[systemd-devel] [RFC] Initial libsystemd-asyncns commit

[Marcel Holtmann]

Hi Andrey,

>>>> why do we have to spawn threads or do forks for DNS. This looks all
>>>> pretty expensive. In ConnMan for example we just wrote our own async
>>>> DNS using a mainloop. Works perfectly fine and is dirt cheap.
>>> 
>>> Well, we don't fork threads/processes for each call but reuse them.
>>> 
>>> What libasyncns does what your solution doesn't do is go via NSS. This
>>> means /etc/hosts, nss-myhostname, nss-ldap, nss-mdns and so on just
>>> work, while that all is lost when doing DNS natively.
>>> 
>>> I am pretty sure we should not bypass NSS for this. 
>> 
>> actually NSS for DNS is pretty nasty stuff. I am pretty sure we should bypass it and create a proper implementation. Is anybody actually using NIS or LDAP for domain name resolution?
>> 
> 
> Yes, there are solutions that are using LDAP for hostname resolution
> quite heavily - actually are based around LDAP without any
> local /etc/hosts.

that is extremely heavy and must suck form a latency point of view. Then again, nothing that a DNS<->LDAP bridge couldn’t easily support. Since dragging LDAP dependencies into every program that has to load NSS modules is not a good idea either.

Regards

Marcel