Application port states – Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) User Manual
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Server and application port states
4
Application port states
lists the application port states.
TABLE 15
Server states
State
Description
ENB:enabled
There is no link to the real server. The real server is configured on the Brocade Virtual ADX but
is not physically connected to the Brocade Virtual ADX.
FAL:failed
The real server has failed to respond to repeated Layer 3 health checks (IP pings). Typically, a
real server changes to the FAILED state from the SUSPECT state.
TST:testing
A real server will go to "Testing" if it is reachable at Layer 2 but not at Layer 3. When you first
add a real server, the Brocade Virtual ADX will first try to ARP it. While it is ARPing, the server
state will read "State: Enabled". After the real server replies to the ARP, the Brocade Virtual
ADX will normally send one ICMP echo request. After it gets the ARP reply and before it gets
the ICMP echo reply, the Brocade Virtual ADX will show the real server state as Testing. If you
have a firewall application on the real server so that it responds to ARP queries but not to
ICMP pings, then the real server will show as "Testing" indefinitely.
Use the show server real command to display detailed state information. The show server
bind command is more concise, though it focuses on port status.
SUS:suspect
The Brocade Virtual ADX associates a time stamp with each packet sent to and received from
the real servers. If the time gap between the last packet received from the server and the last
packet sent to the server grows to 3 or 4 seconds, the Brocade Virtual ADX sends a ping
(Layer 3 health check) to the server. If the server does not respond within the ping interval (a
configurable parameter), the Brocade Virtual ADX changes the state to SUSPECT and resends
the ping, up to the number of retries specified by the ping retries parameter (also
configurable). If the server still does not respond after all the retries, the state changes to
FAILED. If the server does respond, the state changes to ACTIVE.
GDN:grace-dn
The server gracefully shut down. Refer to server force-delete command under the
section.
ACT:active
A real server will go to active as long as it is reachable at Layer 2 and Layer 3, regardless of
whether its ports are bound to anything, or whether its ports pass tests.
UNB:unbind
Used for ports that have not been bound to a virtual server.
AWU:await-unbind
AWD:
await-shutdown
Both can occur when you're trying to unbind or delete ports. You might not even see them in
anything but a live environment. After you remove real servers from a virtual server or delete
virtual servers or unbind ports, normally the Brocade Virtual ADX or stackable waits until
connections in progress finish their business.
TABLE 16
Application port states
State
Description
ENABLED
There is no link to the server. The server is configured on the Brocade Virtual ADX but is not
connected to the Brocade Virtual ADX. (This is the same as the ENABLED server state.)
FAILED
The application has failed to respond to repeated Layer 4 or (if applicable) Layer 7 health checks.
Typically, an application changes to the FAILED state from the SUSPECT state. Note that if a
application does not pass the Layer 4 health check, the Brocade Virtual ADX does not waste
resources on the Layer 7 health check, because the application clearly is not available. When an
application enters the FAILED state, the state of the real server itself moves to the TEST state
while the Brocade Virtual ADX continually tries to reach the failed application.
TEST
The server is still reachable at Layer 3, but the application has failed to respond to its Layer 4 (or
if applicable, Layer 7) health check.