VMware vSphere

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  • 1.  VM High Availibility Question: Virtual IPs?

    Posted Apr 24, 2014 02:19 PM

    When building HA Clusters using other software solutions, I would create two nodes with their own static IP addresses, and the cluster would share a Virtual IP that would only be used when the active node was running.  e.g.  When the application and storage would be brought online, it would perform the last step of plumbing or adding the Virtual IP and begin to accept traffic.

    I am planning to do the same with VMHA, but don't see any options for adding a virtual IP...  is the method or process the same, or am I missing something?  If it's not possible, can I add it to the application startup routine so that the last step adds the VIP?  Anyone have experience doing this?

    Any help assistance is greatly appreciated.  I am fairly new to VMWare.

    Thanks,

    Dumbluck,



  • 2.  RE: VM High Availibility Question: Virtual IPs?

    Posted Apr 24, 2014 02:30 PM

    Hi welcome to the communities,

    are you talking about the "normal" VMware HA or the new VMware app HA? VMware vSphere App HA Documentation

    VMware HA ist not a clustering solution like the software solutions you descibed. In case of a hard failure for example, or if the VM guest OS becomes unresponsive, VMware HA will restart the VM on another host. This means you will have a downtime.

    To get near zero downtime, you will still need the software-clustering solutions.

    Regards

    Tim



  • 3.  RE: VM High Availibility Question: Virtual IPs?

    Posted Apr 24, 2014 02:55 PM

    Tim,

       Thanks.   Yeah, even with the software solutions you will lose the VIP for the amount of time it takes to drop the vip, drop the application, export the storage, and reverse the process on the other node.   Depending on the application it would take about five minutes, which I am fine with.  It's not 100% uptime, but it provides an automated means of ensuring that if something does go wrong, then the system will come back online as quickly as possible.

       As far as VMWare HA and VMWare app HA, I'm not sure of the difference, I will have to look into that... I was thinking of the "normal" I guess.

       I also looked into the DSR, which sounds very interesting, but our application is a reverse proxy that is terminating SSL traffic in order to examine session ids for stateful traffic, e.g. cookies, so I did not think re-distributing load would work for us because of the nature of the traffic.  However, it the reverse proxy went down for five minutes, I could live with that.  I think...  :smileywink:

       Thanks,

    DL.



  • 4.  RE: VM High Availibility Question: Virtual IPs?

    Posted Apr 24, 2014 08:12 PM

    I think if you are talking about regular VMware HA then no there is no virtual IP needed.  One is you need vCenter for doing HA.  If you meet all the requirements though then what happens is the hosts communicate over the management network through heartbeats.  Simply if the heartbeats aren't received for a certain period of time then that host can be considered down.  Believe me that is a very short explanation, which is why there is a book on it.  So it does not work like say a SQL cluster would or anything like that where there is a virtual IP to represent the cluster.



  • 5.  RE: VM High Availibility Question: Virtual IPs?

    Broadcom Employee
    Posted Apr 25, 2014 07:33 AM

    dumbluck wrote:

    When building HA Clusters using other software solutions, I would create two nodes with their own static IP addresses, and the cluster would share a Virtual IP that would only be used when the active node was running.  e.g.  When the application and storage would be brought online, it would perform the last step of plumbing or adding the Virtual IP and begin to accept traffic.

    I am planning to do the same with VMHA, but don't see any options for adding a virtual IP...  is the method or process the same, or am I missing something?  If it's not possible, can I add it to the application startup routine so that the last step adds the VIP?  Anyone have experience doing this?

    Any help assistance is greatly appreciated.  I am fairly new to VMWare.

    Thanks,

    Dumbluck,

    vSphere HA is like an "active / standby" solution. Your VMs are restarted when they fail. We restart the virtual machines, they will have the same IP before and after the restart, no option for a virtual ip or anything like that as it isn't like a traditional "clustering service"



  • 6.  RE: VM High Availibility Question: Virtual IPs?

    Broadcom Employee
    Posted Apr 25, 2014 11:07 AM

    Yes, VMware HA at the moment is not application aware the way HA solution like MSCS does. May be VMware AppHA is attempt to displace MSCS going forward