PT-1667 Added replication channels support to pt-archiver

bin/pt-archiver

@@ -6275,6 +6275,7 @@ sub main {
          OptionParser => $o,
          DSNParser    => $dp,
          Quoter       => $q,
+         channel      => $o->get('channel'),
       );
       # we get each slave's connection handler (and its id, for debug and reporting)
       for my $slave (@$lag_slaves_dsn) {
@@ -7472,6 +7473,18 @@ If C<LOAD DATA LOCAL INFILE> throws an error in the lines of C<The used
 command is not allowed with this MySQL version>, refer to the documentation
 for the C<L> DSN option.
 
+=item --channel
+
+type: string
+
+Channel name used when connected to a server using replication channels.
+Suppose you have two masters, master_a at port 12345, master_b at port 1236 and
+a slave connected to both masters using channels chan_master_a and chan_master_b.
+If you want to run pt-archiver to syncronize the slave against master_a, pt-archiver
+won't be able to determine what's the correct master since SHOW SLAVE STATUS
+will return 2 rows. In this case, you can use --channel=chan_master_a to specify
+the channel name to use in the SHOW SLAVE STATUS command.
+
 =item --charset
 
 short form: -A; type: string

t/pt-archiver/archive_using_channels.t

@@ -0,0 +1,113 @@
+#!/usr/bin/env perl
+
+BEGIN {
+   die "The PERCONA_TOOLKIT_BRANCH environment variable is not set.\n"
+      unless $ENV{PERCONA_TOOLKIT_BRANCH} && -d $ENV{PERCONA_TOOLKIT_BRANCH};
+   unshift @INC, "$ENV{PERCONA_TOOLKIT_BRANCH}/lib";
+};
+
+use strict;
+use warnings FATAL => 'all';
+use English qw(-no_match_vars);
+use Test::More;
+
+use PerconaTest;
+use Sandbox;
+require "$trunk/bin/pt-archiver";
+
+my $dp = new DSNParser(opts=>$dsn_opts);
+my $sb = new Sandbox(basedir => '/tmp', DSNParser => $dp);
+my $master_dbh = $sb->get_dbh_for('master');
+my $slave_dbh  = $sb->get_dbh_for('slave1'); 
+
+if ( !$master_dbh ) {
+   plan skip_all => 'Cannot connect to sandbox master';
+}
+elsif ( !$slave_dbh ) {
+   plan skip_all => 'Cannot connect to sandbox slave';
+} elsif ($sandbox_version lt '5.7') {
+   plan skip_all => 'Only on MySQL 5.7+';
+} else {
+   plan tests => 5;
+}
+
+my ($master1_dbh, $master1_dsn) = $sb->start_sandbox(
+   server => 'chan_master1',
+   type   => 'master',
+);
+my ($master2_dbh, $master2_dsn) = $sb->start_sandbox(
+   server => 'chan_master2',
+   type   => 'master',
+);
+my ($slave1_dbh, $slave1_dsn) = $sb->start_sandbox(
+   server => 'chan_slave1',
+   type   => 'master',
+);
+my $slave1_port = $sb->port_for('chan_slave1');
+
+$sb->load_file('chan_master1', "sandbox/gtid_on.sql", undef, no_wait => 1);
+$sb->load_file('chan_master2', "sandbox/gtid_on.sql", undef, no_wait => 1);
+$sb->load_file('chan_slave1', "sandbox/slave_channels.sql", undef, no_wait => 1);
+
+my $master1_port = $sb->port_for('chan_master1');
+my $num_rows = 40000;
+
+# Load some rows into masters 1 & 2.
+$sb->load_file('chan_master1', "t/pt-archiver/samples/channels.sql", undef, no_wait => 1);
+
+diag("Loading $num_rows into the test.t1 table on first master. This might take some time.");
+diag(`util/mysql_random_data_load --host=127.0.0.1 --port=$master1_port --user=msandbox --password=msandbox test t1 $num_rows`);
+diag("$num_rows rows loaded. Starting tests.");
+$master_dbh->do("FLUSH TABLES");
+
+my $rows = $master1_dbh->selectrow_arrayref('SELECT COUNT(*) FROM test.t1 ');
+
+is(
+    @$rows[0],
+    $num_rows,
+    "All rows were loaded into master 1",
+);
+
+my @args = ('--source', $master1_dsn.',D=test,t=t1', '--purge', '--where', sprintf('id >= %d', $num_rows / 2), '--check-slave-lag', $slave1_dsn);
+
+my ($exit_status, $output);
+
+$output = output(
+   sub { $exit_status = pt_archiver::main(@args) },
+   stderr => 1,
+);
+
+isnt(
+    $exit_status,
+    0,
+    'Must specify a channel name',
+);
+
+like (
+    $output,
+    qr/"channel" was not specified/,
+    'Message saying channel name must be specified'
+);
+
+push @args, ('--channel', 'masterchan1');
+
+output(
+   sub { $exit_status = pt_archiver::main(@args, '--channel', 'masterchan1') },
+   stderr => 1,
+);
+
+is(
+    $exit_status,
+    0,
+    'Ok if channel name was specified',
+);
+
+$sb->stop_sandbox(qw(chan_master1 chan_master2 chan_slave1));
+
+
+# #############################################################################
+# Done.
+# #############################################################################
+$sb->wipe_clean($master_dbh);
+ok($sb->ok(), "Sandbox servers") or BAIL_OUT(__FILE__ . " broke the sandbox");
+exit;

t/pt-archiver/samples/channels.sql

@@ -0,0 +1,6 @@
+DROP DATABASE IF EXISTS test;
+CREATE DATABASE test;
+CREATE TABLE test.t1 (
+    id INT PRIMARY KEY AUTO_INCREMENT,
+    f2 VARCHAR(25)
+) Engine=InnoDB;