探索云原生技术之基石-Docker容器入门篇(4)
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文章目录
探索云原生技术之基石-Docker容器入门篇(4)
本博文一共有7篇，如下
- 探索云原生技术之基石-Docker容器入门篇(1)
- 探索云原生技术之基石-Docker容器入门篇(2)
- 探索云原生技术之基石-Docker容器入门篇(3)
- 探索云原生技术之基石-Docker容器入门篇(4)，=>由于篇幅过长，所以另起一篇
等你对Docker有一定理解的时候可以看高级篇，不过不太建议。
- 探索云原生技术之基石-Docker容器高级篇(1)
- 探索云原生技术之基石-Docker容器高级篇(2)
- 探索云原生技术之基石-Docker容器高级篇(3）-视情况而定
剧透：未来将出云原生技术-Kubernetes（k8s），此时的你可以对Docker进行统一管理、动态扩缩容等等。
看完之后你会对Docker有一定的理解，并能熟练的使用Docker进行容器化开发、以及Docker部署微服务、Docker网络等等。干起来！
什么是云原生
Pivotal公司的Matt Stine于2013年首次提出云原生（Cloud-Native）的概念；2015年，云原生刚推广时，Matt Stine在《迁移到云原生架构》一书中定义了符合云原生架构的几个特征：12因素、微服务、自敏捷架构、基于API协作、扛脆弱性；到了2017年，Matt Stine在接受InfoQ采访时又改了口风，将云原生架构归纳为模块化、可观察、可部署、可测试、可替换、可处理6特质；而Pivotal最新官网对云原生概括为4个要点：DevOps+持续交付+微服务+容器。
总而言之，符合云原生架构的应用程序应该是：采用开源堆栈（K8S+Docker）进行容器化，基于微服务架构提高灵活性和可维护性，借助敏捷方法、DevOps支持持续迭代和运维自动化，利用云平台设施实现弹性伸缩、动态调度、优化资源利用率。
（此处摘选自《知乎-华为云官方帐号》）
什么是Docker
- Docker 是一个开源的应用容器引擎，基于Go语言开发。
- Docker 可以让开发者打包他们的应用以及依赖包到一个轻量级、可移植的容器中，然后发布到任何流行的 Linux 机器上，也可以实现虚拟化。
- 容器是完全使用沙箱机制（容器实例相互隔离），容器性能开销极低（高性能）。
总而言之：
Docker是一个高性能的容器引擎；
可以把本地源代码、配置文件、依赖、环境通通打包成一个容器即可以到处运行；
使用Docker安装软件十分方便，而且安装的软件十分精简，方便扩展。
Docker安装常用的软件
Ubuntu安装
- 拉取Ubuntu镜像
$ docker pull ubuntu- 运行Ubuntu
$ docker run -it --name MyUbuntu ubuntu[root@aubin ~]# docker run -it --name MyUbuntu ubunturoot@9cb5882e5c7d:/# lsbin dev home lib32 libx32 mnt proc run srv tmp varboot etc lib lib64 media opt root sbin sys usrFastDFS安装
$ docker search fastdfs$ docker pull delron/fastdfs$ docker images$ docker run -dti --network=host --name tracker -v /var/fdfs/tracker:/var/fdfs -v /etc/localtime:/etc/localtime delron/fastdfs tracker docker run -dti --network=host --name storage -e TRACKER_SERVER=192.168.184.132:22122 -v /var/fdfs/storage:/var/fdfs -v /etc/localtime:/etc/localtime delron/fastdfs storage$ docker ps #查看容器id$ docker exec -it 容器id /bin/bash#下面这两行命令可以不写，就默认配置$ vi /etc/fdfs/storage.conf$ vi /usr/local/nginx/conf/nginx.conf $ firewall-cmd --zone=public --permanent --add-port=8888/tcp$ firewall-cmd --zone=public --permanent --add-port=22122/tcp$ firewall-cmd --zone=public --permanent --add-port=23000/tcp #重启防火墙$ systemctl restart firewalld#自启动$ docker update --restart=always tracker$ docker update --restart=always storageRabbitMQ安装
$ docker pull rabbitmq #从Docker仓库拉取最新的RabbitMQ镜像$ docker run -d --hostname my-rabbit --name yblog-rabbit -p 15672:15672 -p 5672:5672 rabbitmq #运行RabbitMQ镜像$ docker exec -it yblog-rabbit /bin/bash #进入RabbitMQ容器$ rabbitmq-plugins enable rabbitmq_management #安装RabbitMQ的插件MySQL5.7安装（生产环境）
拉取MySQL镜像
$ docker pull mysql:5.7启动mysql并挂载容器数据卷
$ docker run -d -p 3306:3306 --privileged=true -v /bf/mysql/log:/var/log/mysql -v /bf/mysql/data:/var/lib/mysql -v /bf/mysql/conf:/etc/mysql/conf.d -e MYSQL_ROOT_PASSWORD=123456 --name mysql mysql:5.7在宿主机所在conf目录新建my.cnf文件
- 如果不指定配置文件会导致编码问题（就如下面那样）
查看MySQL编码
mysql> show variables like 'character%';+--------------------------+----------------------------+| Variable_name | Value |+--------------------------+----------------------------+| character_set_client | latin1|| character_set_connection | latin1|| character_set_database | latin1|| character_set_filesystem | binary|| character_set_results | latin1|| character_set_server | latin1|| character_set_system | utf8 || character_sets_dir| /usr/share/mysql/charsets/ |+--------------------------+----------------------------+8 rows in set (0.01 sec)-
可以看出默认的mysql编码格式是：latin1，这样对我们明显是不行的
-
我们要修改成UTF-8或者utf-8mb4
my.cnf 文件：
[client]default_character_set=utf8[mysqld]collation_server=utf8_general_cicharacter_set_server=utf8利用my.cnf文件，解决编码问题
[root@aubin ~]# cd /bf/mysql/conf[root@aubin conf]# vim my.cnf- 然后把上面的my.cnf内容复制进去。
重启容器
$ docker restart mysql 登录MySQL
mysql -u root -p再次查看编码
mysql> show variables like 'character%';+--------------------------+----------------------------+| Variable_name | Value |+--------------------------+----------------------------+| character_set_client | utf8 || character_set_connection | utf8 || character_set_database | utf8 || character_set_filesystem | binary|| character_set_results | utf8 || character_set_server | utf8 || character_set_system | utf8 || character_sets_dir| /usr/share/mysql/charsets/ |+--------------------------+----------------------------+8 rows in set (0.01 sec)- 大功告成了
进入MySQL客户端，查看MySQL编码
show variables like 'character%';进入MySQL客户端
$ docker exec -it mysql /bin/bash登录
mysql -u 你的MySQL帐号 -p- 然后回车。
- 输入密码即可。
Redis6.2.6安装（生产环境）
- 拉取redis镜像
$ docker pull redis6.2.6- 创建宿主机redis配置文件夹
$ mkdir /home/redis$ mkdir /home/redis/data$ vim redis.conf- 再次目录创建redis.conf，内容如下：
# 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.################################## 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.## 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################################## 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################################## NETWORK ###################################### 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 10.0.0.1bind 0.0.0.0## ~~~ 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 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 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################################# GENERAL ###################################### By default Redis does not run as a daemon. Use 'yes' if you need it.# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.daemonize no# If you run Redis from upstart or systemd, Redis can interact with your# supervision tree. Options:# supervised no - no supervision interaction# supervised upstart - signal upstart by putting Redis into SIGSTOP mode# supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET# supervised auto - detect upstart or systemd method based on# UPSTART_JOB or NOTIFY_SOCKET environment variables# Note: these supervision methods only signal "process is ready."#They do not enable continuous liveness pings back to your supervisor.supervised no# If a pid file is specified, Redis writes it where specified at startup# and removes it at exit.## When the server runs non daemonized, no pid file is created if none is# specified in the configuration. When the server is daemonized, the pid file# is used even if not specified, defaulting to "/var/run/redis.pid".## Creating a pid file is best effort: if Redis is not able to create it# nothing bad happens, the server will start and run normally.pidfile /var/run/redis_6379.pid# Specify the server verbosity level.# This can be one of:# debug (a lot of information, useful for development/testing)# verbose (many rarely useful info, but not a mess like the debug level)# notice (moderately verbose, what you want in production probably)# warning (only very important / critical messages are logged)loglevel notice# Specify the log file name. Also the empty string can be used to force# Redis to log on the standard output. Note that if you use standard# output for logging but daemonize, logs will be sent to /dev/nulllogfile "/data/redis.log"# To enable logging to the system logger, just set 'syslog-enabled' to yes,# and optionally update the other syslog parameters to suit your needs.# syslog-enabled no# Specify the syslog identity.# syslog-ident redis# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.# syslog-facility local0# Set the number of databases. The default database is DB 0, you can select# a different one on a per-connection basis using SELECT where# dbid is a number between 0 and 'databases'-1databases 16# By default Redis shows an ASCII art logo only when started to log to the# standard output and if the standard output is a TTY. Basically this means# that normally a logo is displayed only in interactive sessions.## However it is possible to force the pre-4.0 behavior and always show a# ASCII art logo in startup logs by setting the following option to yes.always-show-logo yes################################ SNAPSHOTTING ################################## Save the DB on disk:## save ## Will save the DB if both the given number of seconds and the given# number of write operations against the DB occurred.## In the example below the behaviour will be to save:# after 900 sec (15 min) if at least 1 key changed# after 300 sec (5 min) if at least 10 keys changed# after 60 sec if at least 10000 keys changed## Note: you can disable saving completely by commenting out all "save" lines.## It is also possible to remove all the previously configured save# points by adding a save directive with a single empty string argument# like in the following example:## save ""save 900 1save 300 10save 60 10000# By default Redis will stop accepting writes if RDB snapshots are enabled# (at least one save point) and the latest background save failed.# This will make the user aware (in a hard way) that data is not persisting# on disk properly, otherwise chances are that no one will notice and some# disaster will happen.## If the background saving process will start working again Redis will# automatically allow writes again.## However if you have setup your proper monitoring of the Redis server# and persistence, you may want to disable this feature so that Redis will# continue to work as usual even if there are problems with disk,# permissions, and so forth.stop-writes-on-bgsave-error yes# Compress string objects using LZF when dump .rdb databases?# For default that's set to 'yes' as it's almost always a win.# If you want to save some CPU in the saving child set it to 'no' but# the dataset will likely be bigger if you have compressible values or keys.rdbcompression yes# Since version 5 of RDB a CRC64 checksum is placed at the end of the file.# This makes the format more resistant to corruption but there is a performance# hit to pay (around 10%) when saving and loading RDB files, so you can disable it# for maximum performances.## RDB files created with checksum disabled have a checksum of zero that will# tell the loading code to skip the check.rdbchecksum yes# The filename where to dump the DBdbfilename dump.rdb# 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.dir /data################################# REPLICATION ################################## Master-Replica replication. Use replicaof to make a Redis instance a copy of# another Redis server. A few things to understand ASAP about Redis replication.## +------------------+ +---------------+# | Master | ---> | Replica |# | (receive writes) | | (exact copy) |# +------------------+ +---------------+## 1) Redis replication is asynchronous, but you can configure a master to# stop accepting writes if it appears to be not connected with at least# a given number of replicas.# 2) Redis replicas are able to perform a partial resynchronization with the# master if the replication link is lost for a relatively small amount of# time. You may want to configure the replication backlog size (see the next# sections of this file) with a sensible value depending on your needs.# 3) Replication is automatic and does not need user intervention. After a# network partition replicas automatically try to reconnect to masters# and resynchronize with them.## replicaof # If the master is password protected (using the "requirepass" configuration# directive below) it is possible to tell the replica to authenticate before# starting the replication synchronization process, otherwise the master will# refuse the replica request.## masterauth # When a replica loses its connection with the master, or when the replication# is still in progress, the replica can act in two different ways:## 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will# still reply to client requests, possibly with out of date data, or the# data set may just be empty if this is the first synchronization.## 2) if replica-serve-stale-data is set to 'no' the replica will reply with# an error "SYNC with master in progress" to all the kind of commands# but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,# SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,# COMMAND, POST, HOST: and LATENCY.#replica-serve-stale-data yes# You can configure a replica instance to accept writes or not. Writing against# a replica instance may be useful to store some ephemeral data (because data# written on a replica will be easily deleted after resync with the master) but# may also cause problems if clients are writing to it because of a# misconfiguration.## Since Redis 2.6 by default replicas are read-only.## Note: read only replicas are not designed to be exposed to untrusted clients# on the internet. It's just a protection layer against misuse of the instance.# Still a read only replica exports by default all the administrative commands# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve# security of read only replicas using 'rename-command' to shadow all the# administrative / dangerous commands.replica-read-only yes# Replication SYNC strategy: disk or socket.## -------------------------------------------------------# WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY# -------------------------------------------------------## New replicas and reconnecting replicas that are not able to continue the replication# process just receiving differences, need to do what is called a "full# synchronization". An RDB file is transmitted from the master to the replicas.# The transmission can happen in two different ways:## 1) Disk-backed: The Redis master creates a new process that writes the RDB# file on disk. Later the file is transferred by the parent# process to the replicas incrementally.# 2) Diskless: The Redis master creates a new process that directly writes the#RDB file to replica sockets, without touching the disk at all.## With disk-backed replication, while the RDB file is generated, more replicas# can be queued and served with the RDB file as soon as the current child producing# the RDB file finishes its work. With diskless replication instead once# the transfer starts, new replicas arriving will be queued and a new transfer# will start when the current one terminates.## When diskless replication is used, the master waits a configurable amount of# time (in seconds) before starting the transfer in the hope that multiple replicas# will arrive and the transfer can be parallelized.## With slow disks and fast (large bandwidth) networks, diskless replication# works better.repl-diskless-sync no# When diskless replication is enabled, it is possible to configure the delay# the server waits in order to spawn the child that transfers the RDB via socket# to the replicas.## This is important since once the transfer starts, it is not possible to serve# new replicas arriving, that will be queued for the next RDB transfer, so the server# waits a delay in order to let more replicas arrive.## The delay is specified in seconds, and by default is 5 seconds. To disable# it entirely just set it to 0 seconds and the transfer will start ASAP.repl-diskless-sync-delay 5# Replicas send PINGs to server in a predefined interval. It's possible to change# this interval with the repl_ping_replica_period option. The default value is 10# seconds.## repl-ping-replica-period 10# The following option sets the replication timeout for:## 1) Bulk transfer I/O during SYNC, from the point of view of replica.# 2) Master timeout from the point of view of replicas (data, pings).# 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).## It is important to make sure that this value is greater than the value# specified for repl-ping-replica-period otherwise a timeout will be detected# every time there is low traffic between the master and the replica.## repl-timeout 60# Disable TCP_NODELAY on the replica socket after SYNC?## If you select "yes" Redis will use a smaller number of TCP packets and# less bandwidth to send data to replicas. But this can add a delay for# the data to appear on the replica side, up to 40 milliseconds with# Linux kernels using a default configuration.## If you select "no" the delay for data to appear on the replica side will# be reduced but more bandwidth will be used for replication.## By default we optimize for low latency, but in very high traffic conditions# or when the master and replicas are many hops away, turning this to "yes" may# be a good idea.repl-disable-tcp-nodelay no# Set the replication backlog size. The backlog is a buffer that accumulates# replica data when replicas are disconnected for some time, so that when a replica# wants to reconnect again, often a full resync is not needed, but a partial# resync is enough, just passing the portion of data the replica missed while# disconnected.## The bigger the replication backlog, the longer the time the replica can be# disconnected and later be able to perform a partial resynchronization.## The backlog is only allocated once there is at least a replica connected.## repl-backlog-size 1mb# After a master has no longer connected replicas for some time, the backlog# will be freed. The following option configures the amount of seconds that# need to elapse, starting from the time the last replica disconnected, for# the backlog buffer to be freed.## Note that replicas never free the backlog for timeout, since they may be# promoted to masters later, and should be able to correctly "partially# resynchronize" with the replicas: hence they should always accumulate backlog.## A value of 0 means to never release the backlog.## repl-backlog-ttl 3600# The replica priority is an integer number published by Redis in the INFO output.# It is used by Redis Sentinel in order to select a replica to promote into a# master if the master is no longer working correctly.## A replica with a low priority number is considered better for promotion, so# for instance if there are three replicas with priority 10, 100, 25 Sentinel will# pick the one with priority 10, that is the lowest.## However a special priority of 0 marks the replica as not able to perform the# role of master, so a replica with priority of 0 will never be selected by# Redis Sentinel for promotion.## By default the priority is 100.replica-priority 100# It is possible for a master to stop accepting writes if there are less than# N replicas connected, having a lag less or equal than M seconds.## The N replicas need to be in "online" state.## The lag in seconds, that must be <= the specified value, is calculated from# the last ping received from the replica, that is usually sent every second.## This option does not GUARANTEE that N replicas will accept the write, but# will limit the window of exposure for lost writes in case not enough replicas# are available, to the specified number of seconds.## For example to require at least 3 replicas with a lag <= 10 seconds use:## min-replicas-to-write 3# min-replicas-max-lag 10## Setting one or the other to 0 disables the feature.## By default min-replicas-to-write is set to 0 (feature disabled) and# min-replicas-max-lag is set to 10.# A Redis master is able to list the address and port of the attached# replicas in different ways. For example the "INFO replication" section# offers this information, which is used, among other tools, by# Redis Sentinel in order to discover replica instances.# Another place where this info is available is in the output of the# "ROLE" command of a master.## The listed IP and address normally reported by a replica is obtained# in the following way:## IP: The address is auto detected by checking the peer address# of the socket used by the replica to connect with the master.## Port: The port is communicated by the replica during the replication# handshake, and is normally the port that the replica is using to# listen for connections.## However when port forwarding or Network Address Translation (NAT) is# used, the replica may be actually reachable via different IP and port# pairs. The following two options can be used by a replica in order to# report to its master a specific set of IP and port, so that both INFO# and ROLE will report those values.## There is no need to use both the options if you need to override just# the port or the IP address.## replica-announce-ip 5.5.5.5# replica-announce-port 1234################################## SECURITY #################################### Require clients to issue AUTH before processing any other# commands. This might be useful in environments in which you do not trust# others with access to the host running redis-server.## This should stay commented out for backward compatibility and because most# people do not need auth (e.g. they run their own servers).## Warning: since Redis is pretty fast an outside user can try up to# 150k passwords per second against a good box. This means that you should# use a very strong password otherwise it will be very easy to break.#requirepass# Command renaming.## 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.################################### 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'.## maxclients 10000############################## 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).## If Redis can't remove keys according to the policy, or if the policy is# set to 'noeviction', Redis will start to reply with errors to commands# that would use more memory, like SET, LPUSH, and so on, and will continue# to reply to read-only commands like GET.## This option is usually useful when using Redis as an LRU or LFU cache, or to# set a hard memory limit for an instance (using the 'noeviction' policy).## WARNING: If you have replicas attached to an instance with maxmemory on,# the size of the output buffers needed to feed the replicas are subtracted# from the used memory count, so that network problems / resyncs will# not trigger a loop where keys are evicted, and in turn the output# buffer of replicas is full with DELs of keys evicted triggering the deletion# of more keys, and so forth until the database is completely emptied.## In short... if you have replicas attached it is suggested that you set a lower# limit for maxmemory so that there is some free RAM on the system for replica# output buffers (but this is not needed if the policy is 'noeviction').## maxmemory # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory# is reached. You can select among five behaviors:## volatile-lru -> Evict using approximated LRU among the keys with an expire set.# allkeys-lru -> Evict any key using approximated LRU.# volatile-lfu -> Evict using approximated LFU among the keys with an expire set.# allkeys-lfu -> Evict any key using approximated LFU.# volatile-random -> Remove a random key among the ones with 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.## LRU means Least Recently Used# LFU means Least Frequently Used## Both LRU, LFU and volatile-ttl are implemented using approximated# randomized algorithms.## Note: with any of the above policies, Redis will return an error on write#operations, when there are no suitable keys for eviction.##At the date of writing these commands are: set setnx setex append#incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd#sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby#zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby#getset mset msetnx exec sort## The default is:## maxmemory-policy noeviction# 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. For default Redis will check five keys and pick the one that was# used less 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.## maxmemory-samples 5# Starting from Redis 5, by default a replica will ignore its maxmemory setting# (unless it is promoted to master after a failover or manually). It means# that the eviction of keys will be just handled by the master, sending the# DEL commands to the replica as keys evict in the master side.## This behavior ensures that masters and replicas stay consistent, and is usually# what you want, however if your replica is writable, or you want the replica to have# a different memory setting, and you are sure all the writes performed to the# replica are idempotent, then you may change this default (but be sure to understand# what you are doing).## Note that since the replica by default does not evict, it may end using more# memory than the one set via maxmemory (there are certain buffers that may# be larger on the replica, or data structures may sometimes take more memory and so# forth). So make sure you monitor your replicas and make sure they have enough# memory to never hit a real out-of-memory condition before the master hits# the configured maxmemory setting.## replica-ignore-maxmemory yes############################# LAZY FREEING ##################################### Redis has two primitives to delete keys. One is called DEL and is a blocking# deletion of the object. It means that the server stops processing new commands# in order to reclaim all the memory associated with an object in a synchronous# way. If the key deleted is associated with a small object, the time needed# in order to execute the DEL command is very small and comparable to most other# O(1) or O(log_N) commands in Redis. However if the key is associated with an# aggregated value containing millions of elements, the server can block for# a long time (even seconds) in order to complete the operation.## For the above reasons Redis also offers non blocking deletion primitives# such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and# FLUSHDB commands, in order to reclaim memory in background. Those commands# are executed in constant time. Another thread will incrementally free the# object in the background as fast as possible.## DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.# It's up to the design of the application to understand when it is a good# idea to use one or the other. However the Redis server sometimes has to# delete keys or flush the whole database as a side effect of other operations.# Specifically Redis deletes objects independently of a user call in the# following scenarios:## 1) On eviction, because of the maxmemory and maxmemory policy configurations,# in order to make room for new data, without going over the specified# memory limit.# 2) Because of expire: when a key with an associated time to live (see the# EXPIRE command) must be deleted from memory.# 3) Because of a side effect of a command that stores data on a key that may# already exist. For example the RENAME command may delete the old key# content when it is replaced with another one. Similarly SUNIONSTORE# or SORT with STORE option may delete existing keys. The SET command# itself removes any old content of the specified key in order to replace# it with the specified string.# 4) During replication, when a replica performs a full resynchronization with# its master, the content of the whole database is removed in order to# load the RDB file just transferred.## In all the above cases the default is to delete objects in a blocking way,# like if DEL was called. However you can configure each case specifically# in order to instead release memory in a non-blocking way like if UNLINK# was called, using the following configuration directives:lazyfree-lazy-eviction nolazyfree-lazy-expire nolazyfree-lazy-server-del noreplica-lazy-flush no############################## 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 alwaysappendfsync everysec# appendfsync no# When the AOF fsync policy is set to always or everysec, and a background# saving process (a background save or AOF log background rewriting) is# performing a lot of I/O against the disk, in some Linux configurations# Redis may block too long on the fsync() call. Note that there is no fix for# this currently, as even performing fsync in a different thread will block# our synchronous write(2) call.## In order to mitigate this problem it's possible to use the following option# that will prevent fsync() from being called in the main process while a# BGSAVE or BGREWRITEAOF is in progress.## This means that while another child is saving, the durability of Redis is# the same as "appendfsync none". In practical terms, this means that it is# possible to lose up to 30 seconds of log in the worst scenario (with the# default Linux settings).## If you have latency problems turn this to "yes". Otherwise leave it as# "no" that is the safest pick from the point of view of durability.no-appendfsync-on-rewrite no# Automatic rewrite of the append only file.# Redis is able to automatically rewrite the log file implicitly calling# BGREWRITEAOF when the AOF log size grows by the specified percentage.## This is how it works: Redis remembers the size of the AOF file after the# latest rewrite (if no rewrite has happened since the restart, the size of# the AOF at startup is used).## This base size is compared to the current size. If the current size is# bigger than the specified percentage, the rewrite is triggered. Also# you need to specify a minimal size for the AOF file to be rewritten, this# is useful to avoid rewriting the AOF file even if the percentage increase# is reached but it is still pretty small.## Specify a percentage of zero in order to disable the automatic AOF# rewrite feature.auto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mb# An AOF file may be found to be truncated at the end during the Redis# startup process, when the AOF data gets loaded back into memory.# This may happen when the system where Redis is running# crashes, especially when an ext4 filesystem is mounted without the# data=ordered option (however this can't happen when Redis itself# crashes or aborts but the operating system still works correctly).## Redis can either exit with an error when this happens, or load as much# data as possible (the default now) and start if the AOF file is found# to be truncated at the end. The following option controls this behavior.## If aof-load-truncated is set to yes, a truncated AOF file is loaded and# the Redis server starts emitting a log to inform the user of the event.# Otherwise if the option is set to no, the server aborts with an error# and refuses to start. When the option is set to no, the user requires# to fix the AOF file using the "redis-check-aof" utility before to restart# the server.## Note that if the AOF file will be found to be corrupted in the middle# the server will still exit with an error. This option only applies when# Redis will try to read more data from the AOF file but not enough bytes# will be found.aof-load-truncated yes# When rewriting the AOF file, Redis is able to use an RDB preamble in the# AOF file for faster rewrites and recoveries. When this option is turned# on the rewritten AOF file is composed of two different stanzas:## [RDB file][AOF tail]## When loading Redis recognizes that the AOF file starts with the "REDIS"# string and loads the prefixed RDB file, and continues loading the AOF# tail.aof-use-rdb-preamble yes################################ LUA SCRIPTING ################################ Max execution time of a Lua script in milliseconds.## If the maximum execution time is reached Redis will log that a script is# still in execution after the maximum allowed time and will start to# reply to queries with an error.## When a long running script exceeds the maximum execution time only the# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be# used to stop a script that did not yet called write commands. The second# is the only way to shut down the server in the case a write command was# already issued by the script but the user doesn't want to wait for the natural# termination of the script.## Set it to 0 or a negative value for unlimited execution without warnings.lua-time-limit 5000################################ REDIS CLUSTER ################################# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however# in order to mark it as "mature" we need to wait for a non trivial percentage# of users to deploy it in production.# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++## Normal Redis instances can't be part of a Redis Cluster; only nodes that are# started as cluster nodes can. In order to start a Redis instance as a# cluster node enable the cluster support uncommenting the following:## cluster-enabled yes# Every cluster node has a cluster configuration file. This file is not# intended to be edited by hand. It is created and updated by Redis nodes.# Every Redis Cluster node requires a different cluster configuration file.# Make sure that instances running in the same system do not have# overlapping cluster configuration file names.## cluster-config-file nodes-6379.conf# Cluster node timeout is the amount of milliseconds a node must be unreachable# for it to be considered in failure state.# Most other internal time limits are multiple of the node timeout.## cluster-node-timeout 15000# A replica of a failing master will avoid to start a failover if its data# looks too old.## There is no simple way for a replica to actually have an exact measure of# its "data age", so the following two checks are performed:## 1) If there are multiple replicas able to failover, they exchange messages# in order to try to give an advantage to the replica with the best# replication offset (more data from the master processed).# Replicas will try to get their rank by offset, and apply to the start# of the failover a delay proportional to their rank.## 2) Every single replica computes the time of the last interaction with# its master. This can be the last ping or command received (if the master# is still in the "connected" state), or the time that elapsed since the# disconnection with the master (if the replication link is currently down).# If the last interaction is too old, the replica will not try to failover# at all.## The point "2" can be tuned by user. Specifically a replica will not perform# the failover if, since the last interaction with the master, the time# elapsed is greater than:## (node-timeout * replica-validity-factor) + repl-ping-replica-period## So for example if node-timeout is 30 seconds, and the replica-validity-factor# is 10, and assuming a default repl-ping-replica-period of 10 seconds, the# replica will not try to failover if it was not able to talk with the master# for longer than 310 seconds.## A large replica-validity-factor may allow replicas with too old data to failover# a master, while a too small value may prevent the cluster from being able to# elect a replica at all.## For maximum availability, it is possible to set the replica-validity-factor# to a value of 0, which means, that replicas will always try to failover the# master regardless of the last time they interacted with the master.# (However they'll always try to apply a delay proportional to their# offset rank).## Zero is the only value able to guarantee that when all the partitions heal# the cluster will always be able to continue.## cluster-replica-validity-factor 10# Cluster replicas are able to migrate to orphaned masters, that are masters# that are left without working replicas. This improves the cluster ability# to resist to failures as otherwise an orphaned master can't be failed over# in case of failure if it has no working replicas.## Replicas migrate to orphaned masters only if there are still at least a# given number of other working replicas for their old master. This number# is the "migration barrier". A migration barrier of 1 means that a replica# will migrate only if there is at least 1 other working replica for its master# and so forth. It usually reflects the number of replicas you want for every# master in your cluster.## Default is 1 (replicas migrate only if their masters remain with at least# one replica). To disable migration just set it to a very large value.# A value of 0 can be set but is useful only for debugging and dangerous# in production.## cluster-migration-barrier 1# By default Redis Cluster nodes stop accepting queries if they detect there# is at least an hash slot uncovered (no available node is serving it).# This way if the cluster is partially down (for example a range of hash slots# are no longer covered) all the cluster becomes, eventually, unavailable.# It automatically returns available as soon as all the slots are covered again.## However sometimes you want the subset of the cluster which is working,# to continue to accept queries for the part of the key space that is still# covered. In order to do so, just set the cluster-require-full-coverage# option to no.## cluster-require-full-coverage yes# This option, when set to yes, prevents replicas from trying to failover its# master during master failures. However the master can still perform a# manual failover, if forced to do so.## This is useful in different scenarios, especially in the case of multiple# data center operations, where we want one side to never be promoted if not# in the case of a total DC failure.## cluster-replica-no-failover no# In order to setup your cluster make sure to read the documentation# available at http://redis.io web site.########################## CLUSTER DOCKER/NAT support ######################### In certain deployments, Redis Cluster nodes address discovery fails, because# addresses are NAT-ted or because ports are forwarded (the typical case is# Docker and other containers).## In order to make Redis Cluster working in such environments, a static# configuration where each node knows its public address is needed. The# following two options are used for this scope, and are:## * cluster-announce-ip# * cluster-announce-port# * cluster-announce-bus-port## Each instruct the node about its address, client port, and cluster message# bus port. The information is then published in the header of the bus packets# so that other nodes will be able to correctly map the address of the node# publishing the information.## If the above options are not used, the normal Redis Cluster auto-detection# will be used instead.## Note that when remapped, the bus port may not be at the fixed offset of# clients port + 10000, so you can specify any port and bus-port depending# on how they get remapped. If the bus-port is not set, a fixed offset of# 10000 will be used as usually.## Example:## cluster-announce-ip 10.1.1.5# cluster-announce-port 6379# cluster-announce-bus-port 6380################################## SLOW LOG #################################### The Redis Slow Log is a system to log queries that exceeded a specified# execution time. The execution time does not include the I/O operations# like talking with the client, sending the reply and so forth,# but just the time needed to actually execute the command (this is the only# stage of command execution where the thread is blocked and can not serve# other requests in the meantime).## You can configure the slow log with two parameters: one tells Redis# what is the execution time, in microseconds, to exceed in order for the# command to get logged, and the other parameter is the length of the# slow log. When a new command is logged the oldest one is removed from the# queue of logged commands.# The following time is expressed in microseconds, so 1000000 is equivalent# to one second. Note that a negative number disables the slow log, while# a value of zero forces the logging of every command.slowlog-log-slower-than 10000# There is no limit to this length. Just be aware that it will consume memory.# You can reclaim memory used by the slow log with SLOWLOG RESET.slowlog-max-len 128################################ LATENCY MONITOR ############################### The Redis latency monitoring subsystem samples different operations# at runtime in order to collect data related to possible sources of# latency of a Redis instance.## Via the LATENCY command this information is available to the user that can# print graphs and obtain reports.## The system only logs operations that were performed in a time equal or# greater than the amount of milliseconds specified via the# latency-monitor-threshold configuration directive. When its value is set# to zero, the latency monitor is turned off.## By default latency monitoring is disabled since it is mostly not needed# if you don't have latency issues, and collecting data has a performance# impact, that while very small, can be measured under big load. Latency# monitoring can easily be enabled at runtime using the command# "CONFIG SET latency-monitor-threshold " if needed.latency-monitor-threshold 0############################# EVENT NOTIFICATION ############################### Redis can notify Pub/Sub clients about events happening in the key space.# This feature is documented at http://redis.io/topics/notifications## For instance if keyspace events notification is enabled, and a client# performs a DEL operation on key "foo" stored in the Database 0, two# messages will be published via Pub/Sub:## PUBLISH __keyspace@0__:foo del# PUBLISH __keyevent@0__:del foo## It is possible to select the events that Redis will notify among a set# of classes. Every class is identified by a single character:## K Keyspace events, published with __keyspace@__ prefix.# E Keyevent events, published with __keyevent@__ prefix.# g Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...# $ String commands# l List commands# s Set commands# h Hash commands# z Sorted set commands# x Expired events (events generated every time a key expires)# e Evicted events (events generated when a key is evicted for maxmemory)# A Alias for g$lshzxe, so that the "AKE" string means all the events.## The "notify-keyspace-events" takes as argument a string that is composed# of zero or multiple characters. The empty string means that notifications# are disabled.## Example: to enable list and generic events, from the point of view of the# event name, use:## notify-keyspace-events Elg## Example 2: to get the stream of the expired keys subscribing to channel# name __keyevent@0__:expired use:## notify-keyspace-events Ex## By default all notifications are disabled because most users don't need# this feature and the feature has some overhead. Note that if you don't# specify at least one of K or E, no events will be delivered.notify-keyspace-events ""############################### ADVANCED CONFIG ################################ Hashes are encoded using a memory efficient data structure when they have a# small number of entries, and the biggest entry does not exceed a given# threshold. These thresholds can be configured using the following directives.hash-max-ziplist-entries 512hash-max-ziplist-value 64# Lists are also encoded in a special way to save a lot of space.# The number of entries allowed per internal list node can be specified# as a fixed maximum size or a maximum number of elements.# For a fixed maximum size, use -5 through -1, meaning:# -5: max size: 64 Kb <-- not recommended for normal workloads# -4: max size: 32 Kb <-- not recommended# -3: max size: 16 Kb <-- probably not recommended# -2: max size: 8 Kb <-- good# -1: max size: 4 Kb <-- good# Positive numbers mean store up to _exactly_ that number of elements# per list node.# The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),# but if your use case is unique, adjust the settings as necessary.list-max-ziplist-size -2# Lists may also be compressed.# Compress depth is the number of quicklist ziplist nodes from *each* side of# the list to *exclude* from compression. The head and tail of the list# are always uncompressed for fast push/pop operations. Settings are:# 0: disable all list compression# 1: depth 1 means "don't start compressing until after 1 node into the list,# going from either the head or tail"# So: [head]->node->node->...->node->[tail]# [head], [tail] will always be uncompressed; inner nodes will compress.# 2: [head]->[next]->node->node->...->node->[prev]->[tail]# 2 here means: don't compress head or head->next or tail->prev or tail,# but compress all nodes between them.# 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]# etc.list-compress-depth 0# Sets have a special encoding in just one case: when a set is composed# of just strings that happen to be integers in radix 10 in the range# of 64 bit signed integers.# The following configuration setting sets the limit in the size of the# set in order to use this special memory saving encoding.set-max-intset-entries 512# Similarly to hashes and lists, sorted sets are also specially encoded in# order to save a lot of space. This encoding is only used when the length and# elements of a sorted set are below the following limits:zset-max-ziplist-entries 128zset-max-ziplist-value 64# HyperLogLog sparse representation bytes limit. The limit includes the# 16 bytes header. When an HyperLogLog using the sparse representation crosses# this limit, it is converted into the dense representation.## A value greater than 16000 is totally useless, since at that point the# dense representation is more memory efficient.## The suggested value is ~ 3000 in order to have the benefits of# the space efficient encoding without slowing down too much PFADD,# which is O(N) with the sparse encoding. The value can be raised to# ~ 10000 when CPU is not a concern, but space is, and the data set is# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.hll-sparse-max-bytes 3000# Streams macro node max size / items. The stream data structure is a radix# tree of big nodes that encode multiple items inside. Using this configuration# it is possible to configure how big a single node can be in bytes, and the# maximum number of items it may contain before switching to a new node when# appending new stream entries. If any of the following settings are set to# zero, the limit is ignored, so for instance it is possible to set just a# max entires limit by setting max-bytes to 0 and max-entries to the desired# value.stream-node-max-bytes 4096stream-node-max-entries 100# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in# order to help rehashing the main Redis hash table (the one mapping top-level# keys to values). The hash table implementation Redis uses (see dict.c)# performs a lazy rehashing: the more operation you run into a hash table# that is rehashing, the more rehashing "steps" are performed, so if the# server is idle the rehashing is never complete and some more memory is used# by the hash table.## The default is to use this millisecond 10 times every second in order to# actively rehash the main dictionaries, freeing memory when possible.## If unsure:# use "activerehashing no" if you have hard latency requirements and it is# not a good thing in your environment that Redis can reply from time to time# to queries with 2 milliseconds delay.## use "activerehashing yes" if you don't have such hard requirements but# want to free memory asap when possible.activerehashing yes# The client output buffer limits can be used to force disconnection of clients# that are not reading data from the server fast enough for some reason (a# common reason is that a Pub/Sub client can't consume messages as fast as the# publisher can produce them).## The limit can be set differently for the three different classes of clients:## normal -> normal clients including MONITOR clients# replica -> replica clients# pubsub -> clients subscribed to at least one pubsub channel or pattern## The syntax of every client-output-buffer-limit directive is the following:## client-output-buffer-limit ## A client is immediately disconnected once the hard limit is reached, or if# the soft limit is reached and remains reached for the specified number of# seconds (continuously).# So for instance if the hard limit is 32 megabytes and the soft limit is# 16 megabytes / 10 seconds, the client will get disconnected immediately# if the size of the output buffers reach 32 megabytes, but will also get# disconnected if the client reaches 16 megabytes and continuously overcomes# the limit for 10 seconds.## By default normal clients are not limited because they don't receive data# without asking (in a push way), but just after a request, so only# asynchronous clients may create a scenario where data is requested faster# than it can read.## Instead there is a default limit for pubsub and replica clients, since# subscribers and replicas receive data in a push fashion.## Both the hard or the soft limit can be disabled by setting them to zero.client-output-buffer-limit normal 0 0 0client-output-buffer-limit replica 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60# Client query buffers accumulate new commands. They are limited to a fixed# amount by default in order to avoid that a protocol desynchronization (for# instance due to a bug in the client) will lead to unbound memory usage in# the query buffer. However you can configure it here if you have very special# needs, such us huge multi/exec requests or alike.## client-query-buffer-limit 1gb# In the Redis protocol, bulk requests, that are, elements representing single# strings, are normally limited ot 512 mb. However you can change this limit# here.## proto-max-bulk-len 512mb# Redis calls an internal function to perform many background tasks, like# closing connections of clients in timeout, purging expired keys that are# never requested, and so forth.## Not all tasks are performed with the same frequency, but Redis checks for# tasks to perform according to the specified "hz" value.## By default "hz" is set to 10. Raising the value will use more CPU when# Redis is idle, but at the same time will make Redis more responsive when# there are many keys expiring at the same time, and timeouts may be# handled with more precision.## The range is between 1 and 500, however a value over 100 is usually not# a good idea. Most users should use the default of 10 and raise this up to# 100 only in environments where very low latency is required.hz 10# Normally it is useful to have an HZ value which is proportional to the# number of clients connected. This is useful in order, for instance, to# avoid too many clients are processed for each background task invocation# in order to avoid latency spikes.## Since the default HZ value by default is conservatively set to 10, Redis# offers, and enables by default, the ability to use an adaptive HZ value# which will temporary raise when there are many connected clients.## When dynamic HZ is enabled, the actual configured HZ will be used as# as a baseline, but multiples of the configured HZ value will be actually# used as needed once more clients are connected. In this way an idle# instance will use very little CPU time while a busy instance will be# more responsive.dynamic-hz yes# When a child rewrites the AOF file, if the following option is enabled# the file will be fsync-ed every 32 MB of data generated. This is useful# in order to commit the file to the disk more incrementally and avoid# big latency spikes.aof-rewrite-incremental-fsync yes# When redis saves RDB file, if the following option is enabled# the file will be fsync-ed every 32 MB of data generated. This is useful# in order to commit the file to the disk more incrementally and avoid# big latency spikes.rdb-save-incremental-fsync yes# Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good# idea to start with the default settings and only change them after investigating# how to improve the performances and how the keys LFU change over time, which# is possible to inspect via the OBJECT FREQ command.## There are two tunable parameters in the Redis LFU implementation: the# counter logarithm factor and the counter decay time. It is important to# understand what the two parameters mean before changing them.## The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis# uses a probabilistic increment with logarithmic behavior. Given the value# of the old counter, when a key is accessed, the counter is incremented in# this way:## 1. A random number R between 0 and 1 is extracted.# 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).# 3. The counter is incremented only if R < P.## The default lfu-log-factor is 10. This is a table of how the frequency# counter changes with a different number of accesses with different# logarithmic factors:## +--------+------------+------------+------------+------------+------------+# | factor | 100 hits | 1000 hits | 100K hits | 1M hits | 10M hits |# +--------+------------+------------+------------+------------+------------+# | 0 | 104 | 255 | 255 | 255 | 255 |# +--------+------------+------------+------------+------------+------------+# | 1 | 18 | 49 | 255 | 255 | 255 |# +--------+------------+------------+------------+------------+------------+# | 10 | 10 | 18 | 142 | 255 | 255 |# +--------+------------+------------+------------+------------+------------+# | 100 | 8 | 11 | 49 | 143 | 255 |# +--------+------------+------------+------------+------------+------------+## NOTE: The above table was obtained by running the following commands:## redis-benchmark -n 1000000 incr foo# redis-cli object freq foo## NOTE 2: The counter initial value is 5 in order to give new objects a chance# to accumulate hits.## The counter decay time is the time, in minutes, that must elapse in order# for the key counter to be divided by two (or decremented if it has a value# less <= 10).## The default value for the lfu-decay-time is 1. A Special value of 0 means to# decay the counter every time it happens to be scanned.## lfu-log-factor 10# lfu-decay-time 1########################### ACTIVE DEFRAGMENTATION ######################### WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested# even in production and manually tested by multiple engineers for some# time.## What is active defragmentation?# -------------------------------## Active (online) defragmentation allows a Redis server to compact the# spaces left between small allocations and deallocations of data in memory,# thus allowing to reclaim back memory.## Fragmentation is a natural process that happens with every allocator (but# less so with Jemalloc, fortunately) and certain workloads. Normally a server# restart is needed in order to lower the fragmentation, or at least to flush# away all the data and create it again. However thanks to this feature# implemented by Oran Agra for Redis 4.0 this process can happen at runtime# in an "hot" way, while the server is running.## Basically when the fragmentation is over a certain level (see the# configuration options below) Redis will start to create new copies of the# values in contiguous memory regions by exploiting certain specific Jemalloc# features (in order to understand if an allocation is causing fragmentation# and to allocate it in a better place), and at the same time, will release the# old copies of the data. This process, repeated incrementally for all the keys# will cause the fragmentation to drop back to normal values.## Important things to understand:## 1. This feature is disabled by default, and only works if you compiled Redis# to use the copy of Jemalloc we ship with the source code of Redis.# This is the default with Linux builds.## 2. You never need to enable this feature if you don't have fragmentation# issues.## 3. Once you experience fragmentation, you can enable this feature when# needed with the command "CONFIG SET activedefrag yes".## The configuration parameters are able to fine tune the behavior of the# defragmentation process. If you are not sure about what they mean it is# a good idea to leave the defaults untouched.# Enabled active defragmentation# activedefrag yes# Minimum amount of fragmentation waste to start active defrag# active-defrag-ignore-bytes 100mb# Minimum percentage of fragmentation to start active defrag# active-defrag-threshold-lower 10# Maximum percentage of fragmentation at which we use maximum effort# active-defrag-threshold-upper 100# Minimal effort for defrag in CPU percentage# active-defrag-cycle-min 5# Maximal effort for defrag in CPU percentage# active-defrag-cycle-max 75# Maximum number of set/hash/zset/list fields that will be processed from# the main dictionary scan# active-defrag-max-scan-fields 1000- 运行Redis
$ docker run --restart always -d -v /home/redis/redis.conf:/usr/local/etc/redis/redis.conf -v /home/redis/data:/data --name redis -p 6379:6379 redis:6.2.6 redis-server /usr/local/etc/redis/redis.conf- 进入redis容器
$ docker exec -it redis /bin/bash- 进入redis-cli
root@5d9912d20e4a:/data# redis-cli127.0.0.1:6379> set k1 v1OK查看Redis版本
root@5d9912d20e4a:/data# redis-server -vRedis server v=6.2.6 sha=00000000:0 malloc=jemalloc-5.1.0 bits=64 build=b61f37314a089f19Nginx最新版安装
- 拉取镜像
$ docker pull nginx- 运行容器
docker run --name mynginx -p 80:80 -d nginx- 使用浏览器访问nginx：虚拟机的ip:80
Tomcat服务器安装
- 拉取最新的Tomcat
$ docker pull tomcat- 运行容器
[root@aubin ~]# docker run --name mytomcat -p 8080:8080 -v $PWD/test:/usr/local/tomcat/webapps/test -d tomcata956f63b4aa08014e8584e2f8f9b04cf2603c0e7144f917bb146b947492f2419docker安装最新版Tomcat无法访问
此时我们会发现访问不了这个Tomcat，那是因为webapps目录没有任何东西，此时我们要这样做。
- 把webapps.dist目录的内容复制到webapps目录中（因为webapps.dist包含了Tomcat的首页html）
使用pwd命令检查一下当前目录
root@a956f63b4aa0:/usr/local/tomcat# pwd/usr/local/tomcat开始复制（重点）
cp -r webapps.dist/* ./webapps- 最后把webapps.dist删除即可，反正也没用了。
rm -rf webapps.dist- OK，执行完上述命令之后就完成了！
MongoDB安装
- 拉取镜像
$ docker pull mongo:latest- 运行MongoDB容器
$ docker run -itd --name mongo -p 27017:27017 mongo --auth- –auth：意思是需要密码才能访问容器服务。
$ docker exec -it mongo mongo admin# 创建一个名为 admin，密码为 123456 的用户。> db.createUser({ user:'admin',pwd:'123456',roles:[ { role:'userAdminAnyDatabase', db: 'admin'},"readWriteAnyDatabase"]});# 尝试使用上面创建的用户信息进行连接。> db.auth('admin', '123456')❤️💛🧡本章结束，我们下一章（高级篇）见❤️💛🧡
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