Servers

Your symBalancer distributes traffic to backend servers (slices).

Add Backend Server

Click Add server.
Select the slice you would like to add.
Click Add.

Note

The dropdown will only show slices with a Private IPv4 address, which are not currently assigned to a balancer. Also, slices can only be assigned to balancers in the same region.

Backend Servers List

This is a list of the backend slices assigned to your symBalancer. Rows can have different colors depending on server state, which is explained below.

Backend Server States

UP: Server is passing health checks and balancer is sending traffic.
DRAIN: Server is administratively set to stop passing traffic, but without interrupting any current requests. Balancer will not resume sending traffic until server is set back to UP. This state is typically used when you want to “cleanly” bring a server down for maintenance, without any interruptions to existing connections. Health checks are still being sent.
MAINT: Server is adminisitratively set to stop passing traffic immediately. Balancer will not resume sending traffic until server is set back to UP. Health checks are not being sent.
DOWN: Server is failing health checks and balancer is not passing traffic.

Each row also has the following columns:

Name: Hostname of the slice.
Status: UP, DRAIN, MAINT or DOWN.
IP Address: Private IPv4 of the slice.
Downtime: Number of seconds the slice has been in MAINT or DOWN state since last time the symBalancer settings were modified.

Note

When in DRAIN state, health checks are still happening even though the balancer has stopped sending traffic. This means that if health checks fail, the balancer will set the slice to DOWN. Often this is to be expected, as it was put into DRAIN to cleanly remove it before doing maintenance.

To the right is an ellipsis menu that allows you to administratively set backend server states:

READY: Set the server to UP. Balancer will do health checks, which must pass before it resumes sending traffic.
DRAIN: Set server to DRAIN state.
MAINT: Set server to MAINTENANCE state.
Remove: Remove server from this balancer.