Edge Load Balancing
Edge Load Balancing - overview
The Edge provides load balancing via TCP, HTTP, and HTTPS traffic. The Edge maps a single IP address to a pool of servers for load balancing.
The Edge can have a maximum of 10 uplink and internal interfaces. In the application example above this 3-Tier Application utilizes three different internal interfaces on the Edge. The uplink of the Edge is connected to 10.20.181.0\/24 which is then HTTP & HTTPS load balanced internally to the 192.168.1.2 and 192.168.1.3 Web Servers using the external IP of 10.20.181.170.
All incoming HTTP or HTTPS traffic on IP 10.20.181.170 will be automatically load balanced to the Web Servers.
The Types of Load Balancing that are available are:
- Round Robin (Default) – Each server is used in turn according to the weight assigned to it.
- IP Hash – Selects a server based on a hash of the source IP address of each packet.
- URI – The left part of the URI (before the question mark) is hashed and divided by the total weight of the running servers. The result designates which server will receive the request. Applicable to only HTTP service load balancing.
- Least Connected - New connections are sent to the server with the fewest connections.
Load Balancing Pool Servers Configuration
To set up a site-to-site VPN, switch to the Administration tab, open the first OvDC and select the tab Edge Gateways:
1) Mark and right-click on the EON network and select Edge Gateway Services… from the context menu.
2) Switch to the Load Balancer Tab.
3) Click on the Add… Button to add a Pool of Servers.
4) Type in the desired Name and Description of the Load Balance member Pool and click Next.
5) In our example above we have selected Round Robin as our Balancing Method and clicked Enable for both HTTP and HTTPS services (refer for Balancing Method Descriptions). If desired you can change the assigned port to each service.
6) Configure Health Check enables the Edge to monitor the status of the servers by sending queries and verifying they are answering the queries for each service.
6.1) Type in the desired Monitor Port for the selected services
6.2) Edge supports HTTP and TCP health check modes for HTTP service, SSL and TCP health check modes for HTTPS service, and TCP health check mode for TCP service.
|Mode||Description of service health checks|
|TCP||TCP connection check|
|HTTP||HTTP GET method is used to detect server status. Only responses 2xx and 3xx are valid. Other responses (including a lack of response) indicate a server failure. URI used for HTTP GET requests can be specified in the text field|
|SSL||Tests servers using SSLv3 client hello messages. The server is considered valid only when the response contains server hello messages|
The table above describes the health check parameters listed in the above screenshot. You can change the default values if required.
|Interval||Interval at which a server is pinged.|
|Timeout||Time within which a response from the server must be received.|
|Health Threshold||Number of consecutive successful health checks before a server is declared operational.|
|Unhealth Threshold||Number of consecutive unsuccessful health checks before a server is declared dead.|
7) Add a member server to the Load Balancer Pool. Enter the IP Address, Ratio weight, Port, and Monitor Port for each server you wish to add to the Load Balancer Pool and click OK.
8) Add a member server to the Load Balancer Pool. Enter the IP Address, Ratio weight, Port, and Monitor Port for each server you wish to add to the Load Balancer Pool and click OK.
9) One final check of all settings and click Finish when ready
Load Balancing Virtual Server Configuration
1) Click on the Virtual Servers button and click Add…
2) Type the virtual server Name and Description
2.1) Select the Network in which the Virtual Server will be connected
2.2) Enter the IP address of either the Edge Internal or uplink IP Address
2.3) Enable the Services you want the virtual server to manage and click OK
3) Click on the Firewall Tab and click Add…
4) Add a Firewall Rule for the newly created Virtual Server matching the IP of the Virtual Server in step 2.2 and click OK.
5) Once the Firewall rule has been enabled you can setup a simple test website on each server just with the name Server 1 and Server 2. Connect to the Virtual Server IP with your web browser and hit F5 until you see the website switch from Server 1 to Server 2. In the example above it would be http://220.127.116.11:8080 (IP Address plus port 8080)