Test that pt-kill reconnects using new util/kill-mysql-process. Fix optional DSN by adding magical options rule.

bin/pt-kill

@@ -4086,6 +4086,7 @@ sub main {
                   eval {
                      $dbh      = $cxn->connect();
                      $proc_sth = $dbh->prepare('SHOW FULL PROCESSLIST');
+                     msg('Reconnected to ' . $cxn->name());
                   };
                   return 1 unless $EVAL_ERROR; # try again
                }
@@ -4102,6 +4103,7 @@ sub main {
       my $kill_sth = $dbh->prepare($kill_sql);
       $kill = sub {
          my ($id) = @_;
+         PTDEBUG && _d('Killing process', $id);
          return $retry->retry(
             try => sub {
                return $kill_sth->execute($id);
@@ -4116,6 +4118,7 @@ sub main {
                   eval {
                      $dbh      = $cxn->connect();
                      $kill_sth = $dbh->prepare($kill_sql);
+                     msg('Reconnected to ' . $cxn->name());
                   };
                   return 1 unless $EVAL_ERROR; # try again
                }
@@ -4371,16 +4374,6 @@ sub main {
 # Subroutines.
 # ############################################################################
 
-sub get_cxn {
-   my ( $dp, $dsn, $ac ) = @_;
-   if ( $o->get('ask-pass') ) {
-      $dsn->{p} = OptionParser::prompt_noecho("Enter password: "); 
-   }
-   my $dbh = $dp->get_dbh($dp->get_cxn_params($dsn), {AutoCommit => $ac});
-   $dbh->{InactiveDestroy} = 1; # Because of forking.
-   return $dbh;
-}
-
 # Forks and detaches from parent to execute the given command;
 # does not block parent.
 sub exec_cmd {
@@ -4604,6 +4597,9 @@ L<"--kill"> and L<"--kill-query"> are mutually exclusive.
 
 L<"--daemonize"> and L<"--test-matching"> are mutually exclusive.
 
+This tool accepts additional command-line arguments.  Refer to the
+L<"SYNOPSIS"> and usage information for details.
+
 =over
 
 =item --ask-pass
@@ -4626,6 +4622,12 @@ type: Array
 Read this comma-separated list of config files; if specified, this must be the
 first option on the command line.
 
+=item --database
+
+short form: -D; type: string
+
+The database to use for the connection.
+
 =item --daemonize
 
 Fork to the background and detach from the shell.  POSIX operating systems

t/pt-kill/basics.t

@@ -4,6 +4,7 @@ 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";
+   $ENV{PERCONA_TOOLKIT_TEST_USE_DSN_NAMES} = 1;
 };
 
 use strict;
@@ -25,7 +26,7 @@ if ( !$master_dbh ) {
    plan skip_all => 'Cannot connect to sandbox master';
 }
 else {
-   plan tests => 4;
+   plan tests => 6;
 }
 
 my $output;
@@ -79,6 +80,32 @@ like(
    '--verbose'
 );
 
+# #############################################################################
+# Reconnect if cxn lost.
+# #############################################################################
+$master_dbh->do("CREATE DATABASE IF NOT EXISTS pt_kill_test");
+
+system(qq($trunk/util/kill-mysql-process db=pt_kill_test wait=2 &));
+
+$output = output(
+   sub { pt_kill::main('-F', $cnf, qw(-D pt_kill_test),
+      qw(--run-time 4 --interval 1 --print --verbose)) },
+   stderr => 1,
+);
+
+like(
+   $output,
+   qr/Reconnected/,
+   "kill-mysql-process says it reconnected"
+);
+
+my $n_checks =()= $output =~ m/Checking processlist/g;
+is(
+   $n_checks,
+   4,
+   "pt-kill still checked the processlist 4 times"
+) or diag($output);
+
 # #############################################################################
 # Done.
 # #############################################################################

t/pt-kill/kill.t

@@ -41,7 +41,7 @@ my $cnf='/tmp/12345/my.sandbox.cnf';
 
 # Shell out to a sleep(10) query and try to capture the query.
 # Backticks don't work here.
-system("/tmp/12345/use -h127.1 -P12345 -umsandbox -pmsandbox -e 'select sleep(4)' >/dev/null&");
+system("/tmp/12345/use -h127.1 -P12345 -umsandbox -pmsandbox -e 'select sleep(4)' >/dev/null 2>&1 &");
 sleep 0.5;
 my $rows = $dbh->selectall_hashref('show processlist', 'id');
 my $pid;

util/kill-mysql-process

@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+
+# This script helps test that tools reconnect to MySQL.  Its meant to be ran
+# in the background like system(qq($trunk/util/kill-mysql-process DB)) where
+# DB is the name of special "tracer" database used to isolate the test in
+# the process list.  So, do something like CREATE DATABASE pt_kill_test, then
+# run the test with D=pt_kill_test (presuming pt_kill_test is unique to
+# the test).  This script will then kill any and all processes that are using
+# the pt_kill_test db.
+#
+# Exits 0 if the tracer db is observed and procs are killed, else exits 1.
+
+use strict;
+use warnings FATAL => 'all';
+use Time::HiRes qw(sleep time);
+
+if ( !@ARGV || @ARGV < 1 || @ARGV > 3 ) {
+   print STDERR "Usage: kill-mysql-process OPTION=VALUE\n";
+   print STDERR "Options: db, wait, runtime, interval\n";
+   exit 1;
+}
+
+my %opt = map { my ($op, $val) = split '=', $_; $op => $val; } @ARGV;
+
+$opt{db}       ||= 'tracer_db';
+$opt{runtime}  ||= 5.0;
+$opt{interval} ||= 0.2;
+
+sleep $opt{wait} if $opt{wait};
+
+my $t_start = time;
+while ( time - $t_start < $opt{runtime} ) {
+   my $procs = `/tmp/12345/use -ss -e "show processlist" | grep $opt{db} | cut -f1`;
+   if ( $procs && $procs =~ /\d/ ) {
+      foreach my $proc ( split "\n", $procs ) {
+         chomp $proc;
+         `/tmp/12345/use -e "KILL $proc"`;
+      }
+      exit 0;
+   }
+   sleep $opt{interval};
+}
+
+exit 1;