前導　　

　　上次Redis MQ分散式改造完成之後， 編排的容器穩定運行了一個多月，昨天突然收到ETL端同事通知，沒有采集到解析日誌了。

 趕緊進伺服器看了一下，用於資料接收的receiver容器掛掉了， 嘗試docker container start [containerid],  幾分鐘後該容器再次崩潰。 

初步排查： Redis連線超限

  docker log [containerid]  檢視容器日誌； 重點：CSRedis.RedisException: ERR max number of clients reached

Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[2]
      Executed action EqidManager.Controllers.EqidController.BatchPutEqidAndProfileIds (EqidReceiver) in 7.1767ms
fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HLPR3AP8ODKH", Request id "0HLPR3AP8ODKH:00000001": An unhandled exception was thrown by the application.
CSRedis.RedisException: ERR max number of clients reached
   at CSRedis.CSRedisClient.GetAndExecute[T](RedisClientPool pool, Func`2 handler, Int32 jump, Int32 errtimes)
   at CSRedis.CSRedisClient.ExecuteScalar[T](String key, Func`3 hander)
   at CSRedis.CSRedisClient.LPush[T](String key, T[] value)
   at RedisHelper.LPush[T](String key, T[] value)
   at EqidManager.Controllers.EqidController.BatchPutEqidAndProfileIds(List`1 eqidPairs) in /home/gitlab-runner/builds/haD2h5xC/0/webdissector/datasource/eqid-manager/src/EqidReceiver/Controllers/EqidController.cs:line 31
   at lambda_method(Closure , Object )
   at Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable.Awaiter.GetResult()
   at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.AwaitableResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeActionMethodAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeNextActionFilterAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
   at Microsoft.AspNetCore.Builder.RouterMiddleware.Invoke(HttpContext httpContext)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)
info: Microsoft.AspNetCore.Hosting.Internal.WebHost[2]
      Request finished in 8.9549ms 500 
【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)
【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)
【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)
【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)

【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)
【dockerhost:6379/0】仍然不可用，下一次恢復檢查時間：09/17/2019 03:11:25，錯誤：(ERR max number of clients reached)

 日誌上顯示連線Redis伺服器的客戶端數量超限，頭腦快速思考，目前編排的某容器使用CSRedisCore 對於16個Redis DB例項化了16個客戶端，但Redis伺服器也不至於這麼不經摺騰吧。

趕緊進redis.io官網蒐集相關資料。

After the client is initialized, Redis checks if we are already at the limit of the number of clients that it is possible to handle simultaneously (this is configured using the maxclients

 configuration directive, see the next section of this document for further information).

In case it can't accept the current client because the maximum number of clients was already accepted, Redis tries to send an error to the client in order to make it aware of this condition, and closes the connection immediately. The error message will be able to reach the client even if the connection is closed immediately by Redis because the new socket output buffer is usually big enough to contain the error, so the kernel will handle the transmission of the error.

 大致意思是：Redis伺服器maxclients配置了客戶端連線數， 如果當前連線的客戶端超限，Redis會回發一個錯誤訊息給客戶端，並迅速關閉客戶端連線。

立刻登入Redis伺服器檢視預設配置，確認當前Redis伺服器預設配置是10000

After the client is initialized, Redis checks if we are already at the limit of the number of clients that it is possible to handle simultaneously (this is configured using the maxclients configuration directive, see the next section of this document for further information).

In case it can't accept the current client because the maximum number of clients was already accepted, Redis tries to send an error to the client in order to make it aware of this condition, and closes the connection immediately. The error message will be able to reach the client even if the connection is closed immediately by Redis because the new socket output buffer is usually big enough to contain the error, so the kernel will handle the transmission of the error.

   基本可認定redis客戶端使用方式有問題。

問題定位：CSRedisCore使用方式

　繼續檢視相關資料，可在redis伺服器上利用redis-cli命令：info clients、client list仔細分析客戶端連線。

info clients 命令顯示 現場確實是10000的連線數；

id=2205 addr=172.16.1.3:36954 fd=1276 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2215 addr=172.16.1.3:45923 fd=1277 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2216 addr=172.16.1.3:44233 fd=1278 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2217 addr=172.16.1.3:41144 fd=1279 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2218 addr=172.16.1.3:44528 fd=1280 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2219 addr=172.16.1.3:41626 fd=1281 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2220 addr=172.16.1.3:39045 fd=1282 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2221 addr=172.16.1.3:42862 fd=1283 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2222 addr=172.16.1.3:41356 fd=1284 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=2223 addr=172.16.1.3:36076 fd=1285 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1798 addr=172.16.1.3:44865 fd=1070 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1799 addr=172.16.1.3:40315 fd=1072 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1800 addr=172.16.1.3:44051 fd=1073 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1801 addr=172.16.1.3:45183 fd=1074 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1802 addr=172.16.1.3:42352 fd=1075 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1803 addr=172.16.1.3:44401 fd=1076 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1804 addr=172.16.1.3:41325 fd=1068 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1805 addr=172.16.1.3:42309 fd=1069 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1815 addr=172.16.1.3:33341 fd=1077 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1816 addr=172.16.1.3:42546 fd=1078 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1817 addr=172.16.1.3:43985 fd=1079 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=lpush
id=1818 addr=172.16.1.3:44852 fd=1080 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1819 addr=172.16.1.3:40936 fd=1081 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1820 addr=172.16.1.3:36922 fd=1082 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1821 addr=172.16.1.3:40507 fd=1083 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1822 addr=172.16.1.3:37327 fd=1084 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1823 addr=172.16.1.3:44966 fd=1085 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1825 addr=172.16.1.3:38138 fd=1086 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1836 addr=172.16.1.3:45613 fd=1087 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1837 addr=172.16.1.3:39475 fd=1089 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1838 addr=172.16.1.3:43459 fd=1090 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1839 addr=172.16.1.3:37892 fd=1088 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1840 addr=172.16.1.3:40415 fd=1092 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1841 addr=172.16.1.3:37844 fd=1093 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1842 addr=172.16.1.3:34432 fd=1091 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1843 addr=172.16.1.3:38402 fd=1094 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1844 addr=172.16.1.3:41417 fd=1095 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1845 addr=172.16.1.3:44452 fd=1096 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1856 addr=172.16.1.3:37699 fd=1097 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1857 addr=172.16.1.3:43107 fd=1098 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1858 addr=172.16.1.3:46324 fd=1099 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1859 addr=172.16.1.3:33636 fd=1100 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1860 addr=172.16.1.3:42645 fd=1101 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1861 addr=172.16.1.3:46533 fd=1102 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1862 addr=172.16.1.3:45811 fd=1103 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1863 addr=172.16.1.3:43083 fd=1104 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1864 addr=172.16.1.3:34539 fd=1105 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1865 addr=172.16.1.3:43872 fd=1106 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1874 addr=172.16.1.3:32960 fd=1107 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1875 addr=172.16.1.3:42920 fd=1109 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1876 addr=172.16.1.3:37355 fd=1110 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1877 addr=172.16.1.3:41505 fd=1111 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1878 addr=172.16.1.3:34633 fd=1112 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1879 addr=172.16.1.3:44362 fd=1114 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1882 addr=172.16.1.3:41947 fd=1108 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1883 addr=172.16.1.3:46534 fd=1113 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1884 addr=172.16.1.3:36814 fd=1115 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1885 addr=172.16.1.3:42278 fd=1116 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1893 addr=172.16.1.3:43971 fd=1120 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1894 addr=172.16.1.3:42935 fd=1122 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1896 addr=172.16.1.3:42742 fd=1119 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1898 addr=172.16.1.3:34410 fd=1117 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1899 addr=172.16.1.3:34112 fd=1118 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1900 addr=172.16.1.3:39654 fd=1121 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1901 addr=172.16.1.3:41308 fd=1123 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1902 addr=172.16.1.3:44353 fd=1125 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1904 addr=172.16.1.3:36208 fd=1126 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1905 addr=172.16.1.3:32785 fd=1124 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1915 addr=172.16.1.3:32928 fd=1127 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=1916 addr=172.16.1.3:43645 fd=1128 name= age=26 idle=26 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping

根據官方文件的解釋，redis伺服器收到很多來自ip為172.16.1.3（故障容器在網橋內的Ip 地址）的客戶端連線，這些連線最後發出的是ping命令（這是一個測試命令）

• addr: The client address, that is, the client IP and the remote port number it used to connect with the Redis server.
• fd: The client socket file descriptor number.
• name: The client name as set by CLIENT SETNAME.
• age: The number of seconds the connection existed for.
• idle: The number of seconds the connection is idle.
• flags: The kind of client (N means normal client, check the full list of flags).
• omem: The amount of memory used by the client for the output buffer.
• cmd: The last executed command.

故障容器使用的Redis客戶端是CSRedisCore，該客戶端只是單純將 Msg 寫入Redis list 資料結構，CSRedisCore上相關github issue給了我一些啟發，發現自己將CSRedisClient例項化程式碼寫在 .netcore api Controller建構函式，這樣每次請求構造Controller時都 例項化一次Redis客戶端，最終Redis客戶端不超限才怪。

依賴注入三種模式：　單例（系統內單一例項，一次性注入）；瞬態（每次請求產生例項並注入）；自定義範圍。

有關dotnet apicontroller 以瞬態模式 注入，請查閱連結。

 趕緊將CSRedisCore例項化程式碼移到 startup.cs 並註冊為單例。

大膽求證

info clients命令顯示穩定在53個Redis連線。

client list命令顯示：172.16.1.3（故障容器）建立了50個客戶端連線，編排的另一個容器webapp建立了2個連線，redis-cli命令登入到伺服器建立了1個連線。

127.0.0.1:6379> client list
id=20409 addr=172.16.1.3:44834 fd=18 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20410 addr=172.16.1.3:39881 fd=20 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20411 addr=172.16.1.3:42756 fd=17 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20419 addr=172.16.1.3:46224 fd=21 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20423 addr=172.16.1.3:34748 fd=28 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20424 addr=172.16.1.3:37483 fd=22 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20425 addr=172.16.1.3:44064 fd=29 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20426 addr=172.16.1.3:43993 fd=25 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20427 addr=172.16.1.3:34092 fd=24 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20428 addr=172.16.1.3:35347 fd=27 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20429 addr=172.16.1.3:46126 fd=30 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20430 addr=172.16.1.3:42627 fd=23 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20431 addr=172.16.1.3:35098 fd=26 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20442 addr=172.16.1.3:34471 fd=31 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20443 addr=172.16.1.3:35092 fd=32 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20444 addr=172.16.1.3:46168 fd=33 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20445 addr=172.16.1.3:42879 fd=34 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20446 addr=172.16.1.3:46627 fd=35 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20447 addr=172.16.1.3:44731 fd=36 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20448 addr=172.16.1.3:36705 fd=37 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20449 addr=172.16.1.3:38668 fd=38 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20450 addr=172.16.1.3:45484 fd=39 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20451 addr=172.16.1.3:40802 fd=40 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20459 addr=172.16.1.3:36973 fd=45 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20460 addr=172.16.1.3:37814 fd=41 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20462 addr=172.16.1.3:44642 fd=44 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20463 addr=172.16.1.3:35272 fd=42 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20465 addr=172.16.1.3:42843 fd=47 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20466 addr=172.16.1.3:46785 fd=48 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20468 addr=172.16.1.3:38481 fd=49 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20504 addr=127.0.0.1:40902 fd=60 name= age=1478 idle=0 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=26 qbuf-free=32742 obl=0 oll=0 omem=0 events=r cmd=client
id=20469 addr=172.16.1.3:45822 fd=50 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20470 addr=172.16.1.3:37211 fd=43 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20471 addr=172.16.1.3:39386 fd=46 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20481 addr=172.16.1.3:37346 fd=51 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20482 addr=172.16.1.3:42387 fd=52 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20483 addr=172.16.1.3:41523 fd=53 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20484 addr=172.16.1.3:37088 fd=54 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20485 addr=172.16.1.3:41371 fd=55 name=receiver age=73384 idle=8 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=lpush
id=20486 addr=172.16.1.3:34362 fd=56 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20487 addr=172.16.1.3:45409 fd=57 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20488 addr=172.16.1.3:36119 fd=58 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20489 addr=172.16.1.3:46631 fd=59 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20389 addr=172.16.1.3:42971 fd=8 name=receiver age=73387 idle=73387 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20392 addr=172.16.1.4:42699 fd=11 name=f176f125a4c5 age=73386 idle=4 flags=P db=0 sub=1 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20393 addr=172.16.1.4:40179 fd=12 name=f176f125a4c5 age=73386 idle=0 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=32768 obl=0 oll=0 omem=0 events=r cmd=rpop
id=20400 addr=172.16.1.3:36255 fd=10 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20401 addr=172.16.1.3:36118 fd=9 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20402 addr=172.16.1.3:42346 fd=13 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20403 addr=172.16.1.3:40437 fd=14 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20404 addr=172.16.1.3:37910 fd=15 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20405 addr=172.16.1.3:35374 fd=16 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=ping
id=20408 addr=172.16.1.3:34197 fd=19 name=receiver age=73384 idle=73384 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=0 oll=0 omem=0 events=r cmd=pin

那麼問題來了，修改之後，receiver容器為什麼還穩定建立了50個redis連線？

進一步與CSRedisCore原作者溝通，確定CSRedisCore有預熱機制，預設在連線池中預熱了５０個連線。

bingo，故障和困惑全部排查清楚。

總結

經此一役，在使用CSRedisCore客戶端時，　要深入理解

① Stackexchange.Redis 使用的多路複用連線機制（使用時很容易想到註冊到單例），CSRedisCore開源庫採用連線池機制，在高併發場景下強烈建議註冊為單例， 否則在生產使用中可能會誤用在瞬態請求中例項化，導致redis客戶端幾天之後被佔滿。

② CSRedisCore會預設建立連線池，預熱50個連線， 開發者心裡要有數。

額外的方法論： 儘量不要從某度找答案，要學會問問題，並嘗試從官方、stackoverflow 、github社群尋求解答，你挖過的坑也許別人早就挖過並踏平