To configure agents for failover, you specify two or more target servers for the agent to
use. If one of the servers fails, the agent switches to another server from the
list.
If you did not configure the agent for failover when you installed the agent, you can also
configure it for failover by modifying its properties.
An agent that is configured for failover has a list of servers or agent relays to contact.
If one server or agent relay is not available, the agent tries other servers or agent relays
in the list.
Restriction: The failover list must contain
only servers or only agent relays. An agent can not have both servers and agent relays in
its failover list.
-
Open the /agent-install/conf/agent/installed.properties
file.
-
In the
locked/agent.brokerUrl=failover\:
parameter, provide a list of
server locations or agent relay locations.
This parameter can contain servers or agent relays, but not both.
The agent configuration syntax is
IP_or_hostname\:JMS_port
. Separate each agent relay
or server with a comma. When the agent starts, it selects one server or agent relay at
random to use. If that server or agent relay fails, the agent selects a different server
or agent relay from the list. The agent continues to use the server or agent relay until
that server or agent relay fails.
An example parameter that specifies two agent relays might resemble the following
code:
locked/agent.brokerUrl=failover\:(ah3\://newyork-relay-server.example.com\:7916,ah3\://losangeles-relay-server.example.com\:7916)
.
- Optional:
To make the agent use the servers or agent relays sequentially, append the code
?randomize=false
to the
locked/agent.brokerUrl=failover\:
parameter.
By default, the agent uses entries in the list at random, including when it first
starts. If you specify ?randomize=false
, the agent uses entries in the
list in order, starting from the first entry. In either case, the agent continues to use
the current server or agent relay until it fails, and then the agent switches to another
entry in the list.
For example, the parameter might look like the following
code:locked/agent.brokerUrl=failover\:(ah3\://newyork-relay-server.example.com\:7916,ah3\://losangeles-relay-server.example.com\:7916)?randomize=false
-
List the host names or IP addresses of the agent relays or servers in the
agent.jms.remote.host property, separated by commas.
-
List the agent communication port numbers of the agent relays or servers in the
agent.jms.remote.port property.
For example, if the
agent.jms.remote.host property listed two
servers and both servers use port 7916 for agent communication, the
agent.jms.remote.port looks like
this:
agent.jms.remote.port=7916,7916
Each agent relay or server that
is listed in the
agent.jms.remote.host must have a corresponding port
in the
agent.jms.remote.port property, even if the port numbers are
the same as other agent relays or servers.