Difference between default redis 2.4 and 2.6 configs

redis.conf.diff

--- /dev/fd/63	2012-10-25 16:46:38.000000000 +0100
+++ /dev/fd/62	2012-10-25 16:46:38.000000000 +0100
@@ -1,6 +1,6 @@
 # Redis configuration file example
 
-# Note on units: when memory size is needed, it is possible to specifiy
+# Note on units: when memory size is needed, it is possible to specify
 # it in the usual form of 1k 5GB 4M and so forth:
 #
 # 1k => 1000 bytes
@@ -45,7 +45,7 @@
 # verbose (many rarely useful info, but not a mess like the debug level)
 # notice (moderately verbose, what you want in production probably)
 # warning (only very important / critical messages are logged)
-loglevel verbose
+loglevel notice
 
 # Specify the log file name. Also 'stdout' can be used to force
 # Redis to log on the standard output. Note that if you use standard
@@ -82,17 +82,47 @@
 #   after 60 sec if at least 10000 keys changed
 #
 #   Note: you can disable saving at all commenting all the "save" lines.
+#
+#   It is also possible to remove all the previously configured save
+#   points by adding a save directive with a single empty string argument
+#   like in the following example:
+#
+#   save ""
 
 save 900 1
 save 300 10
 save 60 10000
 
+# By default Redis will stop accepting writes if RDB snapshots are enabled
+# (at least one save point) and the latest background save failed.
+# This will make the user aware (in an hard way) that data is not persisting
+# on disk properly, otherwise chances are that no one will notice and some
+# distater will happen.
+#
+# If the background saving process will start working again Redis will
+# automatically allow writes again.
+#
+# However if you have setup your proper monitoring of the Redis server
+# and persistence, you may want to disable this feature so that Redis will
+# continue to work as usually even if there are problems with disk,
+# permissions, and so forth.
+stop-writes-on-bgsave-error yes
+
 # Compress string objects using LZF when dump .rdb databases?
 # For default that's set to 'yes' as it's almost always a win.
 # If you want to save some CPU in the saving child set it to 'no' but
 # the dataset will likely be bigger if you have compressible values or keys.
 rdbcompression yes
 
+# Since verison 5 of RDB a CRC64 checksum is placed at the end of the file.
+# This makes the format more resistant to corruption but there is a performance
+# hit to pay (around 10%) when saving and loading RDB files, so you can disable it
+# for maximum performances.
+#
+# RDB files created with checksum disabled have a checksum of zero that will
+# tell the loading code to skip the check.
+rdbchecksum yes
+
 # The filename where to dump the DB
 dbfilename dump.rdb
 
@@ -126,7 +156,7 @@
 # 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
+#    still reply to client requests, possibly with out of date data, or the
 #    data set may just be empty if this is the first synchronization.
 #
 # 2) if slave-serve-stale data is set to 'no' the slave will reply with
@@ -135,6 +165,22 @@
 #
 slave-serve-stale-data yes
 
+# You can configure a slave instance to accept writes or not. Writing against
+# a slave instance may be useful to store some ephemeral data (because data
+# written on a slave will be easily deleted after resync with the master) but
+# may also cause problems if clients are writing to it because of a
+# misconfiguration.
+#
+# Since Redis 2.6 by default slaves are read-only.
+#
+# Note: read only slaves are not designed to be exposed to untrusted clients
+# on the internet. It's just a protection layer against misuse of the instance.
+# Still a read only slave exports by default all the administrative commands
+# such as CONFIG, DEBUG, and so forth. To a limited extend you can improve
+# security of read only slaves using 'rename-command' to shadow all the
+# administrative / dangerous commands.
+slave-read-only 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.
@@ -182,7 +228,7 @@
 
 # Command renaming.
 #
-# It is possilbe to change the name of dangerous commands in a shared
+# It is possible 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.
@@ -191,20 +237,23 @@
 #
 # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
 #
-# It is also possilbe to completely kill a command renaming it into
+# It is also possible to completely kill a command renaming it into
 # an empty string:
 #
 # rename-command CONFIG ""
 
 ################################### 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'.
 #
-# 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
@@ -237,7 +286,7 @@
 # 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
+# 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
 # 
@@ -264,21 +313,23 @@
 
 ############################## APPEND ONLY MODE ###############################
 
-# By default Redis asynchronously dumps the dataset on disk. If you can live
-# with the idea that the latest records will be lost if something like a crash
-# 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.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
-# like (you have to comment the "save" statements above to disable the dumps).
-# Still if append only mode is enabled Redis will load the data from the
-# log file at startup ignoring the dump.rdb file.
+# By default Redis asynchronously dumps the dataset on disk. This mode is
+# good enough in many applications, but an issue with the Redis process or
+# a power outage may result into a few minutes of writes lost (depending on
+# the configured save points).
+#
+# The Append Only File is an alternative persistence mode that provides
+# much better durability. For instance using the default data fsync policy
+# (see later in the config file) Redis can lose just one second of writes in a
+# dramatic event like a server power outage, or a single write if something
+# wrong with the Redis process itself happens, but the operating system is
+# still running correctly.
+#
+# AOF and RDB persistence can be enabled at the same time without problems.
+# If the AOF is enabled on startup Redis will load the AOF, that is the file
+# with the better durability guarantees.
 #
-# IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append
-# log file in background when it gets too big.
+# Please check http://redis.io/topics/persistence for more information.
 
 appendonly no
 
@@ -293,16 +344,19 @@
 #
 # no: don't fsync, just let the OS flush the data when it wants. Faster.
 # always: fsync after every write to the append only log . Slow, Safest.
-# everysec: fsync only if one second passed since the last fsync. Compromise.
+# everysec: fsync only one time every second. Compromise.
 #
 # 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
+# "no" that will let the operating system flush the output buffer when
 # it wants, for better performances (but if you can live with the idea of
 # some data loss consider the default persistence mode that's snapshotting),
 # or on the contrary, use "always" that's very slow but a bit safer than
 # everysec.
 #
+# More details please check the following article:
+# http://antirez.com/post/redis-persistence-demystified.html
+#
 # If unsure, use "everysec".
 
 # appendfsync always
@@ -321,7 +375,7 @@
 # BGSAVE or BGREWRITEAOF is in progress.
 #
 # 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
+# the same as "appendfsync none", that in practical terms means that it is
 # possible to lost up to 30 seconds of log in the worst scenario (with the
 # default Linux settings).
 # 
@@ -343,12 +397,30 @@
 # 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
+# Specify a percentage of zero in order to disable the automatic AOF
 # rewrite feature.
 
 auto-aof-rewrite-percentage 100
 auto-aof-rewrite-min-size 64mb
 
+################################ LUA SCRIPTING  ###############################
+
+# Max execution time of a Lua script in milliseconds.
+#
+# If the maximum execution time is reached Redis will log that a script is
+# still in execution after the maximum allowed time and will start to
+# reply to queries with an error.
+#
+# When a long running script exceed the maximum execution time only the
+# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
+# used to stop a script that did not yet called write commands. The second
+# is the only way to shut down the server in the case a write commands was
+# already issue by the script but the user don't want to wait for the natural
+# termination of the script.
+#
+# Set it to 0 or a negative value for unlimited execution without warnings.
+lua-time-limit 5000
+
 ################################## SLOW LOG ###################################
 
 # The Redis Slow Log is a system to log queries that exceeded a specified
@@ -373,89 +445,13 @@
 # You can reclaim memory used by the slow log with SLOWLOG RESET.
 slowlog-max-len 128
 
-################################ VIRTUAL MEMORY ###############################
-
-### WARNING! Virtual Memory is deprecated in Redis 2.4
-### The use of Virtual Memory is strongly discouraged.
-
-# 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.
-#
-# To enable VM just set 'vm-enabled' to yes, and set the following three
-# VM parameters accordingly to your needs.
-
-vm-enabled no
-# vm-enabled yes
-
-# This is the path of the Redis swap file. As you can guess, swap files
-# can't be shared by different Redis instances, so make sure to use a swap
-# file for every redis process you are running. Redis will complain if the
-# swap file is already in use.
-#
-# The best kind of storage for the Redis swap file (that's accessed at random) 
-# is a Solid State Disk (SSD).
-#
-# *** WARNING *** if you are using a shared hosting the default of putting
-# the swap file under /tmp is not secure. Create a dir with access granted
-# only to Redis user and configure Redis to create the swap file there.
-vm-swap-file /tmp/redis.swap
-
-# 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 0 the system will swap 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 between 60 and 80% of your free RAM.
-vm-max-memory 0
-
-# 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).
-#
-# 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 32
-
-# 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.
-#
-# The total swap size is vm-page-size * vm-pages
-#
-# With the default of 32-bytes memory pages and 134217728 pages Redis will
-# use a 4 GB swap file, that will use 16 MB of RAM for the page table.
-#
-# 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 134217728
-
-# 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.
-#
-# The special value of 0 turn off threaded I/O and enables the blocking
-# Virtual Memory implementation.
-vm-max-threads 4
-
 ############################### ADVANCED CONFIG ###############################
 
-# 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
+# Hashes are encoded using a memory efficient data structure when they have a
+# small number of entries, and the biggest entry does not exceed a given
+# threshold. These thresholds can be configured using the following directives.
+hash-max-ziplist-entries 512
+hash-max-ziplist-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
@@ -478,9 +474,9 @@
 
 # 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)
+# 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
+# that is rehashing, the more rehashing "steps" are performed, so if the
 # server is idle the rehashing is never complete and some more memory is used
 # by the hash table.
 # 
@@ -496,10 +492,47 @@
 # want to free memory asap when possible.
 activerehashing yes
 
+# The client output buffer limits can be used to force disconnection of clients
+# that are not reading data from the server fast enough for some reason (a
+# common reason is that a Pub/Sub client can't consume messages as fast as the
+# publisher can produce them).
+#
+# The limit can be set differently for the three different classes of clients:
+#
+# normal -> normal clients
+# slave  -> slave clients and MONITOR clients
+# pubsub -> clients subcribed to at least one pubsub channel or pattern
+#
+# The syntax of every client-output-buffer-limit directive is the following:
+#
+# client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
+#
+# A client is immediately disconnected once the hard limit is reached, or if
+# the soft limit is reached and remains reached for the specified number of
+# seconds (continuously).
+# So for instance if the hard limit is 32 megabytes and the soft limit is
+# 16 megabytes / 10 seconds, the client will get disconnected immediately
+# if the size of the output buffers reach 32 megabytes, but will also get
+# disconnected if the client reaches 16 megabytes and continuously overcomes
+# the limit for 10 seconds.
+#
+# By default normal clients are not limited because they don't receive data
+# without asking (in a push way), but just after a request, so only
+# asynchronous clients may create a scenario where data is requested faster
+# than it can read.
+#
+# Instead there is a default limit for pubsub and slave clients, since
+# subscribers and slaves receive data in a push fashion.
+#
+# Both the hard or the soft limit can be disabled just setting it to zero.
+client-output-buffer-limit normal 0 0 0
+client-output-buffer-limit slave 256mb 64mb 60
+client-output-buffer-limit pubsub 32mb 8mb 60
+
 ################################## 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
+# 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.
 #