Alerting with Nagios
OpenTSDB is great, but it's not (yet) a full monitoring platform. Now that you have a bunch of metrics in OpenTSDB, you want to start sending alerts when thresholds are getting too high. It's easy!
In the tools directory is a Python script check_tsd. This script queries OpenTSDB and returns Nagios compatible output that gives you OK/WARNING/CRITICAL state.
Parameters
Options:
-h, --help show this help message and exit
-H HOST, --host=HOST Hostname to use to connect to the TSD.
-p PORT, --port=PORT Port to connect to the TSD instance on.
-m METRIC, --metric=METRIC
Metric to query.
-t TAG, --tag=TAG Tags to filter the metric on.
-d SECONDS, --duration=SECONDS
How far back to look for data. Default 600s.
-D METHOD, --downsample=METHOD
Downsample function, e.g. one of avg, min, sum, max ... etc
-W SECONDS, --downsample-window=SECONDS
Window size over which to downsample.
-a METHOD, --aggregator=METHOD
Aggregation method: avg, min, sum (default), max .. etc
-x METHOD, --method=METHOD
Comparison method: gt, ge, lt, le, eq, ne.
-r, --rate Use rate value as comparison operand.
-w THRESHOLD, --warning=THRESHOLD
Threshold for warning. Uses the comparison method.
-c THRESHOLD, --critical=THRESHOLD
Threshold for critical. Uses the comparison method.
-v, --verbose Be more verbose.
-T SECONDS, --timeout=SECONDS
How long to wait for the response from TSD.
-E, --no-result-ok Return OK when TSD query returns no result.
-I SECONDS, --ignore-recent=SECONDS
Ignore data points that are that are that recent.
-P PERCENT, --percent-over=PERCENT
Only alarm if PERCENT of the data points violate the
threshold.
-N UTC, --now=UTC Set unix timestamp for "now", for testing
-S, --ssl Make queries to OpenTSDB via SSL (https)
For a complete list of downsample & aggregation modes, see http://opentsdb.net/docs/build/html/user_guide/query/aggregators.html#available-aggregators
Nagios Setup
Drop the script into your Nagios path and set up a command like this:
define command{
command_name check_tsd
command_line $USER1$/check_tsd -H $HOSTADDRESS$ $ARG1$
}
Then define a host in nagios for your TSD server(s). You can give it a check_command that is guaranteed to always return something if the backend is healthy.
define host{
host_name tsd
address tsd
check_command check_tsd!-d 60 -m rate:tsd.rpc.received -t type=put -x lt -c 1
[...]
}
Then define some service checks for the things you want to monitor.
define service{
host_name tsd
service_description Apache too many internal errors
check_command check_tsd!-d 300 -m rate:apache.stats.hits -t status=500 -w 1 -c 2
[...]
}
Testing
If you have want to test your parameters against some specific point in time, you can use the --now <UTC> parameter to specify an explicit unix timestamp which is used as the current timestamp instead of the actual current time. If set, the script will fetch data starting at UTC - duration, ending at UTC.
To see the values retreived, and potentially ignored (due to duration), use the --verbose option.
