How do Targets Work?

[Squidcod]

I'm trying to run the same external probe against multiple different domains. eg google.com yahoo.com msn.com

The documentation is relatively sparse with examples on how to use targets, but it seems like it's the correct place to do the thing.

• Does the following look correct to achieve this goal?
• Will it act as if there were 3 separate probe entries but without having to copy paste? Or will it have an effect on the way the metrics work?
• Can I use the additional label field as I do below?

EDIT: Updated the original question to have a working probe for easier viewing.

probe {
name: "test"
type: EXTERNAL
targets {
host_names: "hello.com, world.com, foo.com"
}
interval_msec: 60000
timeout_msec: 15000
external_probe {
mode: ONCE
command: "python3 /test.py --target=@host_names@"
}
additional_label {
key: "check_type"
value: "CI"
}
}

[manugarg]

Hello @Squidcod,

Sorry for the sparse documentation regarding how targets work.

• This will run 3 (sub)probes in parallel, each probe using a different target.
• All probe metrics have a "dst" label (though we should've probably named it "target", but Cloudprober's earliest use case was network based probing, though it has come a long way since then):

   success{ptype="external", probe="test_install", dst="google.com"}
   total{...}
   latency{...}
   success{ptype="external", probe="test_install", dst="yahoo.com"}
   total{...}
   latency{...}

• Using additional label will add another label to all the metrics. So in the example above, you'll have additional label "target" that will have same values as "dst".

Update, Apr 20, 2023:
I've added some documentation to explain how targets work:
https://cloudprober.org/docs/how-to/targets/

[manugarg]

Apologies for missing it earlier, targets look like this:
targets {
host_names: "google.com","yahoo.com", "msn.com"
}

Ex:

cloudprober/examples/surfacers/default_surfacers.cfg

Line 26 in e441335

host_names: "www.google.com"

[Squidcod]

Thanks for the quick reply.
I'll give that a go.

I was basing it off of the Note in https://cloudprober.org/how-to/external-probe/#configuration
Which suggested supported fields.

[Squidcod]

Hrm

    type: EXTERNAL
    targets { 
        host_names: "hello.com","world.com" 
    }

results in
cloudprober.go:182] Error initializing cloudprober. Err: line 5: unknown field name ""world.com"" in proto.TargetsDef

[manugarg]

It has to be one string: "google.com, yahoo.com, msn.com"

(Sorry, my bad again)

[Squidcod]

Awesome thank you! I see metrics coming in now.
Just to resolve the whole thing I'll put in what I've got (with some internal details altered)

probe {
name: "test"
type: EXTERNAL
targets {
host_names: "hello.com, world.com"
}
interval_msec: 60000
timeout_msec: 15000
external_probe {
mode: ONCE
command: "python3 /test.py --target=@host_names@"
}
additional_label {
key: "check_type"
value: "CI"
}
}