Created attachment 914443 [details]
[R|W separation] There is a query action happened on master db when invoke TestCaseRun.attach_bug method.

Description of problem:
as summary.

Version-Release number of selected component (if applicable):
v3.8.9-1 on test server.

How reproducible:
100%

Steps to Reproduce:
1.Invoke TestCaseRun.attach_bug method like:
n.TestCaseRun.attach_bug({
    'case_run_id': 5376601,
    'bug_id': 22222,
    'bug_system_id': 1,
    'summary': 'Testing TCMS',
    'description': 'qiyang test',
})
2.Check whether there is query action happened on master db. 

Actual results:
There is a query action happened on master db, like:
| 2014-07-03 18:45:34 | nitrate[nitrate] @ tcms-test.app.eng.nay.redhat.com [10.66.78.233] |       318 |     10133 | Query        | SELECT `test_case_bugs`.`id`, `test_case_bugs`.`bug_id`, `test_case_bugs`.`case_run_id`, `test_case_bugs`.`case_id`, `test_case_bugs`.`bug_system_id`, `test_case_bugs`.`summary`, `test_case_bugs`.`description` FROM `test_case_bugs` WHERE (`test_case_bugs`.`case_id` = 46490  AND `test_case_bugs`.`case_id` = 46490  AND `test_case_bugs`.`bug_id` = '22222'  AND `test_case_bugs`.`description` = 'qiyang test'  AND `test_case_bugs`.`summary` = 'Testing TCMS'  AND `test_case_bugs`.`bug_system_id` = 1  AND `test_case_bugs`.`case_run_id` = 5376601 ) |

Expected results:
There is no query action happened on master db.

Additional info: