Update README on allocators

[redis.git] / redis.conf

diff --git a/redis.conf b/redis.conf
index b541cbe203351b8dd4093a292dd2f309dc356a2f..6663a4ec89da056b87ab9a8466b2cd6f59e7a08e 100644 (file)
--- a/redis.conf
+++ b/redis.conf
@@ -1,23 +1,43 @@
 # Redis configuration file example
 
 # Redis configuration file example
 

+# Note on units: when memory size is needed, it is possible to specifiy
+# 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.
+

 # 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
 
 # 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
 

-# When run as a daemon, Redis write a pid file in /var/run/redis.pid by default.
-# You can specify a custom pid file location here.
+# When running daemonized, Redis writes a pid file in /var/run/redis.pid by
+# default. You can specify a custom pid file location here.

 pidfile /var/run/redis.pid
 
 pidfile /var/run/redis.pid
 

-# Accept connections on the specified port, default is 6379
+# Accept connections on the specified port, default is 6379.
+# If port 0 is specified Redis will not listen on a TCP socket.

 port 6379
 
 # If you want you can bind a single interface, if the bind option is not
 port 6379
 
 # If you want you can bind a single interface, if the bind option is not

-# specified all the interfaces will listen for connections.
+# specified all the interfaces will listen for incoming connections.

 #
 # bind 127.0.0.1
 
 #
 # bind 127.0.0.1
 

+# 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 755
+

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

-timeout 300
+timeout 0

 
 # Set server verbosity to 'debug'
 # it can be one of:
 
 # Set server verbosity to 'debug'
 # it can be one of:


@@ -28,10 +48,20 @@ timeout 300
 loglevel verbose
 
 # Specify the log file name. Also 'stdout' can be used to force
 loglevel verbose
 
 # Specify the log file name. Also 'stdout' can be used to force

-# the demon to log on the standard output. Note that if you use standard
+# Redis to log on the standard output. Note that if you use standard

 # output for logging but daemonize, logs will be sent to /dev/null
 logfile stdout
 
 # output for logging but daemonize, logs will be sent to /dev/null
 logfile stdout
 

+# 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 <dbid> where
 # dbid is a number between 0 and 'databases'-1
 # Set the number of databases. The default database is DB 0, you can select
 # a different one on a per-connection basis using SELECT <dbid> where
 # dbid is a number between 0 and 'databases'-1


@@ -66,8 +96,14 @@ rdbcompression yes
 # The filename where to dump the DB
 dbfilename dump.rdb
 
 # The filename where to dump the DB
 dbfilename dump.rdb
 

-# For default save/load DB in/from the working directory
-# Note that you must specify a directory not a file name.
+# The working directory.
+#
+# The DB will be written inside this directory, with the filename specified
+# above using the 'dbfilename' configuration directive.
+# 
+# Also the Append Only File will be created inside this directory.
+# 
+# Note that you must specify a directory here, not a file name.

 dir ./
 
 ################################# REPLICATION #################################
 dir ./
 
 ################################# REPLICATION #################################


@@ -86,6 +122,34 @@ dir ./
 #
 # masterauth <master-password>
 
 #
 # masterauth <master-password>
 

+# When a slave lost the connection with the master, or when the replication
+# is still in progress, the slave can act in two different ways:
+#
+# 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
+#    still reply to client requests, possibly with out of data data, or the
+#    data set may just be empty if this is the first synchronization.
+#
+# 2) if slave-serve-stale data is set to 'no' the slave will reply with
+#    an error "SYNC with master in progress" to all the kind of commands
+#    but to INFO and SLAVEOF.
+#
+slave-serve-stale-data yes
+
+# Slaves send PINGs to server in a predefined interval. It's possible to change
+# this interval with the repl_ping_slave_period option. The default value is 10
+# seconds.
+#
+# repl-ping-slave-period 10
+
+# The following option sets a timeout for both Bulk transfer I/O timeout and
+# master data or ping response timeout. The default value is 60 seconds.
+#
+# It is important to make sure that this value is greater than the value
+# specified for repl-ping-slave-period otherwise a timeout will be detected
+# every time there is low traffic between the master and the slave.
+#
+# repl-timeout 60
+

 ################################## SECURITY ###################################
 
 # Require clients to issue AUTH <PASSWORD> before processing any other
 ################################## SECURITY ###################################
 
 # Require clients to issue AUTH <PASSWORD> before processing any other


@@ -94,18 +158,41 @@ dir ./
 #
 # This should stay commented out for backward compatibility and because most
 # people do not need auth (e.g. they run their own servers).
 #
 # 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 foobared
 
 #
 # requirepass foobared
 

+# Command renaming.
+#
+# It is possilbe to change the name of dangerous commands in a shared
+# environment. For instance the CONFIG command may be renamed into something
+# of hard to guess so that it will be still available for internal-use
+# tools but not available for general clients.
+#
+# Example:
+#
+# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
+#
+# It is also possilbe to completely kill a command renaming it into
+# an empty string:
+#
+# rename-command CONFIG ""
+

 ################################### LIMITS ####################################
 
 ################################### LIMITS ####################################
 

-# Set the max number of connected clients at the same time. By default there
-# is no limit, and it's up to the number of file descriptors the Redis process
-# is able to open. The special value '0' means no limits.
+# 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 ot 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'.
 #
 # Once the limit is reached Redis will close all the new connections sending
 # an error 'max number of clients reached'.
 #

-# maxclients 128
+# maxclients 10000

 
 # Don't use more memory than the specified amount of bytes.
 # When the memory limit is reached Redis will try to remove keys with an
 
 # Don't use more memory than the specified amount of bytes.
 # When the memory limit is reached Redis will try to remove keys with an


@@ -126,6 +213,37 @@ dir ./
 #
 # maxmemory <bytes>
 
 #
 # maxmemory <bytes>
 

+# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
+# is reached? You can select among five behavior:
+# 
+# volatile-lru -> remove the key with an expire set using an LRU algorithm
+# allkeys-lru -> remove any key accordingly to the LRU algorithm
+# volatile-random -> remove a random key 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 expire at all, just return an error on write operations
+# 
+# Note: with all the kind of policies, Redis will return an error on write
+#       operations, when there are not suitable keys for eviction.
+#
+#       At the date of writing this 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 volatile-lru
+
+# LRU and minimal TTL algorithms are not precise algorithms but approximated
+# algorithms (in order to save memory), so you can select as well the sample
+# size to check. For instance for default Redis will check three keys and
+# pick the one that was used less recently, you can change the sample size
+# using the following configuration directive.
+#
+# maxmemory-samples 3
+

 ############################## APPEND ONLY MODE ###############################
 
 # By default Redis asynchronously dumps the dataset on disk. If you can live
 ############################## APPEND ONLY MODE ###############################
 
 # By default Redis asynchronously dumps the dataset on disk. If you can live


@@ -133,7 +251,7 @@ dir ./
 # happens this is the preferred way to run Redis. If instead you care a lot
 # about your data and don't want to that a single record can get lost you should
 # enable the append only mode: when this mode is enabled Redis will append
 # happens this is the preferred way to run Redis. If instead you care a lot
 # about your data and don't want to that a single record can get lost you should
 # enable the append only mode: when this mode is enabled Redis will append

-# every write operation received in the file appendonly.log. This file will
+# every write operation received in the file appendonly.aof. This file will

 # be read on startup in order to rebuild the full dataset in memory.
 #
 # Note that you can have both the async dumps and the append only file if you
 # be read on startup in order to rebuild the full dataset in memory.
 #
 # Note that you can have both the async dumps and the append only file if you


@@ -141,13 +259,14 @@ dir ./
 # Still if append only mode is enabled Redis will load the data from the
 # log file at startup ignoring the dump.rdb file.
 #
 # Still if append only mode is enabled Redis will load the data from the
 # log file at startup ignoring the dump.rdb file.
 #

-# The name of the append only file is "appendonly.log"
-#

 # IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append
 # log file in background when it gets too big.
 
 appendonly no
 
 # IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append
 # log file in background when it gets too big.
 
 appendonly no
 

+# 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 to wait 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.
 # The fsync() call tells the Operating System to actually write data on disk
 # instead to wait 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.


@@ -158,92 +277,171 @@ appendonly no
 # always: fsync after every write to the append only log . Slow, Safest.
 # everysec: fsync only if one second passed since the last fsync. Compromise.
 #
 # always: fsync after every write to the append only log . Slow, Safest.
 # everysec: fsync only if one second passed since the last fsync. Compromise.
 #

-# The default is "always" that's the safer of the options. It's up to you to
-# understand if you can relax this to "everysec" that will fsync every second
-# or to "no" that will let the operating system flush the output buffer when
-# it want, for better performances (but if you can live with the idea of
-# some data loss consider the default persistence mode that's snapshotting).
+# The default is "everysec" 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 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.
+#
+# If unsure, use "everysec".

 
 

-appendfsync always
-# appendfsync everysec
+# appendfsync always
+appendfsync everysec

 # appendfsync no
 
 # appendfsync no
 

-################################ VIRTUAL MEMORY ###############################
-
-# Virtual Memory allows Redis to work with datasets bigger than the actual
-# amount of RAM needed to hold the whole dataset in memory.
-# In order to do so very used keys are taken in memory while the other keys
-# are swapped into a swap file, similarly to what operating systems do
-# with memory pages.
+# 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.

 #
 #

-# To enable VM just set 'vm-enabled' to yes, and set the following three
-# VM parameters accordingly to your needs.
+# This means that while another child is saving the durability of Redis is
+# the same as "appendfsync none", that in pratical terms means that it is
+# possible to lost 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 will growth by the specified percentage.
+# 
+# This is how it works: Redis remembers the size of the AOF file after the
+# latest rewrite (or if no rewrite 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 precentage of zero in order to disable the automatic AOF
+# rewrite feature.

 
 

-vm-enabled no
-# vm-enabled yes
+auto-aof-rewrite-percentage 100
+auto-aof-rewrite-min-size 64mb

 
 

-# vm-max-memory configures the VM to use at max the specified amount of
-# RAM. Everything that deos not fit will be swapped on disk *if* possible, that
-# is, if there is still enough contiguous space in the swap file.
-#
-# With vm-max-memory 10000000 the system will swap almost everything it
-# can. Not a good default, just specify the max amount of RAM you can
-# in bytes, but it's better to leave some margin. For instance specify
-# an amount of RAM that's more or less 80% of your free RAM.
-vm-max-memory 10000000
+################################ LUA SCRIPTING  ###############################

 
 

-# Redis swap files is split into pages. An object can be saved using multiple
-# contiguous pages, but pages can't be shared between different objects.
-# So if your page is too big, small objects swapped out on disk will waste
-# a lot of space. If you page is too small, there is less space in the swap
-# file (assuming you configured the same number of total swap file pages).
+# Max execution time of a Lua script in milliseconds.

 #
 #

-# If you use a lot of small objects, use a page size of 64 or 32 bytes.
-# If you use a lot of big objects, use a bigger page size.
-# If unsure, use the default :)
-vm-page-size 256
-
-# Number of total memory pages in the swap file.
-# Given that the page table (a bitmap of free/used pages) is taken in memory,
-# every 8 pages on disk will consume 1 byte of RAM.
+# If the maximum execution time is reached Redis will log that a script is
+# still in execution after the maxium allowed time and will start to
+# reply to queries with an error.
+#
+# The SHUTDOWN command will be available to shutdown the server without
+# violating the database consistency if the script entered an infinite loop.

 #
 #

-# The total swap size is vm-page-size * vm-pages
+# Set it to 0 or a negative value for unlimited execution without warnings.
+lua-time-limit 5000
+
+################################ REDIS CLUSTER  ###############################

 #
 #

-# With the default of 256-bytes memory pages and 104857600 pages Redis will
-# use a 25 GB swap file, that will use roughly 13 MB of RAM for the page table.
+# 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:

 #
 #

-# It's better to use the smallest acceptable value for your application,
-# but the default is large in order to work in most conditions.
-vm-pages 104857600
+# cluster-enabled yes

 
 

-# Max number of VM I/O threads running at the same time.
-# This threads are used to read/write data from/to swap file, since they
-# also encode and decode objects from disk to memory or the reverse, a bigger
-# number of threads can help with big objects even if they can't help with
-# I/O itself as the physical device may not be able to couple with many
-# reads/writes operations at the same time.
-vm-max-threads 4
+# 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 does not have
+# overlapping cluster configuration file names.
+#
+# cluster-config-file nodes-6379.conf
+
+# In order to setup your cluster make sure to read the documentation
+# available at http://redis.io web site.
+
+################################## 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 1024

 
 ############################### ADVANCED CONFIG ###############################
 
 
 ############################### ADVANCED CONFIG ###############################
 

-# Glue small output buffers together in order to send small replies in a
-# single TCP packet. Uses a bit more CPU but most of the times it is a win
-# in terms of number of queries per second. Use 'yes' if unsure.
-glueoutputbuf yes
-
-# Use object sharing. Can save a lot of memory if you have many common
-# string in your dataset, but performs lookups against the shared objects
-# pool so it uses more CPU and can be a bit slower. Usually it's a good
-# idea.
-#
-# When object sharing is enabled (shareobjects yes) you can use
-# shareobjectspoolsize to control the size of the pool used in order to try
-# object sharing. A bigger pool size will lead to better sharing capabilities.
-# In general you want this value to be at least the double of the number of
-# very common strings you have in your dataset.
-#
-# WARNING: object sharing is experimental, don't enable this feature
-# in production before of Redis 1.0-stable. Still please try this feature in
-# your development environment so that we can test it better.
-shareobjects no
-shareobjectspoolsize 1024
+# Hashes are encoded in a special way (much more memory efficient) when they
+# have at max a given numer of elements, and the biggest element does not
+# exceed a given threshold. You can configure this limits with the following
+# configuration directives.
+hash-max-zipmap-entries 512
+hash-max-zipmap-value 64
+
+# Similarly to hashes, small lists are also encoded in a special way in order
+# to save a lot of space. The special representation is only used when
+# you are under the following limits:
+list-max-ziplist-entries 512
+list-max-ziplist-value 64
+
+# Sets have a special encoding in just one case: when a set is composed
+# of just strings that happens 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 128
+zset-max-ziplist-value 64
+
+# 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 an hash table
+# that is rhashing, 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
+# active rehashing 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 form 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
+
+################################## INCLUDES ###################################
+
+# Include one or more other config files here.  This is useful if you
+# have a standard template that goes to all redis server but also need
+# to customize a few per-server settings.  Include files can include
+# other files, so use this wisely.
+#
+# include /path/to/local.conf
+# include /path/to/other.conf