Redis Transaction Example

1. Normal execution
MULTI
Set K1 v1
Set K2 v2
Get K1
Set K3 v3
Exec


2. Discard Transactions
MULTI
Set K1 v1
Set K2 v2
Set K3 v3
DISCARD


3. All guilt
MULTI
Set K1 v1
Set K2 v2
Set K3 v3
Getset K3
Set K4 v4
Set K5 v5
Exec


ERROR,


4. Injustice has a head
MULTI
INCR K1
Set K2 22
Set K3 33
Set K4 v4
Get K4
Exec


Compilation yes, wrong execution.


5.watch Monitoring
A. Table lock--the worst concurrency, the best consistency
B. Row lock--
(1) Pessimistic lock/Optimistic lock/cas (Check and SET),
Optimistic Lock: Add a version to each row




Set Balance 100
Set Debt 0
WATCH Balance
MULTI
Decrby Balance 20
Incrby Debt 20
Exec


Once the unwatch and exec are executed
All previously added monitoring locks will be canceled.