Solved

SQL - What is an SQL Instance?  What is an SQL Cluster?  Are these related?

Posted on 2014-03-10
6
508 Views
Last Modified: 2014-03-25
What is an SQL instance?
What is an SQL cluster?
The web descriptions are not really clear and don't  give any examples!!!
0
Comment
Question by:brothertruffle880
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
6 Comments
 
LVL 22

Assisted Solution

by:Matt V
Matt V earned 375 total points
ID: 39917924
A SQL instance is a single install of SQL.  It is installed in it's own folder.
An example would be installing SQL 2000 and then installing SQL 2008 into a new folder.  Both are still running, and each is an instance.  You can also install multiple instances of the same version by specifying a new folder for each install.

A SQL cluster is a Microsoft cluster that also runs SQL server.  The SQL instances are clustered into an active-passive (active fails, other node takes over) or active-active (both nodes are active at the same time).
0
 
LVL 22

Assisted Solution

by:65td
65td earned 125 total points
ID: 39919040
A single SQL instance in cluster would have it's own IP address, network name and disk(s) and could only be run as an active/passive cluster.

Multiple instances of SQL which own (again) have it's own network name , ip address and disk(s), could be run as an active/active SQL cluster.
0
 

Author Comment

by:brothertruffle880
ID: 39920341
What is the rationale for having multiple instances rather than just creating copies of a database? or creating another SQL Server?
I'm trying to determine when to create an instance versus when to just copy the database or install SQL server all over again in a different box?

The answers I found on the web are a bit hazy on the rationale for setting up instances of SQL.
0
Edgartown IT Case Study

Learn about Edgartown's quest to ensure the safety and security of the entire town's employee and citizen data. Read the case study!

 
LVL 22

Assisted Solution

by:Matt V
Matt V earned 375 total points
ID: 39920578
If you have a very powerful server, you can do processor based licensing and install multiple instances on one server instead of licensing multiple physical servers.

You can also install mutiple versions as different instances if you have version requirements for your applications.

Usually it is for utilizing hardware better or consolodating licenses.
0
 

Author Comment

by:brothertruffle880
ID: 39934485
Hi 65TD:

What is an Active/Passive cluster?
When would you use it?

BT
0
 
LVL 22

Accepted Solution

by:
Matt V earned 375 total points
ID: 39934604
Active/Passive means that all the databases reside on one server (active) and only fail over to the other server (passive) if the active one goes down.

This is done to save licencing.  You only need the SQL enterprise licence for the active node in this scenario.

This provides some fault tolerance (you are back up quicker than complete hardware failure of one server), without the additional licencing costs.

You can also migrate the databases from the active to the passive node for patching.  As long as you only have databases on one node you are still properly licenced.
0

Featured Post

Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

These days, all we hear about hacktivists took down so and so websites and retrieved thousands of user’s data. One of the techniques to get unauthorized access to database is by performing SQL injection. This article is quite lengthy which gives bas…
Recently, Microsoft released a best-practice guide for securing Active Directory. It's a whopping 300+ pages long. Those of us tasked with securing our company’s databases and systems would, ideally, have time to devote to learning the ins and outs…
Video by: Steve
Using examples as well as descriptions, step through each of the common simple join types, explaining differences in syntax, differences in expected outputs and showing how the queries run along with the actual outputs based upon a simple set of dem…
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…

739 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question