trace chain element consumes too many resources

[NikitaSkrynnik]

Main Issue

#1666

Description

context.WithValue is used in many places (especially in trace chain element). It makes ctx very heavy and significantly slows down some operations like postpone which are also used in many chain elements. As a result forwarder can spend several seconds only on postone.

Solution

Make contexts light and use connection's metadata instead.

[denis-tingaikin]

left side with enabled trace chain element , right side with disabled trace chain element

memory:

cpu: