bash script logging missing hops during outage

I've posted this same question repeatedly but with specific tools in mind.
I think I need to ask my question in a different way in order to get the proper help I need.

Using a bash script, I want to monitor which hops went down during a network outage.

I've tried all kinds of tools and the problem is that all of them end up generating a lot of logging. Since I don't have much space on the device, I cannot log ongoing information and only want to know which hops went down with a time stamp.

Rather than log all kinds of repetitive information, I only want to log as follows.

-Start of outage - timestamp

-Which hop is missing - obviously, the one after which ever is last reached
-Did any other hops go missing and if so, timestamp those changes
-Don't log anything else if nothing much has changed so don't use single cycle checking because that simply creates tons of useless logs.

-End of outage - timestamp

Currently, my outage function is kind of nuts and mainly for static setups and is not quite what I need. I would rather send a few variables to the php app which in turn stores these things into mysql. I also would like to remove all of the tmp files and other useless stuff that seems to have become a part of this function.

function mtr_report() {
      mtr --no-dns --report --report-cycles=1 smartpet.com -p | awk '{printf "%s,%s,%s\n", $1,$2,$3}'
}
function outage()
{
    echo "Server is down looking for the problem"
    #while the network error persists check where is the error
    #this needs to be accurate in terms of timestamps

    # clean report file
    > $OUTAGE_REPORT

    while [ -z $(primary_check) ]; do
        NOW="$(date +"%F %T")#"
        mtr_report > ${FILE_TMP}
        if ! cmp -s $FILE_TMP $FILE_TMP_OLD  ; then
          echo -n "$NOW" >> ${OUTAGE_REPORT}
          # hop down
          grep -vf ${FILE_STATIC_TRACE} ${FILE_TMP} |head -n 1 | tr '\n' '#' | sed 's/#/,0#/'  >> ${OUTAGE_REPORT}
          # hop up
          grep -vf ${FILE_TMP} ${FILE_TMP_OLD} |head -n 1 | tr '\n' '#' | sed 's/#/,1#/'  >> ${OUTAGE_REPORT}
          #cat ${FILE_TMP} | tr '\n' '#' >> ${OUTAGE_REPORT}
          echo >> ${OUTAGE_REPORT}
        fi
        mv $FILE_TMP $FILE_TMP_OLD
    done
    rm "$FILE_TMP_OLD"

    # when server is back send a report
    $CURL -F function=outage  -F "level=@${OUTAGE_REPORT}" $SERVER_URL/app.php
}