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tungd / elixir-dns

DNS library for Elixir
BSD 3-Clause "New" or "Revised" License
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Close the UDP socket after use #28

Closed Hermanverschooten closed 5 years ago

Hermanverschooten commented 5 years ago

I am using DNS.query in a little dns proxy I am writing. I noticed several times my nerves device started complaining about too many open files. After some investigation I traced it back to DNS.query. The UDP socket that is used to query the remote DNS-server is never closed. a simple test was proof:

for x <- 1..1000, do: DNS.query("google.com")
** (Socket.Error) too many open files
    (socket) lib/socket/udp.ex:72: Socket.UDP.open!/1
    (dns) lib/dns.ex:44: DNS.query/3
    (stdlib) erl_eval.erl:680: :erl_eval.do_apply/6
    (stdlib) erl_eval.erl:232: :erl_eval.expr/5
    (elixir) lib/enum.ex:3003: Enum.reduce_range_inc/4

I used :gen_udp.close/1, as I did not find a close in Socket for UDP sockets.