Connect to a copy node by connecting to the primary server and specifying the NodeType connection parameter as part of the connection string. The NodeType connection parameter accepts the following values:
DIRECT This is the default setting when connecting to database server.
When the NodeType connection parameter is set to DIRECT, the database server accepts the connection without performing load balancing or redirection.
PRIMARY If the NodeType connection parameter is set to PRIMARY and you have connected to the primary server, the connection is accepted. If you have connected to a non-primary server (such as, the mirror server, or a copy node), the database server redirects the connection to the primary server.
COPY When the NodeType connection parameter is set to COPY, the database server performs load balancing and chooses a copy node. In a read-only scale-out system, the database server examines the copy nodes in its own branch (including itself if it is not the root node) and chooses the copy node with the lightest load. If the database server does not choose itself, it redirects the client to the chosen database server.
MIRROR If the NodeType connection parameter is set to MIRROR and you have connected to the mirror server, the connection is accepted. If you have connected to a non-mirror server, the database server redirects the connection to the mirror server.
READONLY When the NodeType connection parameter is set to READONLY, you are connected to any read-only server, either a copy node or the mirror. If there are no copy nodes, this is equivalent to the MIRROR setting. If there are copy nodes, this is equivalent to the COPY setting.
Once the root database server determines which copy node the connection should be made to, the connection is automatically redirected (if necessary) to that node.
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