Redis交互速度慢，频繁处理时经常报错 RedisSystemException: RedisException: Connection closed

Redis交互速度很慢，达到几十到一百毫秒一次，且压力测试下经常报错：

org.springframework.data.redis.RedisSystemException: Redis exception; nested exception is io.lettuce.core.RedisException: Connection closed
	at org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:74)
	at org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:41)
	at org.springframework.data.redis.PassThroughExceptionTranslationStrategy.translate(PassThroughExceptionTranslationStrategy.java:44)
	at org.springframework.data.redis.FallbackExceptionTranslationStrategy.translate(FallbackExceptionTranslationStrategy.java:42)
	at org.springframework.data.redis.connection.lettuce.LettuceConnection.convertLettuceAccessException(LettuceConnection.java:277)
	at org.springframework.data.redis.connection.lettuce.LettuceConnection.await(LettuceConnection.java:1085)
	at org.springframework.data.redis.connection.lettuce.LettuceConnection.lambda$doInvoke$4(LettuceConnection.java:938)
	at org.springframework.data.redis.connection.lettuce.LettuceInvoker$Synchronizer.invoke(LettuceInvoker.java:673)
	at org.springframework.data.redis.connection.lettuce.LettuceInvoker$DefaultSingleInvocationSpec.get(LettuceInvoker.java:589)
	at org.springframework.data.redis.connection.lettuce.LettuceKeyCommands.exists(LettuceKeyCommands.java:79)
	at org.springframework.data.redis.connection.DefaultedRedisConnection.exists(DefaultedRedisConnection.java:81)
	at org.springframework.data.redis.core.RedisTemplate.lambda$hasKey$7(RedisTemplate.java:782)
	at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:224)
	at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:191)
	at org.springframework.data.redis.core.RedisTemplate.hasKey(RedisTemplate.java:782)
	at com.bestdata.em.drs.util.RedisUtil.hasKey(RedisUtil.java:98)
	at com.bestdata.em.drs.receive.serivce.impl.HasMoreBusinessServiceImpl.insertFormulaValueToMongoDB(HasMoreBusinessServiceImpl.java:180)
	at com.bestdata.em.drs.receive.serivce.impl.HasMoreBusinessServiceImpl.moreBusinessOperations(HasMoreBusinessServiceImpl.java:113)
	at com.bestdata.em.drs.receive.serivce.FormulaDataProcessingService.sensorFormulaCalculation(FormulaDataProcessingService.java:264)
	at com.bestdata.em.drs.receive.serivce.FormulaDataProcessingService.run(FormulaDataProcessingService.java:167)
	at java.lang.Thread.run(Thread.java:750)
16:18:33.404 [FormulaThreadPoll-9] ERROR c.b.e.d.r.s.i.HasMoreBusinessServiceImpl - Unite Alarm Exception:Redis exception; nested exception is io.lettuce.core.RedisException: Connection closed

问题排查：服务端和redis是否在同一网段

是内网，没问题

问题排查：Redis资源占用

执行top命令
Redis CPU占用一直高达50%~100%，3到5秒就跳一次（此时生产环境有其他程序和redis交互，但是没有特别大）
Redis数据量占用很高，且这是单点部署非集群模式
执行压力测试程序（频繁交互Redis，经常报错RedisSystemException）：Redis CPU占用一直高达100%

优化思路

提高Redis服务器资源配置
Redis改为集群部署模式，分担压力