When you configure a pool in ZXTM, you need to specify the nodes that the pool should send traffic to. You can specify the nodes using either IP Address:Port or Name:Port.
Configuring a Pool in the Admin Interface
The behaviour of the Admin Interface is as follows:
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IP Address: The ZXTM Admin Interface will write the IP address into the Pool configuration.
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Name: The ZXTM Admin Interface will attempt to resolve the name to an IP address using the local resolver setting (/etc/hosts, resolv.conf). If the Name resolves to multiple IP addresses, the ZXTM Admin Interface will add each of these IP addresses to the configuration, creating multiple nodes. If the Name resolves to a single IP address, the ZXTM Admin Interface will add the Name to the configuration.
Behaviour of the ZXTM software
When ZXTM reads a Pool configuration, it will act as follows:
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Nodes identified by IP Address: The IP address unambiguously identifies the node.
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Nodes identified by Name: ZXTM will resolve the name to an IP address using /etc/hosts and resolv.conf, and will use the resulting IP address. ZXTM will also periodically re-resolve names (by default, every 30 seconds) and use the new IP address if it changes. Note: if a named node resolves to multiple IP addresses, ZXTM will not use it, and will raise an error.
Coping with DNS failure:
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At startup: If ZXTM cannot resolve a node name at startup, it will raise an error and will not use that node.
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When running: If the DNS fails while ZXTM is running, ZXTM will continue to use the known IP address for a named node.
