PIP-123: Introduce Pulsar metadata CLI tool
See original GitHub issueMotivation
For a very long time, we have included a CLI command to start the ZooKeeper
shell utility: pulsar zookeeper-shell
, which is essentially a repackaging
of the ZooKeeper tool zkCli.sh
.
This is useful in some cases to either verify the content of metadata or to perform cleanup and modification tasks for which there is not an available option through the Pulsar REST APIs.
While it’s very useful, there are some drawbacks with the zookeeper-shell
as it is today:
1. This is only a ZooKeeper tool (obviously). Since we are adding more metadata backends, we should have a tool that works across all the implementations and presents a single consistent interface.
2. ZooKeeper shell is designed to be an interactive shell and it’s not very good when trying to do non-interactive scriptable operations.
3. ZooKeeper is a bit clunky when using it and it requires the user to retype paths many times. The commands are not very intuitive or documented. It’s not possible to update z-node with multi-lines content.
4. We cannot easily add functionality or improvements into ZooKeeper shell, since it belongs to a different project and the tool has been stagnating for many years.
5. In cases where the z-nodes content is binary (Protobuf) or compressed, there is no easy way to inspect the content from the ZooKeeper shell. Additionally, we can format and colorize JSON content to make it easier to read.
6. The paths used for metadata resources are also often using encodings that make it more difficult to construct on the shell tool.
Part of what is described here is in the pulsar-managed-ledger-admin
CLI tool,
though that is a Python script that requires additional dependencies that are
not typically installed, it only works with ZooKeeper, and it only targets
accessing the managed ledger metadata.
Goal
Introduce a new Java CLI tool to access, inspect and modify metadata that solves all the issues described above.
We would leave the zookeeper-shell
command for now. In the future, once the
new tool is proven, we can consider removing the zookeeper-shell
command.
Proposed changes
Add a new command:
bin/pulsar metadata
with several subcommands:
Get
Examples:
# General path get
$ pulsar metadata get /my-path
# Topic metadata
$ pulsar metadata get topic my-tenant/my-namespace/my-topic
{
# Managed ledger metadata
}
# Namespace get
$ pulsar metadata get namespace my-tenant/my-namespace
{
# Namespace metadata
}
$ pulsar metadata get ledger 12345
{
# BK ledger metadata
}
Delete
Examples:
# General path delete
$ pulsar metadata delete /my-path
# Topic metadata
$ pulsar metadata delete topic my-tenant/my-namespace/my-topic
Scan
Examples:
$ pulsar metadata scan /my-path
/my-path
/my-path/1
/my-path/2
/my-path/3
/my-path/3/1
$ pulsar metadata scan --values /my-path
/my-path
{value}
/my-path/1
{value}
/my-path/2
{value}
Shell
$ pulsar metadata shell
> get topic my-tenant/my-namespace/my-topic
{
# Managed ledger metadata
}
> delete topic my-tenant/my-namespace/my-topic
> cd /my-path
> ls
1
2
3
> delete 1 # Delete keys with relative paths
Issue Analytics
- State:
- Created 2 years ago
- Reactions:7
- Comments:6 (3 by maintainers)
I think it’s will be very useful.
This looks interesting I’ll be looking into it for a while