Operating Mode is an feature of AR System introduced in 9.1.02 Release. its called as Operating mode.
Why was Operating Mode needed ?
When upgrading the server, CMDB, or any AR applications, background processes can slow down that upgrade and switching of operation ownership because of server restart during upgrades. BMC make some recommendations in documentation and/or white papers suggesting customers make some configuration changes before running an upgrade. Some of the product installers perform configuration changes as well.Instead of relying on manual changes or each installer making changes themselves, it would be better if the installers could put the server into an upgrade mode and it would take care of this. So every release BMC add a new capability to the upgrade mode rather than updating lots of documentation or installers.
Operating mode helps two things to drive
- Helped in solving many of the BMC install/upgrade problems
- Also helped in a feature called Zero Down Time upgrade (ZDT).
Who consumes Operating Mode?
All BMC Platform Installers ( AR Server , Atrium Core , Atrium Integrator) and Apps Installers ( ITSM , SRM , SLM) puts the server in Operating mode before installer starts any activity and puts it back to normal mode once its done. Internally Installer call SSI to set/re-set the server in operating mode
Some insights on server info
Possible values (integer):
OPERATING_MODE_NORMAL, 0- normal mode, default, how the server runs today
OPERATING_MODE_UPGRADE_PRIMARY, 1- upgrade mode for the primary server
OPERATING_MODE_UPGRADE_SECONDARY, 2- upgrade mode for secondary servers
By default server runs in normal mode and value is 0. when the install/upgrade is happening on primary server , the operating value is set to 1 ( it will disable few thing which we will talk it later ) , when the install/upgrade is happening on non-primary server(s) the operating mode is set to 2 ( as of now in 9.1.02,9.1.03 and 9.1.04 it does not disable any of the feature , because non-primary server upgrades are all about replacement of file system)
What kind of install/upgrade sets server in Operating mode?
- Fresh installation does not uses operating mode
- DB(Accelerated) only upgrade does not uses operating mode
- Only normal upgrades uses this feature.
What are the features that get disabled when server is set in Operating mode ?
Following operation are disabled on the current server when Operating mode is set.
- Hierarchical groups ( processing of bulk compute because of group hierarchy change or form level property change )
- Object reservation
- FTS Indexing
- Atrium Integrator
- Service Failover
- Server event recording
- SLM Collector
- Approval Server
- Reconciliation Engine
- Atrium Integration Engine
- Business Rules Engine
- Assignment Engine
- E-Mail Engine
- The server will disable signals, just like
- The server only uses AR authentication, just like setting
- The server turns off the global attachment size restriction, just like setting
0does. (A customer may have set the maximum attachment config value to restrict the size of attachments to something like 10 MB. The apps installers need to import some DVF plugins that may be larger than that, so we temporarily turn off the restriction when in upgrade mode.)
- New in 9.1.03 - The server removes any server side limit on the maximum number of entries returned in a query, just like setting AR_SERVER_INFO_MAX_ENTRIES (configuration file item Max-Entries-Per-Query) to 0 does.
- New in 9.1.03 - The server removes any server side limit on the maximum number of menu items returned in a query, just like setting configuration file item Max-Entries-Per-Search-Menu to 0 does
- New in 9.1.03 - The server removes any attachment security validation, just like if there were no inclusion or exclusion lists specified and no validation plug-in specified.
Does the parameter gets changed when server goes in Operating mode ?
No , AR Server internally takes care of disabling parameter , for example if upgrade mode wants to disable escalation , it does not set the Disable-Escalation : T / F in ar.conf , AR Server internally set this parameter off.
What modification are done to AR System Server Group Operation Ranking form ?
If the server is in a server group, Server will change entries in the "AR System Server Group Operation Ranking" form to change the server's behaviour.
For example there are 2 server ( primary server and secondary Server )
Below tables explains what happens when primary server is set in upgrade mode and reset to normal mode.
When Upgrade is Set
When Upgrade mode is reset
|Atrium Integration Engine||1||null||1|
|Business Rule Engine||1||null||1|
|Atrium Integration Engine||2||2||2|
|Business Rule Engine||2||2||2|
So from above table , Primary Serve Administration ranking is not set to null ( or Empty ) and rest of non-primary server Administration ranking are set to null ( or empty ) , by doing this it helps to retain the administration rights with the primary server which is getting upgrade and hence failover of administration rights does not fail over to non-primary server (which was earlier ranked as 2 ). this helps during ZDT upgrades where secondary servers are up and running.
Where does operating mode takes the back-up of ranking information ?
In 9.1.02 & 9.1.03 , backup of all ranking information was stored in ar.conf
In 9.1.04 and onwards , a new field called "Operation backup" on AR System Server Group Operation Ranking will be having back-up
What changes where made to reset operating mode in 91SP4 upgrade installer ?
- Pre 9.1.04 ( i.e. 9.1.02 and 9.1.03) :- Individual installer like AR System use to set the upgrade mode before start of the installation and reset once the installation was done.
- In 9.1.04 :- AR upgrade installer will set the server in upgrade mode and before ending installation, AR installer checks if CMDB component exists. If CMDB doesn't exist, AR installer itself sends SSI call to reset Operating-Mode to 0. If there is CMDB, AR installer doesn't reset the Operating-Mode
- In 9.1.04 :-CMDB upgrade installer - before ending installation, CMDB installer checks if AI component exists. If AI doesn't exist, CMDB installer itself sends SSI call to reset Operating-Mode to 0. If there is AI, CMDB installer doesn't reset the Operating-Mode.
- AI upgrade installer always resets Operating-Mode to 0 on completion
- Apps installer does it individually
Does installer reset operating mode in case installer fails
Yes in all cases either installation is successful or failure , installer re-set the operating mode , but there are chances where installer might not re-set it back , in that case we have to reset it back to normal mode using SSI.
Hope this helps to know few things related to upgrade mode.