Script to periodically sample WCPU using top and aggregate it over all openssl processes

openssl_top_watch.sh

#!/bin/sh
# FreeBSD: sample 'top' every INTERVAL seconds, sum WCPU for lines matching PATTERN,
# write CSV, stop after MISSING_LIMIT consecutive snapshots with zero matches.
#
# Usage:
#   ./openssl_top_watch.sh [interval_secs] [missing_limit] [out_csv]
# Defaults:
#   interval_secs = 5
#   missing_limit = 3
#   out_csv       = /var/tmp/openssl_top_$(hostname -s)_$(date -u +%Y%m%dT%H%M%SZ).csv
#
# Env:
#   PATTERN='openssl'   # awk regex to match process lines (against full line)
#   TOP_N=64            # how many rows to ask 'top' to print (best-effort)

set -eu

INTERVAL="${1:-5}"
MISSING_LIMIT="${2:-3}"
HOST="$(hostname -s 2>/dev/null || hostname)"
STAMP="$(date -u +%Y%m%dT%H%M%SZ)"
CSV="${3:-/var/tmp/openssl_top_${HOST}_${STAMP}.csv}"
PATTERN="${PATTERN:-openssl}"
TOP_N="${TOP_N:-64}"

command -v top >/dev/null || { echo "top not found"; exit 1; }
command -v awk >/dev/null || { echo "awk not found"; exit 1; }

echo "# writing CSV to: $CSV"
echo "timestamp,openssl_wcpu_sum,match_count" > "$CSV"

misses=0
samples=0

trap 'echo "# stop signal"; exit 0' INT TERM

while :; do
  TS="$(date -u +%FT%TZ)"

  # One snapshot; -b=batch, -n=rows; -d=delay-per-refresh (not needed for single)
  SNAP="$(top -b -n "$TOP_N" -d 1 2>/dev/null || true)"

  # Sum WCPU over matching lines in the *process table*.
  # We start after the header line that begins with "PID USERNAME".
  read -r SUM CNT <<EOF
$(printf "%s\n" "$SNAP" | awk -v pat="$PATTERN" '
  start==0 && $1=="PID" && $2=="USERNAME" { start=1; next }
  start==1 && NF==0 { start=0; next }
  start==1 {
    if ($0 ~ pat) {
      # WCPU is the last field that looks like 12.34%
      for (i=NF; i>=1; i--) if ($i ~ /^[0-9.]+%$/) { v=$i; gsub("%","",v); s+=v; c++; break }
    }
  }
  END {
    if (s=="") s=0;
    if (c=="") c=0;
    printf "%.2f %d", s, c
  }')
EOF

  echo "$TS,$SUM,$CNT" >> "$CSV"
  samples=$((samples+1))
  echo "[#${samples}] $TS  openssl_wcpu_sum=${SUM}%  matches=${CNT}"

  if [ "$CNT" -eq 0 ]; then
    misses=$((misses+1))
  else
    misses=0
  fi

  if [ "$misses" -ge "$MISSING_LIMIT" ]; then
    echo "# no \"$PATTERN\" for last $MISSING_LIMIT samples — stopping."
    break
  fi

  sleep "$INTERVAL"
done

echo "# done. CSV: $CSV"