AppMetrics generates a ton of string and string[]

[lazarshulekov]

We found there are two methods that create too much garbage for the GC. Both are inside MetricTags.
Both public string AsMetricName(string metricName) in conjuction with public static MetricTags Concat() create a huge amount of strings and string[]. Especially in the cases where we have a couple of global tags we generate gigbytes of strings which are needed for a single operation - the GetOrAdd inside the DefaultMetricContextRegistry.
In our case we have finite set of Context/Tags combination, so if needed we can provide a unique key when pushing the metrics which can be used inside DefaultMetricContextRegistry.
Can you advise?