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The Info tab shows documentation for the node. Many nodes have required fields. If a required field is not configured, it will be outlined in red. If you attempt to save a node that does not have a value in all of the required fields, a red triangle icon will be displayed above the node.
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Mustache Format
You can use double curly brackets ({{ }}), referred to as “mustaches,” in function nodes, REST API nodes, and other nodes to mark message variables.
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If a deployed slice contains an unknown/unrecognized node, then either :
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remove it or install/reinstall the artifact that contains the missing node
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Restart and restart the service to take effect. New nodes are only registered when the service starts up.
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