Where is the business logic written using the microservice framework istio,?

the Nuggets just read two istio articles, https://github.com/istio/istio

I don"t understand much. Question:
where should the business logic be written when using this micro-service framework? Do you want to write in java?

Mar.04,2021

istio is a proxy behind your program, non-intrusive, and does not need to be changed to existing code. For more information, please see istio architecture

.
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b36e9d-2c067.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b36e9d-2c067.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?