sdk/log: Bad log message when key-value paris are dropped because of key duplication

[pellared]

Currently, when the key-values are discarded because of key duplication

opentelemetry-go/sdk/log/record.go

Lines 195 to 196 in afd4763

	attrs, drop = dedup(attrs)
	r.setDropped(drop)

opentelemetry-go/sdk/log/record.go

Lines 300 to 301 in afd4763

	attrs, drop = dedup(attrs)
	r.setDropped(drop)

opentelemetry-go/sdk/log/record.go

Lines 431 to 432 in afd4763

	kvs, dropped := dedup(val.AsMap())
	r.addDropped(dropped)

then limit reached: dropping log Record attributes log is being emitted which is inaccurate; e.g.

opentelemetry-go/sdk/log/record.go

Lines 104 to 107 in afd4763

	func (r *Record) setDropped(n int) {
	logAttrDropped()
	r.dropped = n
	}

Instead we should log something like key duplication: dropping key-value pair instead.

Moreover Record.DroppedAttributes is also adding the count if dropped key-value pairs during deduplication.

opentelemetry-go/sdk/log/record.go

Lines 353 to 357 in afd4763

	// DroppedAttributes returns the number of attributes dropped due to limits
	// being reached.
	func (r *Record) DroppedAttributes() int {
	return r.dropped
	}

I think we do not need to count the dropped duplicates as this is an error scenario and it would be enough to just log ones when it happens.

[shri-acha]

hi!, if i'm not mistaken, when deduplication is done,when deleting the duplicates it calls in the setDropped()/addDropped(), which then logs wrongfully using logAttrDropped() to which a function for logging is to be added, say logKeyValuePairDropped(), which could log the correct log message of the key value pair dropping?
I'd love to work on this issue.

[pellared]

@shri-acha, yes. I am assigning you.

[shri-acha]

I've just replaced the log messages for now. But I am unsure as to remove the dropped from the struct Record itself.
As you've mentioned that counting the dropped values seem unnecessary. So, in that case should I change the test cases too?

[pellared]

I mentioned only to not count the key-values that are dropped because of deduplication.

Tests are a necessary part of a contribution. From https://github.com/open-telemetry/opentelemetry-go/blob/main/CONTRIBUTING.md#tests:

Each functionality should be covered by tests.

[shri-acha]

hmm.. okay. I have a confusion though,If we wouldn't count the dropped value due to deduplication, wouldn't it affect the existing test cases.
Also, i've added a new commit, i'd understand if my understanding towards solving the problem is correct.