Upstream Servers: The list is where you define the servers that Reblaze will protect. In other words, these are the servers to which Reblaze will send the (scrubbed) web traffic it receives.
This list provides robust capabilities for managing your traffic. You can enable and configure load balancing, which will weight and distribute traffic across your primary servers. You can define backup servers, to which Reblaze will failover your traffic when your primary servers aren’t available. You can take servers offline for maintenance by ticking a single box in the interface. You can even tell Reblaze to keep individual users connected to the same server throughout their sessions.
Adding and deleting servers from this list is straightforward. To add a server, enter its IP in the “New Server” box and click Add, then fill out the rest of the information in the new entry. To delete an existing entry, click on the Delete link next to that entry.
Here are explanations for each field in this list.
Host is the IP/FQDN for each server that Reblaze protects. This can be a normal web server, or it can be a load-balancing server. Note that Reblaze also provides load-balancing capabilities in its own right, as seen in the next field.
Weight is the relative weight of each server for load balancing purposes. Reblaze distributes traffic with a round-robin sequence, according to these weights.
For example, let’s say there are two servers in the list, with the weight of each servers set to one. Therefore, these servers will receive equal amounts of traffic. Suppose instead that the first server was set to three, while the second was set to one. This would mean that the first server would receive three visitors for every visitor sent to the second server.
Max Fails is the maximum number of failed communication attempts that are allowed for this server. Once this number of failures occurs, Reblaze will consider the server to be inactive. If other servers are available, Reblaze will failover the traffic to them. If this was the only server available, Reblaze will return an error to the client (either 504 Timeout, or 502 Bad Gateway).
Fail Timeout: When a server fails, this is the length of time that Reblaze will wait before trying to send traffic to it again. In the example, the timeout is ten seconds.
Is Down: When this box is checked, Reblaze will not attempt to communicate with this server. This allows you to easily take a server offline for temporary maintenance or some other purpose.
Is Backup: when this box is checked, Reblaze will treat this server as a backup. In other words, Reblaze will not attempt to communicate with it unless all the primary servers (i.e., those for which this box is not checked) are unavailable.