How to query stored series by a given tag value?

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Tobias Paul

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Jun 19, 2020, 2:59:24 AM6/19/20

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Is there any possibility to query all stored series (tag combinations and metric names) which have a specific tag value?

For example, if I only know the hostname of a server but not the stored metric names and any other related tags.

Example:

stored series

traffic_in;host=server1;interface=eth0
traffic_out;host=server1;interface=eth0
traffic_in;host=server1;interface=eth1
traffic_out;host=server1;interface=eth1
traffic_in;host=server2;interface=eth0
traffic_out;host=server2;interface=eth0
traffic_in;host=server3;interface=eth0
traffic_out;host=server3;interface=eth0
traffic_in;host=server3;interface=eth1
traffic_out;host=server3;interface=eth1

expected result for "host=server2"

"results": [
{
	 "name": "traffic_in",
	 "tags": {
		 "host": [
			 "server2"
		 ],
		 "interface": [
			 "eth0"
		 ]
	 }
},
{
	 "name": "traffic_out",
	 "tags": {
		 "host": [
			 "server2"
		 ],
		 "interface": [
			 "eth0"
		 ]
	 }
}
]

Brian Hawkins

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Aug 11, 2020, 10:44:08 PM8/11/20

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Not directly no. I've added extension points to allow a plugin to do this sort of thing but it isn't built in. I've had the same desire for exactly your use case, I want to know all metrics that are being reported from a specific host. Why have I not added it you ask? Well processing tag data in Kairos is like drinking from a fire hose. it is easy to get overwhelmed and drown. So making a generic plugin/enhancement that won't kill the system is tricky unless I put a lot of restrictions on it. We could build a pluigin that will only create these secondary indexes on specific tag and it would need a cache so as to not increase C* traffic.