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Add --[no]analyze-before-rename to pt-osc to workaround MySQL 5.6 gotcha wrt InnoDB persistent optimizer stats.

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Daniel Nichter
2015-10-28 11:34:37 -07:00
parent e1d495a10a
commit 82902be3c8
1 changed files with 68 additions and 0 deletions
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68
bin/pt-online-schema-change
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@@ -8171,6 +8171,26 @@ sub main {
# http://bugs.mysql.com/bug.php?id=45694
my $lock_in_share_mode = $server_version < '5.1' ? 0 : 1;
# ########################################################################
# Check if analyze-before-rename is necessary
# Set it on if so, unless user explicitly negated the option (value = 0)
# issue: https://bugs.launchpad.net/percona-toolkit/+bug/1491261
# ########################################################################
if ( !$o->got('analyze-before-rename') || $o->get('analyze-before-rename') ne '0' ) {
if ( $server_version >= '5.6' ) {
my (undef, $innodb_stats_persistent) = $cxn->dbh->selectrow_array("SHOW VARIABLES LIKE 'innodb_stats_persistent'");
if ($innodb_stats_persistent eq 'ON') {
# server is vulnerable to bad query plans for a while
# after table rename or drop_swap. Automatically setting
# analyze-before-rename ON
PTDEBUG && _d('innodb_stats_peristent is ON. Turning on --analyze-before-rename');
$o->set('analyze-before-rename', 1);
}
}
}
# set it to zero if it's 'no' , so we can test it easier later on
$o->get('analyze-before-rename') eq 'no' && $o->set('analyze-before-rename', 0);
# ########################################################################
# Create --plugin.
# ########################################################################
@@ -9573,6 +9593,7 @@ sub validate_tries {
copy_rows
swap_tables
update_foreign_keys
analyze_table
);
my %user_tries;
my $user_tries = $o->get('tries');
@@ -9961,6 +9982,24 @@ sub swap_tables {
$truncated_table_name);
$table_name = $truncated_table_name;
}
# if requested, perform ANALYZE TABLE before renaming
# to update table statistics.
if ( $o->get('analyze-before-rename') ) {
print ts("Analyzing new table...\n");
my $sql_analyze = "ANALYZE TABLE $new_tbl->{name} /* run by pt-online-schema-change */";
osc_retry(
Cxn => $cxn,
Retry => $retry,
tries => $tries->{analyze_table},
stats => $stats,
code => sub {
PTDEBUG && _d($sql_analyze);
$cxn->dbh()->do($sql_analyze);
},
);
}
my $sql = "RENAME TABLE $orig_tbl->{name} "
. "TO " . $q->quote($orig_tbl->{db}, $table_name)
. ", $new_tbl->{name} TO $orig_tbl->{name}";
@@ -10286,6 +10325,21 @@ sub drop_swap {
print ts("Drop-swapping tables...\n");
}
if ( $o->get('analyze-before-rename') ) {
print ts("Analyzing new table...\n");
my $sql_analyze = "ANALYZE TABLE $new_tbl->{name} /* run by pt-online-schema-change */";
osc_retry(
Cxn => $cxn,
Retry => $retry,
tries => $tries->{analyze_table},
stats => $stats,
code => sub {
PTDEBUG && _d($sql_analyze);
$cxn->dbh()->do($sql_analyze);
},
);
}
my @sqls = (
"SET foreign_key_checks=0",
"DROP TABLE IF EXISTS $orig_tbl->{name}",
@@ -10497,6 +10551,7 @@ sub osc_retry {
foreach my $arg ( @required_args ) {
die "I need a $arg argument" unless $args{$arg};
}
my $cxn = $args{Cxn};
my $retry = $args{Retry};
my $tries = $args{tries};
@@ -11053,6 +11108,18 @@ tool's built-in functionality if desired.
=back
=item --[no]analyze-before-rename
default: no
Execute ANALYZE TABLE on new table before swaping with the old one.
This is to circunvent a 5.6 design issue where if C<innodb_stats_persistent>
is enabled (default is yes) then the new table will have no statistics for a
while. On a busy server this can result in many queries executed with poor plans
(i.e FULL TABLE SCANS) possibly bogging down the server.
This option will be turned on automatically if the conditions described above
are met, unless it is explicitly negated (i.e --no-analyze-before-rename).
=item --ask-pass
Prompt for a password when connecting to MySQL.
@@ -11592,6 +11659,7 @@ MAGIC_tries
copy_rows 10 0.25
swap_tables 10 1
update_foreign_keys 10 1
analyze_table 10 1
To change the defaults, specify the new values like: