dnsdist: Raise the maximum number of descriptors to 1M

When running under systemd there is a cap on the number of open file or
socket descriptors that we can have at a given time. We used to set this
to 16k which was a large enough value for most installations, but now that
people are deploying DNSdist to offer DoT/DoH/DoQ/DoH3 to large numbers of
users we are regularly getting complaints that the default value is too low.
On the other hand I'm not aware of any case where having a cap actually
prevented an issue where we would be opening too many descriptors.
Therefore this commit is raising the default value to 1 millions, a large
enough values for even very large setups dealing with > 100k incoming
connections at a time.

Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>

diff --git a/pdns/dnsdistdist/dnsdist.service.in b/pdns/dnsdistdist/dnsdist.service.in
index e0a9b3bbb352a977453d32c41f0c2a17b99a8d87..d2b03db2cfb3dfbdc8679ba44c6a30603e611dd8 100644 (file)
--- a/pdns/dnsdistdist/dnsdist.service.in
+++ b/pdns/dnsdistdist/dnsdist.service.in
@@ -20,7 +20,7 @@ StartLimitInterval=0
 
 # Tuning
 TasksMax=8192
-LimitNOFILE=16384
+LimitNOFILE=1000000
 # Note: increasing the amount of lockable memory is required to use eBPF support
 # LimitMEMLOCK=infinity
 

diff --git a/pdns/dnsdistdist/dnsdist.service.meson.in b/pdns/dnsdistdist/dnsdist.service.meson.in
index 186acece8896e85da1edc7a6a3f0c672430892d3..e5cc5e0568dfed9d4bc9519c6c4f4a5f1282c3d5 100644 (file)
--- a/pdns/dnsdistdist/dnsdist.service.meson.in
+++ b/pdns/dnsdistdist/dnsdist.service.meson.in
@@ -20,7 +20,7 @@ StartLimitInterval=0
 
 # Tuning
 TasksMax=8192
-LimitNOFILE=16384
+LimitNOFILE=1000000
 # Note: increasing the amount of lockable memory is required to use eBPF support
 # LimitMEMLOCK=infinity