Redis Learning Guide, redis

Source: Internet
Author: User
Tags allkeys redis download unix domain socket keep alive strong password virtual environment

Redis Learning Guide, redis

I. Introduction


Redis is an open-source log-type database written in ansi c language that supports Network, memory persistence, and high-performance key-value. It also provides APIs in multiple languages. Speaking of the Key-Value database NoSQL database, you can think of MongoDB.

Similar to Memcached, Memcached supports more storage value types, including string, list, set, and zset) and hash (hash type ). These data types support push/pop, add/remove, Intersection Set and difference set, and more abundant operations, and these operations are atomic. On this basis, redis supports sorting in different ways. Like memcached, data is cached in the memory to ensure efficiency. The difference is that redis periodically writes the updated data to the disk or writes the modification operation to the append record file, and on this basis implements master-slave (master-slave) synchronization.


Ii. Installation Based on windows 64bit

Before installation, make sure you are a windows user with the Administrator account! If you are not an Administrator user, you may need to run it as an administrator or refer to the N methods for enabling the super Administrator Account in Windows 7.

On the redis download page, there is a saying that the redis project does not provide support for the windows system, while Microsoft Open Tech provides a redis implementation based on win64. That is to say, only 64-bit systems are supported. If you are a 32-bit windows system, you can change the system honestly. (* ^__ ^ *)

The Redis project does not officially support Windows. However, the Microsoft Open Tech group develops and maintains this Windows port targeting Win64.

1. Download and install

: Https://

Decompress the package and you will see the following files.

There is almost no installation process in Windows. You can use it after decompression. The following describes the usage of several exe files:

Redis. windows. conf redis configuration file

Redis-benchmark.exe testing tool to test redis read/write Performance

Redis-check-aof.exe aof repair Check log

Redis-check-dump.exe dump check database files

Redis-cli.exe redis client program

Redis-server.exe redis server program

Iii. Use redis tools

1. You can double-click redis-server to run the command or use the DOS command to open the command. After the command is run successfully, you can see the following interface content:

Contains the version number, running process number, and running port information. You will also be reminded to use the redis. windows. conf configuration file. If the startup fails, a memory error is reported. You need to modify the maxheap configuration of the configuration file (this configuration is not assigned a value by default, and is not enabled). The modification is as follows:

# Maxheap <bytes>

# Maxheap 1024000000

Another startup method is to start with the specified redis. conf configuration file, as follows:

If you want to use different configuration files to set different server parameters, the configuration files under the root directory are used by default.

Start redis-server/biran/conf/redis. conf and install the specified configuration file

Redis-server-(read config from stdin) use standard input to read configuration as startup Parameter

Redis-server -- test-memory 256 detects MB memory

Redis-server-version check version number

If you want to use it for a long time, you must register it as a system service.

Go to CMD and switch to the redis directory:

Register the service, which can be saved as a service-install.bat file:

Redis-server.exe -- service-install redis. windows. conf -- loglevel verbose

Redis-server -- service-start

Uninstall the service, which can be saved as a uninstall-service.bat file:

Redis-server -- service-stop

Redis-server -- service-uninstall

When registering a service, you can use the-service-name redisService1 parameter to directly specify the service name. This is suitable for installing multiple instances. The same principle applies when you detach a service.

When starting the redis server, you can also directly specify the configuration file, which can be saved as the startup. bat file:

Redis-server.exe redis. windows. conf


2. configuration parameters of redis. windows. conf

# By default, redis is not running in the background mode. If you need to run the program in the background, change the value of this item to yes. The default value is no.

Daemonize: whether to run in daemon mode

# For example, redis writes the pid to the/run/Redis. pid file group by default when processes in redis are running. You can configure the pid to other file paths.

# When running multiple redis services, you must specify different pid files and ports.

Pidfile: pid File Location

# Specify the redis listening port. The default value is 6379.

# If the port is set to 0, Redis will not listen to TCP sockets.

Port: the port number of the listener.

# Specify that redis only receives requests from this IP address. If this parameter is not set, all requests are processed by default,

# It is best to set this item in the production environment


# Set the timeout time for client connection, in seconds. When the client does not send any commands during this period, close the connection.

# Default value: 0 indicates disabled and never closed

Timeout: Request timeout

# Specify the path for listening to the connected unxi socket. There is no default value for this, so Redis will not listen through unix socket if it is not specified.

# Unixsocket/tmp/redis. sock

# Unixsocketperm 755

# Specify the log record level

# Redis supports four levels: debug, verbose, notice, and warning. The default value is verbose.

# Debug records a lot of information for development and testing

# Varbose provides a lot of concise and useful information, not as many as debug records

# Notice common verbose, usually used in the production environment

# Warning only records very important or serious information.

Loglevel: log information level

# Configure the log file name and full path address

# The default value is stdout and "standard output" is used. The default background mode is output to/dev/null.

Logfile: Location of the log file

# Number of available databases. The default value is 16. The default database is stored in database No. 0 ID. You are advised to set only one database databases 1.

# Use SELECT to query databases <dbid>

# Dbid is between 0 and 'databases'-1

Databases: number of databases Enabled

Save **: the frequency at which snapshots are saved. The first "*" indicates the duration and the third "indicates the number of write operations performed. Snapshots are automatically saved when a certain number of write operations are performed within a certain period of time. You can set multiple conditions.

Rdbcompression: whether to use Compression

Dbfilename: Data snapshot file name (only file name, excluding directory)

Dir: directory for storing data snapshots (this is the Directory)

Appendonly: whether to enable appendonlylog. If it is enabled, a log is recorded for each write operation, which improves data risk resistance but affects efficiency.

Appendfsync: How to synchronize appendonlylog to the disk (three options are force-call fsync for each write, enable fsync once per second, and do not call fsync to wait for the system to synchronize itself)

########## REPLICATION synchronization ##########


# Master-slave Synchronization. Use slaveof configuration to back up Redis instances.

# Note: Data is locally copied from the remote end. That is to say, local hosts can have different database files, bind different IP addresses, and listen on different ports.

# When the local machine is a slave service, it sets the IP address and port of the master service. When Redis is started, it will automatically synchronize data from the master service.

# Slaveof <masterip> <masterport>

# If a password is set for the master service (configured using the "requirepass" option below) and the password for the slave service to connect to the master, slave must perform authentication before synchronization starts, otherwise, its synchronization request is rejected.

# When the local machine is a slave service, set the master service connection password

# Masterauth <master-password>

# When an slave loses its connection to the master or the synchronization is in progress, there are two possible slave actions:

#1) If slave-serve-stale-data is set to "yes" (default), slave will continue to respond to client requests, which may be normal data, it may also be that empty data has not yet been obtained.

#2) If slave-serve-stale-data is set to "no", slave will reply "synchronizing with master in progress" to process various requests, besides the INFO and SLAVEOF commands.

Slave-serve-stale-data yes

# Slave sends a ping request to the server based on the specified interval.

# The time interval can be set through repl_ping_slave_period.

#10 seconds by default

# Repl-ping-slave-period 10

# The options below set the expiration time for large data I/O, Data Request to master, and ping response.

# The default value is 60 seconds.

# Make sure that the value is greater than repl-ping-slave-period. Otherwise, the transmission expiration time between the master and slave is shorter than expected.

# Repl-timeout 60

######### SECURITY ##########

# The client is required to verify the identity and set the password when processing any command.

# This function is useful if you do not trust the requester.

# For backward compatibility, comment out this section. And most people do not need authentication (for example, they run on their own servers .)

# Warning: an external user can try a K password every second to crack the password. This means that you need a strong password. Otherwise, it will be too easy to crack.

# Set the connection password

# Requirepass foobared

# Command rename. You can set multiple

# In a shared environment, you can change the name of a dangerous command. For example, you can change a name that is not easy to guess for CONFIG so that you can still use it, but others cannot know it.

# Example:

# Rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52

# Rename-command info info_biran

# Rename-command set set_biran

# You can even assign an empty string to the command to completely disable the command:

# Rename-command CONFIG ""

######### LIMITS restrictions ##########

# Set the maximum number of connected clients at the same time.

# There is no limit by default. This is related to the number of file descriptors that can be opened by the Redis process.

# The special value "0" indicates no restriction.

# Once this limit is reached, Redis will close all new connections and send an error "reaching the maximum number of users (max number of clients reached )"

# Maxclients 128

# Do not use more memory than the configured upper limit. Once the memory usage reaches the upper limit, Redis will delete the key based on the selected recycle policy (see maxmemmory-policy: Memory policy setting.

# If Redis cannot delete the key due to deletion policy issues, or the policy is set to "noeviction", Redis will reply to the command with more memory errors.

# For example, SET and LPUSH. However, it will continue to respond to read-only commands properly, such as GET.

# This option is useful when Redis is used as the LRU cache or when the "noeviction" policy is set for the instance.

# Warning: when a bunch of slave instances are connected to the memory limit, the memory required to respond to the output cache required by slave is not counted in the memory usage.

# In this way, when a deleted key is requested, the network issue/re-synchronization event will not be triggered, and slave will receive a bunch of delete commands until the database is empty.

# In short, if you have a Server Load balancer instance connected to a master, we recommend that you set the master memory limit to a smaller value to ensure that enough system memory is used as the output cache.

# (It doesn't matter if the policy is set to "noeviction)

# Set the maximum memory. When the maximum memory is reached, Redis will first try to clear expired or expiring keys. After this method is processed, any of them will reach the maximum memory setting, no more write operations can be performed.

# Maxmemory 256000000 allocates MB of memory

# Maxmemory <bytes>

# Memory Policy: if the memory limit is reached, how does Redis Delete the key. You can choose from the following five policies:


# Volatile-lru-> delete an instance based on the expiration time generated by the LRU algorithm.

# Allkeys-lru-> delete any key based on the LRU algorithm.

# Volatile-random-> Delete keys randomly based on expiration settings.

# Allkeys-> random deletion without difference.

# Volatile-ttl-> Delete (supplemented by TTL) based on the latest expiration time)

# Noeviction-> no one will delete it, and an error will be returned directly during the write operation.


# Note: For all policies, if Redis cannot find a suitable key that can be deleted, an error will be returned during the write operation.


# The command involved here: set setnx setex append

# Incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd

# Sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby

# Zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby

# Getset mset msetnx exec sort


# The default value is as follows:

# Maxmemory-policy volatile-lru

# The implementation of LRU and the minimum TTL algorithm is not very accurate, but very close (to save memory), so you can use the example for testing.

# For example, by default, Redis checks the three keys and obtains the oldest one. You can set the number of samples through the following configuration items.

# Maxmemory-samples 3

######### Append only mode pure accumulative MODE ##########

# By default, Redis asynchronously exports data to the disk. Because redis synchronizes data files according to the save conditions above, some data will only exist in the memory for a period of time. In this case, when Redis is down, the latest data is lost.

# If you do not want to lose any piece of data, you should use the pure accumulate mode: once this mode is enabled, Redis will write the data written each time to the appendonly. aof file after receiving it.

# Redis reads the data in this file into the memory every time it starts.


# Note: database files exported asynchronously and pure accumulated files can coexist. (comment out all the above "save" Settings and disable the export mechanism ).

# If the pure accumulate mode is enabled, Redis will load the log file at startup and ignore the exported dump. rdb file.


# Important: View BGREWRITEAOF to learn how to reprocess the log file in the background when the log file is too large.

# Setting: yes is the pure accumulate mode.

Appendonly no

# Set the name and save path of the accumulated file. Default Value: "appendonly. aof"

# Appendfilename appendonly. aof

# Fsync () requests the operating system to immediately write data to the disk. Do not wait.

# Some operating systems will actually fl data to the disk immediately; some of them need to be honed, but they will do so as soon as possible.

# Redis supports three different modes:


# No: do not click it immediately. You can click it again only when the operating system needs to click it. Fast.

# Always: Every write operation is immediately written to the aof file. Slow, but safest.

# Everysec: Write once per second. Compromise.

# The default "everysec" is usually a good balance between speed and data security.

# If you really understand what this means, you can set "no" to achieve better performance (if data is lost, you can only get one snapshot that is not very new );

# On the contrary, you choose "always" to sacrifice speed to ensure data security and integrity.


# If you are not sure about the usage of these modes, we recommend using "everysec"


# Appendfsync always

Appendfsync everysec

# Appendfsync no

# If the AOF synchronization policy is set to "always" or "everysec", background Storage Processes (storing or writing AOF logs in the background) will incur a lot of disk I/O overhead.

# Some Linux configurations may cause Redis to be blocked for a long time due to fsync.

# Note: the current situation has not been perfectly corrected, and even fsync () of different threads will block our write (2) requests.


# Use the following option to alleviate this problem. It can block fsync () during BGSAVE or BGREWRITEAOF processing ().


# This means that if a sub-process is performing the save operation, Redis will be in the "non-synchronous" state.

# This means that in the worst case, 30 seconds of log data may be lost. (Default Linux settings)


# If you have latency problems, set this to "yes"; otherwise, keep "no", which is the safest way to save persistent data.

No-appendfsync-on-rewrite no

# Automatically override AOF files

# If the AOF log file is larger than the specified percentage, Redis can automatically rewrite the AOF log file through BGREWRITEAOF.


# Working principle: Redis remembers the size of the AOF log during the last rewrite (or if no write operation is performed after the restart, the AOF file will be used directly ),

# Compare the reference size with the current size. If the current size exceeds the specified proportion, the rewrite operation is triggered.


# You also need to specify the minimum size of the log to be rewritten, so as to avoid rewriting when the agreed percentage is reached but the size is still small.


# If the percentage is 0, the AOF automatic rewrite feature is disabled.

Auto-aof-rewrite-percentage 100

Auto-aof-rewrite-min-size 64 mb

######### Slow log slow query LOG ##########

# Redis slow query logs can record queries that have exceeded the specified time. The running time does not include various I/O times.

# For example, connect to the client and send response data. Only calculate the actual time of command running (this is the only scenario where the command running thread is blocked and cannot serve other requests at the same time)


# You can configure two parameters for slow query logs: one is the time exceeding the standard, and the Unit is subtle. commands that record the time exceeding the limit are used.

# The other is the length of the slow query log. When a new command is written into the log, the oldest record is deleted.


# The following time unit is microsecond, so 1000000 is 1 second. Note that the negative time will disable slow query logs, and 0 will force all commands to be logged.

Slowlog-log-slower-than 10000

# There is no limit on the length. You only need enough memory. You can use slowlog reset to release memory.

Slowlog-max-len 128

######### Virtual memory ##########

### Warning! Redis 2.4 is against in the virtual environment. Due to performance problems, the VM mechanism of version 2.4 is completely deprecated. We do not recommend using this configuration !!!!!!!!!!!

# The virtual memory allows Redis to save all data sequences in the memory when the memory is insufficient.

# To do this, the high-frequency key will be transferred to the memory, and the low-frequency key will be transferred to the swap file, just like the Memory Page used by the operating system.

# To use virtual memory, set "vm-enabled" to "yes" and set the following three virtual memory parameters as needed.

Vm-enabled no

# This is the path of the swap file. As you may have guessed, the swap file cannot be shared among multiple Redis instances, so make sure that each Redis instance uses an independent swap file.

# SSD is the best medium for storing swap files (randomly accessed ).

# *** Warning ** if you use a shared host, it is not safe to put the default swap file under/tmp.

# Create a writable directory for Redis users and configure Redis to create swap files here.

Vm-swap-file/tmp/redis. swap

# "Vm-max-memory": configure the maximum available memory capacity of the virtual memory.

# If the swap file still has space, all excess parts will be placed in the swap file.

# If "vm-max-memory" is set to 0, the system will use all available memory. We recommend that you set it to 60%-80% of the remaining memory.

# Store all data greater than vm-max-memory into the virtual memory. No matter how small the vm-max-memory settings are, all the index data is stored in the memory (Redis's index data is keys ), that is to say, when vm-max-memory is set to 0, all values exist on the disk. The default value is 0.

Vm-max-memory 0

# Redis swap files are divided into multiple data pages.

# A stored object can be saved on multiple consecutive pages, but one data page cannot be shared by multiple objects.

# Therefore, if your data page is too large, small objects will waste a lot of space.

# If the data page is too small, there will be less swap space for storage (assuming you set the same number of Data Pages)

# If you use many small objects, it is recommended that the page size be 64 or 32 bytes.

# If you use many large objects, use a larger size.

# If you are not sure, use the default value :)

Vm-page-size 32

# Total number of data pages in the swap file.

# Based on the memory split page table (used/unused data page distribution), each 8 data pages on the disk consumes one byte of memory.

# Swap Zone capacity = vm-page-size * vm-pages

# Based on the default 32-byte data page size and 134217728 of the data page size, Redis data page files occupy 4 GB, while paging tables in the memory consume 16 MB of memory.

# Set the minimum and sufficient number for your fulfillment program. The default value below is too large in most cases.

Vm-pages 134217728

# The number of virtual memory I/O threads that can run simultaneously, that is, the number of threads that access the swap file.

# These threads can read and write data from swap files, or process data interaction and encoding/decoding between memory and disk.

# More threads can improve the processing efficiency to a certain extent. Although I/O operations depend on physical devices, they do not increase the efficiency of a single read/write operation because of more threads.

# The special value 0 will disable thread-Level I/O and enable the blocking virtual memory mechanism.

# It is recommended that you set the number of server cores not exceed. If it is set to 0, all operations on swap files are serial. it may cause a long delay, but it guarantees data integrity.

Vm-max-threads 4

######### Advanced config ##########

# When there is a large amount of data, it is suitable to use Hash encoding (this requires more memory), the maximum number of elements cannot exceed the given limit.

# Redis Hash is a HashMap inside the value. If the number of members of this Map is small, it will be stored in a compact format similar to one-dimensional linear, this saves a lot of pointer memory overhead. If any of the following two conditions exceeds the set value, it will be converted into a real HashMap,

# When the value Map contains no more than one members, it is stored in a linear compact format. The default value is 64. That is, if the value contains less than 64 members, it uses linear compact storage, if this value is exceeded, it is automatically converted to a real HashMap.

Hhash-max-zipmap-entries 512

# When the length of each member value in the Map is no more than a few bytes, the linear compact storage is used to save space.

Hash-max-zipmap-value 64

# Similar to the hash-max-zipmap-entries hash, if there are few data elements, you can use another method for encoding to save a lot of space.

# The number of nodes in the list data type follows the compact storage format of de-pointer.

List-max-ziplist-entries 512

# The number of bytes smaller than the node value of the list data type will use the compact storage format

List-max-ziplist-value 64

# There is also a special encoding: The data is a string consisting of 64-bit unsigned integer numbers.

# The following configuration item is used to limit the maximum value of this encoding in this case.

Set-max-intset-entries 512

# Similar to the first and second cases, ordered sequences can also be processed in a special encoding method, saving a lot of space.

# This encoding is only applicable to the ordered sequence with the length and elements meeting the following restrictions:

Zset-max-ziplist-entries 128

Zset-max-ziplist-value 64

# Hash Refresh: every 100 CPUs refresh the Redis master hash table (top-level key-value ing table) in milliseconds ).

# Implementation of the hash table used by redis (see dict. c) adopts the delayed hash refresh mechanism: the more you operate on a hash table, the more frequent the hash refresh operation;

# If the server is very inactive, the hash table is saved in the dot memory.

# By default, 10 hash table refreshes are performed every second to refresh the dictionary and release the memory as soon as possible.

# Suggestion:

# If you are concerned about latency, use "activerehashing no". The latency of each request is 2 milliseconds.

# If you do not care much about latency and want to release the memory as soon as possible, set "activerehashing yes ".

Activerehashing yes

######### INCLUDES des ##########

# Contains one or more other configuration files.

# This is useful when you have a standard configuration Template but each redis server requires personalized settings.

# The File Inclusion feature allows you to attract other configuration files, so make good use of it.

# Include/path/to/local. conf

# Include/path/to/other. conf

After modifying the configuration, remember to save the file as UTF-8 encoding if the configuration file involves Chinese content.

3. Use the redis-cli Client

Test server startup connection 6379> ping


View server level information (test server) 6379> info

# Server

Redis_version: 2.8.19

Redis_git_sha1: 00000000

Redis_git_dirty: 0

Redis_build_id: 9968db13395be4aa

Redis_mode: standalone

OS: Windows

Arch_bits: 64

Multiplexing_api: winsock_IOCP

Gcc_version: 0.0.0

Process_id: 9204

Run_id: fc4a126eaed1572b6855c9af1_d3451eb358c85

Tcp_port: 6379

Uptime_in_seconds: 2365

Uptime_in_days: 0

Hz: 10

Lru_clock: 3087964

Config_file: G: \ software \ redis. windows. conf

# Clients

Connected_clients: 1

Client_longest_output_list: 0

Client_biggest_input_buf: 0

Blocked_clients: 0

# Memory

Used_memory: 11568456

Used_memory_human: 11.03 M

Used_memory_ RSS: 11534800

Used_memory_peak: 11568456

Used_memory_peak_human: 11.03 M

Used_memory_lua: 35840

Mem_fragmentation_ratio: 1.00

Mem_allocator: dlmalloc-2.8

# Persistence

Loading: 0

Rdb_changes_since_last_save: 0

Rdb_bgsave_in_progress: 0

Rdb_last_save_time: 1429148959

Rdb_last_bgsave_status: OK



Aof_enabled: 0

Add data 6379> set user hoojo

OK 6379> get user


View all key information 6379> keys *

1) "key: 000000000308"

2) "key: 000000000900"

3) "key :__ rand_int __"

4) "key: 000000000809"

5) "key: 000000000164"

6) "key: 000000000887"

Basic parameters


Sets the IP address of the detection host. The default value is


Set the port number of the detection host. The default value is 6379.

-S <socket>

Server socket (overwhelming host and port)


Password used to connect to the Master server


Run the specified N commands


Wait for N seconds after the command is executed, for example,-I 0.1 info (wait for 0.1 seconds after execution)


Specify to connect to database n id, for example,-n 3 (connect to database 3)


Read the last parameter from the information entered in the console


Define multiple delimiters as the default output format (default: \ n)

-- Raw

Return the output content in the original data format

-- Latency

Enter a special mode of continuous delay sampling

-- Slave

Simulate a command from the server to the master server to display feedback

-- Pipe

Use MPs Queue Protocol Mode

-- Bigkeys

The listener displays a key value with a large amount of data, -- bigkeys-I 0.1

-- Help

Display command line help information

-- Version

Show version number

4. redis-benchmark performance testing tool

By default, double-clicking is performed based on the default test parameters.

After you enter the preceding command, the following information is displayed, indicating that 10 connections are concurrently and a total of 100 operations are performed. It is easy to understand that a total of 10 operations are performed by 10 users at the same time.

100 requests completed in 0.01 seconds (100 requests completed in 0.01 seconds)

10 parallel clients (10 concurrent clients)

3 bytes payload (3 bytes written each time)

Keep alive: 1 (number of saved links)

100.00% <= 1 milliseconds (100% of Operations completed in less than 1 second)

16666.67 requests per second (16666.67 queries per second)

Command parameter description

Redis-benchmark [-h


-P <port> host port (6379 by default)

-S <socket> host socket (overwrite host and port)

-C <clients> Number of concurrent connections (50 by default)

-N <requests> total number of requests (10000 by default)

-D <size> SET/GET Data byte size (2 by default)

-K <boolean> 1 = keep alive 0 = reconnect (default: 1)

-R <keyspacelen> SET/GET/INCR: Use a random key. When SADD uses this option to get/set keys, mykey_rand: 000000012456 is used to replace the constant key, the <keyspacelen> parameter determines the maximum value of a random number. For example, if the parameter is set to 10, the range of the random number is rand: 000000000000-rand: 000000000009.

-P <numreq> Number of Pipeline requests. Default Value: 1 (no pipeline is used ).

-Q: display query/sec values

-- Csv output in CSV format

-L local loop. Keep running the test

-T <tests> in the test that runs the comma-separated list, the name of the test is the same as the name of the generated output.

-I idle mode. Open N idle connections and wait.

Running example

Performs 20 concurrent operations on the specified server and port, with a total of 100000 operations

Redis-benchmark-h 6379-n 100000-c 20

Test the set write operation for 1000000 times. The random number range is 100000000.

Redis-benchmark-t set-n 1000000-r 100000000

Ping, set, and get operations are tested for 100000 times. The output result is in csv format.

Redis-benchmark-t ping, set, get-n 100000 -- csv

Redis-benchmark-r 10000-n 10000 lpush mylist ele: rand: 000000000000

5. Basic usage of redis-check-aof

Check the local log information and add the -- fix parameter to fix the log file.

A redis-check-aof.exe log. aof

6. redis-check-dump checks database files

Redis-check-dump.exe dump. rdb will output the file size, usage.

Iv. Factors affecting Redis Performance

*Network bandwidth and latency. It is a good practice to use ping to quickly detect the client and server latency before performing the benchmark test. For bandwidth, it is better to estimate the Gbits/s throughput and compare the theoretical bandwidth value of the network. In many cases, Redis's throughput is limited by the CPU before the network.

*CPU is also an important factor. Because of a single thread, Redis has benefited from a fast CPU with a large cache.

*The memory speed and capacity have little impact on small objects. However, you may need to pay attention to objects larger than 10 KB. Generally, purchasing expensive fast memory modules is not really effective.

*Redis runs slowly on virtual machines. Virtualization is too costly for many common operations. Redis does not add much overhead to the required system calls and network interruptions.

*The client and server run on one machine. You can use either the benchmark test TCP/IP delivery or the UNIX domain socket. It depends on the platform, but the UNIX domain socket increases the throughput by 50% than the TCP/IP delivery.

*When pipelining is widely used, the performance benefits of UNIX-domain sockets are reduced.

*When the data size of an Ethernet packet is smaller than the size of an Ethernet packet (approximately 1500 bytes) when accessing Redis over Ethernet, the clustering command uses pipelining to be very effective.

*On a multi-CPU socket server, the performance of Redis becomes dependent on the NUMA configuration and processing location.

*In high-end configurations, the number of client connections is also an important factor. Based on the epool/kqueue model, Redis's event loop is quite scalable.

*For high-end configurations, high throughput may be achieved by optimizing NIC (s) configurations and related interruptions.

*Based on the platform, Redis compilation can use different memory distributors, which may have different behavior in terms of raw speed, internal and external fragmentation.

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.