Prerequisites

Before configuring the Dynamic Message Routing (DMR) settings for each event broker used throughout the message routing network, ensure that you read and observe ALL of the following information:

  • A DMR node consists of a standalone broker or an HA group using the active/standby redundancy model. DMR does not support the active/active redundancy model.
  • Before you can configure DMR, you must know the address (IP or FQDN) of the message backbone for all brokers or HA groups.
  • The message backbone must be enabled on each event broker (refer to Enabling All Messaging Services).
  • The SMF service must be enabled on each event broker (refer to SMF Service Management).
  • The event brokers must have unique physical router names (refer to Router Name Configuration).
  • On software event brokers, the max-connections system scaling parameter must be set to 1000 or greater on each node (refer to Using System Scaling Parameters).

In version 9.6, the internal naming of channels and queues changed to support replication with DMR. Brokers older than version 9.6 cannot learn the new naming, so cluster links between a version 9.6 broker and an older broker will fail.

Do not create any DMR cluster links (in either direction) between a version 9.6 broker and an older broker.

If you are upgrading brokers from version 9.5 or earlier that are part of a DMR network, do not add any new DMR cluster links anywhere in the network until all brokers in the network have been upgraded to version 9.6 or later. Links that existed before the upgrade will continue to function properly.

Network Construction Rules

For the nodes in an event mesh to automatically discover the correct message routing:

  • each node must belong to a cluster (that is, a cluster must be created on each node; see Configuring a DMR Cluster)
  • DMR must be enabled on every participating Message VPN on every node in the cluster. See Enabling and Disabling DMR Mode for details.
  • the set of participating Message VPNs must be the same on each node in the cluster.

In addition, DMR networks must comply with the following cluster linking rules, otherwise the system may raise topology errors:

  • There can be only one cluster link between each pair of nodes.
  • For horizontal scaling configurations, each node within a cluster must be connected to every other node with an internal link. In other words, there must be a full mesh of internal links between nodes.
  • For multi-site connectivity configurations, clusters are connected together with external links between gateway nodes to permit messages published in one cluster to be delivered to consumers connected to another cluster. It is not necessary to have a full mesh of external links between clusters. In other words, each cluster in the network doesn't need to be connected to every other cluster; however, only clusters that are directly connected via an external link can exchange messages.