jcsp / segment_toy

Rust utilities that understand Redpanda storage formats

rp-storage-tool

Purpose

This low level tool is for offline use by Redpanda Engineering when diagnosing faults.

This tool is not for everyday use on live clusters.

Quickstart

# Get a rust toolchain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Compile and run
cargo run --release -- --backend=<aws|gcp|azure> scan --source=<bucket name>

Installation

To run the tool outside a built tree, you may simply copy the statically linked binary.

# Compile
cargo build --release

# Grab the binary
cp target/release/rp-storage-tool /usr/local/bin

Usage

Typical usage

The following examples assume you are running on an AWS instance with IAM roles configured for access to your bucket. If you need to specify static keys, see the "Working with local object stores" section below.

# Scan the bucket, store metadata in a file, and report any metadata anomalies
$ rp-storage-tool --backend aws scan-metadata --source=my-bucket --meta-file my-bucket.json

# Scan the data within a topic of interest, and report any anomalies.  Use the metadata
# file from the last step to avoid re-scanning all objects in the bucket.
$ rp-storage-tool --filter kafka/my-topic/*_* --backend aws scan-data --source=my-bucket --meta-file my-bucket.json

# Having identified an issue, extract the data from a partition for further analysis offline
$ mkdir my-data-dump
$ rp-storage-tool --filter kafka/my-topic/13_63 --backend aws extract --source=my-bucket --meta-file my-bucket.json --sink ./my-data-dump/

Generic parameters

• The --backend argument selects the cloud storage backend. This has a default (AWS) for convenience when working with commands that don't use cloud storage, but ordinarily you should be specifying it.
• The --filter argument controls which topics & partitions will be examined. When scanning metadata we always scan all objects, but will only store+analyze metadata for partitions matching the filter.
• If you are running on a node with authentication already set up (e.g. IAM Roles on AWS), this will Just Work. Otherwise you may need to set the appropriate access key/secret environment variables for the cloud platform you are connecting to.

Subcommands

scan-metadata

This walks the objects in a bucket used by Redpanda Tiered Storage and reports on any inconsistencies. Not all issues this tool reports are harmful, for example segments_outside_manifest may contain objects harmlessly left behind when Redpanda was restarted during an upload.

scan-data

This walks the data within segments (you probably want to use --filter to only scan segments for certain NTPS) to check that it is readable, and that the metadata in the partition manifest is consistent with the data.

extract

For NTPs matching the filter, copy all metadata and data objects into a local folder.

Working with local object stores

This tool uses environment variables for any special configuration of storage backends required for working outside of real cloud environments.

For example, to use the tool with a bucket called data in a minio cluster at aplite:9000:

AWS_ALLOW_HTTP=1 AWS_ACCESS_KEY_ID=minioadmin AWS_SECRET_ACCESS_KEY=minioadmin AWS_REGION=us-east-1 \
  AWS_ENDPOINT=http://aplite:9000 cargo run --release -- --backend aws scan --source data

Building a portable binary

If you are building on a workstation and copying the binary to a remote machine, and your workstation doesn't happen to run the same linux distro as the remote machine, it is useful to build a statically linked binary that will work on any distro.

# A dependency requires this to build: adjust as needed if not on an RPM distro
sudo dnf install -y musl-gcc

# Install the Rust toolchain for musl (statically linked libc)
rustup target add x86_64-unknown-linux-musl

# Build with the musl toolchain
cargo build --release --target=x86_64-unknown-linux-musl

# Output in target/release/rp-storage-tool

segment_toy's Issues

Incorrect decoding of partition manifest

decode-partition-manifest does not decode the attached man.bin correctly. It produces result.json instead of expected.json.