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  • 16、Redis手动创建集群

     写在前面的话:读书破万卷,编码如有神

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    1、手工创建集群
    需要搭建的redis集群如下图所示:
    1.1、首先进行集群配置
    (1)拷贝redis.conf文件6份,分别命名为:redis6381.conf、redis6382.conf、redis6383.conf、redis6384.conf、redis6385.conf、redis6386.conf
    (2)只需要将每个数据库配置文件中的cluster-enable配置选项打开,然后再修改如下内容:pidfile、port、logfile、dbfilename、cluster-config-file
    redis6381.conf 具体的配置如下:
       1 # Redis configuration file example.
       2 #
       3 # Note that in order to read the configuration file, Redis must be
       4 # started with the file path as first argument:
       5 #
       6 # ./redis-server /path/to/redis.conf
       7 
       8 # Note on units: when memory size is needed, it is possible to specify
       9 # it in the usual form of 1k 5GB 4M and so forth:
      10 #
      11 # 1k => 1000 bytes
      12 # 1kb => 1024 bytes
      13 # 1m => 1000000 bytes
      14 # 1mb => 1024*1024 bytes
      15 # 1g => 1000000000 bytes
      16 # 1gb => 1024*1024*1024 bytes
      17 #
      18 # units are case insensitive so 1GB 1Gb 1gB are all the same.
      19 
      20 ################################## INCLUDES ###################################
      21 
      22 # Include one or more other config files here.  This is useful if you
      23 # have a standard template that goes to all Redis servers but also need
      24 # to customize a few per-server settings.  Include files can include
      25 # other files, so use this wisely.
      26 #
      27 # Notice option "include" won't be rewritten by command "CONFIG REWRITE"
      28 # from admin or Redis Sentinel. Since Redis always uses the last processed
      29 # line as value of a configuration directive, you'd better put includes
      30 # at the beginning of this file to avoid overwriting config change at runtime.
      31 #
      32 # If instead you are interested in using includes to override configuration
      33 # options, it is better to use include as the last line.
      34 #
      35 # include /path/to/local.conf
      36 # include /path/to/other.conf
      37 
      38 ################################## MODULES #####################################
      39 
      40 # Load modules at startup. If the server is not able to load modules
      41 # it will abort. It is possible to use multiple loadmodule directives.
      42 #
      43 # loadmodule /path/to/my_module.so
      44 # loadmodule /path/to/other_module.so
      45 
      46 ################################## NETWORK #####################################
      47 
      48 # By default, if no "bind" configuration directive is specified, Redis listens
      49 # for connections from all the network interfaces available on the server.
      50 # It is possible to listen to just one or multiple selected interfaces using
      51 # the "bind" configuration directive, followed by one or more IP addresses.
      52 #
      53 # Examples:
      54 #
      55 # bind 192.168.1.100 10.0.0.1
      56 # bind 127.0.0.1 ::1
      57 #
      58 # ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
      59 # internet, binding to all the interfaces is dangerous and will expose the
      60 # instance to everybody on the internet. So by default we uncomment the
      61 # following bind directive, that will force Redis to listen only into
      62 # the IPv4 lookback interface address (this means Redis will be able to
      63 # accept connections only from clients running into the same computer it
      64 # is running).
      65 #
      66 # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
      67 # JUST COMMENT THE FOLLOWING LINE.
      68 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      69 bind 127.0.0.1
      70 
      71 # Protected mode is a layer of security protection, in order to avoid that
      72 # Redis instances left open on the internet are accessed and exploited.
      73 #
      74 # When protected mode is on and if:
      75 #
      76 # 1) The server is not binding explicitly to a set of addresses using the
      77 #    "bind" directive.
      78 # 2) No password is configured.
      79 #
      80 # The server only accepts connections from clients connecting from the
      81 # IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain
      82 # sockets.
      83 #
      84 # By default protected mode is enabled. You should disable it only if
      85 # you are sure you want clients from other hosts to connect to Redis
      86 # even if no authentication is configured, nor a specific set of interfaces
      87 # are explicitly listed using the "bind" directive.
      88 protected-mode yes
      89 
      90 # Accept connections on the specified port, default is 6379 (IANA #815344).
      91 # If port 0 is specified Redis will not listen on a TCP socket.
      92 port 6381
      93 
      94 # TCP listen() backlog.
      95 #
      96 # In high requests-per-second environments you need an high backlog in order
      97 # to avoid slow clients connections issues. Note that the Linux kernel
      98 # will silently truncate it to the value of /proc/sys/net/core/somaxconn so
      99 # make sure to raise both the value of somaxconn and tcp_max_syn_backlog
     100 # in order to get the desired effect.
     101 tcp-backlog 511
     102 
     103 # Unix socket.
     104 #
     105 # Specify the path for the Unix socket that will be used to listen for
     106 # incoming connections. There is no default, so Redis will not listen
     107 # on a unix socket when not specified.
     108 #
     109 # unixsocket /tmp/redis.sock
     110 # unixsocketperm 700
     111 
     112 # Close the connection after a client is idle for N seconds (0 to disable)
     113 timeout 0
     114 
     115 # TCP keepalive.
     116 #
     117 # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
     118 # of communication. This is useful for two reasons:
     119 #
     120 # 1) Detect dead peers.
     121 # 2) Take the connection alive from the point of view of network
     122 #    equipment in the middle.
     123 #
     124 # On Linux, the specified value (in seconds) is the period used to send ACKs.
     125 # Note that to close the connection the double of the time is needed.
     126 # On other kernels the period depends on the kernel configuration.
     127 #
     128 # A reasonable value for this option is 300 seconds, which is the new
     129 # Redis default starting with Redis 3.2.1.
     130 tcp-keepalive 300
     131 
     132 ################################# GENERAL #####################################
     133 
     134 # By default Redis does not run as a daemon. Use 'yes' if you need it.
     135 # Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
     136 daemonize yes
     137 
     138 # If you run Redis from upstart or systemd, Redis can interact with your
     139 # supervision tree. Options:
     140 #   supervised no      - no supervision interaction
     141 #   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
     142 #   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
     143 #   supervised auto    - detect upstart or systemd method based on
     144 #                        UPSTART_JOB or NOTIFY_SOCKET environment variables
     145 # Note: these supervision methods only signal "process is ready."
     146 #       They do not enable continuous liveness pings back to your supervisor.
     147 supervised no
     148 
     149 # If a pid file is specified, Redis writes it where specified at startup
     150 # and removes it at exit.
     151 #
     152 # When the server runs non daemonized, no pid file is created if none is
     153 # specified in the configuration. When the server is daemonized, the pid file
     154 # is used even if not specified, defaulting to "/var/run/redis.pid".
     155 #
     156 # Creating a pid file is best effort: if Redis is not able to create it
     157 # nothing bad happens, the server will start and run normally.
     158 pidfile /var/run/redis_6381.pid
     159 
     160 # Specify the server verbosity level.
     161 # This can be one of:
     162 # debug (a lot of information, useful for development/testing)
     163 # verbose (many rarely useful info, but not a mess like the debug level)
     164 # notice (moderately verbose, what you want in production probably)
     165 # warning (only very important / critical messages are logged)
     166 loglevel notice
     167 
     168 # Specify the log file name. Also the empty string can be used to force
     169 # Redis to log on the standard output. Note that if you use standard
     170 # output for logging but daemonize, logs will be sent to /dev/null
     171 logfile "redis_6381.log"
     172 
     173 # To enable logging to the system logger, just set 'syslog-enabled' to yes,
     174 # and optionally update the other syslog parameters to suit your needs.
     175 # syslog-enabled no
     176 
     177 # Specify the syslog identity.
     178 # syslog-ident redis
     179 
     180 # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
     181 # syslog-facility local0
     182 
     183 # Set the number of databases. The default database is DB 0, you can select
     184 # a different one on a per-connection basis using SELECT <dbid> where
     185 # dbid is a number between 0 and 'databases'-1
     186 databases 16
     187 
     188 # By default Redis shows an ASCII art logo only when started to log to the
     189 # standard output and if the standard output is a TTY. Basically this means
     190 # that normally a logo is displayed only in interactive sessions.
     191 #
     192 # However it is possible to force the pre-4.0 behavior and always show a
     193 # ASCII art logo in startup logs by setting the following option to yes.
     194 always-show-logo yes
     195 
     196 ################################ SNAPSHOTTING  ################################
     197 #
     198 # Save the DB on disk:
     199 #
     200 #   save <seconds> <changes>
     201 #
     202 #   Will save the DB if both the given number of seconds and the given
     203 #   number of write operations against the DB occurred.
     204 #
     205 #   In the example below the behaviour will be to save:
     206 #   after 900 sec (15 min) if at least 1 key changed
     207 #   after 300 sec (5 min) if at least 10 keys changed
     208 #   after 60 sec if at least 10000 keys changed
     209 #
     210 #   Note: you can disable saving completely by commenting out all "save" lines.
     211 #
     212 #   It is also possible to remove all the previously configured save
     213 #   points by adding a save directive with a single empty string argument
     214 #   like in the following example:
     215 #
     216 #   save ""
     217 
     218 save 900 1
     219 save 300 10
     220 save 60 10000
     221 
     222 # By default Redis will stop accepting writes if RDB snapshots are enabled
     223 # (at least one save point) and the latest background save failed.
     224 # This will make the user aware (in a hard way) that data is not persisting
     225 # on disk properly, otherwise chances are that no one will notice and some
     226 # disaster will happen.
     227 #
     228 # If the background saving process will start working again Redis will
     229 # automatically allow writes again.
     230 #
     231 # However if you have setup your proper monitoring of the Redis server
     232 # and persistence, you may want to disable this feature so that Redis will
     233 # continue to work as usual even if there are problems with disk,
     234 # permissions, and so forth.
     235 stop-writes-on-bgsave-error yes
     236 
     237 # Compress string objects using LZF when dump .rdb databases?
     238 # For default that's set to 'yes' as it's almost always a win.
     239 # If you want to save some CPU in the saving child set it to 'no' but
     240 # the dataset will likely be bigger if you have compressible values or keys.
     241 rdbcompression yes
     242 
     243 # Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
     244 # This makes the format more resistant to corruption but there is a performance
     245 # hit to pay (around 10%) when saving and loading RDB files, so you can disable it
     246 # for maximum performances.
     247 #
     248 # RDB files created with checksum disabled have a checksum of zero that will
     249 # tell the loading code to skip the check.
     250 rdbchecksum yes
     251 
     252 # The filename where to dump the DB
     253 dbfilename dump_6381.rdb
     254 
     255 # The working directory.
     256 #
     257 # The DB will be written inside this directory, with the filename specified
     258 # above using the 'dbfilename' configuration directive.
     259 #
     260 # The Append Only File will also be created inside this directory.
     261 #
     262 # Note that you must specify a directory here, not a file name.
     263 dir ./
     264 
     265 ################################# REPLICATION #################################
     266 
     267 # Master-Slave replication. Use slaveof to make a Redis instance a copy of
     268 # another Redis server. A few things to understand ASAP about Redis replication.
     269 #
     270 # 1) Redis replication is asynchronous, but you can configure a master to
     271 #    stop accepting writes if it appears to be not connected with at least
     272 #    a given number of slaves.
     273 # 2) Redis slaves are able to perform a partial resynchronization with the
     274 #    master if the replication link is lost for a relatively small amount of
     275 #    time. You may want to configure the replication backlog size (see the next
     276 #    sections of this file) with a sensible value depending on your needs.
     277 # 3) Replication is automatic and does not need user intervention. After a
     278 #    network partition slaves automatically try to reconnect to masters
     279 #    and resynchronize with them.
     280 #
     281 # slaveof <masterip> <masterport>
     282 
     283 # If the master is password protected (using the "requirepass" configuration
     284 # directive below) it is possible to tell the slave to authenticate before
     285 # starting the replication synchronization process, otherwise the master will
     286 # refuse the slave request.
     287 #
     288 # masterauth <master-password>
     289 
     290 # When a slave loses its connection with the master, or when the replication
     291 # is still in progress, the slave can act in two different ways:
     292 #
     293 # 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
     294 #    still reply to client requests, possibly with out of date data, or the
     295 #    data set may just be empty if this is the first synchronization.
     296 #
     297 # 2) if slave-serve-stale-data is set to 'no' the slave will reply with
     298 #    an error "SYNC with master in progress" to all the kind of commands
     299 #    but to INFO and SLAVEOF.
     300 #
     301 slave-serve-stale-data yes
     302 
     303 # You can configure a slave instance to accept writes or not. Writing against
     304 # a slave instance may be useful to store some ephemeral data (because data
     305 # written on a slave will be easily deleted after resync with the master) but
     306 # may also cause problems if clients are writing to it because of a
     307 # misconfiguration.
     308 #
     309 # Since Redis 2.6 by default slaves are read-only.
     310 #
     311 # Note: read only slaves are not designed to be exposed to untrusted clients
     312 # on the internet. It's just a protection layer against misuse of the instance.
     313 # Still a read only slave exports by default all the administrative commands
     314 # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
     315 # security of read only slaves using 'rename-command' to shadow all the
     316 # administrative / dangerous commands.
     317 slave-read-only yes
     318 
     319 # Replication SYNC strategy: disk or socket.
     320 #
     321 # -------------------------------------------------------
     322 # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
     323 # -------------------------------------------------------
     324 #
     325 # New slaves and reconnecting slaves that are not able to continue the replication
     326 # process just receiving differences, need to do what is called a "full
     327 # synchronization". An RDB file is transmitted from the master to the slaves.
     328 # The transmission can happen in two different ways:
     329 #
     330 # 1) Disk-backed: The Redis master creates a new process that writes the RDB
     331 #                 file on disk. Later the file is transferred by the parent
     332 #                 process to the slaves incrementally.
     333 # 2) Diskless: The Redis master creates a new process that directly writes the
     334 #              RDB file to slave sockets, without touching the disk at all.
     335 #
     336 # With disk-backed replication, while the RDB file is generated, more slaves
     337 # can be queued and served with the RDB file as soon as the current child producing
     338 # the RDB file finishes its work. With diskless replication instead once
     339 # the transfer starts, new slaves arriving will be queued and a new transfer
     340 # will start when the current one terminates.
     341 #
     342 # When diskless replication is used, the master waits a configurable amount of
     343 # time (in seconds) before starting the transfer in the hope that multiple slaves
     344 # will arrive and the transfer can be parallelized.
     345 #
     346 # With slow disks and fast (large bandwidth) networks, diskless replication
     347 # works better.
     348 repl-diskless-sync no
     349 
     350 # When diskless replication is enabled, it is possible to configure the delay
     351 # the server waits in order to spawn the child that transfers the RDB via socket
     352 # to the slaves.
     353 #
     354 # This is important since once the transfer starts, it is not possible to serve
     355 # new slaves arriving, that will be queued for the next RDB transfer, so the server
     356 # waits a delay in order to let more slaves arrive.
     357 #
     358 # The delay is specified in seconds, and by default is 5 seconds. To disable
     359 # it entirely just set it to 0 seconds and the transfer will start ASAP.
     360 repl-diskless-sync-delay 5
     361 
     362 # Slaves send PINGs to server in a predefined interval. It's possible to change
     363 # this interval with the repl_ping_slave_period option. The default value is 10
     364 # seconds.
     365 #
     366 # repl-ping-slave-period 10
     367 
     368 # The following option sets the replication timeout for:
     369 #
     370 # 1) Bulk transfer I/O during SYNC, from the point of view of slave.
     371 # 2) Master timeout from the point of view of slaves (data, pings).
     372 # 3) Slave timeout from the point of view of masters (REPLCONF ACK pings).
     373 #
     374 # It is important to make sure that this value is greater than the value
     375 # specified for repl-ping-slave-period otherwise a timeout will be detected
     376 # every time there is low traffic between the master and the slave.
     377 #
     378 # repl-timeout 60
     379 
     380 # Disable TCP_NODELAY on the slave socket after SYNC?
     381 #
     382 # If you select "yes" Redis will use a smaller number of TCP packets and
     383 # less bandwidth to send data to slaves. But this can add a delay for
     384 # the data to appear on the slave side, up to 40 milliseconds with
     385 # Linux kernels using a default configuration.
     386 #
     387 # If you select "no" the delay for data to appear on the slave side will
     388 # be reduced but more bandwidth will be used for replication.
     389 #
     390 # By default we optimize for low latency, but in very high traffic conditions
     391 # or when the master and slaves are many hops away, turning this to "yes" may
     392 # be a good idea.
     393 repl-disable-tcp-nodelay no
     394 
     395 # Set the replication backlog size. The backlog is a buffer that accumulates
     396 # slave data when slaves are disconnected for some time, so that when a slave
     397 # wants to reconnect again, often a full resync is not needed, but a partial
     398 # resync is enough, just passing the portion of data the slave missed while
     399 # disconnected.
     400 #
     401 # The bigger the replication backlog, the longer the time the slave can be
     402 # disconnected and later be able to perform a partial resynchronization.
     403 #
     404 # The backlog is only allocated once there is at least a slave connected.
     405 #
     406 # repl-backlog-size 1mb
     407 
     408 # After a master has no longer connected slaves for some time, the backlog
     409 # will be freed. The following option configures the amount of seconds that
     410 # need to elapse, starting from the time the last slave disconnected, for
     411 # the backlog buffer to be freed.
     412 #
     413 # Note that slaves never free the backlog for timeout, since they may be
     414 # promoted to masters later, and should be able to correctly "partially
     415 # resynchronize" with the slaves: hence they should always accumulate backlog.
     416 #
     417 # A value of 0 means to never release the backlog.
     418 #
     419 # repl-backlog-ttl 3600
     420 
     421 # The slave priority is an integer number published by Redis in the INFO output.
     422 # It is used by Redis Sentinel in order to select a slave to promote into a
     423 # master if the master is no longer working correctly.
     424 #
     425 # A slave with a low priority number is considered better for promotion, so
     426 # for instance if there are three slaves with priority 10, 100, 25 Sentinel will
     427 # pick the one with priority 10, that is the lowest.
     428 #
     429 # However a special priority of 0 marks the slave as not able to perform the
     430 # role of master, so a slave with priority of 0 will never be selected by
     431 # Redis Sentinel for promotion.
     432 #
     433 # By default the priority is 100.
     434 slave-priority 100
     435 
     436 # It is possible for a master to stop accepting writes if there are less than
     437 # N slaves connected, having a lag less or equal than M seconds.
     438 #
     439 # The N slaves need to be in "online" state.
     440 #
     441 # The lag in seconds, that must be <= the specified value, is calculated from
     442 # the last ping received from the slave, that is usually sent every second.
     443 #
     444 # This option does not GUARANTEE that N replicas will accept the write, but
     445 # will limit the window of exposure for lost writes in case not enough slaves
     446 # are available, to the specified number of seconds.
     447 #
     448 # For example to require at least 3 slaves with a lag <= 10 seconds use:
     449 #
     450 # min-slaves-to-write 3
     451 # min-slaves-max-lag 10
     452 #
     453 # Setting one or the other to 0 disables the feature.
     454 #
     455 # By default min-slaves-to-write is set to 0 (feature disabled) and
     456 # min-slaves-max-lag is set to 10.
     457 
     458 # A Redis master is able to list the address and port of the attached
     459 # slaves in different ways. For example the "INFO replication" section
     460 # offers this information, which is used, among other tools, by
     461 # Redis Sentinel in order to discover slave instances.
     462 # Another place where this info is available is in the output of the
     463 # "ROLE" command of a master.
     464 #
     465 # The listed IP and address normally reported by a slave is obtained
     466 # in the following way:
     467 #
     468 #   IP: The address is auto detected by checking the peer address
     469 #   of the socket used by the slave to connect with the master.
     470 #
     471 #   Port: The port is communicated by the slave during the replication
     472 #   handshake, and is normally the port that the slave is using to
     473 #   list for connections.
     474 #
     475 # However when port forwarding or Network Address Translation (NAT) is
     476 # used, the slave may be actually reachable via different IP and port
     477 # pairs. The following two options can be used by a slave in order to
     478 # report to its master a specific set of IP and port, so that both INFO
     479 # and ROLE will report those values.
     480 #
     481 # There is no need to use both the options if you need to override just
     482 # the port or the IP address.
     483 #
     484 # slave-announce-ip 5.5.5.5
     485 # slave-announce-port 1234
     486 
     487 ################################## SECURITY ###################################
     488 
     489 # Require clients to issue AUTH <PASSWORD> before processing any other
     490 # commands.  This might be useful in environments in which you do not trust
     491 # others with access to the host running redis-server.
     492 #
     493 # This should stay commented out for backward compatibility and because most
     494 # people do not need auth (e.g. they run their own servers).
     495 #
     496 # Warning: since Redis is pretty fast an outside user can try up to
     497 # 150k passwords per second against a good box. This means that you should
     498 # use a very strong password otherwise it will be very easy to break.
     499 #
     500 # requirepass foobared
     501 
     502 # Command renaming.
     503 #
     504 # It is possible to change the name of dangerous commands in a shared
     505 # environment. For instance the CONFIG command may be renamed into something
     506 # hard to guess so that it will still be available for internal-use tools
     507 # but not available for general clients.
     508 #
     509 # Example:
     510 #
     511 # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
     512 #
     513 # It is also possible to completely kill a command by renaming it into
     514 # an empty string:
     515 #
     516 # rename-command CONFIG ""
     517 #
     518 # Please note that changing the name of commands that are logged into the
     519 # AOF file or transmitted to slaves may cause problems.
     520 
     521 ################################### CLIENTS ####################################
     522 
     523 # Set the max number of connected clients at the same time. By default
     524 # this limit is set to 10000 clients, however if the Redis server is not
     525 # able to configure the process file limit to allow for the specified limit
     526 # the max number of allowed clients is set to the current file limit
     527 # minus 32 (as Redis reserves a few file descriptors for internal uses).
     528 #
     529 # Once the limit is reached Redis will close all the new connections sending
     530 # an error 'max number of clients reached'.
     531 #
     532 # maxclients 10000
     533 
     534 ############################## MEMORY MANAGEMENT ################################
     535 
     536 # Set a memory usage limit to the specified amount of bytes.
     537 # When the memory limit is reached Redis will try to remove keys
     538 # according to the eviction policy selected (see maxmemory-policy).
     539 #
     540 # If Redis can't remove keys according to the policy, or if the policy is
     541 # set to 'noeviction', Redis will start to reply with errors to commands
     542 # that would use more memory, like SET, LPUSH, and so on, and will continue
     543 # to reply to read-only commands like GET.
     544 #
     545 # This option is usually useful when using Redis as an LRU or LFU cache, or to
     546 # set a hard memory limit for an instance (using the 'noeviction' policy).
     547 #
     548 # WARNING: If you have slaves attached to an instance with maxmemory on,
     549 # the size of the output buffers needed to feed the slaves are subtracted
     550 # from the used memory count, so that network problems / resyncs will
     551 # not trigger a loop where keys are evicted, and in turn the output
     552 # buffer of slaves is full with DELs of keys evicted triggering the deletion
     553 # of more keys, and so forth until the database is completely emptied.
     554 #
     555 # In short... if you have slaves attached it is suggested that you set a lower
     556 # limit for maxmemory so that there is some free RAM on the system for slave
     557 # output buffers (but this is not needed if the policy is 'noeviction').
     558 #
     559 # maxmemory <bytes>
     560 
     561 # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
     562 # is reached. You can select among five behaviors:
     563 #
     564 # volatile-lru -> Evict using approximated LRU among the keys with an expire set.
     565 # allkeys-lru -> Evict any key using approximated LRU.
     566 # volatile-lfu -> Evict using approximated LFU among the keys with an expire set.
     567 # allkeys-lfu -> Evict any key using approximated LFU.
     568 # volatile-random -> Remove a random key among the ones with an expire set.
     569 # allkeys-random -> Remove a random key, any key.
     570 # volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
     571 # noeviction -> Don't evict anything, just return an error on write operations.
     572 #
     573 # LRU means Least Recently Used
     574 # LFU means Least Frequently Used
     575 #
     576 # Both LRU, LFU and volatile-ttl are implemented using approximated
     577 # randomized algorithms.
     578 #
     579 # Note: with any of the above policies, Redis will return an error on write
     580 #       operations, when there are no suitable keys for eviction.
     581 #
     582 #       At the date of writing these commands are: set setnx setex append
     583 #       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
     584 #       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
     585 #       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
     586 #       getset mset msetnx exec sort
     587 #
     588 # The default is:
     589 #
     590 # maxmemory-policy noeviction
     591 
     592 # LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated
     593 # algorithms (in order to save memory), so you can tune it for speed or
     594 # accuracy. For default Redis will check five keys and pick the one that was
     595 # used less recently, you can change the sample size using the following
     596 # configuration directive.
     597 #
     598 # The default of 5 produces good enough results. 10 Approximates very closely
     599 # true LRU but costs more CPU. 3 is faster but not very accurate.
     600 #
     601 # maxmemory-samples 5
     602 
     603 ############################# LAZY FREEING ####################################
     604 
     605 # Redis has two primitives to delete keys. One is called DEL and is a blocking
     606 # deletion of the object. It means that the server stops processing new commands
     607 # in order to reclaim all the memory associated with an object in a synchronous
     608 # way. If the key deleted is associated with a small object, the time needed
     609 # in order to execute the DEL command is very small and comparable to most other
     610 # O(1) or O(log_N) commands in Redis. However if the key is associated with an
     611 # aggregated value containing millions of elements, the server can block for
     612 # a long time (even seconds) in order to complete the operation.
     613 #
     614 # For the above reasons Redis also offers non blocking deletion primitives
     615 # such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and
     616 # FLUSHDB commands, in order to reclaim memory in background. Those commands
     617 # are executed in constant time. Another thread will incrementally free the
     618 # object in the background as fast as possible.
     619 #
     620 # DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.
     621 # It's up to the design of the application to understand when it is a good
     622 # idea to use one or the other. However the Redis server sometimes has to
     623 # delete keys or flush the whole database as a side effect of other operations.
     624 # Specifically Redis deletes objects independently of a user call in the
     625 # following scenarios:
     626 #
     627 # 1) On eviction, because of the maxmemory and maxmemory policy configurations,
     628 #    in order to make room for new data, without going over the specified
     629 #    memory limit.
     630 # 2) Because of expire: when a key with an associated time to live (see the
     631 #    EXPIRE command) must be deleted from memory.
     632 # 3) Because of a side effect of a command that stores data on a key that may
     633 #    already exist. For example the RENAME command may delete the old key
     634 #    content when it is replaced with another one. Similarly SUNIONSTORE
     635 #    or SORT with STORE option may delete existing keys. The SET command
     636 #    itself removes any old content of the specified key in order to replace
     637 #    it with the specified string.
     638 # 4) During replication, when a slave performs a full resynchronization with
     639 #    its master, the content of the whole database is removed in order to
     640 #    load the RDB file just transfered.
     641 #
     642 # In all the above cases the default is to delete objects in a blocking way,
     643 # like if DEL was called. However you can configure each case specifically
     644 # in order to instead release memory in a non-blocking way like if UNLINK
     645 # was called, using the following configuration directives:
     646 
     647 lazyfree-lazy-eviction no
     648 lazyfree-lazy-expire no
     649 lazyfree-lazy-server-del no
     650 slave-lazy-flush no
     651 
     652 ############################## APPEND ONLY MODE ###############################
     653 
     654 # By default Redis asynchronously dumps the dataset on disk. This mode is
     655 # good enough in many applications, but an issue with the Redis process or
     656 # a power outage may result into a few minutes of writes lost (depending on
     657 # the configured save points).
     658 #
     659 # The Append Only File is an alternative persistence mode that provides
     660 # much better durability. For instance using the default data fsync policy
     661 # (see later in the config file) Redis can lose just one second of writes in a
     662 # dramatic event like a server power outage, or a single write if something
     663 # wrong with the Redis process itself happens, but the operating system is
     664 # still running correctly.
     665 #
     666 # AOF and RDB persistence can be enabled at the same time without problems.
     667 # If the AOF is enabled on startup Redis will load the AOF, that is the file
     668 # with the better durability guarantees.
     669 #
     670 # Please check http://redis.io/topics/persistence for more information.
     671 
     672 appendonly no
     673 
     674 # The name of the append only file (default: "appendonly.aof")
     675 
     676 appendfilename "appendonly6381.aof"
     677 
     678 # The fsync() call tells the Operating System to actually write data on disk
     679 # instead of waiting for more data in the output buffer. Some OS will really flush
     680 # data on disk, some other OS will just try to do it ASAP.
     681 #
     682 # Redis supports three different modes:
     683 #
     684 # no: don't fsync, just let the OS flush the data when it wants. Faster.
     685 # always: fsync after every write to the append only log. Slow, Safest.
     686 # everysec: fsync only one time every second. Compromise.
     687 #
     688 # The default is "everysec", as that's usually the right compromise between
     689 # speed and data safety. It's up to you to understand if you can relax this to
     690 # "no" that will let the operating system flush the output buffer when
     691 # it wants, for better performances (but if you can live with the idea of
     692 # some data loss consider the default persistence mode that's snapshotting),
     693 # or on the contrary, use "always" that's very slow but a bit safer than
     694 # everysec.
     695 #
     696 # More details please check the following article:
     697 # http://antirez.com/post/redis-persistence-demystified.html
     698 #
     699 # If unsure, use "everysec".
     700 
     701 # appendfsync always
     702 appendfsync everysec
     703 # appendfsync no
     704 
     705 # When the AOF fsync policy is set to always or everysec, and a background
     706 # saving process (a background save or AOF log background rewriting) is
     707 # performing a lot of I/O against the disk, in some Linux configurations
     708 # Redis may block too long on the fsync() call. Note that there is no fix for
     709 # this currently, as even performing fsync in a different thread will block
     710 # our synchronous write(2) call.
     711 #
     712 # In order to mitigate this problem it's possible to use the following option
     713 # that will prevent fsync() from being called in the main process while a
     714 # BGSAVE or BGREWRITEAOF is in progress.
     715 #
     716 # This means that while another child is saving, the durability of Redis is
     717 # the same as "appendfsync none". In practical terms, this means that it is
     718 # possible to lose up to 30 seconds of log in the worst scenario (with the
     719 # default Linux settings).
     720 #
     721 # If you have latency problems turn this to "yes". Otherwise leave it as
     722 # "no" that is the safest pick from the point of view of durability.
     723 
     724 no-appendfsync-on-rewrite no
     725 
     726 # Automatic rewrite of the append only file.
     727 # Redis is able to automatically rewrite the log file implicitly calling
     728 # BGREWRITEAOF when the AOF log size grows by the specified percentage.
     729 #
     730 # This is how it works: Redis remembers the size of the AOF file after the
     731 # latest rewrite (if no rewrite has happened since the restart, the size of
     732 # the AOF at startup is used).
     733 #
     734 # This base size is compared to the current size. If the current size is
     735 # bigger than the specified percentage, the rewrite is triggered. Also
     736 # you need to specify a minimal size for the AOF file to be rewritten, this
     737 # is useful to avoid rewriting the AOF file even if the percentage increase
     738 # is reached but it is still pretty small.
     739 #
     740 # Specify a percentage of zero in order to disable the automatic AOF
     741 # rewrite feature.
     742 
     743 auto-aof-rewrite-percentage 100
     744 auto-aof-rewrite-min-size 64mb
     745 
     746 # An AOF file may be found to be truncated at the end during the Redis
     747 # startup process, when the AOF data gets loaded back into memory.
     748 # This may happen when the system where Redis is running
     749 # crashes, especially when an ext4 filesystem is mounted without the
     750 # data=ordered option (however this can't happen when Redis itself
     751 # crashes or aborts but the operating system still works correctly).
     752 #
     753 # Redis can either exit with an error when this happens, or load as much
     754 # data as possible (the default now) and start if the AOF file is found
     755 # to be truncated at the end. The following option controls this behavior.
     756 #
     757 # If aof-load-truncated is set to yes, a truncated AOF file is loaded and
     758 # the Redis server starts emitting a log to inform the user of the event.
     759 # Otherwise if the option is set to no, the server aborts with an error
     760 # and refuses to start. When the option is set to no, the user requires
     761 # to fix the AOF file using the "redis-check-aof" utility before to restart
     762 # the server.
     763 #
     764 # Note that if the AOF file will be found to be corrupted in the middle
     765 # the server will still exit with an error. This option only applies when
     766 # Redis will try to read more data from the AOF file but not enough bytes
     767 # will be found.
     768 aof-load-truncated yes
     769 
     770 # When rewriting the AOF file, Redis is able to use an RDB preamble in the
     771 # AOF file for faster rewrites and recoveries. When this option is turned
     772 # on the rewritten AOF file is composed of two different stanzas:
     773 #
     774 #   [RDB file][AOF tail]
     775 #
     776 # When loading Redis recognizes that the AOF file starts with the "REDIS"
     777 # string and loads the prefixed RDB file, and continues loading the AOF
     778 # tail.
     779 #
     780 # This is currently turned off by default in order to avoid the surprise
     781 # of a format change, but will at some point be used as the default.
     782 aof-use-rdb-preamble no
     783 
     784 ################################ LUA SCRIPTING  ###############################
     785 
     786 # Max execution time of a Lua script in milliseconds.
     787 #
     788 # If the maximum execution time is reached Redis will log that a script is
     789 # still in execution after the maximum allowed time and will start to
     790 # reply to queries with an error.
     791 #
     792 # When a long running script exceeds the maximum execution time only the
     793 # SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
     794 # used to stop a script that did not yet called write commands. The second
     795 # is the only way to shut down the server in the case a write command was
     796 # already issued by the script but the user doesn't want to wait for the natural
     797 # termination of the script.
     798 #
     799 # Set it to 0 or a negative value for unlimited execution without warnings.
     800 lua-time-limit 5000
     801 
     802 ################################ REDIS CLUSTER  ###############################
     803 #
     804 # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
     805 # WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however
     806 # in order to mark it as "mature" we need to wait for a non trivial percentage
     807 # of users to deploy it in production.
     808 # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
     809 #
     810 # Normal Redis instances can't be part of a Redis Cluster; only nodes that are
     811 # started as cluster nodes can. In order to start a Redis instance as a
     812 # cluster node enable the cluster support uncommenting the following:
     813 #
     814 cluster-enabled yes
     815 
     816 # Every cluster node has a cluster configuration file. This file is not
     817 # intended to be edited by hand. It is created and updated by Redis nodes.
     818 # Every Redis Cluster node requires a different cluster configuration file.
     819 # Make sure that instances running in the same system do not have
     820 # overlapping cluster configuration file names.
     821 #
     822 cluster-config-file nodes-6381.conf
     823 
     824 # Cluster node timeout is the amount of milliseconds a node must be unreachable
     825 # for it to be considered in failure state.
     826 # Most other internal time limits are multiple of the node timeout.
     827 #
     828 # cluster-node-timeout 15000
     829 
     830 # A slave of a failing master will avoid to start a failover if its data
     831 # looks too old.
     832 #
     833 # There is no simple way for a slave to actually have an exact measure of
     834 # its "data age", so the following two checks are performed:
     835 #
     836 # 1) If there are multiple slaves able to failover, they exchange messages
     837 #    in order to try to give an advantage to the slave with the best
     838 #    replication offset (more data from the master processed).
     839 #    Slaves will try to get their rank by offset, and apply to the start
     840 #    of the failover a delay proportional to their rank.
     841 #
     842 # 2) Every single slave computes the time of the last interaction with
     843 #    its master. This can be the last ping or command received (if the master
     844 #    is still in the "connected" state), or the time that elapsed since the
     845 #    disconnection with the master (if the replication link is currently down).
     846 #    If the last interaction is too old, the slave will not try to failover
     847 #    at all.
     848 #
     849 # The point "2" can be tuned by user. Specifically a slave will not perform
     850 # the failover if, since the last interaction with the master, the time
     851 # elapsed is greater than:
     852 #
     853 #   (node-timeout * slave-validity-factor) + repl-ping-slave-period
     854 #
     855 # So for example if node-timeout is 30 seconds, and the slave-validity-factor
     856 # is 10, and assuming a default repl-ping-slave-period of 10 seconds, the
     857 # slave will not try to failover if it was not able to talk with the master
     858 # for longer than 310 seconds.
     859 #
     860 # A large slave-validity-factor may allow slaves with too old data to failover
     861 # a master, while a too small value may prevent the cluster from being able to
     862 # elect a slave at all.
     863 #
     864 # For maximum availability, it is possible to set the slave-validity-factor
     865 # to a value of 0, which means, that slaves will always try to failover the
     866 # master regardless of the last time they interacted with the master.
     867 # (However they'll always try to apply a delay proportional to their
     868 # offset rank).
     869 #
     870 # Zero is the only value able to guarantee that when all the partitions heal
     871 # the cluster will always be able to continue.
     872 #
     873 # cluster-slave-validity-factor 10
     874 
     875 # Cluster slaves are able to migrate to orphaned masters, that are masters
     876 # that are left without working slaves. This improves the cluster ability
     877 # to resist to failures as otherwise an orphaned master can't be failed over
     878 # in case of failure if it has no working slaves.
     879 #
     880 # Slaves migrate to orphaned masters only if there are still at least a
     881 # given number of other working slaves for their old master. This number
     882 # is the "migration barrier". A migration barrier of 1 means that a slave
     883 # will migrate only if there is at least 1 other working slave for its master
     884 # and so forth. It usually reflects the number of slaves you want for every
     885 # master in your cluster.
     886 #
     887 # Default is 1 (slaves migrate only if their masters remain with at least
     888 # one slave). To disable migration just set it to a very large value.
     889 # A value of 0 can be set but is useful only for debugging and dangerous
     890 # in production.
     891 #
     892 # cluster-migration-barrier 1
     893 
     894 # By default Redis Cluster nodes stop accepting queries if they detect there
     895 # is at least an hash slot uncovered (no available node is serving it).
     896 # This way if the cluster is partially down (for example a range of hash slots
     897 # are no longer covered) all the cluster becomes, eventually, unavailable.
     898 # It automatically returns available as soon as all the slots are covered again.
     899 #
     900 # However sometimes you want the subset of the cluster which is working,
     901 # to continue to accept queries for the part of the key space that is still
     902 # covered. In order to do so, just set the cluster-require-full-coverage
     903 # option to no.
     904 #
     905 # cluster-require-full-coverage yes
     906 
     907 # In order to setup your cluster make sure to read the documentation
     908 # available at http://redis.io web site.
     909 
     910 ########################## CLUSTER DOCKER/NAT support  ########################
     911 
     912 # In certain deployments, Redis Cluster nodes address discovery fails, because
     913 # addresses are NAT-ted or because ports are forwarded (the typical case is
     914 # Docker and other containers).
     915 #
     916 # In order to make Redis Cluster working in such environments, a static
     917 # configuration where each node knows its public address is needed. The
     918 # following two options are used for this scope, and are:
     919 #
     920 # * cluster-announce-ip
     921 # * cluster-announce-port
     922 # * cluster-announce-bus-port
     923 #
     924 # Each instruct the node about its address, client port, and cluster message
     925 # bus port. The information is then published in the header of the bus packets
     926 # so that other nodes will be able to correctly map the address of the node
     927 # publishing the information.
     928 #
     929 # If the above options are not used, the normal Redis Cluster auto-detection
     930 # will be used instead.
     931 #
     932 # Note that when remapped, the bus port may not be at the fixed offset of
     933 # clients port + 10000, so you can specify any port and bus-port depending
     934 # on how they get remapped. If the bus-port is not set, a fixed offset of
     935 # 10000 will be used as usually.
     936 #
     937 # Example:
     938 #
     939 # cluster-announce-ip 10.1.1.5
     940 # cluster-announce-port 6379
     941 # cluster-announce-bus-port 6380
     942 
     943 ################################## SLOW LOG ###################################
     944 
     945 # The Redis Slow Log is a system to log queries that exceeded a specified
     946 # execution time. The execution time does not include the I/O operations
     947 # like talking with the client, sending the reply and so forth,
     948 # but just the time needed to actually execute the command (this is the only
     949 # stage of command execution where the thread is blocked and can not serve
     950 # other requests in the meantime).
     951 #
     952 # You can configure the slow log with two parameters: one tells Redis
     953 # what is the execution time, in microseconds, to exceed in order for the
     954 # command to get logged, and the other parameter is the length of the
     955 # slow log. When a new command is logged the oldest one is removed from the
     956 # queue of logged commands.
     957 
     958 # The following time is expressed in microseconds, so 1000000 is equivalent
     959 # to one second. Note that a negative number disables the slow log, while
     960 # a value of zero forces the logging of every command.
     961 slowlog-log-slower-than 10000
     962 
     963 # There is no limit to this length. Just be aware that it will consume memory.
     964 # You can reclaim memory used by the slow log with SLOWLOG RESET.
     965 slowlog-max-len 128
     966 
     967 ################################ LATENCY MONITOR ##############################
     968 
     969 # The Redis latency monitoring subsystem samples different operations
     970 # at runtime in order to collect data related to possible sources of
     971 # latency of a Redis instance.
     972 #
     973 # Via the LATENCY command this information is available to the user that can
     974 # print graphs and obtain reports.
     975 #
     976 # The system only logs operations that were performed in a time equal or
     977 # greater than the amount of milliseconds specified via the
     978 # latency-monitor-threshold configuration directive. When its value is set
     979 # to zero, the latency monitor is turned off.
     980 #
     981 # By default latency monitoring is disabled since it is mostly not needed
     982 # if you don't have latency issues, and collecting data has a performance
     983 # impact, that while very small, can be measured under big load. Latency
     984 # monitoring can easily be enabled at runtime using the command
     985 # "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.
     986 latency-monitor-threshold 0
     987 
     988 ############################# EVENT NOTIFICATION ##############################
     989 
     990 # Redis can notify Pub/Sub clients about events happening in the key space.
     991 # This feature is documented at http://redis.io/topics/notifications
     992 #
     993 # For instance if keyspace events notification is enabled, and a client
     994 # performs a DEL operation on key "foo" stored in the Database 0, two
     995 # messages will be published via Pub/Sub:
     996 #
     997 # PUBLISH __keyspace@0__:foo del
     998 # PUBLISH __keyevent@0__:del foo
     999 #
    1000 # It is possible to select the events that Redis will notify among a set
    1001 # of classes. Every class is identified by a single character:
    1002 #
    1003 #  K     Keyspace events, published with __keyspace@<db>__ prefix.
    1004 #  E     Keyevent events, published with __keyevent@<db>__ prefix.
    1005 #  g     Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...
    1006 #  $     String commands
    1007 #  l     List commands
    1008 #  s     Set commands
    1009 #  h     Hash commands
    1010 #  z     Sorted set commands
    1011 #  x     Expired events (events generated every time a key expires)
    1012 #  e     Evicted events (events generated when a key is evicted for maxmemory)
    1013 #  A     Alias for g$lshzxe, so that the "AKE" string means all the events.
    1014 #
    1015 #  The "notify-keyspace-events" takes as argument a string that is composed
    1016 #  of zero or multiple characters. The empty string means that notifications
    1017 #  are disabled.
    1018 #
    1019 #  Example: to enable list and generic events, from the point of view of the
    1020 #           event name, use:
    1021 #
    1022 #  notify-keyspace-events Elg
    1023 #
    1024 #  Example 2: to get the stream of the expired keys subscribing to channel
    1025 #             name __keyevent@0__:expired use:
    1026 #
    1027 #  notify-keyspace-events Ex
    1028 #
    1029 #  By default all notifications are disabled because most users don't need
    1030 #  this feature and the feature has some overhead. Note that if you don't
    1031 #  specify at least one of K or E, no events will be delivered.
    1032 notify-keyspace-events ""
    1033 
    1034 ############################### ADVANCED CONFIG ###############################
    1035 
    1036 # Hashes are encoded using a memory efficient data structure when they have a
    1037 # small number of entries, and the biggest entry does not exceed a given
    1038 # threshold. These thresholds can be configured using the following directives.
    1039 hash-max-ziplist-entries 512
    1040 hash-max-ziplist-value 64
    1041 
    1042 # Lists are also encoded in a special way to save a lot of space.
    1043 # The number of entries allowed per internal list node can be specified
    1044 # as a fixed maximum size or a maximum number of elements.
    1045 # For a fixed maximum size, use -5 through -1, meaning:
    1046 # -5: max size: 64 Kb  <-- not recommended for normal workloads
    1047 # -4: max size: 32 Kb  <-- not recommended
    1048 # -3: max size: 16 Kb  <-- probably not recommended
    1049 # -2: max size: 8 Kb   <-- good
    1050 # -1: max size: 4 Kb   <-- good
    1051 # Positive numbers mean store up to _exactly_ that number of elements
    1052 # per list node.
    1053 # The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),
    1054 # but if your use case is unique, adjust the settings as necessary.
    1055 list-max-ziplist-size -2
    1056 
    1057 # Lists may also be compressed.
    1058 # Compress depth is the number of quicklist ziplist nodes from *each* side of
    1059 # the list to *exclude* from compression.  The head and tail of the list
    1060 # are always uncompressed for fast push/pop operations.  Settings are:
    1061 # 0: disable all list compression
    1062 # 1: depth 1 means "don't start compressing until after 1 node into the list,
    1063 #    going from either the head or tail"
    1064 #    So: [head]->node->node->...->node->[tail]
    1065 #    [head], [tail] will always be uncompressed; inner nodes will compress.
    1066 # 2: [head]->[next]->node->node->...->node->[prev]->[tail]
    1067 #    2 here means: don't compress head or head->next or tail->prev or tail,
    1068 #    but compress all nodes between them.
    1069 # 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]
    1070 # etc.
    1071 list-compress-depth 0
    1072 
    1073 # Sets have a special encoding in just one case: when a set is composed
    1074 # of just strings that happen to be integers in radix 10 in the range
    1075 # of 64 bit signed integers.
    1076 # The following configuration setting sets the limit in the size of the
    1077 # set in order to use this special memory saving encoding.
    1078 set-max-intset-entries 512
    1079 
    1080 # Similarly to hashes and lists, sorted sets are also specially encoded in
    1081 # order to save a lot of space. This encoding is only used when the length and
    1082 # elements of a sorted set are below the following limits:
    1083 zset-max-ziplist-entries 128
    1084 zset-max-ziplist-value 64
    1085 
    1086 # HyperLogLog sparse representation bytes limit. The limit includes the
    1087 # 16 bytes header. When an HyperLogLog using the sparse representation crosses
    1088 # this limit, it is converted into the dense representation.
    1089 #
    1090 # A value greater than 16000 is totally useless, since at that point the
    1091 # dense representation is more memory efficient.
    1092 #
    1093 # The suggested value is ~ 3000 in order to have the benefits of
    1094 # the space efficient encoding without slowing down too much PFADD,
    1095 # which is O(N) with the sparse encoding. The value can be raised to
    1096 # ~ 10000 when CPU is not a concern, but space is, and the data set is
    1097 # composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
    1098 hll-sparse-max-bytes 3000
    1099 
    1100 # Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
    1101 # order to help rehashing the main Redis hash table (the one mapping top-level
    1102 # keys to values). The hash table implementation Redis uses (see dict.c)
    1103 # performs a lazy rehashing: the more operation you run into a hash table
    1104 # that is rehashing, the more rehashing "steps" are performed, so if the
    1105 # server is idle the rehashing is never complete and some more memory is used
    1106 # by the hash table.
    1107 #
    1108 # The default is to use this millisecond 10 times every second in order to
    1109 # actively rehash the main dictionaries, freeing memory when possible.
    1110 #
    1111 # If unsure:
    1112 # use "activerehashing no" if you have hard latency requirements and it is
    1113 # not a good thing in your environment that Redis can reply from time to time
    1114 # to queries with 2 milliseconds delay.
    1115 #
    1116 # use "activerehashing yes" if you don't have such hard requirements but
    1117 # want to free memory asap when possible.
    1118 activerehashing yes
    1119 
    1120 # The client output buffer limits can be used to force disconnection of clients
    1121 # that are not reading data from the server fast enough for some reason (a
    1122 # common reason is that a Pub/Sub client can't consume messages as fast as the
    1123 # publisher can produce them).
    1124 #
    1125 # The limit can be set differently for the three different classes of clients:
    1126 #
    1127 # normal -> normal clients including MONITOR clients
    1128 # slave  -> slave clients
    1129 # pubsub -> clients subscribed to at least one pubsub channel or pattern
    1130 #
    1131 # The syntax of every client-output-buffer-limit directive is the following:
    1132 #
    1133 # client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
    1134 #
    1135 # A client is immediately disconnected once the hard limit is reached, or if
    1136 # the soft limit is reached and remains reached for the specified number of
    1137 # seconds (continuously).
    1138 # So for instance if the hard limit is 32 megabytes and the soft limit is
    1139 # 16 megabytes / 10 seconds, the client will get disconnected immediately
    1140 # if the size of the output buffers reach 32 megabytes, but will also get
    1141 # disconnected if the client reaches 16 megabytes and continuously overcomes
    1142 # the limit for 10 seconds.
    1143 #
    1144 # By default normal clients are not limited because they don't receive data
    1145 # without asking (in a push way), but just after a request, so only
    1146 # asynchronous clients may create a scenario where data is requested faster
    1147 # than it can read.
    1148 #
    1149 # Instead there is a default limit for pubsub and slave clients, since
    1150 # subscribers and slaves receive data in a push fashion.
    1151 #
    1152 # Both the hard or the soft limit can be disabled by setting them to zero.
    1153 client-output-buffer-limit normal 0 0 0
    1154 client-output-buffer-limit slave 256mb 64mb 60
    1155 client-output-buffer-limit pubsub 32mb 8mb 60
    1156 
    1157 # Client query buffers accumulate new commands. They are limited to a fixed
    1158 # amount by default in order to avoid that a protocol desynchronization (for
    1159 # instance due to a bug in the client) will lead to unbound memory usage in
    1160 # the query buffer. However you can configure it here if you have very special
    1161 # needs, such us huge multi/exec requests or alike.
    1162 #
    1163 # client-query-buffer-limit 1gb
    1164 
    1165 # In the Redis protocol, bulk requests, that are, elements representing single
    1166 # strings, are normally limited ot 512 mb. However you can change this limit
    1167 # here.
    1168 #
    1169 # proto-max-bulk-len 512mb
    1170 
    1171 # Redis calls an internal function to perform many background tasks, like
    1172 # closing connections of clients in timeout, purging expired keys that are
    1173 # never requested, and so forth.
    1174 #
    1175 # Not all tasks are performed with the same frequency, but Redis checks for
    1176 # tasks to perform according to the specified "hz" value.
    1177 #
    1178 # By default "hz" is set to 10. Raising the value will use more CPU when
    1179 # Redis is idle, but at the same time will make Redis more responsive when
    1180 # there are many keys expiring at the same time, and timeouts may be
    1181 # handled with more precision.
    1182 #
    1183 # The range is between 1 and 500, however a value over 100 is usually not
    1184 # a good idea. Most users should use the default of 10 and raise this up to
    1185 # 100 only in environments where very low latency is required.
    1186 hz 10
    1187 
    1188 # When a child rewrites the AOF file, if the following option is enabled
    1189 # the file will be fsync-ed every 32 MB of data generated. This is useful
    1190 # in order to commit the file to the disk more incrementally and avoid
    1191 # big latency spikes.
    1192 aof-rewrite-incremental-fsync yes
    1193 
    1194 # Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good
    1195 # idea to start with the default settings and only change them after investigating
    1196 # how to improve the performances and how the keys LFU change over time, which
    1197 # is possible to inspect via the OBJECT FREQ command.
    1198 #
    1199 # There are two tunable parameters in the Redis LFU implementation: the
    1200 # counter logarithm factor and the counter decay time. It is important to
    1201 # understand what the two parameters mean before changing them.
    1202 #
    1203 # The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis
    1204 # uses a probabilistic increment with logarithmic behavior. Given the value
    1205 # of the old counter, when a key is accessed, the counter is incremented in
    1206 # this way:
    1207 #
    1208 # 1. A random number R between 0 and 1 is extracted.
    1209 # 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).
    1210 # 3. The counter is incremented only if R < P.
    1211 #
    1212 # The default lfu-log-factor is 10. This is a table of how the frequency
    1213 # counter changes with a different number of accesses with different
    1214 # logarithmic factors:
    1215 #
    1216 # +--------+------------+------------+------------+------------+------------+
    1217 # | factor | 100 hits   | 1000 hits  | 100K hits  | 1M hits    | 10M hits   |
    1218 # +--------+------------+------------+------------+------------+------------+
    1219 # | 0      | 104        | 255        | 255        | 255        | 255        |
    1220 # +--------+------------+------------+------------+------------+------------+
    1221 # | 1      | 18         | 49         | 255        | 255        | 255        |
    1222 # +--------+------------+------------+------------+------------+------------+
    1223 # | 10     | 10         | 18         | 142        | 255        | 255        |
    1224 # +--------+------------+------------+------------+------------+------------+
    1225 # | 100    | 8          | 11         | 49         | 143        | 255        |
    1226 # +--------+------------+------------+------------+------------+------------+
    1227 #
    1228 # NOTE: The above table was obtained by running the following commands:
    1229 #
    1230 #   redis-benchmark -n 1000000 incr foo
    1231 #   redis-cli object freq foo
    1232 #
    1233 # NOTE 2: The counter initial value is 5 in order to give new objects a chance
    1234 # to accumulate hits.
    1235 #
    1236 # The counter decay time is the time, in minutes, that must elapse in order
    1237 # for the key counter to be divided by two (or decremented if it has a value
    1238 # less <= 10).
    1239 #
    1240 # The default value for the lfu-decay-time is 1. A Special value of 0 means to
    1241 # decay the counter every time it happens to be scanned.
    1242 #
    1243 # lfu-log-factor 10
    1244 # lfu-decay-time 1
    1245 
    1246 ########################### ACTIVE DEFRAGMENTATION #######################
    1247 #
    1248 # WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested
    1249 # even in production and manually tested by multiple engineers for some
    1250 # time.
    1251 #
    1252 # What is active defragmentation?
    1253 # -------------------------------
    1254 #
    1255 # Active (online) defragmentation allows a Redis server to compact the
    1256 # spaces left between small allocations and deallocations of data in memory,
    1257 # thus allowing to reclaim back memory.
    1258 #
    1259 # Fragmentation is a natural process that happens with every allocator (but
    1260 # less so with Jemalloc, fortunately) and certain workloads. Normally a server
    1261 # restart is needed in order to lower the fragmentation, or at least to flush
    1262 # away all the data and create it again. However thanks to this feature
    1263 # implemented by Oran Agra for Redis 4.0 this process can happen at runtime
    1264 # in an "hot" way, while the server is running.
    1265 #
    1266 # Basically when the fragmentation is over a certain level (see the
    1267 # configuration options below) Redis will start to create new copies of the
    1268 # values in contiguous memory regions by exploiting certain specific Jemalloc
    1269 # features (in order to understand if an allocation is causing fragmentation
    1270 # and to allocate it in a better place), and at the same time, will release the
    1271 # old copies of the data. This process, repeated incrementally for all the keys
    1272 # will cause the fragmentation to drop back to normal values.
    1273 #
    1274 # Important things to understand:
    1275 #
    1276 # 1. This feature is disabled by default, and only works if you compiled Redis
    1277 #    to use the copy of Jemalloc we ship with the source code of Redis.
    1278 #    This is the default with Linux builds.
    1279 #
    1280 # 2. You never need to enable this feature if you don't have fragmentation
    1281 #    issues.
    1282 #
    1283 # 3. Once you experience fragmentation, you can enable this feature when
    1284 #    needed with the command "CONFIG SET activedefrag yes".
    1285 #
    1286 # The configuration parameters are able to fine tune the behavior of the
    1287 # defragmentation process. If you are not sure about what they mean it is
    1288 # a good idea to leave the defaults untouched.
    1289 
    1290 # Enabled active defragmentation
    1291 # activedefrag yes
    1292 
    1293 # Minimum amount of fragmentation waste to start active defrag
    1294 # active-defrag-ignore-bytes 100mb
    1295 
    1296 # Minimum percentage of fragmentation to start active defrag
    1297 # active-defrag-threshold-lower 10
    1298 
    1299 # Maximum percentage of fragmentation at which we use maximum effort
    1300 # active-defrag-threshold-upper 100
    1301 
    1302 # Minimal effort for defrag in CPU percentage
    1303 # active-defrag-cycle-min 25
    1304 
    1305 # Maximal effort for defrag in CPU percentage
    1306 # active-defrag-cycle-max 75
    View Code
    剩下的配置文件内容,只需要参考redis6381.conf,把其中涉及到6381修改为自己对应的6382、6383、6384...就可以了。
    1.2、分别启动这些Redis数据库
    (1)启动6个redis示例:
      ./redis-server redis6381.conf
      ./redis-server redis6382.conf
      ./redis-server redis6383.conf
      ./redis-server redis6384.conf
      ./redis-server redis6385.conf
      ./redis-server redis6386.conf
    (2)执行命令:ps -ef|grep redis
      501 12169     1   0  8:11上午 ??         0:00.03 ./redis-server 127.0.0.1:6381 [cluster]
      501 12171     1   0  8:11上午 ??         0:00.02 ./redis-server 127.0.0.1:6382 [cluster]
      501 12173     1   0  8:11上午 ??         0:00.02 ./redis-server 127.0.0.1:6383 [cluster]
      501 12175     1   0  8:11上午 ??         0:00.02 ./redis-server 127.0.0.1:6384 [cluster]
      501 12177     1   0  8:11上午 ??         0:00.01 ./redis-server 127.0.0.1:6385 [cluster]
      501 12179     1   0  8:11上午 ??         0:00.01 ./redis-server 127.0.0.1:6386 [cluster]
      501 12181 11792   0  8:11上午 ttys004    0:00.01 grep redis
    (3)可以用cluster info来进行查看,目前这6个redis实例是孤立的,它们之间还没有建立集群的关系
    127.0.0.1:6381机器上执行命令:cluster info
    127.0.0.1:6382机器上执行命令:cluster info

    1.3、连接节点,使用cluster meet,把所有的数据库都放到一个集群中来
    在127.0.0.1:6381机器上执行如下命令:
    1.4、可以通过cluster info,或者cluster nodes查看信息
    在127.0.0.1:6381机器上执行 cluster info、cluster nodes。(在其它的机器上执行也是一样的效果)
    1.5、设置部分数据库为slave,使用cluster replicate
    在127.0.0.1:6384机器上执行:cluster replicate 5f0fa9ce5b911e4ed2e7230929a9a5951a58d48b
    在127.0.0.1:6385机器上执行:cluster replicate 6a80d0d12cbb927e6efffb417a4fe15028edf33b
    在127.0.0.1:6386机器上执行:cluster replicate 7d09251534236145bea1aac58aa095b789bf857d
    1.6、分配插槽
    使用cluster addSlots,这个命令目前只能一个一个加,如果要加区间的话,就得客户端编写代码来循环添加了。
    有个实用的技巧:把所有的Redis停下来,然后直接修改node的配置文件,只需要配置master的数据库就可以了,然后再重启数据库。
    nodes-6381.conf的配置如下:(其它的5个文件也照着这样去配置)

    重写启动6个redis数据库实例

      ./redis-server redis6381.conf
      ./redis-server redis6382.conf
      ./redis-server redis6383.conf
      ./redis-server redis6384.conf
      ./redis-server redis6385.conf
      ./redis-server redis6386.conf

     可以使用cluster keyslot key来查看每个key应该放到哪个插槽里面,如下:

    1.7、通过cluster info查看集群信息,如果显示ok,那就是可以使用了
     
     
     
     
     
     
     
     
     
     
     
     
     
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  • 原文地址:https://www.cnblogs.com/xinhuaxuan/p/9363901.html
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