Define custom tags for service's series

[VinceTT]

Is it possible to add custom influxdb tags for shinken service's series ?
Maybe a predefined field of service configuration can be used to do this ?

[fpeyre]

I will take a look on this today.

[fpeyre]

Ok after quick test, I propose the following thing

We can add a macro for our host/service like _INFLUX_TAG. The value associate to this macro is our custom_tag. The tag key in influxdb is custom, its value is our _INFLUX_TAG value.

Before the end of the week I should be able to code this function for testing

[VinceTT]

Hi @fpeyre, thanks so much for your reply.

For me your solution is very interesting and will allow me to classify my datas.
Do you think there is a way to extend this to mulitple custom tags without too impact on performances ?

[fpeyre]

This is a little tricky and related to InfluxDB.

First many link/information about InfluxDB and how it works:

• A tag_key can't have more than one value for a data (I mean custom can be Val1, "Val2" or null, but not in the same time Val1 and Val2)
  They have a discussion on this feature here: Tags should support multiple values influxdata/influxdb#2670

• InfluxDB is limited by what they call series cardinality(= number of unique series) (https://docs.influxdata.com/influxdb/v1.1/concepts/glossary/#series-cardinality)

• This give us an idea of hardware requirements/number of unique series we can have (https://docs.influxdata.com/influxdb/v1.1/guides/hardware_sizing/#general-hardware-guidelines-for-a-single-node)

Now in our case:

• Currently, we create a measurement for each metrics that we have in our Shinken. For example, a basic check_ping send 2 perfdata (rta and pl) so we have 2 series for all service/hosts using check_ping.

• The measurement had 2 tags: host and service, so the cardinality is related to your number of hosts/services and metrics

Adding a new tag add is a new factor to increase this cardinality. In a majority of use case, it's something we can take the liberty of doing.

To answer to your question, I can code something to use many tag.

For example :

_INFLUX_TAG    T1: v1, T2:v2, T3:V3

Who make the service/host have 3 tags T1, T2 and T3 with respective values v1, v2 and v3.
But dependently how you use it and your usecase , you can increase the cardinality realy fast.

[VinceTT]

Thanks for this information about the influxdb cardinality !
I understand better the impact on performances of adding tags.
In my point of view, your solution with the format _INFLUX_TAG T1: v1, T2:v2, T3:V3 is flexible and allow all possible configurations.

[fpeyre]

I make a branch with the feature, available here: https://github.com/savoirfairelinux/mod-influxdb/tree/add_custom_tag
I test it , it works with the format _INFLUX_TAG T1: v1, T2:v2, T3:V3 so you can test it

I must write some test but i have not time to do it now. Maybe we can merge the branch and make a new release on shinken install during January

[VinceTT]

Thanks @fpeyre !
I'll try it out now.