multi opens the transaction, exec executes the transaction
example:
set age 10
multi
set age 20
set age 30
exec
get age
final age=30
cancel transaction discard
Empty the command queue of the transaction and exit the transaction context, that is, the transaction is rolled back
set age 10
multi
set age 20
set age 30
discard
get age
final age=10
optimistic locking transaction processing watch
watch age, if other sessions modify the age after monitoring the age, it will not be able to commit when the transaction is committed.