Mirroring: what happens if principal loses contact with both mirror and wittness?

Posted by TiborKaraszi on SQL Blog See other posts from SQL Blog or by TiborKaraszi
Published on Fri, 16 Apr 2010 05:46:00 GMT Indexed on 2010/04/16 6:14 UTC
Read the original article Hit count: 249

Filed under:

availability

Imagine a database mirroring setup where you have two LANs with a WAN link in between. Let's call them site A and site B. Say that principal is currently in site A, and both mirror and witness are in site B. I.e., we are running database mirroring with a witness, and assuming we are running safety FULL (synchronous), we have auto-fail over. Now, what is really fail over when it comes to mirroring? the simple answer is that the mirror will finish the recovery process (UNDO) and make the database available....(read more)

Related posts about availability

AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using AlwaysOn Availability Groups

as seen on SQL Server Central - Search for 'SQL Server Central'
SQL Server 2012 AlwaysOn Availability Groups provides a unified high availability and disaster recovery (HADR) solution that improves upon legacy functionality previously found across disparate features. Prior to SQL Server 2012, several customers used database mirroring to provide local high availability… >>> More
High Availability - "Keeping Active"

as seen on Oracle Technology Network - Search for 'Oracle Technology Network'
Use Oracle Active Data Guard to set up a physical standby database for reporting and recovery. >>> More
Stratus: Where High-Availability Leads to Profitability

as seen on Internet.com - Search for 'Internet.com'
Server Snapshot: Stratus' fault-tolerant servers are designed to fill a clearly defined niche. Its positioning as the "availability company" has set it apart from the OEM Rat Pack and resulted in steady growth. >>> More
Stratus: Where High-Availability Leads to Profitability

as seen on Internet.com - Search for 'Internet.com'
Server Snapshot: Stratus' fault-tolerant servers are designed to fill a clearly defined niche. Its positioning as the "availability company" has set it apart from the OEM Rat Pack and resulted in steady growth. >>> More
Availability Best Practices on Oracle VM Server for SPARC

as seen on Oracle Blogs - Search for 'Oracle Blogs'
This is the first of a series of blog posts on configuring Oracle VM Server for SPARC (also called Logical Domains) for availability. This series will show how to how to plan for availability, improve serviceability, avoid single points of failure, and provide resiliency against hardware and software… >>> More

Developer IT