write_tsdb plugin: Prevent DNS flooding on connection error. #2059
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kev009
reviewed
Nov 27, 2016
| =item B<DNS_Random_Cache_TTL> I<ttl> | ||
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| 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 |
kev009
reviewed
Nov 28, 2016
| 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: 600s e.g; 10 min). | ||
| 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 |
kev009
reviewed
Nov 28, 2016
| request the DNS at the same time when the connection fails. Default value is | ||
| 15 * the write_tsdb interval (or the global interval if write_tsdb interval is not | ||
| defined). | ||
| You can also define a jitter, a random interval to wait in addition to |
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I would instead suggest calling this a "splay" in both config param and documentation, but just a minor nit.
* Rename ->sock_info to ->ai. * Use cf_utils_get_cdtime() to parse time options. * Optimize away the use_dnsrandomttl global variable.
Also rename the global variables to match the config options.
The defaults have been set to the more reasonable 1*interval.
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Since it got buried in the commit diff, I suggest splay in place of jitter for describing the option but otherwise LGTM |
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As a non-native english speaker I've had to look up splay, so jitter sounds better. |
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I stole splay from cfengine, which seems to have spread it to Chef and Salt |
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Alright, we're going to stick with "jitter" then. |
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