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g3proxy/doc/configuration/resolvers/fail_over.rst

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+.. _configuration_resolver_fail_over:
+
+fail_over
+=========
+
+This is a virtual resolver designed to fail over between (real) resolvers.
+
+Rules for result selection:
+
+1. The **success** result of the primary resolver will always be used before the timeout.
+2. The first **success** result either from the primary or the standby resolver will be used after the timeout.
+3. If no success result, the last error one will be used.
+
+primary
+-------
+
+**required**, **type**: string
+
+Set the primary resolver to use.
+
+standby
+-------
+
+**required**, **type**: string
+
+Set the standby resolver to use.
+
+timeout
+-------
+
+**optional**, **type**:
+
+Set the timeout for primary lookup.
+
+**default**: 100ms
+
+negative_ttl
+------------
+
+**optional**, **type**: u32
+
+Time-to-Live (TTL) for negative caching of failed DNS lookups.
+
+**default**: 30