gevent.resolver.dnspython – Pure Python hostname resolver

class Resolver(hub=None)[source]

Bases: AbstractResolver

An experimental resolver that uses dnspython.

This is typically slower than the default threaded resolver (unless there’s a cache hit, in which case it can be much faster). It is usually much faster than the c-ares resolver. It tends to scale well as more concurrent resolutions are attempted.

Under Python 2, if the idna package is installed, this resolver can resolve Unicode host names that the system resolver cannot.

Note

This does not use dnspython’s default resolver object, or share any classes with import dns. A separate copy of the objects is imported to be able to function in a non monkey-patched process. The documentation for the resolver object still applies.

The resolver that we use is available as the resolver attribute of this object (typically gevent.get_hub().resolver.resolver).

Caution

Many of the same caveats about DNS results apply here as are documented for gevent.resolver.ares.Resolver. In addition, the handling of symbolic scope IDs in IPv6 addresses passed to getaddrinfo exhibits some differences.

On PyPy, getnameinfo can produce results when CPython raises socket.error, and gevent’s DNSPython resolver also raises socket.error.

Caution

This resolver is experimental. It may be removed or modified in the future. As always, feedback is welcome.

New in version 1.3a2.

Changed in version 20.5.0: The errors raised are now much more consistent with those raised by the standard library resolvers.

Handling of localhost and broadcast names is now more consistent.

close()[source]

Release resources held by this object.

Subclasses that define resources should override.

New in version 22.10.1.

property resolver

The dnspython resolver object we use.

This object has several useful attributes that can be used to adjust the behaviour of the DNS system:

  • cache is a dns.resolver.LRUCache. Its maximum size can be configured by calling resolver.cache.set_max_size()

  • nameservers controls which nameservers to talk to

  • lifetime configures a timeout for each individual query.

Next page: gevent.resolver.blocking – Non-cooperative resolver

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