GC-freq.awk

#! /usr/bin/awk -f
 
# Awk script to parse Java .out log and print GC frequency per minute
# 
# Assumes following JVM flags are set:
# -XX:+PrintGCDetails
# -XX:+PrintGCTimeStamps 
# -verbose:gc 
 
BEGIN {print "t,count"}
 
/\[GC:/ {
  split($7, a, ":");
  t=a[1]":"a[2];
  freq[t]++ ;
  if (start[1] == null) {
    start[1] = a[1];
    start[2] = a[2];
  }
  end[1] = a[1];
  end[2] = a[2];
}
 
END {
  for (hour = start[1]; hour <= end[1]; hour++) {
    for (minute = 0; minute <= 59; minute++) {
      t = sprintf("%02d:%02d", hour, minute);
      if (freq[t] == null) {
        printf "%s,%d\n", t, 0;
      } else {
        printf "%s,%d\n", t, freq[t];
      }
    }
  }
}