[Postgres-xc-bugs] backup/restore problem using BARRIER

[Hitoshi H. <hem...@la...>]

Hi folks,

This is a backup/restore problem assuming we understand
the BARRIER feature properly.


============================================================================
POSTGRES-XC BUG REPORT TEMPLATE
============================================================================

Your name : Hitoshi Hemmi
Your email address : hem...@la...


System Configuration:
---------------------
Architecture : x86_64

Operating Systems :
A. CentOS release 6.2 x86_64
B. RHEL5.7 x86_64
We tried in two environments. See also "Compilers"

Postgres-XC version : Postgres-XC 1.0beta2

Compilers used :
A. gcc (GCC) 4.4.6 20110731 (Red Hat 4.4.6-3)
B. gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-51)

Description of problems:
==============================================
We tested online backup/restore feature using BARRIER,
and found anomalies in restored serial values.

(Outline of procedure)
0. Setup all coordinators and datanodes for online backups.

1. Create a table via coordinator:
# CREATE TABLE tbl(I serial, j int);

2. First dataload via coordinator:
# INSERT INTO tbl(j) VALUES (generate_series(1,10));

3. Base backup of all coordinators and datanodes:
$ pg_basebackup -h localhost -p xxxx -D /xxxx

4. Second dataload via coordinator:
　# INSERT INTO tbl(j) VALUES (generate_series(11,20));

5. Install BARRIER via coordinator:
　# CREATE BARRIER 'test';

6. Archive WALs for all coordinators and datanodes:
　# SELECT pg_start_backup('xxx');
　# SELECT pg_stop_backup();

7. Third dataload via coordinator:
　# INSERT INTO tbl(j) VALUES (generate_series(21, 30));

8. Stop all coordinators and datanodes.

9. Discard existing database cluster, and resore base backups.

10. create recovery.conf for all coordinators and datanodes.

11. Start datanodes and coordinators.

12. Issue SELECT * ... and observe the result:
testdb=# SELECT * FROM tbl ORDER BY i;
i | j
----+----
1 | 1
2 | 2
3 | 3
4 | 4
5 | 5
6 | 6
7 | 7
8 | 8
9 | 9
10 | 10
12 | 11
13 | 12
14 | 13
15 | 14
16 | 15
17 | 16
18 | 17
19 | 18
20 | 19
21 | 20
(20 rows)

*** Please note the displacement.

==============================================

Thanks

-- 
Hitoshi HEMMI
NTT Open Source Software Center
hem...@la...
(Please note that my address has changed.)
Tel:(03)5860-5115
Fax:(03)5463-5490