Redis群集实现Asp.net Mvc分布式Session
Session的缺点
众所周知Asp.net Session默认存储在IIS中，IIS的重启会导致Session丢失。
如果你的网站使用了session,当网站并发过大时可能引起溢出。
配置Redis 集群
安装Redis
创建一个文件，进入该文件夹
下载Redis 地址：http://download.redis.io/releases/redis-3.0.4.tar.gz
tar -xvf redis-3.0.4.tar.gz 解压文件
cd redis-3.0.4 进入解压的文件
make && make install 安装
创建三个文件夹
把redis.conf文件分别复制到这三个文件夹
然后分别进入这三个文件夹修改配置文件和指定不同的端口
1.daemonize yes （开启后台运行）
2.port 6379 （端口）
3.pidfile /var/run/redis-6379.pid （Redis 以守护进程的方式运行的时候,Redis 默认会把 pid 文件放在/var/run/redis.pid,你可以配置到其他地址。当运行多个 redis 服务时,需要指定不同的 pid 文件和端口）
4.cluster-enabled yes (是否启用集群)
5.cluster-config-file "nodes-6379.conf" (nodes 节点文件)
安装ruby环境
yum -y install zlib ruby rubygems
gem install redis
开启服务
分别开启这三个实例
查看是否开启
创建集群
首先，进入redis的安装包路径下：
cd /usr/local/src/redis/redis-3.0.1/src/
执行命令：
./redis-trib.rb create --replicas 0 ./redis-trib.rb create --replicas 0 192.168.1.108:6379 192.168.1.108:6380 192.168.1.108:6381
进入redis-cli -p 6379 -c
Cluster nodes 查看集群信息
配置完成
使用 StackExchange.Redis驱动连接到redis
代码是我从Asp.net vnext Caching 程序集中copy下来的
配置类型
public class RedisCacheOptions
{
/// <summary>
/// 连接配置
/// </summary>
public string Configuration { get; set; }
/// <summary>
/// 实例名字
/// </summary>
public string InstanceName { get; set; }
}
static void Main(string[] args)
{
string key = "myKey";
object state = null;
string value1 = "yyyyyyyyyyyyyy";
byte[] value = Encoding.Default.GetBytes(value1);
Stream valueStream;
Console.WriteLine("Connecting to cache");
var cache = new RedisCache(new RedisCacheOptions
{
InstanceName = "sessionId",
Configuration = "192.168.1.108:6379,192.168.1.108:6380,192.168.1.108:6381"
});
Console.WriteLine("Connected");
Console.WriteLine("Setting");
valueStream = cache.Set(key, state, context =>
{
context.Data.Write(value, 0, value.Length);
});
RedisCache 集体实现
public class RedisCache : IDistributedCache
{
//Lua 脚本
private const string SetScript = (@"
redis.call('HMSET', KEYS[1], 'absexp', ARGV[1], 'sldexp', ARGV[2], 'data', ARGV[4])
if ARGV[3] ~= '-1' then
redis.call('EXPIRE', KEYS[1], ARGV[3])
end
return 1");
//key
private const string AbsoluteExpirationKey = "absexp";
//key
private const string SlidingExpirationKey = "sldexp";
//key
private const string DataKey = "data";
private const long NotPresent = -1;
private ConnectionMultiplexer _connection;
private IDatabase _cache;
private readonly RedisCacheOptions _options;
private readonly string _instance;
/// <summary>
/// 初始化配置
/// </summary>
/// <param name="optionsAccessor"></param>
public RedisCache(RedisCacheOptions optionsAccessor)
{
_options = optionsAccessor;
_instance = optionsAccessor.InstanceName;
}
public void Connect()
{
if (_connection == null)
{
_connection = ConnectionMultiplexer.Connect(_options.Configuration);
_cache = _connection.GetDatabase();
}
}
/// <summary>
/// set到Redis中
/// </summary>
/// <param name="key"></param>
/// <param name="state"></param>
/// <param name="create"></param>
/// <returns></returns>
public Stream Set(string key, object state, Action<ICacheContext> create)
{
Connect();
var context = new CacheContext(key) { State = state };
//设置绝对过期时间
//context.SetAbsoluteExpiration(DateTimeOffset.Now.AddMilliseconds(22222));
//设置滑动过期时间
context.SetSlidingExpiration(TimeSpan.FromSeconds(22222));
create(context);
var value = context.GetBytes();
//Lua脚本赋值
var result = _cache.ScriptEvaluate(SetScript, new RedisKey[] { _instance + key },
new RedisValue[]
{
context.AbsoluteExpiration?.Ticks ?? NotPresent,
context.SlidingExpiration?.Ticks ?? NotPresent,
context.GetExpirationInSeconds() ?? NotPresent,
value
});
return new MemoryStream(value, writable: false);
}
public bool TryGetValue(string key, out Stream value)
{
value = GetAndRefresh(key, getData: true);
return value != null;
}
public void Refresh(string key)
{
var ignored = GetAndRefresh(key, getData: false);
}
private Stream GetAndRefresh(string key, bool getData)
{
Connect();
RedisValue[] results;
if (getData)
{
results = _cache.HashMemberGet(_instance + key, AbsoluteExpirationKey, SlidingExpirationKey, DataKey);
}
else
{
results = _cache.HashMemberGet(_instance + key, AbsoluteExpirationKey, SlidingExpirationKey);
}
if (results.Length >= 2)
{
DateTimeOffset? absExpr;
TimeSpan? sldExpr;
MapMetadata(results, out absExpr, out sldExpr);
Refresh(key, absExpr, sldExpr);
}
if (results.Length >= 3 && results[2].HasValue)
{
return new MemoryStream(results[2], writable: false);
}
return null;
}
private void MapMetadata(RedisValue[] results, out DateTimeOffset? absoluteExpiration, out TimeSpan? slidingExpiration)
{
absoluteExpiration = null;
slidingExpiration = null;
var absoluteExpirationTicks = (long?)results[0];
if (absoluteExpirationTicks.HasValue && absoluteExpirationTicks.Value != NotPresent)
{
absoluteExpiration = new DateTimeOffset(absoluteExpirationTicks.Value, TimeSpan.Zero);
}
var slidingExpirationTicks = (long?)results[1];
if (slidingExpirationTicks.HasValue && slidingExpirationTicks.Value != NotPresent)
{
slidingExpiration = new TimeSpan(slidingExpirationTicks.Value);
}
}
/// <summary>
/// 刷新缓存过期时间
/// </summary>
/// <param name="key"></param>
/// <param name="absExpr"></param>
/// <param name="sldExpr"></param>
private void Refresh(string key, DateTimeOffset? absExpr, TimeSpan? sldExpr)
{
TimeSpan? expr = null;
if (sldExpr.HasValue)
{
if (absExpr.HasValue)
{
var relExpr = absExpr.Value - DateTimeOffset.Now;
expr = relExpr <= sldExpr.Value ? relExpr : sldExpr;
}
else
{
expr = sldExpr;
}
_cache.KeyExpire(_instance + key, expr);
// TODO: Error handling
}
}
/// <summary>
/// 移除指定key
/// </summary>
/// <param name="key"></param>
public void Remove(string key)
{
Connect();
_cache.KeyDelete(_instance + key);
}
}
运行结果
源码：http://pan.baidu.com/s/1gdm8F9h
分类: Asp.net vnext