Bug #40843 | Issues when multiple mysql instances with 'ibmdb2i' interact with DB2 | ||
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Submitted: | 19 Nov 2008 9:00 | Modified: | 20 Aug 2009 12:28 |
Reporter: | Nidhi Shrotriya | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Documentation | Severity: | S3 (Non-critical) |
Version: | 5.1.29rc | OS: | Other (IBM i) |
Assigned to: | MC Brown | CPU Architecture: | Any |
[19 Nov 2008 9:00]
Nidhi Shrotriya
[24 Nov 2008 10:07]
Nidhi Shrotriya
From MySQL server log: ibmdb2i error 2021: See message MCH3401 in joblog for job 144225/QUSER/QSQSRVR.
[1 Apr 2009 9:23]
Nidhi Shrotriya
IBM's Response: is working as designed. As documented, will need IASPs to truly separate the different instances of MySQL. If you do have IASPs configured, you can set the MySQL ibmdb2i_rdb_name option with the name of the IASP. This will cause the IBMDB2I engine to communicate with the specified user database. One caveat to note is that, while multiple user databases can have schemas with an identical name, a user database cannot contain a schema name that also exists in the system database.
[14 Apr 2009 6:59]
Nidhi Shrotriya
The documentation talks about running multiple mysql server instances (and not always strictly using IASPs for that). It doesn't seem to be suggesting the mishappenings that could happen due to using multiple MySQL server instances without IASPs. From IBMRedBook- Security: You may want to maintain multiple MySQL databases that are totally independent from each other in all aspects. Although you may be able to do this with one MySQL server instance, using separated MySQL server instances can be a more robust way for such a purpose. Catering for different globally scoped MySQL environments: You may encounter a situation where you cannot or should not mix multiple MySQL databases within one MySQL server instance due to conflicting requirements such as: – Using different IBM i independent ASP (IASP): For example, if you want to create and maintain two MySQL databases in two different IASPs for some reasons (which is controlled by the IBMDB2I system variable named ibmdb2i_rdb_name), you can run two instances of MySQL server with each using a different IASP to serve this purpose. I believe the documentation while mentioning about using multiple MySQL server instances without IASPs should cover this, as this is also an available option and scenarios mentioned here can rise.
[20 Apr 2009 10:43]
Nidhi Shrotriya
Same issue occurs while multiple server instances using 1 IASP. Hence the bug could be reproduced with the following 2 scenarios Multiple server instances using no IASP. Multiple server instances using same IASP. The documentation should mention about the data security/inconsistency possibility for the above 2 cases and hence different IASPs should strictly be used with different server instances. I guess, this could be documented in IBMRedbook as well as in MySQL Doc.
[15 May 2009 7:19]
Nidhi Shrotriya
Setting it to documentation based on IBM(Timothy Clark)'s response - We could add it to the MySQL reference material and IBM would take care of it as below - I think you have raised some valid documentation concerns. I do not believe that experienced IBM i users will be surprised by the interaction between multiple MySQL instances, but I can see how users who are less familiar with the platform would find additional documentation helpful. Because the IBM Redbook is a printed publication, we cannot easily update it. However, we are working to publish a web page with Redbook errata and additions, and I can add this information there.
[20 Aug 2009 12:28]
MC Brown
A note has been added intot he DB2 Notes section that highlights the issues and how to get round them by using separate IASPs.