xrdsum

XrootD plugin for calculating checksums and storing them in extended attributes. Currently supports ADLER32 checksum and HDFS as backend. Borrows heavily from cephsum plugin.

This plugin is designed to easily accommodate new checksum types and backends. Additional dependencies for backends are defined as optional dependencies for the package (see usage instructions).

Usage

xrdsum requires Python version >=3.8. To install, run:

pip install xrdsum[hdfs]

xrdsum --help
Usage: xrdsum [OPTIONS] COMMAND [ARGS]...

  Callback to give the --verbose and --debug options to all commands

Options:
  -v, --verbose         Verbose output
  -d, --debug           Debug output
  -l, --log-file TEXT   Log file
  --install-completion  Install completion for the current shell.
  --show-completion     Show completion for the current shell, to copy it or
                        customize the installation.
  --help                Show this message and exit.

Commands:
  get     Get the checksum of a file.
  verify  Check if a file has the correct checksum.

Example:

/usr/bin/time -v xrdsum --verbose  --debug get  /xrootd/dteam/user/jwalder/file_1GB_020 --read-size 128

xrootd config

# ensure cksum adler32 is included in the tpc directive, in order to calculate by default on transfer
ofs.tpc cksum adler32 fcreds ?gsi =X509_USER_PROXY autorm xfr 40 pgm /etc/xrootd/xrdcp-tpc.sh

# add this line to trigger external checksum calculation. Would be overwritten by other xrootd.chksum lines
xrootd.chksum max 50 adler32 /etc/xrootd/xrdsum.sh

with /etc/xrootd/xrdcp-tpc.sh containing:

#!/bin/sh

# from https://github.com/snafus/cephsum/blob/master/scripts/xrdcp-tpc.sh
#Original code
#/usr/bin/xrdcp --server -f $1 root://$XRDXROOTD_PROXY/$2

# Get the last two variables as SRC and DST, all others are assumed as additional arguments
OTHERARGS="${@:1:$#-2}"
DSTFILE="${@:$#:1}"
SRCFILE="${@:$#-1:1}"


/usr/bin/xrdcp $OTHERARGS --server -f $SRCFILE root://$XRDXROOTD_PROXY/$DSTFILE

and with /etc/xrootd/xrdsum.sh containing:

#!/usr/bin/env bash

RESULT=$(xrdsum get --store-result --chunk-size 64 --verbose --storage-catalog /etc/xrootd/storage.xml "$1")
ECODE=$?

# XRootD expects return on stdout - checksum followed by a new line
printf "%s\n" "$RESULT"
exit "$ECODE"

Conda installation example

wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh
bash Miniconda3-latest-Linux-x86_64.sh -b -p /miniconda
rm -f Miniconda3-latest-Linux-x86_64.sh
export PATH="/miniconda/bin:$PATH"
conda init
conda update -y conda
conda install python=3.10
pip install xrdsum[hdfs]