Config connections

Config connections in dubbo

Control connections at server-side

Limit server-side accept to no more than 10 connections

<dubbo:provider protocol="dubbo" accepts="10" />

OR

<dubbo:protocol name="dubbo" accepts="10" />

Control connections at client-side

Limit client-side creating connection to no more than 10 connections for interface com.foo.BarService.

<dubbo:reference interface="com.foo.BarService" connections="10" />

OR

<dubbo:service interface="com.foo.BarService" connections="10" />

Last modified November 25, 2020: fix sample code issue for SPI.md (#659) (0576d68)