AlwaysOn High Availability Groups on SQL with Microsoft NAV
I have planned to do setup AlwaysOn High Availability Groups for SQL with primary & one secondary. My question is how to connect with Microsoft Navision Application & during failover how connection will get changed to connect with secondary db as primary.
As mentioned by BlackTiger, this is a SQL feature.
We use this setup, and it works really well. It provides more stability, and also allows us to force external reports used in our Web Applications to read from the Secondary Node, to take load off the Primary Node.
All NAV Clients, connect to the availability group. When the Primary Node of the Availability Group goes down, it will automatically switch to the Secondary Node, making it available for write transactions.
Can you explain how it will get connect automatically as Server names are different.
Ex. Primary DB running Node 1 and Secondary DB running Node 2. If Node 1 get failover how Node 2 will get automatically connect. Is there any setup to be done in NAV ?
Compare it with network load balance (NLB) cluster for NAV. You use a DNS name or IP to connect to the NLB cluster and the NLB redirects you to one of the nodes. Clients do not connect to a node (application server) directly.
The SQL server fail over cluster works basically the same. You connect the NAV Service Tier (NST) to the cluster and not to a SQL node directly. So you don't have to configure anything special in NAV.
The cluster will redirect the NSTs to the active SQL node. After fail over the address of the cluster stays the same. The cluster will then redirect the NST to the other SQL server that has became the active node.
How does it react if the SQL servers and NAV Servers Nodes are on 2 different sites and the connection would breakdown, would both sites be able to continue to operate and when the connection is reactivated the data able to syncronize?