Failover and Switchover

Hi ,
I needs some clarifications regarding the manual failover and Swithover.
As i know these both are role transitions from primary to standby and also switchover is done during Planned tasks. And fail over is the one which is done during sudden unplanned events.
Also switchover can be done at any point of time.
Assume do to some unexpected events , my primary database is down and failed to Up. so i need to do a manual failover....
My question here is , Anyway i am going to do manually, but why i need to do a failover? I can initiate a switchover right?
Even if i do a failover , if my database is not in the flash back mode , then i need to rebuild a new standby database....
Why i want to make myself in trouble by using failover insttead of a switchover.
Regards,
Mohammed

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https://forums.oracle.com/message/9362002#9362002

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DATAGUARD FAILOVER AND SQITCHOVER TESTING

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Connection failover and transaction failover

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Load balancing, failover and fallback in Non-Clustered WebLogic environment

hi,
Has anyone implemented WebLogic 10.3.3 (or 10.3.4) in a Non-Clustered environment, but also got load balancing, failover and fallback work?
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hi,
Has anyone implemented WebLogic 10.3.3 (or 10.3.4) in a Non-Clustered environment, but also got load balancing, failover and fallback work?
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Agent Failover and AD Integration in Operations Manager

Hi
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http://technet.microsoft.com/en-us/library/hh212922.aspx
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zamn

Hi,
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http://blogs.technet.com/b/quenguyen/archive/2011/07/13/monitoring-non-domain-servers-using-scom.aspx
http://blogs.technet.com/b/stefan_stranger/archive/2012/04/17/monitoring-non-domain-members-with-om-2012.aspx
For the second question, as we can read from the below link:
http://blogs.technet.com/b/meamcs/archive/2013/05/10/is-ad-integration-or-manual-scom-agents-required-to-allow-automatic-windows-agent-failover-between-multiple-scom-management-servers.aspx
SCOM windows agents automatic failover does not require AD integration or PowerShell scripting or Configuration Manager or manual agents installation specially for small to medium environment and agents distribution between different SCOM management servers
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Regards,
Yan Li
Regards, Yan Li

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Hi MvKalyan,
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PO for LAN failover and stateful failover link?

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How does failover and load distribution work in Operations Manager resource pools?

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Hi,
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Multi site Exchange 2010 deployment. Failover and Autodiscover

I have made some significant changes to my Exchange environment that have me a little confused as to how to proceed.
A few months ago I upgraded from SP1 to SP3 UR5 and my previous strategy for DR stopped working.
Just to give a little background:
I have two sites connected with a 100Mb ethernet link that each have a dag member with a hub transport and two CAS servers. These servers at each site are load balanced with a Kemp Technologies LM-2200 cluster.
Previous to the upgrade we were working in warm standby where a passive copy of the mailbox databases were being held in the second site but not being used until needed. When needed we would change the load balancer to connect users to the second site
or in the case of a site failure we would change DNS to point to the second site. After the upgrade things changed and I could no longer do cross site RPC out of the box and when I enabled cross site RPC it still did not work like previous so I figured
this would be a good opportunity to strengthen my setup and try to go for a more automatic failover design were each site gets its own namespace and the CAS servers can redirect users to the correct site based on the current state of the DAG.
This works great aside from the folks who are not connected to the domain to get SCP. For instance I have activesync devices and OWA users on the outside. If the primary site goes down before these devices make an attempt to connect they will
not know that the site is down and their mailbox is now active in the secondary site. The device will just fail to connect.
Is there any way to make autodiscover site resilient? The only thing I can think of is using round robin DNS for autodiscover but that would likely cause some connection troubles if the site that is randomly resolved happens to be down.
Thoughts on this would be appreciated.
Thank you,
Nick

I realize that DAC mode does nothing but prevent the databases from mounting without open communication between the DAG members. I was not insinuating that it would help with my DR strategy other than that I know I could run into trouble if I do not
enable it and the DAG members come online but cannot talk to each other.
I realize that the alternate witness does not activate without intervention. If you read my reply you would see that I am not interested in full DR being automatic.
"I do not expect to have zero intervention when doing a datacenter switchover but I would prefer to have it as automated as possible when there is a simple failure of the primary dag member and the witness is still available. We have had this happen
a few times when the information store service has failed due to bugs in old code and the second site came online without difficulty."
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Regardless of all that the original question I had has not been answered. How does autodiscover get handled in a scenario like this? If my autodiscover addresses are pointed at a site that is not operational devices will not know where to go
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IP failover and firewall

Hello
and thanks for spending Your time reading my post!
I am trying to set up two mini-servers with IP failover. But to my big surprise it's almost as complicated as setting up heartbeat on two linux boxes. In the 10.6 server documentation I didn't find anything - the documentation for 10.3 helps... So much for my complaints
I have two problems:
The first - and really important one - is, that the failover does not work with the firewall running. What happens is, that the backup-server takes over the IP as expected (as ifconfig, the logfile and my mailbox show...), but one cannot reach the IP from the net. As soon as I shut down the firewall everything works fine. But I really don't want servers to run without firewall!
The second one is the - whats the right word - switch back, when the primary server is up and running again. The backupserver sees the running primary server but still tries to get its IP:
+mDNSResponder[38]: setsockopt - IPMULTICASTIF error 192.168.1.251 -1 errno 49 (Can't assign requested address)+
Has anyone a hint for me?
Thanks in advance,
Sven
Message was edited by: Sven Koesling (typos

Sorry, it took a long time, but I think I figured it out:
In Server-Admin You have to configure the options of the firewall - in german the button is called "Erweitert" (the last one) according to the fail-over IP address.
You have to allow the communication through the desired ports from Your network to the fail-over IP address. E.g. allow anything on port 3128 from 192.168.1-net to 192.168.1.5 where 192.168.1.5 is Your fail-over IP address.
Greetings
Sven

Session Failover and Clustering

          Let's say that we have two WebServers (NES) with the weblogic plugin (say WS1 and WS2) and a cluster with two WebLogicCommerce AppServers (say AS1 and AS2). Let's assume that each WebServer and AppServer runs on its own machine (total: 4 machines). Now, let's assume that the WebServer "obj.conf" files (on both WS1 and WS2) are setup so that they point to the servers in the cluster (WebLogicCluster="AS1:7601,AS2:7601").
          When a new request comes in to one of the WebServers (say WS1), the plugin will route it to one of the AppServers using Round-Robin (say AS1). A session will now be initiated in AS1 and it sends a response back to the client.
          Question 1: How does the other proxy in WS2 know that all future requests for this client need to be forwarded to AS1?
          Question 2: For failover, does the cluster automatically replicate the session state existing in AS1 onto AS2 before sending the response (does AS2 automatically become the secondary)?
          Now let's assume that AS1 crashes/dies. When the next request from the client comes to WS1 or WS2, they will forward it to AS1 (assuming that WS2 knows about the client session in AS1) . Since AS1 has crashed, will the client eventually get a timeout error message?
          Question 3: To ensure that the session failover happens so that AS2 gets the request instead (becomes the primary), do we need to setup a WebLogic Proxy Server? If so, why can't the plugins for NES provide the failover themselves?
          Thank you very much for your help!
          Giri


          Thank you very much for your responses. It has been very helpful and I am clear on the session/clustering stuff. I have new questions on EJB and clustering which I will post as a separate thread.
          Giri
          "Jason Rosenberg" <[email protected]> wrote:
          >And also, if the browser has cookies disabled, it is important for
          >the app server to embed the WebLogicSession info via url rewriting,
          >otherwise the proxy or NES will not be able to route the session
          >properly.
          >
          >So, in all http responses, be sure to pass the url string through
          >response.encodeURL(). This will do the right thing depending
          >on whether cookies are enabled or not.
          >
          >I've just only recently figured this out. Haven't actually tried it
          >all out yet, so forgive me if it is not quite this simple, but this
          >seems to be the gist of it...
          >
          >Jason
          >
          >
          >"Justin James" <[email protected]> wrote in message news:[email protected]...
          >>
          >> Giri,
          >>
          >> I'm not a weblogic representative, but I tried to replicate this proxing service inside a load balancing switch(BigIP) and I
          >discovered a few things. The weblogic server sets a cookie (WebLogicSession)that the webserver plugin uses to manage the proxying.
          >The cookie (found in the HTTP header information) contains encoded information about the primary and secondary application servers
          >that the session is bound too. Any web server can read the cookie to determine how to dispatch the request to the primary server.
          >If the primary server does not respond, the request is forwarded to the secondary server by the plugin. Regardless of cluster size,
          >the session is replicated to only one other server.
          >>
          >> <[email protected]> wrote:
          >> >Giri Alwar wrote:
          >> >
          >> >> I need a couple of clarifications. First with regard to Question 1, I understand that plugins provide load balancing and
          >failover but what I really was asking is how the plugin in WS2 knows that a session for the client has been initiated in AS1 as a
          >result of WS1 sending the initial request to AS1. If WS2 gets a future request from the client, it needs to know this to send the
          >request to AS1. Does the plugin talk to the cluster to find out if there is a primary and who it is?
          >> >>
          >> >
          >> >> I should have clarified that my other questions pertain to in-memory replication. If I do not persist the session in a database
          >then does the client get an error message (timeout) when AS1 goes down (assuming we use NES with the WebLogic plugin)?
          >> >
          >> >Plugins' know how to route requests based on cookies. If it can't reach the primary server it will automatically try secondary.
          >In your case it doesn't matter if it reaches to proxy 1 or proxy 2, it is still the same.
          >> >
          >> >- Prasad
          >> >
          >> >> To prevent this error message and achieve failover, do I need to use WebLogic as the proxy server? If so, why isn't the NES
          >plugin doing this?
          >> >
          >> >> Thanks.
          >> >> Giri
          >> >>
          >> >> Prasad Peddada <[email protected]> wrote:
          >> >> >Giri Alwar wrote:
          >> >> >
          >> >> >> Let's say that we have two WebServers (NES) with the weblogic plugin (say WS1 and WS2) and a cluster with two
          >WebLogicCommerce AppServers (say AS1 and AS2). Let's assume that each WebServer and AppServer runs on its own machine (total: 4
          >machines). Now, let's assume that the WebServer "obj.conf" files (on both WS1 and WS2) are setup so that they point to the servers
          >in the cluster (WebLogicCluster="AS1:7601,AS2:7601").
          >> >> >>
          >> >> >> When a new request comes in to one of the WebServers (say WS1), the plugin will route it to one of the AppServers using
          >Round-Robin (say AS1). A session will now be initiated in AS1 and it sends a response back to the client.
          >> >> >>
          >> >> >> Question 1: How does the other proxy in WS2 know that all future requests for this client need to be forwarded to AS1?
          >> >> >
          >> >> > Plugin takes care of load balancing and failover, it is all transparent to the client.
          >> >> >
          >> >> >
          >> >> >> Question 2: For failover, does the cluster automatically replicate the session state existing in AS1 onto AS2 before sending
          >the response (does AS2 automatically become the secondary)?
          >> >> >
          >> >> > If you have only two yes it is automatically your secondary. Yes, replication is synchronous.
          >> >> >
          >> >> >>
          >> >> >> Now let's assume that AS1 crashes/dies. When the next request from the client comes to WS1 or WS2, they will forward it to
          >AS1 (assuming that WS2 knows about the client session in AS1) . Since AS1 has crashed, will the client eventually get a timeout
          >error message?
          >> >> >
          >> >> > If you are using some kind of persistence then you will be able to retrieve the session information and since the server
          >is not available the request will automatically failover.
          >> >> >
          >> >> >> Question 3: To ensure that the session failover happens so that AS2 gets the request instead (becomes the primary), do we
          >need to setup a WebLogic Proxy Server? If so, why can't the plugins for NES provide the failover themselves?
          >> >> >
          >> >> > No, you need only one. Either NES or weblogic proxy.
          >> >> >
          >> >> >
          >> >> >> Thank you very much for your help!
          >> >> >> Giri
          >> >> >
          >> >> >- Prasad
          >> >> >
          >> >
          >>
          >
          >

Vip Failover and rolling patch

Hi,
For the purpose of implementing security features in the 2 Node RAC DB EE=10.2.0.5 [ID 1340831.1], I want to apply patch for bug:12880299 which is rolling available.
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Regards

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PIX Failover and HW.

Hi all,
I have some more question about HW and PIX failover.
What happens when I connect two PIXs..
one UR license and one FO license and my
FO PIX takes activity over and my PIX with UR license will be corrupted so that I will need to disconnect it completely to repair it? I know that when someone wants to use FO PIX standalone than PIX reboots per 24 hours cycle. How PIX determines that it is not used standalone? I think that when I switch off first PIX in pair so second PIX in pair with FO license will function standalone.
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jl

I guess you won't take magic as an answer? ;-)
I am assuming you are using Serial Failover, no?
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If this answers your question (I believe it does) please check the box so we can see one of those nice red checks :-)
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According to what I've found in UCCX 9.0 installation guides, the secondary node in a HA installation looks at the primary for NTP. What happens in the case of failover when the primary is unavailable?
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I'm not positive on what this looks like in production, but I would suspect it's not critical for the secondary to keep processing calls. It doesn't depend on the time on any other server to function properly. Maybe the log files will have timestamps which do not line up with your CUCM log files.
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Anthony Holloway
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2 App servers in farm will be auto failover and load balanced?

Dear all,
We are going to setup following SharePoint farm:
2 WFE
2 APP
2 OWA
2 SQL with shared NAS
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But I am not so sure about the part about load balance. If all the 8 server instance are working properly, the new request come from WFE2 will be sent to APP1 or APP2? Or it depends on which service application is asking?
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Thanks.
Mark

Here is a good artcicle on how SharePoint load balances service applications:
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