a scanning function and exposing it via a new CLI command

New Features:

• Add a prototype find_dead_zc_locks function to traverse zero-copy lock paths in Zookeeper and print locks missing the specified host
• Expose the detection logic through a new find-dead-zero-copy-locks command in the CLI

[sourcery-ai[bot]]

Reviewer's Guide

Introduces a prototype mechanism to scan Zookeeper’s zero-copy lock hierarchy and identify locks with no matching host by adding a detection function and exposing it through a new CLI command.

Sequence diagram for the new 'find-dead-zero-copy-locks' CLI command

sequenceDiagram
    actor User
    participant CLI
    participant "remove_hosts_from_table()"
    participant "find_dead_zc_locks()"
    participant "zk_client"
    participant "get_children()"
    User->>CLI: Run 'find-dead-zero-copy-locks' command
    CLI->>"remove_hosts_from_table()": Call with args (ctx, zookeeper_table_path, shard_name, fqdn)
    "remove_hosts_from_table()"->>"find_dead_zc_locks()": Call with same args
    "find_dead_zc_locks()"->>"zk_client": Open Zookeeper client
    "find_dead_zc_locks()"->>"get_children()": Get children of zc_root_path
    loop For each table
        "find_dead_zc_locks()"->>"get_children()": Get children of table_path
        loop For each part
            "find_dead_zc_locks()"->>"get_children()": Get children of part_path
            loop For each lock
                "find_dead_zc_locks()"->>"get_children()": Get children of lock_path
                alt If no host in fqdn
                    "find_dead_zc_locks()"->>CLI: Print lock_path
                end
            end
        end
    end
    "find_dead_zc_locks()"-->>"zk_client": Close Zookeeper client

Class diagram for new and modified functions in Zookeeper zero-copy lock detection

classDiagram
    class remove_hosts_from_table {
        +remove_hosts_from_table(ctx: Context, zookeeper_table_path: str, shard_name: str, fqdn: list)
    }
    class find_dead_zc_locks {
        +find_dead_zc_locks(ctx, zc_root_path, shard_name, fqdn)
    }
    remove_hosts_from_table --> find_dead_zc_locks: calls
    class zk_client {
        +__enter__()
        +__exit__()
    }
    find_dead_zc_locks --> zk_client: uses
    class get_children {
        +get_children(zk, path)
    }
    find_dead_zc_locks --> get_children: uses

File-Level Changes

Change	Details	Files
Prototype detection function for dead zero copy locks	Traverse zero-copy root path → tables → parts → lock nodes Filter lock entries by shard_name and collect host children Mark and print lock paths missing any fqdn hosts	ch_tools/chadmin/internal/zookeeper_clean.py
New CLI command to invoke dead lock detection	Add find-dead-zero-copy-locks under zookeeper_group Define arguments: zookeeper-table-path, shard-name, fqdn list Call find_dead_zc_locks with parsed parameters	ch_tools/chadmin/cli/zookeeper_group.py

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