connectblock_benchmark.bt

#!/usr/bin/env bpftrace

/*

  USAGE:

  bpftrace contrib/tracing/connectblock_benchmark.bt <start height> <end height> <logging threshold in ms>

  - <start height> sets the height at which the benchmark should start. Setting
    the start height to 0 starts the benchmark immediately, even before the
    first block is connected.
  - <end height> sets the height after which the benchmark should end. Setting
    the end height to 0 disables the benchmark. The script only logs blocks
    over <logging threshold in ms>.
  - Threshold <logging threshold in ms>

  This script requires a 'dashd' binary compiled with eBPF support and the
  'validation:block_connected' USDT. By default, it's assumed that 'dashd' is
  located in './src/dashd'. This can be modified in the script below.

  EXAMPLES:

  bpftrace contrib/tracing/connectblock_benchmark.bt 300000 680000 1000

  When run together 'dashd -reindex', this benchmarks the time it takes to
  connect the blocks between height 300.000 and 680.000 (inclusive) and prints
  details about all blocks that take longer than 1000ms to connect. Prints a
  histogram with block connection times when the benchmark is finished.


  bpftrace contrib/tracing/connectblock_benchmark.bt 0 0 500

  When running together 'dashd', all newly connected blocks that
  take longer than 500ms to connect are logged. A histogram with block
  connection times is shown when the script is terminated.

*/

BEGIN
{
  $start_height = $1;
  $end_height = $2;
  $logging_threshold_ms = $3;

  if ($end_height < $start_height) {
    printf("Error: start height (%d) larger than end height (%d)!\n", $start_height, $end_height);
    exit();
  }

  if ($end_height > 0) {
    printf("ConnectBlock benchmark between height %d and %d inclusive\n", $start_height, $end_height);
  } else {
    printf("ConnectBlock logging starting at height %d\n", $start_height);
  }

  if ($logging_threshold_ms > 0) {
    printf("Logging blocks taking longer than %d ms to connect.\n", $3);
  }

  if ($start_height == 0) {
    @start = nsecs;
  }
}

/*
  Attaches to the 'validation:block_connected' USDT and collects stats when the
  connected block is between the start and end height (or the end height is
  unset).
*/
usdt:./src/dashd:validation:block_connected /arg1 >= $1 && (arg1 <= $2 || $2 == 0 )/
{
  $height = arg1;
  $transactions = arg2;
  $inputs = arg3;
  $sigops =  arg4;
  $duration = (uint64) arg5;

  @height = $height;

  @blocks = @blocks + 1;
  @transactions = @transactions + $transactions;
  @inputs = @inputs + $inputs;
  @sigops = @sigops + $sigops;

  @durations = hist($duration / 1000);

  if ($height == $1 && $height != 0) {
    @start = nsecs;
    printf("Starting Connect Block Benchmark between height %d and %d.\n", $1, $2);
  }

  if ($2 > 0 && $height >= $2) {
    @end = nsecs;
    $duration = @end - @start;
    printf("\nTook %d ms to connect the blocks between height %d and %d.\n", $duration / 1000000, $1, $2);
    exit();
  }
}

/*
  Attaches to the 'validation:block_connected' USDT and logs information about
  blocks where the time it took to connect the block is above the
  <logging threshold in ms>.
*/
usdt:./src/dashd:validation:block_connected / (uint64) arg5 / 1000> $3 /
{
  $hash = arg0;
  $height = (int32) arg1;
  $transactions = (uint64) arg2;
  $inputs = (int32) arg3;
  $sigops = (int64) arg4;
  $duration = (int64) arg5;


  printf("Block %d (", $height);
  /* Prints each byte of the block hash as hex in big-endian (the block-explorer format) */
  $p = $hash + 31;
  unroll(32) {
      $b = *(uint8*)$p;
      printf("%02x", $b);
      $p -= 1;
  }
  printf(")  %4d tx  %5d ins  %5d sigops  took %4d ms\n", $transactions, $inputs, $sigops, (uint64) $duration / 1000);
}


/*
  Prints stats about the blocks, transactions, inputs, and sigops processed in
  the last second (if any).
*/
interval:s:1 {
  if (@blocks > 0) {
    printf("BENCH %4d blk/s %6d tx/s %7d inputs/s %8d sigops/s (height %d)\n", @blocks, @transactions, @inputs, @sigops, @height);

    zero(@blocks);
    zero(@transactions);
    zero(@inputs);
    zero(@sigops);
  }
}

END
{
  printf("\nHistogram of block connection times in milliseconds (ms).\n");
  print(@durations);

  clear(@durations);
  clear(@blocks);
  clear(@transactions);
  clear(@inputs);
  clear(@sigops);
  clear(@height);
  clear(@start);
  clear(@end);
}