Revert "metrics bugfix: switch getTps() to getSum()"

[cserwen]

This reverts commit 767612c.

What is the purpose of the change

revert #108

fix #128, fix #123, fix #121, fix #114

Brief changelog

XX

Verifying this change

XXXX

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[ferrirW]

What is the reason for changing to sum before? Is it necessary?

[cserwen]

What is the reason for changing to sum before? Is it necessary?

最早的版本就是 TPS，使用的getTps()，#108 改成了 getSum，理论上应该增加个指标叫 tpm，而不是在原本的基础上改 @ferrirW