标签：数据库配置 服务 ps命令 center man mem 模块 col 内存耗尽
由于原来项目使用的缓存中间件无法在国产麒麟操作系统里面使用，准备在项目中引入redis做为单机缓存。
Redis默认不是以守护进程的方式运行，可以通过将配置项daemonize修改为yes，这样启动redis-server后会自动在后台运行。
将bind配置为127.0.0.1可以避免redis受外部攻击。另外使用requirepass配置项，可以设置访问redis服务器数据时先要输入密码。
一个小遗憾是redis只支持在配置文件中使用明文保存访问密码，这里提供一个动态生成配置文件的思路增加安全性：
首先将redis.conf备份成redis.conf.tml，在里面的requirepass配置好密码密文。
在启动redis服务前使用其它程序读取redis.conf.tml的requirepass配置项，把密文解密，替换requirepass值生成redis配置文件redis.conf.，启动redis服务后把redis.conf删除，这样就达到保密效果。
为避免redis占用内存无限膨胀，导致把系统内存耗尽，建议将maxmemory设置为1024mb。（实际用ps命令查看，会发现redis-server最多会使用比maxmemory多一些的内存）
同时配置内存淘汰策略maxmemory-policy为allkeys-lru，让redis在内存满时在所有的key中使用LRU算法对数据进行淘汰。
Redis提供了logfile配置项，可以指定日志输出位置。但默认情况下redis会把所有日志输出到同一个文件，天常日久，这个日志文件会越积越大。
建议修改redis的源码，把里面的redisLog函数改为按天输出日志。
由于我们只需要使用redis做数据库缓存，所以不需要持久化。也不需要担心redis重启出现“缓存雪崩”的现象，因为我们业务服务器有很多台，不会同时重启。
单台业务服务器tps有限，缓存清零对数据库也不会产生太大压力。
关闭持久化方法把原来的save配置屏蔽，增加save ""
设置slowlog-log-slower-than 5000，把所有响应时间大于5ms的请求记录起来，方便出故障时定位问题。
有一些redis命令会消耗redis服务器比较多资源，导致查询缓存效率下降。为了防止新手误操作，我们可以把这些命令改名，配置如下：
rename-command MONITOR "DANGEROUS_CMD_MONITOR"
rename-command FLUSHALL "DANGEROUS_CMD_FLUSHALL"
rename-command FLUSHDB "DANGEROUS_CMD_FLUSHDB"
rename-command CONFIG "DANGEROUS_CMD_CONFIG"
rename-command KEYS "DANGEROUS_CMD_KEYS"
优化前：
[huangcihui:/home/huangcihui] redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -q -r 10000 -d 512 PING_INLINE: 56148.23 requests per second PING_BULK: 55617.35 requests per second SET: 57570.52 requests per second GET: 56085.25 requests per second INCR: 55309.73 requests per second LPUSH: 54764.51 requests per second RPUSH: 57570.52 requests per second LPOP: 54644.81 requests per second RPOP: 54884.74 requests per second SADD: 50327.12 requests per second HSET: 58445.36 requests per second SPOP: 53191.49 requests per second LPUSH (needed to benchmark LRANGE): 54945.05 requests per second LRANGE_100 (first 100 elements): 11693.17 requests per second LRANGE_300 (first 300 elements): 3824.09 requests per second LRANGE_500 (first 450 elements): 2342.19 requests per second LRANGE_600 (first 600 elements): 1671.12 requests per second MSET (10 keys): 40192.93 requests per second [huangcihui:/home/huangcihui] redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -q -r 10000 -d 512 PING_INLINE: 55340.34 requests per second PING_BULK: 54854.64 requests per second SET: 53937.43 requests per second GET: 54347.82 requests per second INCR: 52910.05 requests per second LPUSH: 54674.69 requests per second RPUSH: 51894.13 requests per second LPOP: 53676.86 requests per second RPOP: 53022.27 requests per second SADD: 53676.86 requests per second HSET: 55401.66 requests per second SPOP: 56085.25 requests per second LPUSH (needed to benchmark LRANGE): 54347.82 requests per second LRANGE_100 (first 100 elements): 11160.71 requests per second LRANGE_300 (first 300 elements): 3383.98 requests per second LRANGE_500 (first 450 elements): 2246.33 requests per second LRANGE_600 (first 600 elements): 1592.66 requests per second MSET (10 keys): 37622.27 requests per second [huangcihui:/home/huangcihui] redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -q -r 10000 -d 512 PING_INLINE: 54734.54 requests per second PING_BULK: 54024.85 requests per second SET: 54854.64 requests per second GET: 52798.31 requests per second INCR: 55463.12 requests per second LPUSH: 55432.37 requests per second RPUSH: 55834.73 requests per second LPOP: 54495.91 requests per second RPOP: 53705.69 requests per second SADD: 52521.01 requests per second HSET: 54229.93 requests per second SPOP: 54585.15 requests per second LPUSH (needed to benchmark LRANGE): 55648.30 requests per second LRANGE_100 (first 100 elements): 11225.86 requests per second LRANGE_300 (first 300 elements): 3598.29 requests per second LRANGE_500 (first 450 elements): 2222.77 requests per second LRANGE_600 (first 600 elements): 1620.25 requests per second MSET (10 keys): 38684.72 requests per second
优化后：
[huangcihui:/home/huangcihui] redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -q -r 10000 -d 512 -a pass123 PING_INLINE: 51361.07 requests per second PING_BULK: 46838.41 requests per second SET: 49043.65 requests per second GET: 50150.45 requests per second INCR: 51786.64 requests per second LPUSH: 55493.89 requests per second RPUSH: 50150.45 requests per second LPOP: 56915.20 requests per second RPOP: 55928.41 requests per second SADD: 56369.79 requests per second HSET: 58651.02 requests per second SPOP: 57703.40 requests per second LPUSH (needed to benchmark LRANGE): 56593.10 requests per second LRANGE_100 (first 100 elements): 11723.33 requests per second LRANGE_300 (first 300 elements): 3954.76 requests per second LRANGE_500 (first 450 elements): 2504.95 requests per second LRANGE_600 (first 600 elements): 1733.61 requests per second MSET (10 keys): 44444.45 requests per second [huangcihui:/home/huangcihui] redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -q -r 10000 -d 512 -a pass123 PING_INLINE: 57339.45 requests per second PING_BULK: 56561.09 requests per second SET: 56116.72 requests per second GET: 56625.14 requests per second INCR: 57142.86 requests per second LPUSH: 59880.24 requests per second RPUSH: 51387.46 requests per second LPOP: 51599.59 requests per second RPOP: 51334.70 requests per second SADD: 55865.92 requests per second HSET: 57937.43 requests per second SPOP: 58719.91 requests per second LPUSH (needed to benchmark LRANGE): 56625.14 requests per second LRANGE_100 (first 100 elements): 11845.53 requests per second LRANGE_300 (first 300 elements): 3999.20 requests per second LRANGE_500 (first 450 elements): 2414.70 requests per second LRANGE_600 (first 600 elements): 1702.16 requests per second MSET (10 keys): 39494.47 requests per second [huangcihui:/home/huangcihui] redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -q -r 10000 -d 512 -a pass123 PING_INLINE: 51786.64 requests per second PING_BULK: 38417.21 requests per second SET: 55524.71 requests per second GET: 39047.25 requests per second INCR: 44822.95 requests per second LPUSH: 53276.50 requests per second RPUSH: 58582.31 requests per second LPOP: 57208.24 requests per second RPOP: 55066.08 requests per second SADD: 52910.05 requests per second HSET: 55187.64 requests per second SPOP: 57405.28 requests per second LPUSH (needed to benchmark LRANGE): 57570.52 requests per second LRANGE_100 (first 100 elements): 10960.11 requests per second LRANGE_300 (first 300 elements): 3794.20 requests per second LRANGE_500 (first 450 elements): 2355.44 requests per second LRANGE_600 (first 600 elements): 1705.41 requests per second MSET (10 keys): 44130.62 requests per second
经优化后运行效率会有小提升
Redis提供三种集群模式，分别是主从，哨兵，分片三种。但因为我们只打算做为单机缓存，所以不需要配置。
Redis提供了多数据库配置，最多支持256个数据库。我们可以规定不同业务模块使用不同的数据库，这样可以避免数据库主键名称冲突。
但即使同一业务模块，也经常容易出现主键名称相同的情况，所以键名需要制定一些规范：统一使用”前缀:” + 具体值。
例如set uname:13560453764 huangcihui
前缀可以使用excel管理起来，这样基本可以解决键名冲突问题。
最好对所有键设置失效时间，失效时间最好是某个范围内的随机数，这样可以避免缓存同时失效的情况。
部署redis前最好先执行压测命令，看一下性能是否有异常。如果有异常需要考虑是否调整操作系统参数。
redis-benchmark -h 127.0.0.1 -p 6379 -c 100 -n 100000 -k 1 -e -a pass123 -q
注意需要使用-k参数，设置长连接，不然测试结果性能会差很多。（我的机器上测试相差5倍）
标签：数据库配置 服务 ps命令 center man mem 模块 col 内存耗尽
原文地址：https://www.cnblogs.com/kingstarer/p/12400574.html
