Redis基础知识(学习笔记7--关键参数配置说明)

1. 基础说明

# Redis configuration file example.
#
# Note that in order to read the configuration file, Redis must be
# started with the file path as first argument:
#
# ./redis-server /path/to/redis.conf

# Note on units: when memory size is needed, it is possible to specify
# it in the usual form of 1k 5GB 4M and so forth:
#
# 1k => 1000 bytes
# 1kb => 1024 bytes
# 1m => 1000000 bytes
# 1mb => 1024*1024 bytes
# 1g => 1000000000 bytes
# 1gb => 1024*1024*1024 bytes
#
# units are case insensitive so 1GB 1Gb 1gB are all the same.

明确了 启动方式,必须指定参数(文件)

Note that in order to read the configuration file, Redis must be started with the file path as first argument

例如  ./redis-server /path/to/redis.conf

另外,也说明了内存配置时,用到的大小单位,且单位是大小不敏感的。

2. INCLUDES

################################## INCLUDES ###################################

# Include one or more other config files here.  This is useful if you
# have a standard template that goes to all Redis servers but also need
# to customize a few per-server settings.  Include files can include
# other files, so use this wisely.

....

指定要在当前配置文件中包含的配置文件。这样做的目的便于对配置信息的管理:可以将不同场景的配置进行单独的定义,然后在当前核心配置文件中根据不同场景选择包含进来不同的配置文件。

3.MODULES

################################## MODULES #####################################

# Load modules at startup. If the server is not able to load modules
# it will abort. It is possible to use multiple loadmodule directives.
#
# loadmodule /path/to/my_module.so
# loadmodule /path/to/other_module.so
# loadmodule /path/to/args_module.so [arg [arg ...]]

Redis 配置文件中可以通过加载不同的第三方模块,来增强、扩展Redis的功能

4.网络NETWORK

################################## NETWORK #####################################

# By default, if no "bind" configuration directive is specified, Redis listens
# for connections from all available network interfaces on the host machine.
# It is possible to listen to just one or multiple selected interfaces using
# the "bind" configuration directive, followed by one or more IP addresses.
# Each address can be prefixed by "-", which means that redis will not fail to
# start if the address is not available. Being not available only refers to
# addresses that does not correspond to any network interface. Addresses that
# are already in use will always fail, and unsupported protocols will always BE
# silently skipped.
#
# Examples:
#
# bind 192.168.1.100 10.0.0.1     # listens on two specific IPv4 addresses
# bind 127.0.0.1 ::1              # listens on loopback IPv4 and IPv6
# bind * -::*                     # like the default, all available interfaces
#
# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
# internet, binding to all the interfaces is dangerous and will expose the
# instance to everybody on the internet. So by default we uncomment the
# following bind directive, that will force Redis to listen only on the
# IPv4 and IPv6 (if available) loopback interface addresses (this means Redis
# will only be able to accept client connections from the same host that it is
# running on).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# COMMENT OUT THE FOLLOWING LINE.
#
# You will also need to set a password unless you explicitly disable protected
# mode.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bind 127.0.0.1 -::1

# By default, outgoing connections (from replica to master, from Sentinel to
# instances, cluster bus, etc.) are not bound to a specific local address. In
# most cases, this means the operating system will handle that based on routing
# and the interface through which the connection goes out.
#
# Using bind-source-addr it is possible to configure a specific address to bind
# to, which may also affect how the connection gets routed.
#
# Example:
#
# bind-source-addr 10.0.0.1

# Protected mode is a layer of security protection, in order to avoid that
# Redis instances left open on the internet are accessed and exploited.
#
# When protected mode is on and the default user has no password, the server
# only accepts local connections from the IPv4 address (127.0.0.1), IPv6 address
# (::1) or Unix domain sockets.
#
# By default protected mode is enabled. You should disable it only if
# you are sure you want clients from other hosts to connect to Redis
# even if no authentication is configured.
protected-mode yes

# Redis uses default hardened security configuration directives to reduce the
# attack surface on innocent users. Therefore, several sensitive configuration
# directives are immutable, and some potentially-dangerous commands are blocked.
#
# Configuration directives that control files that Redis writes to (e.g., 'dir'
# and 'dbfilename') and that aren't usually modified during runtime
# are protected by making them immutable.
#
# Commands that can increase the attack surface of Redis and that aren't usually
# called by users are blocked by default.
#
# These can be exposed to either all connections or just local ones by setting
# each of the configs listed below to either of these values:
#
# no    - Block for any connection (remain immutable)
# yes   - Allow for any connection (no protection)
# local - Allow only for local connections. Ones originating from the
#         IPv4 address (127.0.0.1), IPv6 address (::1) or Unix domain sockets.
#
# enable-protected-configs no
# enable-debug-command no
# enable-module-command no

# Accept connections on the specified port, default is 6379 (IANA #815344).
# If port 0 is specified Redis will not listen on a TCP socket.
port 6379

# TCP listen() backlog.
#
# In high requests-per-second environments you need a high backlog in order
# to avoid slow clients connection issues. Note that the Linux kernel
# will silently truncate it to the value of /proc/sys/net/core/somaxconn so
# make sure to raise both the value of somaxconn and tcp_max_syn_backlog
# in order to get the desired effect.
tcp-backlog 511

# Unix socket.
#
# Specify the path for the Unix socket that will be used to listen for
# incoming connections. There is no default, so Redis will not listen
# on a unix socket when not specified.
#
# unixsocket /run/redis.sock
# unixsocketperm 700

# Close the connection after a client is idle for N seconds (0 to disable)
timeout 0

# TCP keepalive.
#
# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
# of communication. This is useful for two reasons:
#
# 1) Detect dead peers.
# 2) Force network equipment in the middle to consider the connection to be
#    alive.
#
# On Linux, the specified value (in seconds) is the period used to send ACKs.
# Note that to close the connection the double of the time is needed.
# On other kernels the period depends on the kernel configuration.
#
# A reasonable value for this option is 300 seconds, which is the new
# Redis default starting with Redis 3.2.1.
tcp-keepalive 300

# Apply OS-specific mechanism to mark the listening socket with the specified
# ID, to support advanced routing and filtering capabilities.
#
# On Linux, the ID represents a connection mark.
# On FreeBSD, the ID represents a socket cookie ID.
# On OpenBSD, the ID represents a route table ID.
#
# The default value is 0, which implies no marking is required.
# socket-mark-id 0

说明:

(1) bind 127.0.0.1(IPv4 本地表示方法) -::1(IPv6 本地表示方法);默认的只能直接本地访问

(2)protected-mode yes : 受保护模式, 开启, 保证安全性;默认的只能直接本地访问

(3)port: 指定端口号

(4)tcp-backlog:在linux系统中控制tcp三次握手已完成连接队列的长度。在高并发系统中,通常需要设置一个较高的tcp-backlog来避免客户端连接速度慢的问题(三次握手的速度)。已完成连接队列的长度也与操作系统中somaxconn参数有关,取二者最小min(tcp-backlog,somaxconn)。linux查看已完成连接队列的长度:$ /proc/sys/net/core/somaxconn

【tcp-backlog是一个TCP连接的队列,主要用于解决高并发场景下客户端慢连接问题。这里设置的值就是这个队列的长度。该队列与TCP连接的三次握手有关,不同的linux内核,backlog队列中存放的元素(客户端连接)类型是不同的。

***Linux内核2.2版本之前,该队列中存放的是已经完成了第一次握手的所有客户端连接,其中就包含已完成三次握手的客户端连接。此时的backlog队列中的连接具有两种状态:未完成三次握手的连接状态SYN_RECEIVED,已完成三次握手连接状态为ESTABLISHED,只有ESTABLISHED状态的连接才会被Redis处理。

***Linux内核2.2版本之后,TCP系统维护了两个队列:SYN_RECEIVED队列和ESTABLISHED队列。SYN_RECEIVED队列中存放的是未完成三次握手的连接;ESTABLISHED队列中存放的是已完成三次握手的连接,此时的的backlog就是ESTABLISHED队列。 】

补充下知识点 --查看Linux内核版本

uname -a
或
cat /proc/version

补充下知识点 --修改somaxconn的方法步骤

step 1
vim /etc/sysctl.conf   ##打开配置文件
step 2
net.core.somaxconn=2048 ##文件最后 添加这样一句话,此处2048代表你要修改后的值,请注意替换。
step 3
文件保存退出。
step 4
sysctl -p   ##重启生效

 

(5)timeout:不再使用的连接 超时时间(关闭时间),单位秒;超过timeout,服务端会断开连接。为0则服务端不会主动断开连接(依赖于TCP 本身的默认属性,为2H后断开),不能小于0

(6)tcp-keepalive:表示针对空闲连接,为了保持可用,server 端每隔tcp-keepalive这么长的时间,就去探测一下。

5.TLS/SSL模块

################################# TLS/SSL #####################################

# By default, TLS/SSL is disabled. To enable it, the "tls-port" configuration
# directive can be used to define TLS-listening ports. To enable TLS on the
# default port, use:

6.GENERAL模块

################################# GENERAL #####################################
。。。。。。。。。

6.1 daemonize 

默认值为no

默认情况下,Redis不作为守护进程运行(老版本默认)。如果需要可以修改daemonize为‘yes’。

注意,Redis在守护进程时会在var/run/redis.pid中写入一个pid文件。当Redis被upstart或systemd监管时,这个参数没有影响。

6.2 pidfile

该配置用于指定redis允许时pid写入的文件,无论是否采用守护进程的方式启动,pid都会写入到该配置的文件中。

说明:如果没有在conf文件中显式配置pid文件,不同的启动方式,pid文件产生的效果是不同的:(1)采用守护进程方式启动(后台方式启动即daemonize 为yes):pid文件为 /var/run/redis.pid。(2)采用前台方式启动(daemonize 为no):不产生pid文件。

6.3  loglevel notice 和 logfile ""

日志级别 和 日志文件

关于logfile的说明:指定日志文件。如果设置为空字符串,则强制将日志记录到标准输出设备(显示器)。如果使用的是守护进程方式启动,设置为空串,则意味着将日志发送到设备/dev/null(空设备--即不显示)。--所以这个建议进行设置。

6.4 databases 16

设置数据库的数量。默认数据库是0号数据库。可以使用select<dbid>,在每个连接上进行选择。其中dbid介于0 和’databases‘-1 之间的数字。

7.安全策略

################################## SECURITY ###################################

# Warning: since Redis is pretty fast, an outside user can try up to
# 1 million passwords per second against a modern box. This means that you
# should use very strong passwords, otherwise they will be very easy to break.
# Note that because the password is really a shared secret between the client
# and the server, and should not be memorized by any human, the password
# can be easily a long string from /dev/urandom or whatever, so by using a
# long and unguessable password no brute force attack will be possible.

# Redis ACL users are defined in the following format:
#
#   user <username> ... acl rules ...
#
# For example:
#
#   user worker +@list +@connection ~jobs:* on >ffa9203c493aa99
#
# The special username "default" is used for new connections. If this user
# has the "nopass" rule, then new connections will be immediately authenticated
# as the "default" user without the need of any password provided via the
# AUTH command. Otherwise if the "default" user is not flagged with "nopass"
# the connections will start in not authenticated state, and will require
# AUTH (or the HELLO command AUTH option) in order to be authenticated and
# start to work.
#
# The ACL rules that describe what a user can do are the following:
#
#  on           Enable the user: it is possible to authenticate as this user.
#  off          Disable the user: it's no longer possible to authenticate
#               with this user, however the already authenticated connections
#               will still work.
#  skip-sanitize-payload    RESTORE dump-payload sanitization is skipped.
#  sanitize-payload         RESTORE dump-payload is sanitized (default).
#  +<command>   Allow the execution of that command.
#               May be used with `|` for allowing subcommands (e.g "+config|get")
#  -<command>   Disallow the execution of that command.
#               May be used with `|` for blocking subcommands (e.g "-config|set")
#  +@<category> Allow the execution of all the commands in such category
#               with valid categories are like @admin, @set, @sortedset, ...
#               and so forth, see the full list in the server.c file where
#               the Redis command table is described and defined.
#               The special category @all means all the commands, but currently
#               present in the server, and that will be loaded in the future
#               via modules.
#  +<command>|first-arg  Allow a specific first argument of an otherwise
#                        disabled command. It is only supported on commands with
#                        no sub-commands, and is not allowed as negative form
#                        like -SELECT|1, only additive starting with "+". This
#                        feature is deprecated and may be removed in the future.
#  allcommands  Alias for +@all. Note that it implies the ability to execute
#               all the future commands loaded via the modules system.
#  nocommands   Alias for -@all.
#  ~<pattern>   Add a pattern of keys that can be mentioned as part of
#               commands. For instance ~* allows all the keys. The pattern
#               is a glob-style pattern like the one of KEYS.
#               It is possible to specify multiple patterns.
# %R~<pattern>  Add key read pattern that specifies which keys can be read 
#               from.
# %W~<pattern>  Add key write pattern that specifies which keys can be
#               written to. 
#  allkeys      Alias for ~*
#  resetkeys    Flush the list of allowed keys patterns.
#  &<pattern>   Add a glob-style pattern of Pub/Sub channels that can be
#               accessed by the user. It is possible to specify multiple channel
#               patterns.
#  allchannels  Alias for &*
#  resetchannels            Flush the list of allowed channel patterns.
#  ><password>  Add this password to the list of valid password for the user.
#               For example >mypass will add "mypass" to the list.
#               This directive clears the "nopass" flag (see later).
#  <<password>  Remove this password from the list of valid passwords.
#  nopass       All the set passwords of the user are removed, and the user
#               is flagged as requiring no password: it means that every
#               password will work against this user. If this directive is
#               used for the default user, every new connection will be
#               immediately authenticated with the default user without
#               any explicit AUTH command required. Note that the "resetpass"
#               directive will clear this condition.
#  resetpass    Flush the list of allowed passwords. Moreover removes the
#               "nopass" status. After "resetpass" the user has no associated
#               passwords and there is no way to authenticate without adding
#               some password (or setting it as "nopass" later).
#  reset        Performs the following actions: resetpass, resetkeys, resetchannels,
#               allchannels (if acl-pubsub-default is set), off, clearselectors, -@all.
#               The user returns to the same state it has immediately after its creation.
# (<options>)   Create a new selector with the options specified within the
#               parentheses and attach it to the user. Each option should be 
#               space separated. The first character must be ( and the last 
#               character must be ).
# clearselectors            Remove all of the currently attached selectors. 
#                           Note this does not change the "root" user permissions,
#                           which are the permissions directly applied onto the
#                           user (outside the parentheses).
#
# ACL rules can be specified in any order: for instance you can start with
# passwords, then flags, or key patterns. However note that the additive
# and subtractive rules will CHANGE MEANING depending on the ordering.
# For instance see the following example:
#
#   user alice on +@all -DEBUG ~* >somepassword
#
# This will allow "alice" to use all the commands with the exception of the
# DEBUG command, since +@all added all the commands to the set of the commands
# alice can use, and later DEBUG was removed. However if we invert the order
# of two ACL rules the result will be different:
#
#   user alice on -DEBUG +@all ~* >somepassword
#
# Now DEBUG was removed when alice had yet no commands in the set of allowed
# commands, later all the commands are added, so the user will be able to
# execute everything.
#
# Basically ACL rules are processed left-to-right.
#
# The following is a list of command categories and their meanings:
# * keyspace - Writing or reading from keys, databases, or their metadata 
#     in a type agnostic way. Includes DEL, RESTORE, DUMP, RENAME, EXISTS, DBSIZE,
#     KEYS, EXPIRE, TTL, FLUSHALL, etc. Commands that may modify the keyspace,
#     key or metadata will also have `write` category. Commands that only read
#     the keyspace, key or metadata will have the `read` category.
# * read - Reading from keys (values or metadata). Note that commands that don't
#     interact with keys, will not have either `read` or `write`.
# * write - Writing to keys (values or metadata)
# * admin - Administrative commands. Normal applications will never need to use
#     these. Includes REPLICAOF, CONFIG, DEBUG, SAVE, MONITOR, ACL, SHUTDOWN, etc.
# * dangerous - Potentially dangerous (each should be considered with care for
#     various reasons). This includes FLUSHALL, MIGRATE, RESTORE, SORT, KEYS,
#     CLIENT, DEBUG, INFO, CONFIG, SAVE, REPLICAOF, etc.
# * connection - Commands affecting the connection or other connections.
#     This includes AUTH, SELECT, COMMAND, CLIENT, ECHO, PING, etc.
# * blocking - Potentially blocking the connection until released by another
#     command.
# * fast - Fast O(1) commands. May loop on the number of arguments, but not the
#     number of elements in the key.
# * slow - All commands that are not Fast.
# * pubsub - PUBLISH / SUBSCRIBE related
# * transaction - WATCH / MULTI / EXEC related commands.
# * scripting - Scripting related.
# * set - Data type: sets related.
# * sortedset - Data type: zsets related.
# * list - Data type: lists related.
# * hash - Data type: hashes related.
# * string - Data type: strings related.
# * bitmap - Data type: bitmaps related.
# * hyperloglog - Data type: hyperloglog related.
# * geo - Data type: geo related.
# * stream - Data type: streams related.
#
# For more information about ACL configuration please refer to
# the Redis web site at https://redis.io/docs/latest/operate/oss_and_stack/management/security/acl/.

# ACL LOG
#
# The ACL Log tracks failed commands and authentication events associated
# with ACLs. The ACL Log is useful to troubleshoot failed commands blocked
# by ACLs. The ACL Log is stored in memory. You can reclaim memory with
# ACL LOG RESET. Define the maximum entry length of the ACL Log below.
acllog-max-len 128

# Using an external ACL file
#
# Instead of configuring users here in this file, it is possible to use
# a stand-alone file just listing users. The two methods cannot be mixed:
# if you configure users here and at the same time you activate the external
# ACL file, the server will refuse to start.
#
# The format of the external ACL user file is exactly the same as the
# format that is used inside redis.conf to describe users.
#
# aclfile /etc/redis/users.acl

# IMPORTANT NOTE: starting with Redis 6 "requirepass" is just a compatibility
# layer on top of the new ACL system. The option effect will be just setting
# the password for the default user. Clients will still authenticate using
# AUTH <password> as usually, or more explicitly with AUTH default <password>
# if they follow the new protocol: both will work.
#
# The requirepass is not compatible with aclfile option and the ACL LOAD
# command, these will cause requirepass to be ignored.
#
# requirepass foobared

# New users are initialized with restrictive permissions by default, via the
# equivalent of this ACL rule 'off resetkeys -@all'. Starting with Redis 6.2, it
# is possible to manage access to Pub/Sub channels with ACL rules as well. The
# default Pub/Sub channels permission if new users is controlled by the
# acl-pubsub-default configuration directive, which accepts one of these values:
#
# allchannels: grants access to all Pub/Sub channels
# resetchannels: revokes access to all Pub/Sub channels
#
# From Redis 7.0, acl-pubsub-default defaults to 'resetchannels' permission.
#
# acl-pubsub-default resetchannels

# Command renaming (DEPRECATED).
#
# ------------------------------------------------------------------------
# WARNING: avoid using this option if possible. Instead use ACLs to remove
# commands from the default user, and put them only in some admin user you
# create for administrative purposes.
# ------------------------------------------------------------------------
#
# It is possible to change the name of dangerous commands in a shared
# environment. For instance the CONFIG command may be renamed into something
# hard to guess so that it will still be available for internal-use tools
# but not available for general clients.
#
# Example:
#
# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
#
# It is also possible to completely kill a command by renaming it into
# an empty string:
#
# rename-command CONFIG ""
#
# Please note that changing the name of commands that are logged into the
# AOF file or transmitted to replicas may cause problems.

(1)requirepass 安全设置

可以通过 # requirepass foobared,进行手动设置。而命令行设置 : config set requirepass "????" 。若已设置密码则需要登录 命令 : auth XXXX 。登录成功 获取用户密码 : config get requirepass。

 (2)rename-command 安全设置

 改写命令;例如,我们禁用 flushall、flushdb的命令

那么可以在 # rename-command CONFIG "" 加上下面脚本:

# rename-command CONFIG ""
rename-command flushall ""  ##禁用flushall;删除所有DB
rename-connand flushdb "" ##禁用flushdb;只删除当前DB

 8. CLIENTS 部分

################################### CLIENTS ####################################

# Set the max number of connected clients at the same time. By default
# this limit is set to 10000 clients, however if the Redis server is not
# able to configure the process file limit to allow for the specified limit
# the max number of allowed clients is set to the current file limit
# minus 32 (as Redis reserves a few file descriptors for internal uses).
#
# Once the limit is reached Redis will close all the new connections sending
# an error 'max number of clients reached'.
#
# IMPORTANT: When Redis Cluster is used, the max number of connections is also
# shared with the cluster bus: every node in the cluster will use two
# connections, one incoming and another outgoing. It is important to size the
# limit accordingly in case of very large clusters.
#
# maxclients 10000

该模块用于设置与客户端相关的属性,其中仅包含一个属性maxclients。

maxclients用于设置redis可并发处理的客户端连接数量,默认为10000。如果到达了该最大连接数,则会拒绝新的连接,并返回一个异常信息--max number of clients reached 

注意: 还受限于 the process file limit to allow for the specified limit【可打开的文件描述符最大阈值】

其设置查看的命令

ulimit -m

9.MEMORY MANAGEMENT 

该配置可以控制最大可用内存即相关内容移除问题。

############################## MEMORY MANAGEMENT ################################

# Set a memory usage limit to the specified amount of bytes.
# When the memory limit is reached Redis will try to remove keys
# according to the eviction policy selected (see maxmemory-policy).
#
。。。。。。。。。

9.1  maxmemory <bytes>

设置内存最大使用值,单位为字节数。当内存达到内存限制时,redis将根据选择的逐出策略 maxmemory-policy,尝试删除符合条件的key。

如果策略设置的是不移除,则会给写操作命令返回Error。对于只读的命令,没影响。

9.2 maxmemory-policy

逐出策略。

# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
# is reached. You can select one from the following behaviors:
#
# volatile-lru -> Evict using approximated LRU, only keys with an expire set.
# allkeys-lru -> Evict any key using approximated LRU.
# volatile-lfu -> Evict using approximated LFU, only keys with an expire set.
# allkeys-lfu -> Evict any key using approximated LFU.
# volatile-random -> Remove a random key having an expire set.
# allkeys-random -> Remove a random key, any key.
# volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
# noeviction -> Don't evict anything, just return an error on write operations.
#

9.3 maxmemory-samples 5

# LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated
# algorithms (in order to save memory), so you can tune it for speed or
# accuracy. By default Redis will check five keys and pick the one that was
# used least recently, you can change the sample size using the following
# configuration directive.
#
# The default of 5 produces good enough results. 10 Approximates very closely
# true LRU but costs more CPU. 3 is faster but not very accurate. The maximum
# value that can be set is 64.
#

该属性用于指定挑选要删除的key的样本数量。样本的选择采用的是LRU算法,其不能修改。单从样本中再选择移除的key,采用的是maxmemory-policy参数指定的算法。

9.4 maxmemory-eviction-tenacity 10

设置移除容忍度。数值越小表示容忍度越低,需要移除的数据移除延迟越小;数值越大,表示容忍度越高,需要移除的数据移除延迟越大。

10.THREADED I/O

该配置模块用于配置Redis对多线程IO模型的支持。

################################ THREADED I/O #################################

# Redis is mostly single threaded, however there are certain threaded
# operations such as UNLINK, slow I/O accesses and other things that are
# performed on side threads.
#
# Now it is also possible to handle Redis clients socket reads and writes
# in different I/O threads. Since especially writing is so slow, normally
# Redis users use pipelining in order to speed up the Redis performances per
# core, and spawn multiple instances in order to scale more. Using I/O
# threads it is possible to easily speedup two times Redis without resorting
# to pipelining nor sharding of the instance.
#
# By default threading is disabled, we suggest enabling it only in machines
# that have at least 4 or more cores, leaving at least one spare core.
# Using more than 8 threads is unlikely to help much. We also recommend using
# threaded I/O only if you actually have performance problems, with Redis
# instances being able to use a quite big percentage of CPU time, otherwise
# there is no point in using this feature.
#
# So for instance if you have a four cores boxes, try to use 2 or 3 I/O
# threads, if you have a 8 cores, try to use 6 threads. In order to
# enable I/O threads use the following configuration directive:
#
# io-threads 4
#
# Setting io-threads to 1 will just use the main thread as usual.
# When I/O threads are enabled, we only use threads for writes, that is
# to thread the write(2) syscall and transfer the client buffers to the
# socket. However it is also possible to enable threading of reads and
# protocol parsing using the following configuration directive, by setting
# it to yes:
#
# io-threads-do-reads no
#
# Usually threading reads doesn't help much.
#
# NOTE 1: This configuration directive cannot be changed at runtime via
# CONFIG SET. Also, this feature currently does not work when SSL is
# enabled.
#
# NOTE 2: If you want to test the Redis speedup using redis-benchmark, make
# sure you also run the benchmark itself in threaded mode, using the
# --threads option to match the number of Redis threads, otherwise you'll not
# be able to notice the improvements.

(1)io-threads

该属性用于指定要启用多线程IO模型时,需使用的线程数量。

(2)io-threads-do-reads

将io线程设置为1将照常使用主线程。当启用IO线程时,只使用线程进行写入,也就是说,通过线程执行write(2)系统调用,并将客户端缓冲区传输到套接字。

但是,也可以使用以下配置指令启用读取线程和协议解析,方法是将其设置为yes.

补充知识--查看CPU的命令

lscpu

 

补充知识--redis 关闭方式

redis-cli shutdown

 

posted @ 2024-06-23 23:27  东山絮柳仔  阅读(68)  评论(0编辑  收藏  举报