[syslog-ng] syslog-ng 3.3.7 DNS resolving Problem

[Gergely Nagy]

Daniel Neubacher <daniel.neubacher at xing.com> writes:

> I've got none of these errors with syslog-ng 3.4 beta1 - does this
> make sense?

Interesting... all DNS-related code should be the same between 3.4beta1
and the latest 3.3 git master (compared to 3.3.7, both have a fix that
uses thread-safe lookups).

Compared to 3.3.7, 3.4 beta1 has only one patch that is relevant:

commit 11b20b28f7586b2bf10c281328f28d93f39e279c
Author: Balazs Scheidler <bazsi at balabit.hu>
Date:   Fri Dec 14 17:54:39 2012 +0100

    resolve_sockaddr: fixed unsafe use of non-reentrant APIs to resolve IP addresses to names

    As it seems the use of the DNS cache hid the fact that we're not thread
    safe when resolving IPs to DNS names. This patch attempts to use
    getnameinfo() API if available that is thread safe and protects
    all other paths with a mutex.

    Reported-By: Brian Kroth <bpkroth at gmail.com>
    Tested-By: Gergely Nagy <algernon at balabit.hu>
    Signed-off-by: Balazs Scheidler <bazsi at balabit.hu>

https://github.com/balabit/syslog-ng-3.3/commit/11b20b28f7586b2bf10c281328f28d93f39e279c.patch

Come to think of it, the lack of this patch might very well be the cause
of your issue. Can you check if the latest 3.3 git master works for you?

There's an easily buildable tarball available at:
 http://packages.madhouse-project.org/syslog-ng/3.3/3.3.7/syslog-ng-3.3.7-20130105-v3.3.7-14-g45eaa.tar.gz

If this does fix the problem, then my apologies, I should've thought of
it way sooner. :|

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