Official website introduction:
Because the Hive service does not have worker roles, another mechanism is needed to enable the automatic propagation of client configurations to the other hosts in your cluster. Gateway roles fulfill this function. Gateways in fact aren't really roles and do not have state, but they act as indicators for where client configurations should be placed. Hive gateways are created by default when the Hive service is added.
translate:
Since the Hive service does not have a worker role, additional mechanisms are required to enable automatic propagation of client configuration to other hosts in the cluster. The gateway role performs this function. gateways are not really roles and have no state , but they serve to tell clients where configuration should be placed. When adding a Hive service, a Hive gateway is created by default.
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