需要注意的是：ServiceStack.Redis 中GetClient()方法，只能拿到Master redis中获取连接，而拿不到slave 的readonly连接。这样 slave起到了冗余备份的作用，读的功能没有发挥出来，如果并发请求太多的话，则Redis的性能会有影响。
所以，我们需要的写入和读取的时候做一个区分，写入的时候，调用client.GetClient() 来获取writeHosts的Master的redis 链接。读取，则调用client.GetReadOnlyClient()来获取的readonlyHost的 Slave的redis链接。
或者可以直接使用client.GetCacheClient() 来获取一个连接，他会在写的时候调用GetClient获取连接，读的时候调用GetReadOnlyClient获取连接，这样可以做到读写分离，从而利用redis的主从复制功能。
1. 配置文件 app.config
<!-- redis Start -->
<add key="SessionExpireMinutes" value="180" />
<add key="redis_server_master_session" value="127.0.0.1:6379" />
<add key="redis_server_slave_session" value="127.0.0.1:6380" />
<add key="redis_max_read_pool" value="300" />
<add key="redis_max_write_pool" value="100" />
<!--redis end-->
2. Redis操作的公用类RedisCacheHelper
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Text;
using System.Web;
using ServiceStack.Common.Extensions;
using ServiceStack.Redis;
using ServiceStack.Logging;
namespace Weiz.Redis.Common
{
public class RedisCacheHelper
{
private static readonly PooledRedisClientManager pool = null;
private static readonly string[] writeHosts = null;
private static readonly string[] readHosts = null;
public static int RedisMaxReadPool = int.Parse(ConfigurationManager.AppSettings["redis_max_read_pool"]);
public static int RedisMaxWritePool = int.Parse(ConfigurationManager.AppSettings["redis_max_write_pool"]);
static RedisCacheHelper()
{
var redisMasterHost = ConfigurationManager.AppSettings["redis_server_master_session"];
var redisSlaveHost = ConfigurationManager.AppSettings["redis_server_slave_session"];
if (!string.IsNullOrEmpty(redisMasterHost))
{
writeHosts = redisMasterHost.Split(‘,‘);
readHosts = redisSlaveHost.Split(‘,‘);
if (readHosts.Length > 0)
{
pool = new PooledRedisClientManager(writeHosts, readHosts,
new RedisClientManagerConfig()
{
MaxWritePoolSize = RedisMaxWritePool,
MaxReadPoolSize = RedisMaxReadPool,
AutoStart = true
});
}
}
}
public static void Add<T>(string key, T value, DateTime expiry)
{
if (value == null)
{
return;
}
if (expiry <= DateTime.Now)
{
Remove(key);
return;
}
try
{
if (pool != null)
{
using (var r = pool.GetClient())
{
if (r != null)
{
r.SendTimeout = 1000;
r.Set(key, value, expiry - DateTime.Now);
}
}
}
}
catch (Exception ex)
{
string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "存储", key);
}
}
public static void Add<T>(string key, T value, TimeSpan slidingExpiration)
{
if (value == null)
{
return;
}
if (slidingExpiration.TotalSeconds <= 0)
{
Remove(key);
return;
}
try
{
if (pool != null)
{
using (var r = pool.GetClient())
{
if (r != null)
{
r.SendTimeout = 1000;
r.Set(key, value, slidingExpiration);
}
}
}
}
catch (Exception ex)
{
string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "存储", key);
}
}
public static T Get<T>(string key)
{
if (string.IsNullOrEmpty(key))
{
return default(T);
}
T obj = default(T);
try
{
if (pool != null)
{
using (var r = pool.GetClient())
{
if (r != null)
{
r.SendTimeout = 1000;
obj = r.Get<T>(key);
}
}
}
}
catch (Exception ex)
{
string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "获取", key);
}
return obj;
}
public static void Remove(string key)
{
try
{
if (pool != null)
{
using (var r = pool.GetClient())
{
if (r != null)
{
r.SendTimeout = 1000;
r.Remove(key);
}
}
}
}
catch (Exception ex)
{
string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "删除", key);
}
}
public static bool Exists(string key)
{
try
{
if (pool != null)
{
using (var r = pool.GetClient())
{
if (r != null)
{
r.SendTimeout = 1000;
return r.ContainsKey(key);
}
}
}
}
catch (Exception ex)
{
string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "是否存在", key);
}
return false;
}
public static IDictionary<string, T> GetAll<T>(IEnumerable<string> keys) where T : class
{
if (keys == null)
{
return null;
}
keys = keys.Where(k => !string.IsNullOrWhiteSpace(k));
if (keys.Count() == 1)
{
T obj = Get<T>(keys.Single());
if (obj != null)
{
return new Dictionary<string, T>() { { keys.Single(), obj } };
}
return null;
}
if (!keys.Any())
{
return null;
}
IDictionary<string, T> dict = null;
if (pool != null)
{
keys.Select(s => new
{
Index = Math.Abs(s.GetHashCode()) % readHosts.Length,
KeyName = s
})
.GroupBy(p => p.Index)
.Select(g =>
{
try
{
using (var r = pool.GetClient(g.Key))
{
if (r != null)
{
r.SendTimeout = 1000;
return r.GetAll<T>(g.Select(p => p.KeyName));
}
}
}
catch (Exception ex)
{
string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "获取", keys.Aggregate((a, b) => a + "," + b));
}
return null;
})
.Where(x => x != null)
.ForEach(d =>
{
d.ForEach(x =>
{
if (dict == null || !dict.Keys.Contains(x.Key))
{
if (dict == null)
{
dict = new Dictionary<string, T>();
}
dict.Add(x);
}
});
});
}
IEnumerable<Tuple<string, T>> result = null;
if (dict != null)
{
result = dict.Select(d => new Tuple<string, T>(d.Key, d.Value));
}
else
{
result = keys.Select(key => new Tuple<string, T>(key, Get<T>(key)));
}
return result
.Select(d => new Tuple<string[], T>(d.Item1.Split(‘_‘), d.Item2))
.Where(d => d.Item1.Length >= 2)
.ToDictionary(x => x.Item1[1], x => x.Item2);
}
}
}