Redundant Setup to minimize downtime

Hi,

We have OAS4.0 running as a web server and oracle 8.1.7 as a database server. This web server points to the database server.

Whenever OAS or the database server is down our website is down completely. We need to have a setup where the downtime is not much... say 1/2 hour at the max.

Whats the best way to implement redundant systems so that we have our site up and running most of the time. We are looking for redundancy for both OAS and the database server.

I suggested Standby databases for the database to the management but one of my coworkers suggested that we do Mirroring of servers... Both OAS and the database server should be mirrored on a seperate machine.(We have windows 2000)

I am not sure how good this solution is and what will be the issues we will face. I am not even sure whether its even good for the Databases( If that was the case why would oracle provide standby database feature)

Also can you please suggest the alternatives I have.

Thanks

[Edited by ronnie on 10-21-2002 at 10:22 AM]

Your coworker is correct. Go to http://www.oracle.com and search for "Fail Safe" - this is oracle's WinNT/2K sollution exactly aimed for the "cheap and efficient" high availability requiremnets you are looking for.

Basicaly you will have to setup a cluster from two of your Win2K servers (clustering software provided by Microsoft) and on top of that you'll have to instal Oracle's Fail Safe (which BTW is free of charge). Then you will add your database and application server into cluser configuration, so that in case of one server failure the other one will take controll over all its clustered resources (including database instance and/or application server).

BTW, standby database configuration is primarily ment for "disaster recovery" purposes, which is not the same as "high availability" that you are looking for.

Hey, as long as budgets are unlimited, why not do both?

Thanks Guys.

Clustering basically has multiple Nodes pointing to one shared storage device where the data is
stored.

http://www.microsoft.com/windows2000...ss/cluster.asp

I might seem stupid in asking this ...
but what happens when the shared device crashes or fails. How do you make sure that this does not introduce downtime in your setup.

and also if there is one shared storage and multiple nodes will be accessing it.... wont I need to configure Oracle Parallel server ???I didnt see any mention of this in the articles on oracle's web site.


Thanks

[Edited by ronnie on 10-21-2002 at 04:56 PM]

Quote:

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Originally posted by ronnie
I might seem stupid in asking this ...
but what happens when the shared device crashes or fails. How do you make sure that this does not introduce downtime in your setup.

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Ah, the $64,000 question. The key is to configure your disk with redundancy (ie RAID). You must look at each component and determine if it is a single point of failure. If it is, there must be a backup for it.

Quote:

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and also if there is one shared storage and multiple nodes will be accessing it.... wont I need to configure Oracle Parallel server ???I didnt see any mention of this in the articles on oracle's web site.
[Edited by ronnie on 10-21-2002 at 04:56 PM]

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No, failsafe (as I understand it) is a failover technology and not a parallel technology. For example, you have two boxes b0 and b1. With failsafe, b0 will handle all the requests. When b0 dies, b1 kicks in and processes requests. When b0 is alive, b1 does nothing (in terms of servicing requests).

With parallel server, both b0 and b1 will be servicing requests. When b0 goes down, b1 takes over b0's requests and continues service his own requests.

Just to add a bit on Jeff's comments and to make it more clear about what happens when one server dies in your situation.

During normal operation, your b0 will run your database and your b1 will run your application server (or vice versa). So both boxes will perform their roles just like they do now.

In case your b0 fails, the box b1 will take over its database service and it will handle both application server and the database untill you fix your box b0, when everything goes back to normal.

Similarly, in case your box b1 dies, b0 will take over its load, running both database and application server untill b1 is repaired.

This is so called active-active configuration. In this configuration it is advisable that both boxes have sufficient free resources during normal operation, so that they can take additional load of another server in case of emergency.

Thanks a lot jeff and jurij,

Can I use Oracle Failsafe with OAS 4.0.8 or its Microsoft clustering which will handle the OAS part of it.

The documentation says Oracle Fail Safe supports iAS.
Thanks

I'm realy not sure about that, but I vauguly recall that indeed only iAS can be registered with Fail Safe configuration.

OFS versions(3.1.2;3.2.1;3.3.1) on Windows 2000 for OAS supports on 11i onwards

How stable and reliable is oracle Fail Safe.

Can you please share your experiences with it.

Thanks