MySQL Bugs: #34486: Problem setting falcon_record_chill_threshold and falcon_index_chill

Bug #34486	Problem setting falcon_record_chill_threshold and falcon_index_chill_threshold
Submitted:	12 Feb 2008 10:50	Modified:	18 Oct 2008 15:24
Reporter:	Philip Stoev	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Falcon storage engine	Severity:	S3 (Non-critical)
Version:	6.0-BK	OS:	Any
Assigned to:	Vladislav Vaintroub	CPU Architecture:	Any

Description:
Those two Falcon configuration options:

falcon_record_chill_threshold
falcon_index_chill_threshold 

are listed as dynamic in the manual, page http://dev.mysql.com/doc/refman/6.0/en/se-falcon-configuration.html, however using SET GLOBAL on them does not result in the new values being visible in SHOW VARIABLES.

How to repeat:
mysql> SET GLOBAL falcon_index_chill_threshold = 1;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like '%chill%';
+-------------------------------+-------+
| Variable_name                 | Value |
+-------------------------------+-------+
| falcon_index_chill_threshold  | 4     |
| falcon_record_chill_threshold | 5     |
+-------------------------------+-------+
2 rows in set (0.01 sec)

Suggested fix:
If those options are not settable at runtime, then please reflect this in the manual. The error message should be like this:

mysql> set global falcon_debug_server = 1;
ERROR 1238 (HY000): Variable 'falcon_debug_server' is a read only variable

Verified as described.

[11:59] root@(none)>SET GLOBAL falcon_index_chill_threshold = 50;

[11:59] root@(none)>show variables like '%chill%';
+-------------------------------+-------+
| Variable_name                 | Value |
+-------------------------------+-------+
| falcon_index_chill_threshold  | 4     |
| falcon_record_chill_threshold | 5     |
+-------------------------------+-------+
2 rows in set (0.03 sec)       

[12:00] root@(none)>select @@GLOBAL.falcon_index_chill_threshold;
+---------------------------------------+
| @@GLOBAL.falcon_index_chill_threshold |
+---------------------------------------+
|                                     4 |
+---------------------------------------+
1 row in set (0.00 sec)

Vlad, Please look into this problem. It is similar to 33041.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/42896

ChangeSet@1.2822, 2008-02-23 09:14:00+01:00, vvaintroub@wva. +7 -0
  Isolation level should be set before
  starting a transaction.
  ---
  Bug#34486 : falcon_index_chill_threshold, falcon_record_chill_threshold 
  cannot be set.
  
  Solved by passing new values down to Configuration.

Using StorageHandler::dictionaryConnection is a good approach to getting the values set in database->configuration.

Pushed into 6.0.4-alpha

Fix is in 6.0.5-alpha.

Documented bugfix in the 6.0.5 manual as follows:

        SET GLOBAL falcon_record_chill_threshold and SET GLOBAL
        falcon_index_chill_threshold did not work.