July 2, 2010 at 9:12 am
I have a SQL2008 server running on an HP server. We need a failover solution. I read some on the clustering and it seems that it works much better on nearly identical hardware. ( i wasn't looking to buy 2 new servers.) and it looks like you really need a shared data source.
Has anyone had any experience with CA ARCserve High Availability (used to be called XOSoft), That looks like a decent solution for dissimilar devices.
(or any other suggestions)
thanks
July 2, 2010 at 9:42 am
I have no experience with the solutions you mentioned, but I am currently using Database Mirroring as a solution. You database is simply synchronized on another instance on another server. You can have a manual failover or with a 3rd box acting as a witness (basically a monitor) it can do the failover automatically. If your application will support this type of failover, or you are using ODBC connections it will work well.
lavigne
@wcucomputernerd
July 2, 2010 at 9:52 am
Mirroring is an option. But you need to decide what you are trying to protect against.
If you're worried about OS failure, either will work.
If you're concerned with disk failure, clustering isn't for you.
If you're main concern is with database corruption, again, clustering won't help you there.
If you're limited on licenses, mirroring requires an extra license.
Some more information would be helpful for you to fully think through what you want to get out of these high availabilty solutions.
What versions are your OS and SQL Servers?
July 2, 2010 at 9:59 am
ok, what I need is no downtime, (that's why I was looking at the CA product, the db's are mirrored and if primary goes down or needs maint, the secondary takes over automatically)
the companies on the sql server run their business via the db, if it's not available they cannot work.
I had thought about a storage array, but if the array goes down they are still SOL. so I would have to have a mirror array also.
July 2, 2010 at 3:20 pm
calvo (7/2/2010)
Mirroring is an option. But you need to decide what you are trying to protect against.If you're worried about OS failure, either will work.
If you're concerned with disk failure, clustering isn't for you.
If you're main concern is with database corruption, again, clustering won't help you there.
If you're limited on licenses, mirroring requires an extra license.
Some more information would be helpful for you to fully think through what you want to get out of these high availabilty solutions.
What versions are your OS and SQL Servers?
Mirroring (and clustering) do not require additional licenses as long as the additional server is working in a failover-only capacity.
The witness server can run as a seperate instance on the mirror (failover) server; the witness can even be an Express Edition server.
I would also add that if you're worried about disk failure, clustering is usually fine as well. If you have a cluster setup, you're likely on a SAN and, through the RAID setup, you have redundancy.
SQL guy and Houston Magician
July 2, 2010 at 3:23 pm
I would add that mirroring is pretty good (and fairly easy to set up) with automatic failover.
SQL guy and Houston Magician
July 13, 2010 at 9:36 am
Hello,
I have several years of experience with CA's XOSoft. It works very well in both a disaster recovery or high availability scenario.
It works with the same hardware (or not) and can be for local or remote site replication. The best function of this product is that it will manage failing over your user's connection (HA mode) to the secondary server in both in a domain setup or workgroup setup.
There are other 3rd party products like Double-Take and Sonasoft but no one else does the fail over like XOSoft.
Not a sale rep for CA but just a user of the product and I highly recommend it over other products including Microsoft's log shipping, database mirroring or even MS clustering.
Hope this helps
Rudy
July 13, 2010 at 11:24 pm
MS made some major improvements for clustering in terms of setting it up. In my opinion, it is MUCH easier to setup and recover from a node that needs rebuilt compared to sql server 2005.
July 15, 2010 at 7:15 am
I'm just gonna add my 2 cents.... I'm in the same boat (only a little further down the river). I was thinking about CA's product but my end result was why purchase something just for SQL replication when MS already has it.
CA's product does replication for the whole server which is really cool but if you don't need that kind of replication (or don't want to spend the money)then stay with a SQL solution.
I also didn't choose clustering b/c it is more expensive than mirroring. You have to have Windows Enterprise to run clustered servers so while SQK 2008 Standard supports clustering you have to fork out the money for the O.S. and another license for SQL.
Mirroring costs only that of another server and Standard O.S. license. Also I am running two very different machines for the Principal and Mirrored servers. As long as they can handle the workload it doesn't really matter.
July 15, 2010 at 7:21 am
i did the webex with CA and really like it, still considering it, but now trying to read more about mirroring
(the cost is certainly better)
thanks for the input thus far.
July 15, 2010 at 7:25 am
_taz_
Also it's not always just about failover it's about failback too. Some products take a long time to failback to the primary server which isn't always acceptable.
July 15, 2010 at 7:35 am
mirroring has automatic failover and failback?
how is it on the client side? with CA it seems as though the clients would drop connection to database, then they just log out and back into the app and no changes needed on client side.
once I get the mirror up can i switch which one is primary? (probably buy a more robust new server)
can i do a manual failover? (like if I wanted to do maintenance on one)
July 15, 2010 at 8:31 am
I looked at database mirroring.
Here is what I found:
1) With mirroring, failing over (either way) requires work to be done at the application/workstation to point application to the new server. If you have 20 clients, then you would have to visit each client to make the change so that it properly works with the new database location.
2) CA XOSoft does not require any change at the server and/or the client/application side. Yes you may lose connection until the secondary server is online but that's it. Once failed over and you ping the original server's name or IP it will reply as it now points to the fail over server.
3) Mirroring back once a failure has happened is not as easy as XOSoft.
4) Mirroring requires more work to setup and maintain. XOSoft doesn't. So mirroring is free but what about your time/cost to support it.
5) XOSoft works with all versions and editions of SQL server. Mirroring does not.
That's about it. Management agreed and we put it in. For us, its a better solution than mirroring.
Rudy
July 15, 2010 at 8:46 am
Rudy Panigas (7/15/2010)
I looked at database mirroring.Here is what I found:
1) With mirroring, failing over (either way) requires work to be done at the application/workstation to point application to the new server. If you have 20 clients, then you would have to visit each client to make the change so that it properly works with the new database location.
Actually failover is automatic, you define the failover partner in the connection string. When the primary is unavailable the application attempts to connect to the failover machine. If you have a witness server then the server side failover is automatic too.
SQL guy and Houston Magician
July 15, 2010 at 10:50 am
[/quote]
Actually failover is automatic, you define the failover partner in the connection string. When the primary is unavailable the application attempts to connect to the failover machine. If you have a witness server then the server side failover is automatic too.
[/quote]
Interesting to know how the application reconnects to the failover server now that it has a different name. The CA product make a DNS change to handle this problem
Rudy
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