diff --git a/redis.conf b/redis.conf index d7d29303..b1ea6c2e 100644 --- a/redis.conf +++ b/redis.conf @@ -298,21 +298,23 @@ slave-read-only yes ############################## 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). # -# 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. +# 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. # -# IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append -# log file in background when it gets too big. +# AOF and RDB persistence can be enabled at the same time without problems. +# If the AOF is enabled on startup Redis will load the AOF, that is the file +# with the better durability guarantees. +# +# Please check http://redis.io/topics/persistence for more information. appendonly no @@ -327,7 +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. -# 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 @@ -337,6 +339,9 @@ appendonly no # 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