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SQL Anywhere 12.0.1 » SQL Anywhere Server - Database Administration » Database maintenance » SQL Anywhere read-only scale-out


SQL Anywhere web services high availability and scale-out solutions

The following SQL Anywhere components are required to configure high availability and/or scale-out solutions for hosting web applications:

  • Relay Server (RS)   The Relay Server is the entry point for HTTP requests (typically from the Internet), providing virtual hosting and load balancing capability. The Relay Server accepts and routes HTTP requests that target virtual entities called a server farm. Each server farm may consist of one or more SQL Anywhere database/web servers. The Relay Server is the HTTP/WEB access point that relays all HTTP requests to an appropriate back-end server for processing. See Introduction to the Relay Server.

  • Outbound Enabler (OE)   The Outbound Enabler provides a bridge between the Relay Server and a back-end database server. There is one Outbound Enabler process for each back-end server residing within a server farm. Its purpose is to ensure that its designated back-end server is operational, and it is responsible for establishing a communication channel with the Relay Server and forwarding requests to its back-end server. Since the Outbound Enabler initiates the connection to the Relay Server, it can easily make an outbound connection from a LAN, through a firewall, to a Relay Server situated in the DMZ. See Outbound Enabler.

  • SQL Anywhere (back-end) server   SQL Anywhere (back-end) server is an advanced database and web server that can host web applications written entirely in SQL. SQL Anywhere servers may be deployed to mitigate demanding environments requiring high availability and scale-out solutions. High availability provides fault tolerance capabilities to protect against interruption of service and scale-out provides load balancing to increase throughput during peak loads.

 High availability
 High-availability plus scale-out
 OE configuration
 SQL Anywhere configuration
 Relay server configuration
 Client/application configuration
 See also