From b2bf471e7d79534a6b0f0df09525f9d494420cb8 Mon Sep 17 00:00:00 2001
From: Frank Cizmich <frank.cizmich@percona.com>
Date: Thu, 31 Jul 2014 18:26:45 -0300
Subject: [PATCH] modified RowChecksum module and updated it in
 pt-table-checksum (only tool that uses it)

---
 bin/pt-table-checksum | 29 +++++++++++++++--------------
 lib/RowChecksum.pm    | 39 ++++++++++++++++++++++++++-------------
 2 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/bin/pt-table-checksum b/bin/pt-table-checksum
index 31143ee1..940c2cfe 100755
--- a/bin/pt-table-checksum
+++ b/bin/pt-table-checksum
@@ -5977,9 +5977,10 @@ sub find_replication_differences {
    }
    my ($dbh, $repl_table) = @args{@required_args};
 
-   my $ts_clause = $self->{start_ts} ? " AND ts >= '$self->{start_ts}' " : ''; # issue 1311654
+  
+   my $ts_clause = $self->{start_ts} ? " AND ts >= '$self->{start_ts}' " : ''; # only check rows created in this run 
+   my $tries = 5;  # try again up to five times if replication checksum don't agree. 
    my $ok_to_leave = 0;
-   my $tries = 5;  # number of times to try again if replication checksum don't agree. 
    my $diffs;
    do {
       my $sql
@@ -5993,16 +5994,15 @@ sub find_replication_differences {
          . "WHERE (master_cnt <> this_cnt OR master_crc <> this_crc "
          .        "OR ISNULL(master_crc) <> ISNULL(this_crc)) $ts_clause"
          . ($args{where} ? " AND ($args{where})" : "");
-         PTDEBUG && _d($sql);
-         $diffs = $dbh->selectall_arrayref($sql, { Slice => {} });
-         $tries--;
-         if (@$diffs) { 
-            sleep 1;
-         } else {
-            $ok_to_leave = 1;
-         }
-
-      } until ($ok_to_leave || !$tries);
+      PTDEBUG && _d($sql);
+      $diffs = $dbh->selectall_arrayref($sql, { Slice => {} });
+      $tries--;
+      if (@$diffs) { 
+         sleep 1;
+      } else {
+         $ok_to_leave = 1;
+      }
+   } until ($ok_to_leave || !$tries);
    return $diffs;
 }
 
@@ -8978,8 +8978,9 @@ sub main {
    $print_header = 1;
    $exit_status  = 0;
 
-   $start_ts = full_ts(); # issue 1311654
-   PTDEBUG && _d("initial start_ts: [$start_ts]");
+   # get start time
+   $start_ts = full_ts(); 
+   PTDEBUG && _d("initial start_ts: $start_ts");
 
    # ########################################################################
    # Get configuration information.
diff --git a/lib/RowChecksum.pm b/lib/RowChecksum.pm
index c567c19b..ff3d9e83 100644
--- a/lib/RowChecksum.pm
+++ b/lib/RowChecksum.pm
@@ -459,19 +459,32 @@ sub find_replication_differences {
    }
    my ($dbh, $repl_table) = @args{@required_args};
 
-   my $sql
-      = "SELECT CONCAT(db, '.', tbl) AS `table`, "
-      . "chunk, chunk_index, lower_boundary, upper_boundary, "
-      . "COALESCE(this_cnt-master_cnt, 0) AS cnt_diff, "
-      . "COALESCE("
-      .   "this_crc <> master_crc OR ISNULL(master_crc) <> ISNULL(this_crc), 0"
-      . ") AS crc_diff, this_cnt, master_cnt, this_crc, master_crc "
-      . "FROM $repl_table "
-      . "WHERE (master_cnt <> this_cnt OR master_crc <> this_crc "
-      .        "OR ISNULL(master_crc) <> ISNULL(this_crc))"
-      . ($args{where} ? " AND ($args{where})" : "");
-   PTDEBUG && _d($sql);
-   my $diffs = $dbh->selectall_arrayref($sql, { Slice => {} });
+  
+   my $ts_clause = $self->{start_ts} ? " AND ts >= '$self->{start_ts}' " : ''; # only check rows created in this run 
+   my $tries = 5;  # try again up to five times if replication checksum don't agree. 
+   my $ok_to_leave = 0;
+   my $diffs;
+   do {
+      my $sql
+         = "SELECT CONCAT(db, '.', tbl) AS `table`, "
+         . "chunk, chunk_index, lower_boundary, upper_boundary, "
+         . "COALESCE(this_cnt-master_cnt, 0) AS cnt_diff, "
+         . "COALESCE("
+         .   "this_crc <> master_crc OR ISNULL(master_crc) <> ISNULL(this_crc), 0"
+         . ") AS crc_diff, this_cnt, master_cnt, this_crc, master_crc "
+         . "FROM $repl_table "
+         . "WHERE (master_cnt <> this_cnt OR master_crc <> this_crc "
+         .        "OR ISNULL(master_crc) <> ISNULL(this_crc)) $ts_clause"
+         . ($args{where} ? " AND ($args{where})" : "");
+      PTDEBUG && _d($sql);
+      $diffs = $dbh->selectall_arrayref($sql, { Slice => {} });
+      $tries--;
+      if (@$diffs) { 
+         sleep 1;
+      } else {
+         $ok_to_leave = 1;
+      }
+   } until ($ok_to_leave || !$tries);
    return $diffs;
 }