Added in 3.1.6. Adding Users

http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/2/html/Management_Console_Installation_Guide/chap-Management_Console_Installation_Guide-Configuration.html#sect-Management_Console_Installation_Guide-Configuring_Cumin-Adding_User

Red_Hat_Enterprise_MRG-Management_Console_Installation_Guide-2-en-US-2-1

In the recent reorg of the book, we had as a goal a streamlined install and config process with as little "noise" as possible and only essential instructions for end users in the main text with other information pushed off into an appendix.

The reason is that based on feedback from the field, users were frustrated or confused by optional settings or "extra" information.  The prevailing opinion seemed to be "Just the facts, ma'am, please"

In that light, this content on max_connections should probably be in an appendix "Tuning the Cumin Database".

Also, there is a sibling release note to this one that covers setting max_fsm_pages.  I thought I had posted that one, too, but it should also be in a database appendix.  My mistake, I will post the link forthwith.

(In reply to comment #1)
> Added in 3.1.6. Adding Users

Here is the original BZ for the aditional release note on max_fsm_pages.  The note can be found in the MRG Release Notes version 2.

https://bugzilla.redhat.com/show_bug.cgi?id=699859

Okay, thanks for the clarification on appendix-appropriate content.

I've moved the max_connections content to Appendix A4. Tuning the Cumin Database. Please also review the max_fsm_pages section, I've rearranged the content but hopefully haven't altered the meaning.

http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/2/html/Management_Console_Installation_Guide/sect-Management_Console_Installation_Guide-Medium_Deployment_Configuration-Tuning_Cumin_DB.html

Red_Hat_Enterprise_MRG-Management_Console_Installation_Guide-2-en-US-2-2

It looks right to me, thanks

(In reply to comment #4)
> Okay, thanks for the clarification on appendix-appropriate content.
> 
> I've moved the max_connections content to Appendix A4. Tuning the Cumin
> Database. Please also review the max_fsm_pages section, I've rearranged the
> content but hopefully haven't altered the meaning.
> 
> http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/2/html/Management_Console_Installation_Guide/sect-Management_Console_Installation_Guide-Medium_Deployment_Configuration-Tuning_Cumin_DB.html
> 
> Red_Hat_Enterprise_MRG-Management_Console_Installation_Guide-2-en-US-2-2

Missed this on first review.  

The opening few sentences here are misleading -- the number of concurrent users supported by the MRG Management Console is really related to page update speeds.  Multiple cumin-web instances can be run to allow for larger numbers of users while still retaining quick update speeds.  This is covered in section A.1.

What this section is talking about is the number of simultaneous connections that the backing database supports.  The number of connections used by cumin will be a function of the number of cumin-web and cumin-data processes that are running, NOT the number of users actually logged in to cumin through a web browser.

So, max_connections is ultimately related to the number of concurrent users cumin can support, but only indirectly in so far as it impacts the number of cumin-web instances that can be run successfully.

This is why the original release note spoke strictly in terms of database connections.  

I suggest something like this for this section (shifted around a bit) -- the meaning in the first 2 paragraphs must be preserved in the final cut:

"The max_connections parameter controls the number of simultaneous database connections allowed by the PostgreSQL server; the default value is 100. The value must be large enough to support the cumin-web and cumin-data processes that make up the MRG Management Console.

It is a good idea to check the value of this parameter if the MRG Managmenet Console is configured to run multiple cumin-web instances (section A.1) or other applications besides Cumin use the same PostgreSQL server.

The maximum number of concurrent connections needed by Cumin can be estimated with the following formula: 

(formula goes here)

For a default configuration this number will be 43 but running multiple cumin-web instances will increase the number significantly.

If you receive the error message OperationalError: FATAL: sorry, too many clients already in the user interface, or contained in a cumin log file, this means that the available database connections were exhausted and a Cumin operation failed. 

To change the allowed number of database connections, edit the /var/lib/pgsql/data/postgresql.conf file and set the max_connections parameter.  The PostgreSQL server must be restarted for this change to take effect."

** Important -- max_fsm_pages section only applies to RHEL 5 **

It turns out that in PostgreSQL version 8.4, the code related to free space management was rewritten.  There is no max_fsm_pages in 8.4.x, the procedure in the MCIG will not apply in those cases.

RHEL 6 carries a version of Postgres > 8.4, so the max_fsm_pages section will not apply to those customers.  We need to flag this as RHEL 5 only.

Fixed max_connections section according to comment 6.

As for max_fsm_pages, I added an admonition as below:

"The following procedure is only applicable on a Red Hat Enterprise Linux 5 operating system, in which the PostgreSQL 8.4 database is in use. Red Hat Enterprise Linux 6 carries a later version of PostgreSQL, in which the max_fsm_pages parameter is no longer valid."

Please edit for technical accuracy, thank you. 

http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/2/html/Management_Console_Installation_Guide/sect-Management_Console_Installation_Guide-Medium_Deployment_Configuration-Tuning_Cumin_DB.html

Thanks Cheryn,

  max_connections looks good, thanks.

  max_fsm_pages looks good, with one tiny tweak -- RHEL 5 uses PostgreSQL 8.1

Sorry, my fault for not specifying the RHEL 5 version specifically in my comment.  The rewrite did actually happen in 8.4, true, but there is a gap between el5 and el6 versions.

Changed the PostgreSQL version number to 8.1.

Red_Hat_Enterprise_MRG-Management_Console_Installation_Guide-2-en-US-2-6

- checked:
  - commands
  - PostgreSQL versions
  - configuration file
  - text

VERIFIED