peer.address in tag is not in common tags of opentracing

[changjiang2016]

peer.address is not common tags of opentracing.Why not use tags,such as peer.hostname and peer.port, instead of peer.address in the code ?

[malafeev]

because it's a trick to extract hostname/port when:

• database is in memory
• database is a file
• default port is different for different databases
• jdbc url format is not standardised

would you like to submit a PR to fix all cases for major databases jdbc url variations?

[whiskeysierra]

peer.address is not common tags of opentracing

It now is: https://github.com/opentracing/specification/pull/53