pgwrites.d

#!/usr/sbin/dtrace -qs

/*
 * USAGE      : pgwrites.d
 *
 * DESCRIPTION:
 *   Count buffer and wal dirty writes over time
 *
 */

dtrace:::BEGIN
{
    /* starting values */
    bufferwrite = 0;
    walwrite = 0;

    bufferwrite_total = 0;
    walwrite_total = 0;
    seconds_total = 0;
}

postgresql*:::buffer-write-dirty-start
{
    bufferwrite++;
}

postgresql*:::wal-buffer-write-dirty-start
{
    walwrite++;
}

profile:::tick-1s
/seconds_total % 25 == 0/
{
    printf("Buffer dirty writes: %6d  WAL dirty writes: %6d\n",
           bufferwrite, walwrite);
}

profile:::tick-1s
{

    bufferwrite_total += bufferwrite;
    walwrite_total += walwrite;
    seconds_total++;

    bufferwrite = 0;
    walwrite = 0;
}

dtrace:::END
{
    printf("\nAverage count/sec\n");
    printf("Avg buffer writes: %6d Avg WAL writes: %6d\n",
           bufferwrite_total/seconds_total,
           walwrite_total/seconds_total);
}