redis.conf AOF section comments improved.

[redis.git] / redis.conf

diff --git a/redis.conf b/redis.conf
index 2b4b6479682bd1c73ffc699a1a4fec2d8f8316cc..b1ea6c2ee4d2419860f0c0a0c5cf15c8850e9a96 100644 (file)
--- a/redis.conf
+++ b/redis.conf
@@ -114,6 +114,15 @@ stop-writes-on-bgsave-error yes
 # the dataset will likely be bigger if you have compressible values or keys.
 rdbcompression yes
 
 # 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
 
 # The filename where to dump the DB
 dbfilename dump.rdb
 


@@ -156,6 +165,22 @@ dir ./
 #
 slave-serve-stale-data yes
 
 #
 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.
 # 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.


@@ -246,7 +271,7 @@ slave-serve-stale-data yes
 # 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
 # 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
 # 
 # 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
 # 


@@ -273,21 +298,23 @@ slave-serve-stale-data yes
 
 ############################## APPEND ONLY MODE ###############################
 
 
 ############################## 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.
+# 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.

 #
 #

-# 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.
+# 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
 
 
 appendonly no
 


@@ -302,7 +329,7 @@ appendonly no
 #
 # 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.
 #
 # 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
 #
 # 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


@@ -312,6 +339,9 @@ appendonly no
 # or on the contrary, use "always" that's very slow but a bit safer than
 # everysec.
 #
 # 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
 # If unsure, use "everysec".
 
 # appendfsync always


@@ -421,12 +451,11 @@ slowlog-max-len 1024
 
 ############################### ADVANCED CONFIG ###############################
 
 
 ############################### ADVANCED CONFIG ###############################
 

-# Hashes are encoded in a special way (much more memory efficient) when they
-# have at max a given number 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
 
 # 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