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
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Configuration;
usingSystem.Linq;
usingSystem.Text;
usingSystem.Web;
usingServiceStack.Common.Extensions;
usingServiceStack.Redis;
usingServiceStack.Logging;
namespaceWeiz.Redis.Common
{
publicclassRedisCacheHelper
{
PRivatestaticreadonly PooledRedisClientManager pool =null;
privatestaticreadonlystring[] writeHosts =null;
privatestaticreadonlystring[] readHosts =null;
publicstaticint RedisMaxReadPool =int.Parse(ConfigurationManager.AppSettings["redis_max_read_pool"]);
publicstaticint RedisMaxWritePool =int.Parse(ConfigurationManager.AppSettings["redis_max_write_pool"]);
staticRedisCacheHelper()
{
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 =newPooledRedisClientManager(writeHosts, readHosts,
newRedisClientManagerConfig()
{
MaxWritePoolSize =RedisMaxWritePool,
MaxReadPoolSize =RedisMaxReadPool,
AutoStart =true
});
}
}
}
publicstaticvoid Add<T>(stringkey, 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);
}
}
publicstaticvoid Add<T>(stringkey, 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);
}
}
publicstatic T Get<T>(stringkey)
{
if (string.IsNullOrEmpty(key))
{
returndefault(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);
}
returnobj;
}
publicstaticvoid Remove(stringkey)
{
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);
}
}
publicstaticbool Exists(stringkey)
{
try
{
if (pool !=null)
{
using (var r =pool.GetClient())
{
if (r !=null)
{
r.SendTimeout =1000;
returnr.ContainsKey(key);
}
}
}
}
catch(Exception ex)
{
string msg =string.Format("{0}:{1}发生异常!{2}","cache","是否存在", key);
}
returnfalse;
}
publicstatic IDictionary<string, T> GetAll<T>(IEnumerable<string> keys)where T :class
{
if (keys ==null)
{
returnnull;
}
keys = keys.Where(k => !string.IsNullOrWhiteSpace(k));
if (keys.Count() ==1)
{
T obj = Get<T>(keys.Single());
if (obj !=null)
{
returnnew Dictionary<string, T>() { { keys.Single(), obj } };
}
returnnull;
}
if (!keys.Any())
{
returnnull;
}
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));
}
returnnull;
})
.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)));
}
returnresult
.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);
}
}
}