Make a simple second kill with Redis.

Here is a simple next order operation

<?phpinclude "MMysql.class.php"; $configArr =[' host ' =>, ' Port ' =>, ' user ' =>, ' passwd ' =>, ' dbname ' => ]; $db = new Mmysql ($CONFIGARR); $sql = "SELECT * from sdb_b2c_products where product_id= '"; $product = $db->dosql ($sql if (! $product) {echo "Error:not find product"; return;} $product = $product [0];if ($product [' Store ']-$product [' Freez ']<1) {echo "Error:no store"; return;} $sql = "SELECT * from Sdb_b2c_member_addrs where member_id= ' 256187 '"; $addr = $db->dosql ($sql); $addr = $addr [0]; $data =[ ' order_id ' =>date (' Ymdhis '). Rand (100,999), ' total_amount ' = $product [' Price '], ' final_amount ' and ' = ' $product [' Price '], ' pay_status ' = ' 0 ', ' createtime ' =>time (), ' shipping_id ' = ' + ', ' shipping ' = ' Yun da ', ' member_id ' = > ' 636389 ', ' ship_area ' + $addr [' area '], ' shipname ' = ' + $addr [' name '], ' ship_addr ' + $addr [' addr ']; er = $db->insert (' sdb_b2c_orders ', $data); if (er) {$sql = "update sdb_b2c_products set freez=freez+1 where product_id = '->dosql '; $db ($sql); echo "Order create success"; return;}Else{echo "Error:order create fail"; return;}? >

The code is interpreted as:

Find goods in the product table, get physical inventory and virtual inventory, if the time inventory minus virtual inventory less than 1, it means that there is no inventory

If there is physical inventory, go to the memeber_id as ' 256187 ' for the address information of the member, and then create the order

If the order creation is successful, the virtual inventory is updated.

Using JMeter to test the effect under concurrency, set 500 threads to simulate concurrency

Pre-test set the actual inventory store is 50, virtual inventory Freez is 0, under normal circumstances Freez can only reach 50, otherwise there will be oversold situation

The actual test, in the case of high concurrency, is usually greater than 50, at around 54 Freez.

Due to the availability of inventory, there is a time lag in the middle of changing the inventory, and there is a problem of oversold in all high concurrency.

The following code has been modified to use the Redis list as a queue.

<?php$store=50; $redis =new redis () $result = $redis->connect (' 127.0.0.1 ', 6379); $res = $redis->llen (' pro38 ') , echo $res, $count = $store-$res; for ($i =0; $i < $count; $i + +) {$redis->lpush (' pro38 ', 1);} echo $redis->llen (' pro38 ');? >

Above is a list that adds a Redis inventory of 50

The following post-order code

<?phpinclude "MMysql.class.php"; $configArr =[' host ' = ' 121.41.38.44 ', ' port ' = ' 3306 ', ' user ' = ' Yuancheng ', ' passwd ' = ' Yuancheng ', ' dbname ' = ' laiyifendb ',]; $db = new Mmysql ($CONFIGARR); $redis =new Redis (); $ result= $redis->connect (' 127.0.0.1 ', 6379), $count = $redis->lpop (' pro38 '), if (! $count) {echo "Error:no store Redis "; return;} $sql = "SELECT * from sdb_b2c_products where product_id= '"; $product = $db->dosql ($sql); if (! $product) {echo "Error: Not find product "; return;} $product = $product [0];if ($product [' Store ']-$product [' Freez ']<1) {echo "Error:no store"; return;} $sql = "SELECT * from Sdb_b2c_member_addrs where member_id= ' 256187 '"; $addr = $db->dosql ($sql); $addr = $addr [0]; $data =[ ' order_id ' =>date (' Ymdhis '). Rand (100,999), ' total_amount ' = $product [' Price '], ' final_amount ' and ' = ' $product [' Price '], ' pay_status ' = ' 0 ', ' createtime ' =>time (), ' shipping_id ' = ' + ', ' shipping ' = ' Yun da ', ' member_id ' = > ' 636389 ', ' ship_area ' + $addr [' area '], ' shipname ' and ' = ' $addr [' name '], ' ship_addr ' + $addr[' addr ',]; er = $db->insert (' sdb_b2c_orders ', $data); if (er) {$sql = "Update sdb_b2c_products set freez= freez+1 where product_id= ' ""; $db->dosql ($sql); echo "Order create success"; return;} Else{echo "Error:order create fail"; return;}? >

After testing, this method can prevent the occurrence of oversold

Make a simple second kill with Redis.