write_tsdb plugin: Rename options to "Resolve{Interval,Jitter}".

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

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 27c4e16..b043a89 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -8143,6 +8143,8 @@ packets.
 Synopsis:
 
  <Plugin write_tsdb>
+   ResolveInterval 60
+   ResolveJitter 60
    <Node "example">
      Host "tsd-1.my.domain"
      Port "4242"
@@ -8151,7 +8153,35 @@ 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<ResolveInterval> I<seconds>
+
+=item B<ResolveJitter> I<seconds>
+
+When I<collectd> connects to a TSDB node, it will request the DNS. This can
+become a problem if the TSDN node is unavailable or badly configured because
+collectd will request DNS in order to reconnect for every metric, which can
+flood your DNS. So you can cache the last value for I<ResolveInterval> seconds
+(default: B<600>, i.e. 10 minutes).
+
+You can also define a jitter, a random interval to wait in addition to
+I<ResolveInterval>. This prevents all your collectd servers to resolve the
+hostname at the same time when the connection fails. Default value is 15 * the
+interval of the I<write_tsdb plugin> (defaults to 10 seconds).
+
+B<Note:> If the DNS resolution has already been successful when the socket
+closes, the plugin will try to reconnect immediately with the cached
+information. DNS is queried only when the socket is closed for a longer than
+I<ResolveInterval> + I<ResolveJitter> seconds.
+
+=back
+
+Inside the B<Node> blocks, the following options are recognized:
 
 =over 4