Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Dual Processors = Automatic CPU Failover?

Posted on 2007-03-25
13
Medium Priority
?
693 Views
Last Modified: 2013-12-10
Dumb Question, I fear, but...in dual-processor servers--like Dell PowerEdge 1900, for example, with, let's say, two dual-core or quad-core Xeon processors--does the server fail operations over transparently to the remaining processor if one of the two suddenly dies?  Is this just implicit in all dual-processor machines?
0
Comment
Question by:mtn_lion
[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
  • 5
  • 5
  • 3
13 Comments
 
LVL 63

Expert Comment

by:☠ MASQ ☠
ID: 18789122
This "standby processing capability" for multi-core processors is part of Intel's development strategy.  

Yes, theoretically processing should fall-over to the remaining core but this in itself needs hardware programming so that the transfer of affinity is seamless.  You also need to bear in mind that, unless you are specifically transfering the affinity from one core to another and that the second core is pretty much unused, just waiting for a failiure so it can take over, that your actual processing power will be significantly reduced.

Currently if one core fails suddenly it is still likely you will be left with an inherently unstable system.
0
 

Author Comment

by:mtn_lion
ID: 18789309
Uh, thanks, masqueraid, for your prompt reply, but...I think I was hoping for a simpler answer.  Also, to be clear, I wasn't asking about fail-over between *cores* but between separate processors in a dual-processor system (regardless of processor type).  Surely there is a simple answer.  If I buy an "off the shelf" server with two processors in it, and one fails, will the server just keep on running as a one-cpu server?
0
 
LVL 63

Expert Comment

by:☠ MASQ ☠
ID: 18789346
Sorry, misread your question as integrated processors.  Yes, multiple processor based servers already cope with this.

I'll save the other comment until someone asks the question I answered :)
0
Introducing the WatchGuard 420 Access Point

WatchGuard's newest access point includes an 802.11ac Wave 2 chipset, providing the fastest speeds for VoIP, video and music streaming, and large data file transfers. Additionally, enjoy the benefits of strong security as the 3rd radio delivers dedicated WIPS protection!

 
LVL 69

Accepted Solution

by:
Callandor earned 1000 total points
ID: 18789358
I don't think failover will occur.  When a system boots up, all the hardware is made aware of what is present, unless the device is designed for hot-swapping.  A failure of a processor in the middle of a calculation, for example, would be catastrophic because OS'es just send tasks to cpus and expect results back.  A cluster would provide failover from one server to another, but that is at a higher level than a processor.
0
 

Author Comment

by:mtn_lion
ID: 18789363
No worries, happens to me all the time.  So...seamless transition from two to one upon failure, then, right?
0
 
LVL 69

Expert Comment

by:Callandor
ID: 18789374
Oops - MASQUERAID had it right - there are servers that do automatically detect processor failure and act on it.  For example: http://www.serverwatch.com/hreviews/article.php/3662151
0
 

Author Comment

by:mtn_lion
ID: 18789380
My last post was pre-Callandor.  Now things are getting interesting.  That makes sense, C.  So likely a server would crash on failure of one cpu?
0
 
LVL 63

Assisted Solution

by:☠ MASQ ☠
☠ MASQ ☠ earned 1000 total points
ID: 18789388
Callandor has the better answer.  When I'm talking about "multiple processor based servers" I'm talking about clusters.  Processors failing within a single machine will (just the same as in dual core) leave the system unstable.  You would be able to restart an individual machine and it could run with a processor "down"  but if it failed in use there is no mechanism to allow the other processor(s) to take over active tasks.
0
 
LVL 63

Expert Comment

by:☠ MASQ ☠
ID: 18789391
This is what happens with multiple cross posts :)
0
 

Author Comment

by:mtn_lion
ID: 18789397
If I read that article right, that's only on the enterprise-class, $30K 4-way server, and it's a proprietary feature.  So I'm thinking you're right, C., for off-the-shelf small biz servers, e.g., Dell PowerEdge 2900.  And now I see M's last post, which agrees.  Likely crash, then likely successful functioning on remaining single cpu after restart (assuming no other damage done).

What say I split the points?
0
 
LVL 69

Expert Comment

by:Callandor
ID: 18789408
Sounds good - the automatic failover is an option for expensive machines, but not for Dell Poweredge 1900's.
0
 
LVL 63

Expert Comment

by:☠ MASQ ☠
ID: 18789427
No problem (unless Callandor has already posted!)

The "Real-Time Capacity" being offered on the Unisys platform only (AFAIK) falls over when processing power is reduced, a restart is still required following actual processor failure.
0
 

Author Comment

by:mtn_lion
ID: 18789498
Thanks, guys.  Good discussion, always nice to learn some stuff!
0

Featured Post

Supports up to 4K resolution!

The VS192 2-Port 4K DisplayPort Splitter is perfect for anyone who needs to send one source of DisplayPort high definition video to two or four DisplayPort displays. The VS192 can split and also expand DisplayPort audio/video signal on two or four DisplayPort monitors.

Question has a verified solution.

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

Data center, now-a-days, is referred as the home of all the advanced technologies. In-fact, most of the businesses are now establishing their entire organizational structure around the IT capabilities.
This article will show how Aten was able to supply easy management and control for Artear's video walls and wide range display configurations of their newsroom.
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …
In this video, Percona Solutions Engineer Barrett Chambers discusses some of the basic syntax differences between MySQL and MongoDB. To learn more check out our webinar on MongoDB administration for MySQL DBA: https://www.percona.com/resources/we…

704 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