Avoid calling URI.toString when populating tracing span tags #3308
Description
Feature Request
Looking at flame graphs for our service we found 3% of our cpu time was spent on calling toString for a string that should already exist.
Is your feature request related to a problem? Please describe
Current implementation wastes CPU cycles
Describe the solution you'd like
redisUriStr is passed to create a URI class and then toString is called on the URI class to populate the span tag for server.address. We can avoid this toString call and pass redisUriStr directly for server.address. Unless the toString produces a different string from the one passed in to create the URI class, I think this is a reasonable change.
Describe alternatives you've considered
An alternative is to cache the URI object and resulting strings, but that seems like overkill. If this channel attribute is immutable (channel.attr(ConnectionBuilder.REDIS_URI).get();) we could probably extend the change to cache all the span tags we generate if the URI is not going to change for the channel. In our flame graph analysis another 3% of wasted CPU time was in instantiating this URI class every time span tags need to be populated.
Teachability, Documentation, Adoption, Migration Strategy
Not sure, not really a user facing feature. More of an optimization. Let me know if this belongs under a different category from Feature Request