redis 5.0.4配置文件翻譯及詳解

前言

在redis配置文件裏修改一些配置的時候，總會看到一些對配置的解釋，每次讀到都感受頗有收穫，甚至感受比網上的不少資料都要好，所以下決心本身完整翻譯並整理一份。

翻譯及介紹

part1 初始介紹

• 原文：

# 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.

• 譯文

Redis配置文件示例.

爲了能讀取到配置文件，注意Redis服務必須以配置文件的路徑做爲第一個參數啓動
./redis-server /path/to/redis.conf

關於單位，當你須要指定內存的大小時，可使用以下的單位來指定

1k => 1000 bytes
1kb => 1024 bytes
1m => 1000000 bytes
1mb => 1024*1024 bytes
1g => 1000000000 bytes
1gb => 102410241024 bytes

單位是大小寫不敏感的 因此 1GB 1Gb 1gB 都是同樣的

part2 INCLUDES

• 原文

# 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.
#
# Notice option "include" won't be rewritten by command "CONFIG REWRITE"
# from admin or Redis Sentinel. Since Redis always uses the last processed
# line as value of a configuration directive, you'd better put includes
# at the beginning of this file to avoid overwriting config change at runtime.
#
# If instead you are interested in using includes to override configuration
# options, it is better to use include as the last line.
#
# include /path/to/local.conf
# include /path/to/other.conf

• 譯文

在這裏包含一個或多個配置文件。若是您有一個適用於全部Redis服務器的標準模板，可是還須要自定義每一個服務器的一些設置，那麼這是很是有用的。引入文件能夠包含其餘的文件，因此用這種方式是很明智的。

注意選項「include」不會被來自admin或Redis哨兵的命令「CONFIG REWRITE」重寫。由於Redis老是使用最後一次處理做爲配置指令的值,
因此您最好在此文件的開頭放入include，以免在運行時覆蓋配置更改。

但反過來若是您感興趣的是使用include覆蓋配置，最好把include配置放在文件的最後。

include /path/to/local.conf
include /path/to/other.conf

part3 MODULES

• 原文

# 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

• 譯文

在啓動時加載模塊。若是服務沒法加載模塊它將停止。可使用多個loadmodule模塊加載指令。

loadmodule /path/to/my_module.so
loadmodule /path/to/other_module.so

part4 NETWORK

• 原文

# By default, if no "bind" configuration directive is specified, Redis listens
# for connections from all the network interfaces available on the server.
# It is possible to listen to just one or multiple selected interfaces using
# the "bind" configuration directive, followed by one or more IP addresses.
#
# Examples:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1
#
# ~~~ 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 into
# the IPv4 loopback interface address (this means Redis will be able to
# accept connections only from clients running into the same computer it
# is running).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# JUST COMMENT THE FOLLOWING LINE.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bind 127.0.0.1

# 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 if:
#
# 1) The server is not binding explicitly to a set of addresses using the
#    "bind" directive.
# 2) No password is configured.
#
# The server only accepts connections from clients connecting from the
# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from 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, nor a specific set of interfaces
# are explicitly listed using the "bind" directive.
protected-mode yes

# 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 an high backlog in order
# to avoid slow clients connections 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 /tmp/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) Take the connection alive from the point of view of network
#    equipment in the middle.
#
# 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

• 譯文

默認狀況下，若是沒有指定「bind」配置指令，則Redis偵聽服務器上全部可用網絡接口的鏈接。可使用「bind」配置指令監聽一個或多個選定的接口，而後監聽一個或多個IP地址。

例如：
bind 192.168.1.100 10.0.0.1
bind 127.0.0.1 ::1

警告：若是運行Redis的計算機直接暴露在internet上，綁定到全部接口是危險的，會將實例暴露給internet上的每一個人。所以，在默認狀況下，咱們取消對如下bind指令的註釋，這將迫使Redis只監聽IPv4環回接口地址(這意味着Redis將只能接受來自運行在同一臺計算機上的客戶端的鏈接)。

若是您肯定但願實例偵聽全部接口只需註釋下面的行。

bind 127.0.0.1

protected-mode是一種安全保護層，爲了不在internet上打開的Redis實例被訪問和利用。

當保護模式打開時，若是:
1)服務器沒有使用「綁定」指令顯式綁定到一組地址。
2)未設置密碼。

服務器只接受來自IPv4和IPv6環回地址127.0.0.1和::1的客戶端鏈接，以及來自Unix域套接字的鏈接。

默認狀況下啓用了受保護模式。只有在您肯定但願其餘主機的客戶端鏈接到Redis(即便沒有配置任何身份驗證)，或者使用「bind」指令顯式列出一組特定的接口時，才應該禁用它。

protected-mode yes

接受指定端口上的鏈接，默認是6379 (IANA #815344)。若是端口0被指定，Redis將不會監聽TCP套接字。

port 6379

TCP監聽 backlog 。

在每秒請求數很高的環境中，您須要一個高的backlog，以免緩慢的客戶端鏈接問題。請注意，Linux內核將靜默地將其截斷爲/proc/sys/net/core/somaxconn的值，所以請確保同時提升somaxconn和tcp_max_syn_backlog的值，以得到所需的效果。

tcp-backlog 511

Unix 套接字。

爲Unix套接字指定用於監聽傳入鏈接的路徑。沒有默認值，因此在未指定時，Redis不會監聽unix套接字。

unixsocket / tmp / redis.sock
unixsocketperm 700

在客戶端空閒N秒後關閉鏈接(0表示禁用)

timeout 0

TCP keepalive.

若是該值不爲0，將使用 SO_KEEPALIVE 這一默認的作法來向客戶端鏈接發送TCP ACKs

這樣的好處有如下兩個緣由
1）檢測已經死亡的對端
2）保持鏈接在網絡環境中的存活

在Linux上，指定的值(以秒爲單位)是用於發送ack的週期。
注意，關閉鏈接須要雙倍的時間。
對於其餘內核，週期取決於內核配置。

此選項的合理值是300秒，即從Redis 3.2.1開始的新Redis默認值。

tcp-keepalive 300