Which parameters need to be changed to improve repairs?

error: Repair job has failed with the error message: 
Repair command #1158 failed with error Repair session 
b836f570-700d-11ef-9447-377b26201515 
for range [(9164824941183028599,-9164226683701868787], 
(6868832037534058657,6892120122899442963], 

(9091534174371255880,9164824941183028599]] failed with error 
[repair #b836f570-700d-11ef-9447-377b26201515 on test/tab_ext

[(9164824941183028599,-9164226683701868787], 

(6868832037534058657,6892120122899442963], (9091534174371255880,9164824941183028599]]] 
Validation failed in test-east-prod-cassandra-vm0.az.com/10.2.1.5.:7000. 

Check the logs on the repair