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Help with speeding up my working script to take less time - how to use more CPU usage for a script

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# 1  
Old 06-09-2019
Help with speeding up my working script to take less time - how to use more CPU usage for a script

Hello experts,

we have input files with 700K lines each (one generated for every hour). and we need to convert them as below and move them to another directory once.

Sample INPUT:-
[root@tst01 INPUT]#  cat test1
[root@tst01 INPUT]#

Sample output:-
[root@tst01 INPUT]#  cat ../OUTPUT/test1
2019-05-30 09:40:00;86400;;NormalizedPortInfo;PctDiscards;0.0;Interface;Vl111
2019-05-30 09:40:00;86400;;NormalizedPortInfo;HistoricalInterfaceSpeed;1000000000;Interface;Vl111
2019-05-30 09:40:00;86400;;NormalizedPortInfo;SpeedIn;1000000000;Interface;Vl111
2019-05-30 09:40:00;86400;;NormalizedPortInfo;FrameSizeIn;209.65929490852145;Interface;Vl111
2019-05-30 09:40:00;86400;;NormalizedPortInfo;PctDiscardsIn;0.0;Interface;Vl111
2019-05-30 09:40:00;86400;;NormalizedPortInfo;NonunicastIn;124;Interface;Vl111
[root@tst01 INPUT]#

I wrote a script which is working - what does is to convert epoch time to normal date in the 1st column, replace 2nd column with fixed values (86400) and remap the remaining columns as they are into different columns
The problem here is that my script processing ~ 40 lines / second resulting only 144K lines are done in an hour. we need to finish all 700K in <1 hour. CPU usage is just 12% of 1 core where it has 12-cores in single CPU. How could I improve its speed (in terms of script) and how could I let my script use all CPU cores to do parellel processing?

My working script but processes only 40 lines per second
cat /usr/local/bin/
mkdir -p ${BASEDIR}/INPUT
mkdir -p ${BASEDIR}/OUTPUT
mkdir -p ${BASEDIR}/DONE
for inp in *
tail -n +2 ${inp} >/tmp/tempp
\mv /tmp/tempp ${inp}
cat ${inp} | while read line
TIMES=`echo "${line}" |awk -F, '{print $1}'`
INTMF=`echo "${line}" |awk -F, '{print $3}'`
METRIC=`echo "${line}" |awk -F, '{print $4}'`
VALU=`echo "${line}" |awk -F, '{print $5}'`
MFDISP=`echo "${line}" |awk -F, '{print $6}'`
DEVC=`echo "${line}" |awk -F, '{print $7}'`
CNAME=`echo "${line}" |awk -F, '{print $8}'`
#TIMES=`echo "${line}" |awk -F, '{print $1}'`
NON_MIL=`expr "${TIMES}" / 1000`
EPO2DT=`date -d @${NON_MIL} '+%Y-%m-%d %H:%M:%S'`
echo "${EPO2DT};${DURA};${DEVC};${INTMF};${METRIC};${VALU};${MFDISP};${CNAME}" >>${OUTPUTDIR}/${inp}
\mv ${BASEDIR}/INPUT/${inp} ${DONEDIR}

[root@tst01 INPUT]#

Last edited by Scrutinizer; 06-10-2019 at 03:17 AM.. Reason: quote tags -> code tags
# 2  
Old 06-09-2019
No surprise the execution of your script is a bit sluggish - you execute 16 processes per input line. As you are using awk anyhow, why not do the entire thing with it?
# 3  
Old 06-09-2019
Try this, save it as into file small.awk
$1=strftime("%Y-%m-%d %H:%M:%S")
print $1,$2,$7,$3,$4,$5,$6,$NF

Run as :
awk -f small.awk test1 > ../OUTPUT/test1_done
See if this speeds up processing of one file.

Please specify the operating system in the future, when making such requests.
Due to date invocation in your script, i would figure linux.

Hope that helps

Last edited by Peasant; 06-09-2019 at 04:14 PM.. Reason: Mistake.
This User Gave Thanks to Peasant For This Post:
# 4  
Old 06-09-2019
Thanks Rudic & Peasant.

@Peasant - your solution worked awesome, didn't even take 1 second to finish a file.
# 5  
Old 06-09-2019
Three comments on Peasant's fine proposal:
- not all awk versions provide strftime(); gawk may be required.
- calling strftime() without a time stamp will return the system time; insert $1 for the desired output. Eliminating nanoseconds from it may be required.
- a heading was required.

For awks without strftime(), try (reducing process count as far as possible)

paste -d, <(date +"%Y-%m-%d %H:%M:%S" -f<(sed 's/^/@/; s/000,.*$//' file)) <(cut -d, -f2- file) | 
awk -F, -vOFS=";" '
        {$2 = "86400" OFS $7
         $7 = $8; NF--
2019-05-30 10:40:00;86400;;NormalizedPortInfo;PctDiscards;0.0;Interface;Vl111
2019-05-30 10:40:00;86400;;NormalizedPortInfo;HistoricalInterfaceSpeed;1000000000;Interface;Vl111
2019-05-30 10:40:00;86400;;NormalizedPortInfo;SpeedIn;1000000000;Interface;Vl111
2019-05-30 10:40:00;86400;;NormalizedPortInfo;FrameSizeIn;209.65929490852145;Interface;Vl111
2019-05-30 10:40:00;86400;;NormalizedPortInfo;PctDiscardsIn;0.0;Interface;Vl111
2019-05-30 10:40:00;86400;;NormalizedPortInfo;NonunicastIn;124;Interface;Vl111

These 2 Users Gave Thanks to RudiC For This Post:
# 6  
Old 06-09-2019
Thanks Rudic for your script. My server is running RHEL 6 so i guess its awk has that capability.

I marked this thread as "solved"
# 7  
Old 06-09-2019
Even the shell becones faster if builtins are used: let the read command read the fields into variables, use $(( )) rather than expr, write the output file in one stream.
# set constants before the loop
cd "$INPUTDIR" || exit
for inp in *
  # the following code block has redirected stdin and stdout
  # delete header line#1 
  read x
  # write header
    NON_MIL=$(( TIMES / 1000 ))
    EPO2DT=`date -d @${NON_MIL} '+%Y-%m-%d %H:%M:%S'`
  } <"$inp"  >"$OUTPUTDIR/$inp"
  # after the block the files are closed
  \mv "$inp" "$DONEDIR"

This User Gave Thanks to MadeInGermany For This Post:

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