redis配置注意事项(适合于较大配置)

  根据官方的建议,redis-server的相关配置建议如下,但是有些并不合适,LZ会进行说明(如果redis使用的内存还不到1GB,或者大量qps还不到1000的应用,这已经淘汰了99%的应用,很多配置基本上就无所谓了,基本上没这么大影响,保证高可用即可,不会有性能问题的;):

1、vm.overcommit_memory = 1。实际中最好让redis主节点仅使用50-60%的内存,剩余的用于执行bgsave和创建写命令的缓冲区,保证最大可能的sla。

2、禁用linux内核特性transparent huge pages,echo never > /sys/kernel/mm/transparent_hugepage/enabled,oracle也如此要求,TPH和传统的大页在机制上有些不同,参见http://blog.itpub.net/26736162/viewspace-2214374/。

3、避免使用swap或禁用

4、设置maxmemory,限制redis使用的内存数量,而非自动,否则发生交换就奇慢无比了;

5、如果是ssd的话,复制模式下建议master节点启用持久化选项(当超过数GB时,保存快照会对前端影响较大,如果能够容忍极端情况下小部分更新丢失,应在slave节点机进行,而非master节点,主要可能是国外数据没国内这么大);

6、一般应使用显示的redis.conf,而非使用内置的配置,可在启动时通过命令行指定/etc/redis.conf;

7、应显示设置rdb、aof日志文件目录及文件名,logfile参数;默认为工作目录:

# The filename where to dump the DB
dbfilename dump.rdb   # rdb文件名

# The working directory.
#
# The DB will be written inside this directory, with the filename specified
# above using the 'dbfilename' configuration directive.
#
# The Append Only File will also be created inside this directory.
#
# Note that you must specify a directory here, not a file name.    # rdb存储目录
dir ./
[root@XXX redis-3.2.12]# ll | grep dump
-rw-r--r--  1 root root  19274 Aug  8 20:12 dump_16379.rdb
-rw-r--r--  1 root root   1259 Aug  8 22:23 dump_46379.rdb
-rw-r--r--  1 root root 446620 Nov 23 02:05 dump.rdb

 

############################## APPEND ONLY MODE ###############################

# By default Redis asynchronously dumps the dataset on disk. This mode is
# good enough in many applications, but an issue with the Redis process or
# a power outage may result into a few minutes of writes lost (depending on
# the configured save points).
#
# The Append Only File is an alternative persistence mode that provides
# much better durability. For instance using the default data fsync policy
# (see later in the config file) Redis can lose just one second of writes in a
# dramatic event like a server power outage, or a single write if something
# wrong with the Redis process itself happens, but the operating system is
# still running correctly.
#
# AOF and RDB persistence can be enabled at the same time without problems.
# If the AOF is enabled on startup Redis will load the AOF, that is the file
# with the better durability guarantees.
#
# Please check http://redis.io/topics/persistence for more information.

appendonly yes

# The name of the append only file (default: "appendonly.aof")

appendfilename "appendonly.aof"

# The fsync() call tells the Operating System to actually write data on disk
# instead of waiting for more data in the output buffer. Some OS will really flush
# data on disk, some other OS will just try to do it ASAP.
#
# Redis supports three different modes:
#
# no: don't fsync, just let the OS flush the data when it wants. Faster.
# always: fsync after every write to the append only log. Slow, Safest.
# everysec: fsync only one time every second. Compromise.
#
# The default is "everysec", as that's usually the right compromise between
# speed and data safety. It's up to you to understand if you can relax this to
# "no" that will let the operating system flush the output buffer when
# it wants, for better performances (but if you can live with the idea of
# some data loss consider the default persistence mode that's snapshotting),
# or on the contrary, use "always" that's very slow but a bit safer than
# everysec.
#
# More details please check the following article:
# http://antirez.com/post/redis-persistence-demystified.html
#
# If unsure, use "everysec".

# appendfsync always   AOF默认每秒写一次,跟mysql的innodb redo刷新机制是一样的
appendfsync everysec
# appendfsync no

 

8、各个版本的详细配置可参考:

 

9、重要的是:

1、单进程架构,这意味着单个key的value不能过大,例如几兆,这会严重影响TPS,具体拆分可以参考:https://blog.csdn.net/beyond59241/article/details/78889867/
2、支持多database,不过最好使用多个instance的方式,有些客户端可能不支持多instance,同时性能也比较难以排查
3、不支持namespace的概念,所以最好使用前提前规划,比如namespace:key_name的方式,避免日后混乱
4、vm.swappiness=0 在os swap期间,进程会block直到完成,所以应该尽量避免

10、客户端缓冲大小配置,尤其是是在行情接收场景中。https://blog.csdn.net/luyaoying001/article/details/80264347

11、其它实践可以参考:https://www.cnblogs.com/ajianbeyourself/p/4472788.html

12、避免快照所在盘磁盘空间满,否则容易出现redis挂起。

 

posted @ 2016-09-25 20:00  zhjh256  阅读(676)  评论(0编辑  收藏  举报