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Softwares should be same on all the servers (Also recommended to keep hardware's same)
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Maximum 32 clusters supported by Microsoft windows server 2008
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Multiple DNS records for the same server
1. Kentico webfarm
Limitations:
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Requires ultimate or extra license for additional server.
2. Windows Azure:
Limitations:
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If you create 2 instances in windows azure it requires additional web-farm licensing in kentico.
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Smart search and full text search works but need to make some tweaks after each installation.
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Need to convert the current website project to a windows azure application(Needs to be done manually). Once converted to an application you cannot test it it on your local computer for testing purpose.
3. Windows server 2008
A. We use syncronisation softwares which syncs every few min or seconds. SQL Express has an replication feature which replicates the query in the other Server.
Limitations:
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We are trusting the third party sync softwares.
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Not a real time synchronisation (Can be a realt ime if we use DSF-R windows function for sync)
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Kentico doesn't support this fully as when you upgrade your instance it has to be done manually on both
B. DNS Round Robin - DNS load balancing
Limitations:
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Even if one server goes down it doesn't understand. Have to manualy change settings so that it doesn't go to the failed server
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Can be a high load on one server and less load on other server
C. NLB (Network load balancing) (Active-Active Cluster)
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Does not consider server load only looks at number of incoming requests and distributes based on percentage.
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Detects down servers and re-directs traffic to other servers.
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Goes to a shared IP/Name and then redirects your requests to other servers.
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It doesn't do anything with the File sharing or database replication.
D. Failover Clustering:(Active-Passive Cluster)
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Inbuilt feature in windows server 2008
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Looks at a shared storage for data - can be an iSCSI hard drive or NTFS - requires a sharing hard disk in the cluster.
E. Clustering requirmenet:
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Windows server 2008 Enterprise or Datacenter version
F. Shared Storage options for windows server 2008 :
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Fibre Channel
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SAS
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iSCSi
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Witness disk holds cluster configuration. This will hold the database configuration and will replicate to the other nodes.
http://stackoverflow.com/questions/3590954/how-to-add-javascript-if-the-url-has-a-certain-word