Configure Consul in a Cluster¶
The Consul processes of all PLOSSYS 5 servers in a cluster have to be connected for cross-server service discovery and system configuration. If one PLOSSYS 5 server fails, the entire system remains functional.
Backup the Configuration¶
If you expand an already existent PLOSSYS 5 single server to a cluster, first export the configuration of PLOSSYS 5.
Perform the following configuration step on <server_1>:
plossys config export <plossys_5_backup>.yml
Hint - more options
For more information about the export via PLOSSYS CLI, refer to Administrate the System Configuration.
Adjust the Consul Services¶
Perform the following configuration steps on <server_1>, <server_2> and <server_3>:
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Open the Consul configuration file: C:\ProgramData\SEAL Systems\config\consul.json
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Delete the following line: "bind_addr": "127.0.0.1",Hint - multiple network interfaces If a server has several network interfaces with private IP addresses, do not delete the complete line but replace 127.0.0.1with the appropriate IP address.
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Search for the following line: "bootstrap_expect": 1,and replace it by the following line: "bootstrap_expect": 3,
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Add the following line at any position: "retry_join": ["<server_1>", "<server_2>", "<server_3>"]Caution - JSON structure Pay attention to keep the JSON structure in the configuration file! For further information, refer to http://json.org/json-de.html. 
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Save the file. 
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Delete the contents of the following directory: C:\ProgramData\SEAL Systems\data\seal-consul-agent
Import the Backup of the Configuration¶
After the configuration has been changed on all PLOSSYS 5 servers, Consul runs in the cluster mode. Now, the backup of the configuration can be imported.
Hint - only one server
The configuration has to be imported on one PLOSSYS 5 server only due to the configuration is automatically update on all PLOSSYS 5 servers belonging to a cluster.
Perform the following configuration step on <server_1>:
plossys config import <plossys_5_backup>.yml
Hint - more options
For more information about the import via PLOSSYS CLI, refer to Administrate the System Configuration.