Details
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Bug
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Status: Done
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High
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Resolution: Fixed
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None
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None
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None
Description
I am testing pt-table-checksum and this test is failing: t/pt-table-checksum/ignore_columns.t
If you have a sandbox with at least a master and a slave, you can reproduce the problem as follow:
I am going to assume the master is running on port 12345 and the slave is at port 12346
On the master, run:
CREATE DATABASE IF NOT EXISTS test;
USE test;
DROP TABLE IF EXISTS `issue_94`;
CREATE TABLE `issue_94` (
a INT NOT NULL,
b INT NOT NULL,
c CHAR(16) NOT NULL,
INDEX idx (a)
);
INSERT INTO issue_94 VALUES
(1,2,'apple'),
(3,4,'banana'),
(5,6,'kiwi'),
(7,8,'orange'),
(9,10,'grape'),
(11,12,'coconut');
So, on the master and on the slave, you will have these rows:
mysql --port=12345 -e "SELECT * FROM test.issue_94"
+----+----+---------+ | a | b | c | +----+----+---------+ | 1 | 2 | apple | | 3 | 4 | banana | | 5 | 6 | kiwi | | 7 | 8 | orange | | 9 | 10 | grape | | 11 | 12 | coconut | +----+----+---------+
On the slave run: update test.issue_94 set c=''
and now on the slave you will have the column c empty on all rows:
mysql --port=12346 -e "SELECT * FROM test.issue_94"
+----+-----+--+
| a | b | c |
+----+----+---+
| 1 | 2 | |
| 3 | 4 | |
| 5 | 6 | |
| 7 | 8 | |
| 9 | 10 | |
| 11 | 12 | |
+----+----+---+
The problem starts here:
If you run pt-table-checksum, checksumming all columns, produces this output
bin/pt-table-checksum h=127.0.0.1,P=12345,u=msandbox,p=msandbox -d test -t issue_94
Checking if all tables can be checksummed ...
Starting checksum ...
TS ERRORS DIFFS ROWS DIFF_ROWS CHUNKS SKIPPED TIME TABLE
05-08T15:57:51 0 1 6 0 1 0 0.094 test.issue_94
which is correct.
Then re-run pt-table-checksum ignoring column c:
bin/pt-table-checksum h=127.0.0.1,P=12345,u=msandbox,p=msandbox -d test -t issue_94 --ignore-columns c
Checking if all tables can be checksummed ...
Starting checksum ...
TS ERRORS DIFFS ROWS DIFF_ROWS CHUNKS SKIPPED TIME TABLE
05-08T15:57:54 0 1 6 0 1 0 0.033 test.issue_94
As you can see, it says DIFFS 1 which is incorrect since the column c was ignored and all other columns have the same values.
If you run again
bin/pt-table-checksum h=127.0.0.1,P=12345,u=msandbox,p=msandbox -d test -t issue_94 --ignore-columns c
it shows the correct value, DIFFS 0 but if you re-run pt-table-checksum WITHOUT ignoring the column c, the result will be invalid again, until you re-run the 2 twice with or without --ignore-columns c
It seems like the first time is somehow getting an old value and re-running the program it gets the correct values.
