Amazon MQ network of brokers
Amazon MQ supports ActiveMQ's network of brokers feature.
A network of brokers is comprised of multiple simultaneously active single-instance brokers or active/standby brokers. Creating a network of brokers can increase availability, fault tolerance, and load balancing with multiple broker instances.
How does a Network of Brokers work?
A network of brokers is established by connecting one broker to another using network connectors. A network connector provides on-demand message from one broker to another. Network connectors are configured in the broker configuration as either non-duplex or duplex connections. For non-duplex connections, messages are forwarded only from one broker to the other. For duplex connections, messages are forwarded both ways between both brokers.
If the network connector is configured as duplex, messages are also forwarded from Broker2 to Broker1. For example, here is a duplex networkConnector entry in a broker configuration:
You can use both non-duplex and duplex connections in a network of brokers. You may want to introduce a duplex connection to another broker to improve traffic, or to avoid a limit increase. Duplex connections are also useful for partial migration from on-premises to Amazon MQ managed brokers.
How Does a Network of Brokers Handle Credentials?
For broker A to connect to broker B in a network, broker A must use valid credentials,
like any other producer or consumer. Instead of providing a password in broker A's
<networkConnector> configuration, you must first create a user
on broker A with the same values as another user on broker B (these are
separate, unique users that share the same username and
password values). When you specify the userName attribute in the
<networkConnector> configuration, Amazon MQ will add the password
automatically at runtime.
Important
Don't specify the password attribute for the
<networkConnector>. We don't recommend storing plaintext
passwords in broker configuration files, because this makes the passwords visible in
the Amazon MQ console. For more information, see Configure Network Connectors for Your Broker.
Cross region
To configure a network of brokers that spans Amazon regions, deploy brokers in those regions, and configure network connectors to the endpoints of those brokers.
To configure a network of brokers like this example, you could add
networkConnectors entries to the configurations of
Broker1 and Broker4 that reference the
wire-level endpoints of those brokers.
Network connectors for Broker1:
<networkConnectors>
<networkConnector name="1_to_2" userName="myCommonUser" duplex="true"
uri="static:(ssl://b-9876l5k4-32ji-109h-8gfe-7d65c4b132a1-2.mq.us-west-2.amazonaws.com:61617)"/>
<networkConnector name="1_to_3" userName="myCommonUser" duplex="true"
uri="static:(ssl://b-743c885d-2244-4c95-af67-a85017ff234e-3.mq.us-east-2.amazonaws.com:61617)"/>
<networkConnector name="1_to_4" userName="myCommonUser" duplex="true"
uri="static:(ssl://b-62a7fb31-d51c-466a-a873-905cd660b553-4.mq.us-east-2.amazonaws.com:61617)"/>
</networkConnectors>Network connector for Broker2:
<networkConnectors>
<networkConnector name="2_to_3" userName="myCommonUser" duplex="true"
uri="static:(ssl://b-743c885d-2244-4c95-af67-a85017ff234e-3.mq.us-east-2.amazonaws.com:61617)"/>
</networkConnectors>Network connectors for Broker4:
<networkConnectors>
<networkConnector name="4_to_3" userName="myCommonUser" duplex="true"
uri="static:(ssl://b-743c885d-2244-4c95-af67-a85017ff234e-3.mq.us-east-2.amazonaws.com:61617)"/>
<networkConnector name="4_to_2" userName="myCommonUser" duplex="true"
uri="static:(ssl://b-9876l5k4-32ji-109h-8gfe-7d65c4b132a1-2.mq.us-west-2.amazonaws.com:61617)"/>
</networkConnectors>Dynamic Failover With Transport Connectors
In addition to configuring networkConnector elements, you can configure your
broker transportConnector options to enable dynamic failover, and to rebalance
connections when brokers are added or removed from the network.
<transportConnectors>
<transportConnector name="openwire" updateClusterClients="true" rebalanceClusterClients="true" updateClusterClientsOnRemove="true"/>
</transportConnectors>
In this example both updateClusterClients and
rebalanceClusterClients are set to true. In this case clients
will be provided a list of brokers in the network, and will request them to rebalance if a
new broker joins.
Available options:
-
updateClusterClients: Passes information to clients about changes in the network of broker topology. -
rebalanceClusterClients: Causes clients to re-balance across brokers when a new broker is added to a network of brokers. -
updateClusterClientsOnRemove: Updates clients with topology information when a broker leaves a network of brokers.
When updateClusterClients is set to true, clients can be configured to
connect to a single broker in a network of brokers.
failover:(ssl://b-1234a5b6-78cd-901e-2fgh-3i45j6k178l9-1.mq.us-east-2.amazonaws.com:61617)When a new broker connects, it will receive a list of URIs of all brokers in the network. If the connection to the broker fails, it can dynamically switch to one of the brokers provided when it connected.
For more information on failover, see Broker-side Options for Failover