Finding directories older than N days in HDFS

Question

Can hadoop fs -ls be used to find all directories older than N days (from the current date)?

I am trying to write a clean up routine to find and delete all directori

Answer 1

If you happen to be using CDH distribution of Hadoop, it comes with a very useful HdfsFindTool command, which behaves like Linux's find command.

If you're using the default parcels information, here's how you'd do it:

hadoop jar /opt/cloudera/parcels/CDH/jars/search-mr-*-job.jar \
org.apache.solr.hadoop.HdfsFindTool -find PATH -mtime +N

Where you'd replace PATH with the search path and N with number of days.

Answer 2

For real clusters it is not a good idea, to use ls. If you have admin rights, it is more suitable to use fsimage.

I modify script above to illustrate idea.

first, fetch fsimage

curl "http://localhost:50070/getimage?getimage=1&txid=latest" > img.dump

convert it to text (same output as lsr gives)

hdfs oiv -i img.dump -o fsimage.txt

Script:

#!/bin/bash
usage="Usage: dir_diff.sh [days]"

if [ ! "$1" ]
then
  echo $usage
  exit 1
fi

now=$(date +%s)
curl "http://localhost:50070/getimage?getimage=1&txid=latest" > img.dump
hdfs oiv -i img.dump -o fsimage.txt
cat fsimage.txt | grep "^d" | while read f; do 
  dir_date=`echo $f | awk '{print $6}'`
  difference=$(( ( $now - $(date -d "$dir_date" +%s) ) / (24 * 60 * 60 ) ))
  if [ $difference -gt $1 ]; then
    echo $f;
  fi
done

Answer 3

hdfs dfs -ls /hadoop/path/*.txt|awk '$6 < "2017-10-24"'

Answer 4

I didn't have the HdfsFindTool, nor the fsimage from curl, and I didn't much like the ls to grep with while loop using date awk and hadoop and awk again. But I appreciated the answers.

I felt like it could be done with just one ls, one awk, and maybe an xargs.

I also added the options to list the files or summarize them before choosing to delete them, as well as choose a specific directory. Lastly I leave the directories and only concern myself about the files.

#!/bin/bash
USAGE="Usage: $0 [N days] (list|size|delete) [path, default /tmp/hive]"
if [ ! "$1" ]; then
  echo $USAGE
  exit 1
fi
AGO="`date --date "$1 days ago" "+%F %R"`"

echo "# Will search for files older than $AGO"
if [ ! "$2" ]; then
  echo $USAGE
  exit 1
fi
INPATH="${3:-/tmp/hive}"

echo "# Will search under $INPATH"
case $2 in
  list)
    hdfs dfs -ls -R "$INPATH" |\
      awk '$1 ~ /^[^d]/ && ($6 " " $7) < '"\"$AGO\""
  ;;
  size)
    hdfs dfs -ls -R "$INPATH" |\
      awk '$1 ~ /^[^d]/ && ($6 " " $7) < "'"$AGO"'" {
           sum += $5 ; cnt += 1} END {
           print cnt, "Files with total", sum, "Bytes"}'
  ;;
  delete)
    hdfs dfs -ls -R "$INPATH" |\
      awk '$1 ~ /^[^d]/ && ($6 " " $7) < "'"$AGO"'" {print $8}' | \
      xargs hdfs dfs -rm -skipTrash
  ;;
  *)
    echo $USAGE
    exit 1
  ;;
esac

I hope others find this useful.

Answer 5

This script lists all the directories that are older than [days] :

#!/bin/bash
usage="Usage: $0 [days]"

if [ ! "$1" ]
then
  echo $usage
  exit 1
fi

now=$(date +%s)
hadoop fs -lsr | grep "^d" | while read f; do 
  dir_date=`echo $f | awk '{print $6}'`
  difference=$(( ( $now - $(date -d "$dir_date" +%s) ) / (24 * 60 * 60 ) ))
  if [ $difference -gt $1 ]; then
    echo $f;
  fi
done