pt-table-checksum reports diffs on timestamp columns in 5.5 vs 5.6

Hi, I have tried to reproduce it with Master(5.5) and Slave (5.6) but unable to found any differences for timestamp column.
Can you please provide exact steps to reproduce it?

Master:

mysql> show create table test \G
*************************** 1. row ***************************
       Table: test
Create Table: CREATE TABLE `test` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(10) DEFAULT NULL,
  `bdate` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

mysql> select version();
+-------------------------+
| version() |
+-------------------------+
| 5.5.36-34.2-rel34.2-log |
+-------------------------+
1 row in set (0.00 sec)

mysql>

Slave:

mysql> select version();
+----------------+
| version() |
+----------------+
| 5.6.15-rel63.0 |
+----------------+
1 row in set (0.00 sec)

mysql>

nilnandan@nilnandan-Dell-XPS:~$ pt-table-checksum --socket=/tmp/mysql_sandbox5536.sock --recursion-method=DSN=h=localhost,D=percona,t=dsns --databases=nil
            TS ERRORS DIFFS ROWS CHUNKS SKIPPED TIME TABLE
08-05T16:03:18 0 0 2904 4 0 0.160 nil.test
nilnandan@nilnandan-Dell-XPS:~$

Looks like it might be specific to the datetime column type. Use this create table statement instead.

CREATE TABLE `test` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(10) DEFAULT NULL,
  `bdate` datetime NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1

Ignore the last comment. It had been a little while since I encountered this issue and I forgot what caused it. I think it is a bit more complicated than just a column of type timestamp. I will look into how to reproduce it.

Ok, I think I see why you didn't see the issue and I did. What function are you using to hash with? I am using FNV_64. I ran some tests and I don't see the issue if i use the CRC32 has function.

Do you need anything else from me?

[Expired for Percona Toolkit because there has been no activity for 60 days.]

Hi Joe,

Just noticed you "bumped" this issue.
There's a chance this will get fixed along with: https://bugs.launchpad.net/percona-toolkit/+bug/1388870

I'm attaching a patch for pt-tabl-checksum from that fix.
Please try it out if you have a chance.

Regards

That will probably work.

I just noticed that the link in the original bug description was referencing the 'head' revision. I have updated the link to the correct revision so it once again points to the correct line.

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PT-649