Exchange Queue Length

Exchange Queue length indicates two types of exchange database log file queues

• Copy queue length (logs) - (CQL)  Indicates the number of log files waiting to be copied and inspected.
• Replay queue length (logs) - (RQL)  Indicates the number of log files waiting to be replayed into this copy of the database.

During regular operations, the Microsoft Exchange Information Store service (store.exe) and the Microsoft Exchange Replication service (msexchangerepl.exe) on DAG members hosting an active database copy write two values to the cluster registry at HKLM\Cluster\ExchangeActiveManager\LastLog:

• DatabaseGUID with a decimal value representing the last log generated by the active copy
• DatabaseGUID_TIME with the system time of when that log file was generated 
   
  These values are written to the cluster registry on the server hosting the active copy, and native cluster registry replication is used to propagate this information to all other DAG members. DAG members that host a passive copy of the database use this information (the last log file generated by the active copy) along with information about the last log file replicated to the passive copy, to determine the CQL for the database copy. Thus, it is critical that all DAG members have up-to-date values, as the CQL is used by Active Manager to evaluating whether or not to mount a database in response to a failover.
  
  If replay queue length is greater than 6 then  EMC database switchover will fail in the replay lag check you need to perform switchover from command line in this case
  
  This example performs a switchover of the database DB4 to the Mailbox server MBX5. In this example, the database copy on MBX5 has a replay queue greater than 6
  
  

  Move-ActiveMailboxDatabase DB4 MBX5 -SkipLagChecks

  In this example, a copy of the database DB4 hosted on MBX3 is activated and mounted as the new active mailbox database. This command makes DB4 the new active mailbox database and it doesn't override the database mount dial settings on MBX3.
  

  Move-ActiveMailboxDatabase DB4 -ActivateOnServer MBX3 

  -MountDialOverride:None
  

  
  This example performs a switchover of the database DB2 to the Mailbox server MBX1. When the command completes, MBX1 hosts the active copy of DB2. Because the MountDialOverride parameter is set to None, MBX1 mounts the database using its own defined database auto mount dial settings.
  

  Move-ActiveMailboxDatabase DB2 -ActivateOnServer MBX1 -MountDialOverride:None
  

  This example performs a switchover of the database DB1 to the Mailbox server MBX3. When the command completes, MBX3 hosts the active copy of DB1. Because the MountDialOverride parameter is specified with a value of Good Availability, MBX3 mounts the database using a database auto mount dial setting of GoodAvailability.
  

  Move-ActiveMailboxDatabase DB1 -ActivateOnServer MBX3 

  -MountDialOverride:GoodAvailability
  

  
  This example performs a switchover of the database DB3 to the Mailbox server MBX4. When the command completes, MBX4 hosts the active copy of DB3. Because the MountDialOverride parameter isn't specified, MBX4 mounts the database using a database auto mount dial setting of Lossless.
  

  Move-ActiveMailboxDatabase DB3 -ActivateOnServer MBX4
  

  
  This example performs a server switchover for the Mailbox server MBX1. All active mailbox database copies on MBX1 will be activated on one or more other Mailbox servers with healthy copies of the active databases on MBX1.
  

  Move-ActiveMailboxDatabase -Server MBX1
  

  
  
  This example performs a switchover of the database DB5 to the Mailbox server MBX6. In this example, the database copy on MBX6 has a ContentIndexState of Failed. As a result, the SkipClientExperienceChecks parameter must be specified to activate the database copy on MBX6.
  

  Move-ActiveMailboxDatabase DB5 MBX6 -SkipClientExperienceChecks
  

  
  

Updating Exchange 2010 DAG Nodes

When i upgraded first it was an Exchange 2010 RTM  CAS HUB MBX server and upgrade to SP2 directly from RTM was pretty strait forward and went successfull without any hassle.

Here i am outlining the process from RTM to SP1 and SP1 to SP2

1. Upgrading from Exchange 2010 RTM to SP1:

What is new in MS Exchange 2013

Exchange Administration Center: The EAC brings to mind the quote, "You're riding it, dude!" Yes, I cannot help but think of the line from "Finding Nemo" whenever I think of the new admin console for Exchange. But seriously, the GUI-based EMC (Exchange Management Console) and the Web-based ECP (Exchange Control Panel) are being replaced by a single Web-based UI that is, frankly, my least favorite of all the new Exchange 2013 features. I don't like Web-based consoles for administration; they always feel clunky and unfriendly. Plus, it has that Metro look, which leaves me cold. We'll see if I can get used to it.

Exchange architecture revisions: Exchange 2007 and 2010 are broken into five server roles, mainly to address performance issues like CPU performance, which would suffer if Exchange were running as one monolothic application. But Microsoft has made progress on the performance side, so Exchange 2013 has just two roles: Client Access server role and Mailbox server role. The Mailbox server role includes all the typical server components (including unified messaging), and the Client Access server role handles all the authentication, redirection, and proxy services. Gone is the Edge Transport role, but you can deploy Exchange 2013 with an Exchange 2010 Edge Transport server role.

A new managed store: The store service has been completely rewritten in managed code (C#). Although this change bodes well in terms of higher availability and resiliency, it doesn't mean the ESE (Extensible Storage Engine) database engine has been replaced with SQL, as many admins would like. Exchange 2013 continues to use ESE as the database engine. But now each database runs in its own dedicated worker process, so a hung process in one database will not cause problems in other databases. Fast Search (an add-on to SharePoint 2010) is also integrated into the managed store for improved search and indexing.

Modernized public folders: Rather than just getting rid of public folders (something promised for future releases), Microsoft has embraced them once again. They are no longer managed through the separate Public Folder Management Console; instead, they are managed via the EAC. That makes them public folder mailboxes, which means they use regular mailbox databases. In turn, this means they can be made part of a data availability group for disaster recovery.

Lots o' PowerShell cmdlets: Although 13 cmdlets have been removed (many having to do with the old public folder management), Exchange 2013 brims with 187 new PowerShell cmdlets. That may not be the final tally when the final version ships next year, but it shows that command-line management tools are still growing. I wasn't kidding years back when I told everyone to learn PowerShell. It's not going away.

DLP (data loss prevention): DLP is new in Exchange 2013's transport rules, but it's also a continuation of Mail Tips in that it warns users when they may be violating policies meant to prevent disclosure of sensitive data. Such disclosures are usually inadvertent, so the use of DLP-fired reminders lets users be aware when they are putting something like a credit card number or Social Security number in an email. The built-in DLP policies are based on regulatory standards like PCI.

Outlook Web Access enhancements: The whole of OWA is redesigned -- yay! One awesome feature is support for offline access, which lets users write messages in their browser when offline, then have the messages delivered when they connect to the Internet. OWA supports this feature in Microsoft's Internet Explorer 10, Apple's Safari 5, and Google's Chrome 16 (or later), all of which support the HTML5 local data storage feature. There's also a new set of UI layouts that users can choose from for desktop, tablet, and smartphone use -- a smart approach.

Built-in antimalware: Exchange has had antispam capabilities for quite some time; as of Exchange 2007 you could even choose whether to turn on antispam in the Edge role or in the Hub Transport role. Exchange 2013 extends antispam to a broader set of antimalware capabilities, such as to block phishing attempts.
In addition to these highly visible changes, Exchange 2013 will also show improvements in high availability and site resilience with DAG, as well as in its unified messaging capabilities, but no large overhauls are expected in those areas.
For Exchange admins who work with the GUI management console daily, the biggest challenge will be the new Web-based UI. But whatever your feelings are about Web-based consoles, I believe you'll like the overall changes in Exchange 2013, especially with enhanced integration with SharePoint and Lync 2013.