From 4d2560c24c87d31e6449fdc368e4d2a14625465c Mon Sep 17 00:00:00 2001
From: "Brian Fraser fraserb@gmail.com" <>
Date: Wed, 6 Jun 2012 12:21:26 -0300
Subject: [PATCH 1/3] pt-osc: Wait for the slaves to replicate the table before
 working on them.

---
 bin/pt-online-schema-change | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index a0a8a99b..d38cb3e6 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -5680,6 +5680,18 @@ sub main {
             PTDEBUG && _d('Getting table row estimate on replicas');
             my @too_large;
             foreach my $slave ( @$slaves ) {
+               PTDEBUG && _d('Waiting until', $slave->name(),
+                             'replicates the table');
+               my $slave_has_repl_table;
+               do {
+                  sleep 0.5;
+                  $slave_has_repl_table = $tp->check_table(
+                     dbh => $slave->dbh(),
+                     db  => $tbl->{db},
+                     tbl => $tbl->{tbl}
+                  );
+               } while ( !$slave_has_repl_table );
+
                my ($n_rows) = NibbleIterator::get_row_estimate(
                   Cxn   => $slave,
                   tbl   => $tbl,

From 02eb9b7a0a8937a408de42d0a07eb67e4744b7f9 Mon Sep 17 00:00:00 2001
From: "Brian Fraser fraserb@gmail.com" <>
Date: Wed, 6 Jun 2012 13:28:59 -0300
Subject: [PATCH 2/3] Moved the slave replication wait to execute earlier

---
 bin/pt-online-schema-change | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index d38cb3e6..697f25d8 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -5546,6 +5546,20 @@ sub main {
       }
    };
 
+   for my $slave (@$slaves) {
+      PTDEBUG && _d('Waiting until', $slave->name(),
+                     'replicates the table');
+      my $slave_has_repl_table;
+      do {
+         $slave_has_repl_table = $tp->check_table(
+            dbh => $slave->dbh(),
+            db  => $new_tbl->{db},
+            tbl => $new_tbl->{tbl},
+         );
+         sleep 0.5 unless $slave_has_repl_table;
+      } while ( !$slave_has_repl_table );
+   }
+
    # #####################################################################
    # Step 2: Alter the new, empty table.  This should be very quick,
    # or die if the user specified a bad alter statement.
@@ -5680,18 +5694,6 @@ sub main {
             PTDEBUG && _d('Getting table row estimate on replicas');
             my @too_large;
             foreach my $slave ( @$slaves ) {
-               PTDEBUG && _d('Waiting until', $slave->name(),
-                             'replicates the table');
-               my $slave_has_repl_table;
-               do {
-                  sleep 0.5;
-                  $slave_has_repl_table = $tp->check_table(
-                     dbh => $slave->dbh(),
-                     db  => $tbl->{db},
-                     tbl => $tbl->{tbl}
-                  );
-               } while ( !$slave_has_repl_table );
-
                my ($n_rows) = NibbleIterator::get_row_estimate(
                   Cxn   => $slave,
                   tbl   => $tbl,

From 000fdd86b84f41a838a5e6a869170582117051ea Mon Sep 17 00:00:00 2001
From: "Brian Fraser fraserb@gmail.com" <>
Date: Wed, 6 Jun 2012 13:36:53 -0300
Subject: [PATCH 3/3] pt-osc: Nicer waiting code

---
 bin/pt-online-schema-change | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index 697f25d8..37ffca7f 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -5549,15 +5549,11 @@ sub main {
    for my $slave (@$slaves) {
       PTDEBUG && _d('Waiting until', $slave->name(),
                      'replicates the table');
-      my $slave_has_repl_table;
-      do {
-         $slave_has_repl_table = $tp->check_table(
-            dbh => $slave->dbh(),
-            db  => $new_tbl->{db},
-            tbl => $new_tbl->{tbl},
-         );
-         sleep 0.5 unless $slave_has_repl_table;
-      } while ( !$slave_has_repl_table );
+      sleep 0.5 while ! $tp->check_table(
+                           dbh => $slave->dbh(),
+                           db  => $new_tbl->{db},
+                           tbl => $new_tbl->{tbl}
+                      );
    }
 
    # #####################################################################