Hi,

The SQL Server 2005 has wonderfool features (databse mirroring) for high
available solutions.
What features of the SSAS can help us to buid high avalable solution. Are
there these features ever?

Thanks,
Vladimir Chtepa

The following article is for AS2k, but I believe a lot of the concepts
still apply to SSAS:

Creating Large-Scale, Highly Available OLAP Sites
================================================== =
http://www.microsoft.com/downloads/d...9989a445-142b-
4872-ac68-2b50f05228e2&displaylang=en

Mirroring is not applicable to SSAS as it is not a transactional system,
but an NLB scenario can give you even higher availability than you would
get from mirroring on the relational database.

SSAS is also fully "cluster aware" and now that it has named instances
it can also support Active/Active clusters.

--
Regards
Darren Gosbell [MCSD]
Blog: http://www.geekswithblogs.net/darrengosbell

In article <O14Vmhn7FHA.2384 (AT) TK2MSFTNGP12 (DOT) phx.gbl>, vc.nospam@diacom-
systemhaus.nospam.de says...

Hi Darren,

1. The handling of AS2K by "Creating Large-Scale, Highly Available OLAP
Sites" is pretty awkward. I would expect more cushy solution with SSAS. Is
there any changing with SSAS related to it?

2. If SSAS runs with activated write back it is really transactional system.

3. I do not undestand your comment related to "cluster aware" in conjunction
with ability of SSAS to run named instance.
Could you please explain it in detail.

thanks,
Vladimir Chtepa

"Darren Gosbell" <jam (AT) newsgroups (DOT) nospam> schrieb im Newsbeitrag
news:MPG.1dec5c831faeb8759897e0 (AT) news (DOT) microsoft.com...

Hi Vladimir and Darren,

There are definitely some new high availability features in AS 2005, as
outlined in this Flash Tip:

http://www.microsoft.com/technet/abo...sh/tips/tips_1
01205.mspx

Flash Tip: High Availability in Analysis Services
By Carl Rabeler, carl (AT) solidqualitylearning (DOT) com

Q: How can I get high availability when using Analysis Services?

A: A typical approach to high availability in Microsoft SQL Server 2000
Analysis Services is to use Windows Network Load Balancing (NLB) to
distribute user queries across multiple Analysis Services instances on
disparate machines while also increasing availability. You keep the
databases on these machines in sync with file-based backup and restore
(required for large databases due to the 2-GB .cab file size limitation)
from a secondary server on which cube and dimension processing is
performed. For more information, read the Microsoft white paper
"Creating Large-Scale, Highly Available OLAP Sites."

Even though SQL Server 2000 Analysis Services isn't cluster aware, you
can cluster an Analysis Services 2000 database. SQL Server 2005 Analysis
Services is cluster aware and fully supports active/active clustering,
which means you can create a failover cluster to ensure high
availability. In addition, Analysis Services 2005 has a
server-synchronization feature, which lets you incrementally synchronize
metadata and data changes between a source database and a destination
(production) database while users continue to query the destination
database.

Unlike Analysis Services 2000, with Analysis Services 2005 you can't
simply copy the data files from the data folder of an Analysis Services
2005 instance on one machine to the data folder on another machine.
These files are encrypted by default (using the machine name as part of
the key) unless you modify the .config file to change the
RequiredProtectionLevel setting from 1 to 0.
...

If you have access to the SQL PASS site, there was a good sesion in
Sept. 2005, which covered this:

http://ew.sqlpass.org/ew/pass/displa...onference_id=1
1&event_id=1301
Security

Thierry D'Hers , Microsoft

Abstract:

The next version of Analysis Services has a lot of new functionality
that makes it easier to manage large scale BI applications. This
presentation will focus on the new DDL (data definition language),
scripting, trace and profiling. New innovative features for
troubleshooting Analysis Services will be also be covered. We will
discuss support for clustering, multi-instancing, as well as a new
feature that allows replicating Analysis Services databases.
...

- Deepak

Deepak Puri
Microsoft MVP - SQL Server

*** Sent via Developersdex http://www.developersdex.com ***

The references Deepak posted to this thread have a couple of new
enhancements, one that jumps out being the automatic synchronisation of
metadata.

Well, yes and no. SSAS still stores the writeback data in a table in
relational server. So if you want high availability in a writeback
scenario you need to setup high availability for SSAS and the relational
engine.

AS2k could be run on a cluster, but there were quite a few manual steps
involved in setting it up. Being cluster aware means that there are less
manual steps involved (and hence a lot less chances of getting things
wrong)

Named instances only really help when you have an Active/Active cluster.
You can then have cluster/AS1 and cluster/AS2 which appear as 2
different AS servers. These virtual servers could be running on separate
nodes or both on the one node if a failover has occurred. In AS2k there
is only one default instance so you could not run AS2k in an
Active/Active configuration.

--
Regards
Darren Gosbell [MCSD]
Blog: http://www.geekswithblogs.net/darrengosbell

In article <e0JNx3q7FHA.3044 (AT) TK2MSFTNGP10 (DOT) phx.gbl>, vc.nospam@diacom-
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