Excess FD errors

[chris-wood]

Running from a fresh build of tip of master on macOS, I'm seeing the following:

$ echo "google.com" | ./zdns A
{"data":{"protocol":"udp","resolver":"[2001:558:feed::2]:53"},"error":"write udp 10.0.0.184:59008-\u003e[2001:558:feed::2]:53: address 2001:558:feed::2: non-IPv4 address","name":"google.com","status":"ERROR","timestamp":"2021-09-05T20:38:25-07:00"}
FATA[0000] unable to create socketlisten udp 10.0.0.184:0: socket: too many open files 

I assume this isn't expected, so I'm wondering if this is a regression. I could of course be using it wrong, too! Happy to provide any additional information if it would be helpful.

[zakird]

I don't think this is a regression. ZDNS does preemptively open thr FDs at the start now. You either need to decrease the number of workers or increase the number of the FDs you can open.

…

On Mon, Sep 6, 2021 at 8:06 AM Christopher Wood ***@***.***> wrote: Running from a fresh build of tip of master on macOS, I'm seeing the following: $ echo "google.com" | ./zdns A {"data":{"protocol":"udp","resolver":"[2001:558:feed::2]:53"},"error":"write udp 10.0.0.184:59008-\u003e[2001:558:feed::2]:53: address 2001:558:feed::2: non-IPv4 address","name":"google.com","status":"ERROR","timestamp":"2021-09-05T20:38:25-07:00"} FATA[0000] unable to create socketlisten udp 10.0.0.184:0: socket: too many open files I assume this isn't expected, so I'm wondering if this is a regression. I could of course be using it wrong, too! Happy to provide any additional information if it would be helpful. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#250>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABREUCXI5HIYOGZJENRRKTUATKIDANCNFSM5DQUMCPA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[chris-wood]

Capping the number of worker threads did the trick. Maybe bumping the default down to something smaller would be useful? The fix wasn't obvious to me 🤷 If not, we can close.

[zakird]

At the very least we should output a useful error so that the user knows what's going on and how to fix