Rich Olivieri,

SharePoint Architect, MicroLink LLC

rolivieri@microlinkllc.com

Redundancy and Availability “Redundancy refers to the use of multiple servers in a

load-balanced environment for any of several purposes, such as to improve farm performance, to scale out to accommodate additional users, and to improve availability.”

“Availability is a more specialized concept that refers to a multiple-server environment that is designed to accept connections and operate normally even when one or more of the servers in the farm are not operational.”

- http://technet.microsoft.com/en-us/library/cc263044.aspx

SharePoint 2007 RedundancyApplication Server Role Can be Redundant?

Web Role Yes

Query Role Yes

Index Service Role No*

Windows SharePoint Services 3.0 Search

No

Excel Calculation Services Yes

Number of Nines

Acceptable uptime

percentage

Downtime

per day

Downtime

per month

Downtime

per year

95 72.00 minutes 36 hours 18.26 days

99 14.40 minutes 7 hours 3.65 days

99.9 86.40 seconds 43 minutes 8.77 hours

99.99 8.64 seconds 4 minutes 52.60 minutes

99.999 0.86 seconds 26 seconds 5.26 minutes

http://technet.microsoft.com/en-us/library/cc748824.aspx

Availability Requirements

Recovery Time Objective (RTO). RTO is the allowable duration that an application can be down.

Recovery Point Objective (RPO). RPO is the amount of data loss that the customer can tolerate.

-http://technet.microsoft.com/en-us/library/cc531332.aspx

Cannot Connect to …. The dreaded “Cannot connect to the database

server…or configuration database…”

SQL Clustering – availability at the SQL instance

SQL Mirroring – availability at the database.

* Mirroring available with SQL 2005 SP1

Demo: SQL Mirroring and SQL Alias

References

Database Mirroring Best Practices and Performance Considerations. Microsoft(r) TechNet. [Online] March 10, 2006. [Cited: 10 09, 2008.] http://www.microsoft.com/technet/prodtechnol/sql/2005/technologies/dbm_best_pract.mspx.

Case Study of High Availability for SharePoint using Database Mirroring (white paper). Microsoft TechNet. [Online] April 2008. [Cited: September 22, 2008.] http://technet.microsoft.com/en-us/library/cc531332.aspx.

Microsoft. How to transfer the logins and the passwords between instances of SQL Server 2005. Microsoft Help and Support. [Online] July 11, 2006. [Cited: October 13, 2008.] http://support.microsoft.com/kb/918992/.

Microsoft. Using Database Mirroring with Office SharePoint Server and Windows SharePoint Services. Microsoft TechNet. [Online] July 24, 2008. [Cited: October 13, 298.] http://technet.microsoft.com/en-us/library/cc262910.aspx.

Talmage, Ron. Database Mirroring in SQL Server 2005. Microsoft TechNet. [Online] April 1, 2005. [Cited: October 14, 2008.] http://www.microsoft.com/technet/prodtechnol/sql/2005/dbmirror.mspx.

Microsoft. Setting Up Login Accounts for Database Mirroring. MSDN: SQL Server Developer Center. [Online] September 2007. [Cited: October 14, 2008.] http://msdn.microsoft.com/en-us/library/ms366346(SQL.90).aspx.

Curry, Ben and English, Bill. Microsoft Office SharePoint Server 2007 Best Practices. Redmond: Microsoft Press, 2008.

Plan for redundancy (Office SharePoint Server). Microsoft TechNet. [Online] July 15, 2008. [Cited: September 22, 2008.] http://technet.microsoft.com/en-us/library/cc263044.aspx.

Plan for availability (Office SharePoint Server). Microsoft TechNet. [Online] September 5, 2008. [Cited: September 22, 2008.] http://technet.microsoft.com/en-us/library/cc748824.aspx.