# 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 limts.
+# is able to open. The special value '0' means no limits.
# Once the limit is reached Redis will close all the new connections sending
# an error 'max number of clients reached'.
#
# 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
################################ VIRTUAL MEMORY ###############################
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.
+#
+# The swap file name may contain "%p" that is substituted with the PID of
+# the Redis process, so the default name /tmp/redis-%p.vm will work even
+# with multiple instances as Redis will use, for example, redis-811.vm
+# for one instance and redis-593.vm for another one.
+#
+# Useless to say, the best kind of disk for a 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-%p.vm
+
# 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
+# 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.
#
# 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 defualt :)
-vm-page-size 256
+# 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,
#
# The total swap size is vm-page-size * vm-pages
#
-# With the default of 256-bytes memory pages and 104857600 pages Redis will
-# use a 25 GB swap file, that will use rougly 13 MB of RAM for the page table.
+# 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 104857600
+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 ###############################