EF + Redis (StackExchange. Redis) implements distributed locks, which is feasible in self-testing. stackexchange. redis

EF + Redis (StackExchange. Redis) implements distributed locks, which is feasible in self-testing. stackexchange. redis

E-commerce platforms will have a flash sale, for example, 1 yuan flash sale. The most important thing about flash sales is inventory. In many cases, if the inventory is not properly processed, the oversold status may occur.

This article uses redis as the cache, StackExchange framework, and message queue to implement distributed locks

I. Results

First look at the effect,

 

High concurrency of form Order Construction

Open multiple console applications to process orders

2. Configure Redis

  <Redis.Service>    <DbConfig Name="Order_DBName"  Hosts="127.0.0.1:6379" dbNum="2">    </DbConfig>    <DbConfig Name="Product_DbName" Hosts="127.0.0.1:6379" dbNum="1">    </DbConfig>

Simulate user order

      private void button1_Click(object sender, EventArgs e)        {            var orderCount = Convert.ToInt32(txt_OrderCount.Text);            var productId = Convert.ToInt32(txt_ProductId.Text);            var productCount = Convert.ToInt32(txt_ProductCount.Text);            for (int i = 0; i < orderCount; i++)            {                RedisOrderModel cacheOrder = new RedisOrderModel()                {                    Count = productCount,                    OrderNo = (orderNo += 1).ToString(),                    ProductId = productId                };                orderRedis.Push(cacheOrder);            }                    }

Console program processing order

Public void QueueList () {RedisOrderMessage redis = new RedisOrderMessage (); while (true) {try {var cacheOrder = redis. pop (); if (cacheOrder = null) {Console. writeLine ("no order, rest 100 milliseconds"); Thread. sleep (1000); continue;} while (ThreadCount <= 0) {Console. writeLine ("the Thread is full and the rest is 100 milliseconds"); Thread. sleep (100);} // ThreadCount --; Thread thread = new Thread (new ThreadStart (cacheOrder. createOrder); thread. start (); Console. writeLine ("processing order, rest 100 milliseconds"); Thread. sleep (100);} catch (Exception ex) {Console. writeLine (ex. message + "," + ex. stackTrace); Thread. sleep (1000) ;}finally {ThreadCount ++ ;}}}

 

Use distributed locks to determine whether the inventory is sufficient

Public void LockStore (string productId, int count) {var keyInfo = AddSysCustomKey (productId); if (! Exists (keyInfo) {throw new Exception ("commodity cache does not exist");} var redisConfig = ReadRedisConfig. getRedisConfig (DB_Name); var lockdb = redisConfig. getDatabase (-1); var db = redisConfig. getDatabase (); var token = Environment. machineName; while (true) {// db. lockRelease (keyInfo, token); var con = lockdb. lockTake (keyInfo, token, TimeSpan. fromSeconds (10.0), CommandFlags. none); // var con = db. lockTake (keyInfo, token, TimeSpan. fromSeconds (20), CommandFlags. none); if (con) {try {var product = ConvertObj <CacheProduct> (db. stringGet (keyInfo); if (product. count <count) {throw new Exception ("insufficient quantity, order failed");} product. count-= count; var json = ConvertJson (product); db. stringSet (keyInfo, json);} finally {lockdb. lockRelease (keyInfo, token) ;}break ;}}}

Source Code address:

 

Https://github.com/buruainiaaaa/CacheDemo.git