Setting up Multi-Galaxy Communication
- Last UpdatedJun 14, 2022
- 3 minute read
Multi-Galaxy communication (MGC) lets multiple GR nodes to talk to each other at runtime. MGC is also required for configuring remote GR nodes. To configure multi-galaxy communication, you must configure servers that will perform galaxy service discovery, and then pair the galaxies that will be part of the multi-galaxy.
The functionality of tools such as Object Viewer, Galaxy Browser, ViewApps, and Managed InTouch applications is very similar in a multi-Galaxy environment as it is when working within a single galaxy. However, setting up the multi-galaxy environment requires some basic configuration.
The configuration workflow, using a two-galaxy pair as an example, is as follows:
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Configure a three node system.
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IDE node 0 (no GR)
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GR node 1 (no IDE): contains Galaxy 1
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GR node 2 (no IDE): contains Galaxy 2
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Prepare the multi-galaxy environment by adjusting galaxy names as necessary. Each galaxy in a multi-galaxy environment must have a unique name.
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From the IDE, connect to Galaxy1 on Node1.
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To configure the service discovery servers for Galaxy 1, select Configure from the Galaxy menu, then select Communication and open the Service discovery servers dialog.
Set Node 1 as the Primary node for both Local Galaxy servers and the Multi-Galaxy servers. See Defining Service Discovery for additional information about the Local and Multi-Galaxy servers. You can configure secondary nodes for redundancy if needed.
Important! There can be only one Cross Galaxy Server in a multi-galaxy environment. All GRs in the environment must point to the same Cross Galaxy Server node. You can specify nodes by name or by IP address.

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To configure multi-galaxy communication, select Configure from the Galaxy menu, then select Communication and open the Multi-galaxy configuration dialog.
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From the IDE, click the [+] button and add Galaxy 1 (on GR Node 1) as a paired galaxy.
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Select the checkbox to enable Remote Pairing. Then, enter a passphrase. The passphrase must be the same for each galaxy to be paired, and must meet a minimum complexity standard:
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Minimum length is nine characters, including at least eight alphanumeric characters (with at least one upper case and one lower case letter and at least one number)
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At least one symbol: ! @ # $ % ^ & * ( )

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Click OK. A message that pairing has been enabled is displayed.
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Now, add Galaxy 2 (on GR Node 2) the same way that you added Galaxy 1. The Remote Galaxy Repository Pairing dialog appears.

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Enter Node 1 as the Target Galaxy Repository, and enter the same Passphrase as you entered for Galaxy 1.
Node 1 is now listed as a paired Galaxy Repository in the Multi-Galaxy Configuration dialog.
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To change the Cross Galaxy Server
Use this procedure to change the Cross Galaxy Server for a previously paired Galaxy:
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From the IDE, connect to the Galaxy on a remote node.
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Configure Service Discovery Servers for the Galaxy.
Set the node as the Local Galaxy Server. Set the new node as the Multi-Galaxy Server. You can configure secondary nodes for redundancy if needed.

When pairing, the GR node initiating the pairing gets a copy of the primary Multi-Galaxy server node if none has been configured.