Prevent DNS flood when TSDB is not available

[collectd.git] / src / collectd.conf.pod

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 27c4e16..4d05352 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -8143,6 +8143,7 @@ packets.
 Synopsis:
 
  <Plugin write_tsdb>
+   DNS_Cache_TTL 60
    <Node "example">
      Host "tsd-1.my.domain"
      Port "4242"
@@ -8151,7 +8152,22 @@ Synopsis:
  </Plugin>
 
 The configuration consists of one or more E<lt>B<Node>E<nbsp>I<Name>E<gt>
-blocks. Inside the B<Node> blocks, the following options are recognized:
+blocks and global directives.
+
+Global directives are:
+
+=over 4
+
+=item B<DNS_Cache_TTL> I<ttl>
+
+When Collectd connects to a TSDB node, it will request the DNS. This can become
+a problem is the TSDN node is unavailable or badly configured because Collected
+will request DNS in order to reconnect for every metric, which can flood your DNS.
+So you can cache the last value for C<ttl> seconds (default: 60s).
+
+=back
+
+Inside the B<Node> blocks, the following options are recognized:
 
 =over 4