Add option to enable gen128Bit for tracer

[pengsrc]

Signed-off-by: Jingwen Peng [email protected]

[CLAassistant]

All committers have signed the CLA.

[coveralls]

Coverage decreased (-0.2%) to 85.413% when pulling 1fd68ba on pengsrc:master into 1f15fec on uber:master.

[black-adder]

thanks for this, do you mind adding a small test to cover the new option?

[pengsrc]

No problem, I'll add it.

[coveralls]

Coverage decreased (-0.08%) to 85.532% when pulling 3ccac6f on pengsrc:master into 1f15fec on uber:master.

[coveralls]

Coverage increased (+0.1%) to 85.71% when pulling 63ce24d on pengsrc:master into 1f15fec on uber:master.

[pengsrc]

@black-adder Hi, the related tests have been added, please check that.

[black-adder]

Thanks! Just be careful if you have other services using different languages (java) which don't have this feature since those clients will lose the top 64 bits of the trace id when they report.

[pengsrc]

Thanks for this nice advice!