Hi,
I'm testing Oracle RAC (10.2.0.4 64bit on 2 nodes Linux RHEL5 x86-64) with some failure scenarios.
I stress the database with :
- 100 users connections on a service.
- For all TAF is enabled with at SESSION level with BASIC method
- Connetions are Load balanced across 2 instances :
select inst_id, count(username) from gv$session where username not in ('SYS', 'SYSTEM') and username is not null group by inst_id;
INST_ID COUNT(USERNAME)
---------- ---------------
1 51
2 49
When I shutdown a node I can (sometimes) see that some sessions are not reconnected on surviving instance :
INST_ID COUNT(USERNAME)
---------- ---------------
2 76 <--<< 24 sessions are missing !
When I checking surviving instance alert.log I can see that same number of "GCS Shadows" are closed :
...
* dead instance detected - domain 0 invalid = TRUE
Communication channels reestablished
Master broadcasted resource hash value bitmaps
Non-local Process blocks cleaned out
Fri Apr 17 16:00:11 2009
LMS 0: 14 GCS shadows cancelled, 11 closed <--<<
Fri Apr 17 16:00:11 2009
LMS 1: 13 GCS shadows cancelled, 13 closed <--<<
Set master node info
...
1. The "GCS shadows cancelled, XX closed" alert.log entries seem match my missing number of sessions. Is that true ?
2. I know what GCS is but but I don't understand why it occurs. Any clue ?
Thanks for help
Tom
[Updated on: Fri, 17 April 2009 09:29]
Report message to a moderator
] 
Blog
Search
Help
Members
Register
Login
Home
