bitcoin/contrib/tracing/connectblock_benchmark.bt
0xb10c 53c9fa9e62
tracing: drop block_connected hash.toString() arg
The tracepoint `validation:block_connected` was introduced in #22006.
The first argument was the hash of the connected block as a pointer
to a C-like String. The last argument passed the hash of the
connected block as a pointer to 32 bytes. The hash was only passed as
string to allow `bpftrace` scripts to print the hash. It was
(incorrectly) assumed that `bpftrace` cannot hex-format and print the
block hash given only the hash as bytes.

The block hash can be printed in `bpftrace` by calling
`printf("%02x")` for each byte of the hash in an `unroll () {...}`.
By starting from the last byte of the hash, it can be printed in
big-endian (the block-explorer format).

```C
  $p = $hash + 31;
  unroll(32) {
      $b = *(uint8*)$p;
      printf("%02x", $b);
      $p -= 1;
  }
```

See also: https://github.com/bitcoin/bitcoin/pull/22902#discussion_r705176691

This is a breaking change to the block_connected tracepoint API, however
this tracepoint has not yet been included in a release.
2021-10-18 14:35:25 +02:00

157 lines
4.3 KiB
Plaintext
Executable File

#!/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 'bitcoind' binary compiled with eBPF support and the
'validation:block_connected' USDT. By default, it's assumed that 'bitcoind' is
located in './src/bitcoind'. This can be modified in the script below.
EXAMPLES:
bpftrace contrib/tracing/connectblock_benchmark.bt 300000 680000 1000
When run together 'bitcoind -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 'bitcoind', 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/bitcoind: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/bitcoind: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);
}