Agent Unreachable

This is a NuoDB Manager command. See NuoDB Manager.

Description

In the unlikely situation where network failure causes a broker to be unreachable, this command can instruct the domain to discard knowledge of an unreachable broker. An example of this is on Amazon EC2, if an instance goes down, the socket does not get closed immediately (it can take up to an hour), so this command can help to tell other brokers to hangup the socket explicitly. See also the heartbeatPeerTimeout property (see NuoDB Manager Properties), which has the same effect.

Syntax

agent unreachable host hostname

Parameters

Interactive Example

The agent unreachable command, in interactive mode, will first list all the hosts in the domain and then ask which one is unreachable:

nuodb [domain] > agent unreachable
 
[broker] * ec2-52-24-143-83.us-west-2.compute.amazonaws.com/52.24.143.83:48004 (us-west-2) CONNECTED
[broker] ip-172-31-13-183/52.24.2.248:48004 (us-west-2) CONNECTED
[broker] ip-172-31-14-56/52.24.98.113:48004 (us-west-2) CONNECTED

host: 52.24.2.248

Scripting Example

The same agent unreachable command can be executed with --command as follows:

nuodbmgr --broker host --password password \
    --command "agent unreachable host 52.24.2.248"