# 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:
# 与hash似，数据元素较少的list，可以用另一种方式来编码从而节省大量空间。
# 这种特殊的方式只有在符合下面限制时才可以用：
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 happen 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有一种特殊编码的情况：当set数据全是十进制64位有符号整型数字构成的字符串时。
# 下面这个配置项就是用来设置set使用这种编码来节省内存的最大长度。
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:
# 与hash和list相似，有序集合也可以用一种特别的编码方式来节省大量空间。
# 这种编码只适合长度和元素都小于下面限制的有序集合：
zset-max-ziplist-entries 128
zset-max-ziplist-value 64
# HyperLogLog sparse representation bytes limit. The limit includes the
# 16 bytes header. When an HyperLogLog using the sparse representation crosses
# this limit, it is converted into the dense representation.
#
# A value greater than 16000 is totally useless, since at that point the
# dense representation is more memory efficient.
#
# The suggested value is ~ 3000 in order to have the benefits of
# the space efficient encoding without slowing down too much PFADD,
# which is O(N) with the sparse encoding. The value can be raised to
# ~ 10000 when CPU is not a concern, but space is, and the data set is
# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
#
# HyperLogLog稀疏结构表示字节的限制。该限制包括
# 16个字节的头。当HyperLogLog使用稀疏结构表示
# 这些限制，它会被转换成密度表示。
# 值大于16000是完全没用的，因为在该点
# 密集的表示是更多的内存效率。
# 建议值是3000左右，以便具有的内存好处, 减少内存的消耗
# 不会减慢太多PFADD操作时间，
# 它是O（N）使用稀疏编码的话。该值可以提高到
# 10000左右如果CPU不是一个问题的话，但空间，数据集是
# 由许多HyperLogLogs与基数在0 - 15000范围内。
hll-sparse-max-bytes 3000
# 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 a hash table
# 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.
#
# The default is to use this millisecond 10 times every second in order to
# actively rehash 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 from 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.
#
# 启用哈希刷新，每100个CPU毫秒会拿出1个毫秒来刷新Redis的主哈希表（顶级键值映射表）。
# redis所用的哈希表实现（见dict.c）采用延迟哈希刷新机制：你对一个哈希表操作越多，哈希刷新
# 操作就越多；反之，如果服务器是空闲的，那么哈希刷新就不会完成，哈希表就会占用更多的一些
# 内存而已。
#
# 默认是每秒钟进行10次哈希表刷新，用来刷新字典，然后尽快释放内存。
#
# 建议：
# 如果你对延迟比较在意，不能够接受Redis时不时的对请求有2毫秒的延迟的话，就用
# "activerehashing no"，如果不太在意延迟而希望尽快释放内存就设置"activerehashing yes"
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 including MONITOR clients
# slave -> slave clients
# pubsub -> clients subscribed 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 by setting them to zero.
#
# 客户端的输出缓冲区的限制，可用于强制断开那些因为某种原因从服务器读取数据的速度不够快的客户端，
# （一个常见的原因是一个发布/订阅客户端消费消息的速度无法赶上生产它们的速度）
#
# 可以对三种不同的客户端设置不同的限制：
# normal -> 正常客户端
# slave -> slave和 MONITOR 客户端
# pubsub -> 至少订阅了一个pubsub channel或pattern的客户端
#
# 下面是每个client-output-buffer-limit语法:
# client-output-buffer-limit <class><hard limit> <soft limit> <soft seconds>
#
# 一旦达到硬限制客户端会立即被断开，或者达到软限制并持续达到指定的秒数（连续的）。
# 例如，如果硬限制为32兆字节和软限制为16兆字节/10秒，客户端将会立即断开
# 如果输出缓冲区的大小达到32兆字节，或客户端达到16兆字节并连续超过了限制10秒，就将断开连接。
#
# 默认normal客户端不做限制，因为他们在不主动请求时不接收数据（以推的方式），只有异步客户端
# 可能会出现请求数据的速度比它可以读取的速度快的场景。
#
# pubsub和slave客户端会有一个默认值，因为订阅者和slaves以推的方式来接收数据
#
# 把硬限制和软限制都设置为0来禁用该功能
#
client-output-buffer-limit normal 0 0 0
client-output-buffer-limit slave 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60