WikiData Import 2020-07-30

Environment

1. Mac Pro Mid 2010
2. 12 core 3.46 GHz
3. 64 GB RAM
4. macOS High Sierra 10.13.6
5. Source Disk: 4 TB 7200 rpm hard disk WD Gold WDC WD4002FYYZ Blackmagic speed rating: 175 MB/s write 175 MB/s read
6. Target Disk: 4 TB SSD Samsung 860 EVO Blackmagic speed rating: 257 MB/s write 270 MB/s read

7. java -version
   openjdk version "11.0.5" 2019-10-15
   OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.5+10)
   OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.5+10, mixed mode)
   

Summary

1. trying to replicate success story of https://issues.apache.org/jira/projects/JENA/issues/JENA-1909
2. download of 110 GB took some 6 h 30 min
3. unzipping to to some 2160 GB took more than 1/2 day
4. import is in progress

Download and unpack

This download was done with the "latest-all.nt" dataset.

wget https://dumps.wikimedia.org/wikidatawiki/entities/latest-all.nt.bz2

--2020-07-30 06:40:18--  https://dumps.wikimedia.org/wikidatawiki/entities/latest-all.nt.bz2
Resolving dumps.wikimedia.org (dumps.wikimedia.org)... 2620::861:1:208:80:154:7, 208.80.154.7
Connecting to dumps.wikimedia.org (dumps.wikimedia.org)|2620::861:1:208:80:154:7|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 118776910150 (111G) [application/octet-stream]
Saving to: ‘latest-all.nt.bz2’
latest-all.nt.bz2     0%[                    ] 635.10M  5.02MB/s    eta 6h 19m
...
latest-all.nt.bz2   100%[===================>] 110.62G  4.88MB/s    in 6h 31m  
2020-07-30 13:11:49 (4.82 MB/s) - ‘latest-all.nt.bz2’ saved [118776910150/118776910150]
bzip2 -dk latest-all.nt.bz2
ls -l latest-all.nt
-rw-------  1 wf  admin  1980899328 Jul 30 17:56 latest-all.nt
# failed to limited disk space
# retry next morning
nohup bzip2 -ckd latest-all.nt.bz2 > /Volumes/Torterra/wikidata2020-07-31/latest-all.nt&
...
ls -l latest-all.nt 
-rw-r--r--  1 wf  admin  2162713035569 Jul 31 22:24 latest-all.nt

bzip2 issue

the first bzip failed - see retry for how bzip is used to extract from rotating disk to SSD

bzip2: I/O or other error, bailing out.  Possible reason follows.
bzip2: No space left on device
	Input file = latest-all.nt.bz2, output file = latest-all.nt
bzip2: Deleting output file latest-all.nt, if it exists.

Counting an copying

date;cp -p /Volumes/Torterra/wikidata2020-07-31/latest-all.nt .;date
Sat Aug  1 07:42:32 CEST 2020
Sat Aug  1 12:21:06 CEST 2020
date;wc -l latest-all.nt;date
Sat Aug  1 07:42:43 CEST 2020
 13738317356 latest-all.nt
Sat Aug  1 10:52:57 CEST 2020

Scripts

wikidata2jena

#!/bin/bash
# WF 2020-05-10

# global settings
jena=apache-jena-3.16.0
tgz=$jena.tar.gz
jenaurl=http://mirror.easyname.ch/apache/jena/binaries/$tgz
base=/Volumes/Torterra/wikidata2020-08-01
data=$base/data
tdbloader=$jena/bin/tdb2.tdbloader

getjena() {
# download
if [ ! -f $tgz ]
then
  echo "downloading $tgz from $jenaurl"
	wget $jenaurl
else
  echo "$tgz already downloaded"
fi
# unpack
if [ ! -d $jena ]
then
  echo "unpacking $jena from $tgz"
	tar xvzf $tgz
else
  echo "$jena already unpacked"
fi
# create data directory
if [ ! -d $data ]
then
  echo "creating $data directory"
  mkdir -p $data
else
  echo "$data directory already created"
fi
}

#
# show the given timestamp
#
timestamp() {
 local msg="$1"
 local ts=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
 echo "$msg at $ts"
}

#
# load data for the given data dir and input
#
loaddata() {
	local data="$1"
	local input="$2"
  timestamp "start loading $input to $data"
  $tdbloader --loader=parallel --loc "$data" "$input" > tdb2-out.log 2> tdb2-err.log
	timestamp "finished loading $input to $data"
}

getjena
export TMPDIR=$base/tmp
if [ ! -d $TMPDIR ]
then
  echo "creating temporary directory $TMPDIR"
  mkdir $TMPDIR
else
  echo "using temporary directory $TMPDIR"
fi
loaddata $data latest-all.nt