[Ethereum] How to calculate the average time to mine a block

Here is a Perl script that will calculate your average hashrate and display the important lines in your ethminer log files:

ℹ  21:19:58.840|ethminer  B-) Submitted and accepted.
✘  20:23:53.048|ethminer  FAILURE: GPU gave incorrect result!`

This script works on Linux and Mac OS X as the Perl interpreter is available on these platforms by default. For Windows, you may have to try Perl from perl.org.

Note that this hashrate is calculated when ethminer is calculating it's hashes, and does not include the time that ethminer is getting a new work package from geth (or the pool) or when it is submitting the results to geth/pool.

Copy the following lines into $HOME/bin/calcHashrate, and set the executable bit for this file by running the command chmod 700 $HOME/bin/calcHashrate.

calcHashrate

#!/usr/bin/perl -W
use Getopt::Long;

my $DEFAULTHASHLINES = 1000;
my $DEFAULTACCEPTLINES = 4;
my $DEFAULTFAILURELINES = 4;

my ($hashlines, $acceptlines, $failurelines, $removecolour, $help);

GetOptions(
  "hashlines:i"    => \$hashlines,
  "acceptlines:i"  => \$acceptlines,
  "failurelines:i" => \$failurelines,
  "removecolour"   => \$removecolour,
  "help"           => \$help
);

die "Usage: $0 [options]\n\n" .
    " where the options are:\n" .
    "  --hashlines=x     Calculate average hashrate over the last x lines, default $DEFAULTHASHLINES\n" .
    "  --acceptlines=y   Display the last y 'accept' lines, default $DEFAULTACCEPTLINES\n" .
    "  --failurelines=z  Display the last z 'FAILURE' lines, default $DEFAULTFAILURELINES\n" .
    "  --removecolour    Don't display colour in the accept and failure lines\n" .
    "  --help            Display this help\n\n" .
    "Enjoy. BokkyPooBah 2016.\n\n" .
    "Stopped"
  if defined $help;

$hashlines = $DEFAULTHASHLINES
  unless defined $hashlines;
$acceptlines = $DEFAULTACCEPTLINES
  unless defined $acceptlines;
$failurelines = $DEFAULTFAILURELINES
  unless defined $failurelines;

my (@hashlinearray, @acceptlinearray, @failurelinearray) = ((), (), ());
while (<>) {
  if (/(\d\d:\d\d:\d\d.\d\d\d).*:\s(\d+).*=\s(\d+).*\/\s(\d+\.\d+)/) {
    push @hashlinearray, $_;
    shift @hashlinearray
      if ($#hashlinearray >= $hashlines);
  } elsif (/accept/) {
    push @acceptlinearray, $_;
    shift @acceptlinearray
      if ($#acceptlinearray >= $acceptlines);
  } elsif (/FAILURE/) {
    push @failurelinearray, $_;
    shift @failurelinearray
      if ($#failurelinearray >= $failurelines);
  }
}

my ($totalhashes, $totalperiod) = (0, 0);
my ($lasttime) = ();
foreach (@hashlinearray) {
  if (/(\d\d:\d\d:\d\d.\d\d\d).*:\s(\d+).*=\s(\d+).*\/\s(\d+\.\d+)/) {
    my ($time, $rate, $hashes, $period) = $_ =~ /(\d\d:\d\d:\d\d.\d\d\d).*:\s(\d+).*=\s(\d+).*\/\s(\d+\.\d+)/;
    $totalhashes += $hashes;
    $totalperiod += $period;
    $lasttime = $time;
  }
}

foreach (@acceptlinearray) {
  s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g
    if defined $removecolour;
  print;
}

foreach (@failurelinearray) {
  s/\x1b\[[0-9;]*m//g
    if defined $removecolour;
  print;
}

if ($totalperiod > 0) {
  my $averagehashrate = $totalhashes / $totalperiod / 1000 / 1000;
  printf "%s %.3f MH/s\n", $lasttime, $averagehashrate;
} else {
  print "No statistics\n";
}

Sample Usage

user@Kumquat:~$ calcHashrate --help
Usage: calcHashrate [options]

 where the options are:
  --hashlines=x     Calculate average hashrate over the last x lines, default 1000
  --acceptlines=y   Display the last y 'accept' lines, default 4
  --failurelines=z  Display the last z 'FAILURE' lines, default 4
  --removecolour    Don't display colour in the accept and failure lines
  --help            Display this help

Enjoy. BokkyPooBah 2016.

Stopped at ./calcHashrate line 18.

Run the script with the default settings, calculating the average hashrate over the last 1,000 lines, show up to 4 accept lines and show up to 4 FAILURE lines. The line at the bottom shows the last hashrate time and the average hashrate in megahashes per second.

user@Kumquat:~$ calcHashrate logs/ethminer.log --removecolour
  ℹ  21:24:12.221|ethminer  B-) Submitted and accepted.
  ℹ  21:24:14.671|ethminer  B-) Submitted and accepted.
  ℹ  21:24:17.519|ethminer  B-) Submitted and accepted.
  ℹ  21:24:30.835|ethminer  B-) Submitted and accepted.
  ✘  18:11:00.367|ethminer  FAILURE: GPU gave incorrect result!
  ✘  18:41:12.725|ethminer  FAILURE: GPU gave incorrect result!
  ✘  20:03:32.135|ethminer  FAILURE: GPU gave incorrect result!
  ✘  20:23:53.048|ethminer  FAILURE: GPU gave incorrect result!
21:25:04.239 62.619 MH/s

Run the script to just display the hashrate over the last 1,000 hashrate lines.

user@Kumquat:~$ calcHashrate ethminer.log --acceptlines=0 --failurelines=0
21:25:04.239 62.619 MH/s

When 2 blocks are generated at the same time, the agreement on which block is the "winner" depends on the next block.

If there's blocks b1 and b2 for height H, the block that is mined at H+1 determines which of b1 and b2 is on the main chain. If H+1 built on b1, then b1 is the block; if the miner mining the block at H+1 instead chose b2, then b2 is the block on the main chain.

The community agrees on the "longest" chain. Sometimes there are multiple chains of equal length, and that's why it can be important to wait for a number of block confirmations, before considering that a transaction will not be undone by a chain reorganization.