- What's New
- Function Overview
- Product Bulletin
-
Service Overview
- Infographics for Comparing DCS for Redis with Open-Source Redis
- What Is DCS?
- Application Scenarios
- Security
- DCS Instance Types
- DCS Instance Specifications
-
Command Compatibility
- Commands Supported and Disabled by DCS for Redis 4.0
- Commands Supported and Disabled by DCS for Redis 5.0
- Commands Supported and Disabled by DCS for Redis 6.0
- Commands Supported and Disabled in Web CLI
- Command Restrictions
- Other Command Usage Restrictions
- Commands Supported and Disabled by DCS for Redis 3.0 (Discontinued)
- Commands Supported and Disabled by DCS for Memcached (Discontinued)
- Disaster Recovery and Multi-Active Solution
- Cache Engine Differences
- Comparing DCS and Open-Source Cache Services
- Notes and Constraints
- Billing
- Permissions Management
- Basic Concepts
- Related Services
- Billing
- Getting Started
-
User Guide
- Process of Using DCS
- Creating a User and Granting DCS Permissions
- Buying a DCS Redis Instance
-
Accessing a DCS Redis Instance
- Configuring Redis Network Connections
- Controlling DCS Redis Access
-
Connecting to Redis on a Client
- Connecting to Redis on redis-cli
- Connecting to Redis on Jedis (Java)
- Connecting to Redis on Lettuce (Java)
- Connecting to Redis on Redisson (Java)
- Connecting to Redis on redis-py (Python)
- Connecting to Redis on go-redis (Go)
- Connecting to Redis on hiredis (C++)
- Connecting to Redis on StackExchange.Redis (C#)
- Connecting to Redis on phpredis (PHP)
- Connecting to Redis on predis (PHP)
- Connecting to Redis on ioredis (Node.js)
- Connecting to Redis on the Console
- Public Access to a DCS Redis 3.0 Instance (Discontinued)
- Accessing a DCS Memcached Instance (Discontinued)
-
Managing Instances
- Viewing and Modifying Basic Settings of a DCS Instance
- Viewing DCS Background Tasks
- Viewing Client Connection Information of a DCS Instance
- Modifying Configuration Parameters of a DCS Instance
- Configuring DCS Instance Parameter Templates
- Configuring DCS Instance Tags
- Renaming Critical Commands for DCS Instances
- Exporting a DCS Instance List
- Performing a Master/Standby Switchover for a DCS Instance
- Managing DCS Instance Shards and Replicas
- Backing Up or Restoring Instance Data
- Changing an Instance
- Managing Lifecycle of an Instance
- Diagnosing and Analyzing an Instance
- Migrating Instance Data
-
Testing Instance Performance
- Testing Redis Performance Using memtier_benchmark
- Testing Redis Performance Using redis-benchmark
- Comparing redis-benchmark and memtier_benchmark
-
Reference for a Redis Performance Test
- Test Data of Master/Standby DCS Redis 3.0 Instances
- Test Data of Proxy Cluster DCS Redis 3.0 Instances
- Test Data of Master/Standby DCS Redis 4.0 or 5.0 Instances
- Test Data of Proxy Cluster DCS Redis 4.0 or 5.0 Instances
- Test Data of Redis Cluster DCS Redis 4.0 or 5.0 Instances
- Test Data of Master/Standby DCS Redis 6.0 Instances
- Test Data of Redis Cluster DCS Redis 6.0 Instances
- Test Data of Redis Backup, Restoration, and Migration
- Applying for More DCS Quotas
- Viewing Monitoring Metrics and Configuring Alarms
- Viewing DCS Audit Logs
- Best Practices
-
API Reference
- Before You Start
- API Overview
- Calling APIs
- Examples
-
API V2
- Lifecycle Management
-
Instance Management
- Updating a Bandwidth Auto Scaling Policy
- Querying a Bandwidth Auto Scaling Policy
- Deleting a Bandwidth Auto Scaling Policy
- Querying Details of an Instance Parameter Modification Record
- Master/Standby Switchover
- Changing the Password
- Resetting a Password
- Querying DCS Instance Statuses
- Restarting DCS Instances or Clearing DCS Instance Data
- Querying Statistics of All Running Instances
- Enabling or Disabling Client IP Pass-through
- Modifying the Bandwidth of an Instance
- Enabling/Modifying Public Access
- Disabling Public Access to an Instance
- Switching Master/Replica Roles on a Cluster Shard
- Asynchronous Master/Replica Node Switchover
- Querying Whether Specifications of an Instance Can Be Increased
- Obtaining Shard Bandwidth of an Instance
- Modifying Instance Shard Bandwidth
- Asynchronously Exporting Instances
- Starting or Stopping a Specified Instance Node
- Obtaining the Instance Engine Version by Instance ID
- Upgrading the Minor Version of an Instance
- Shards and Replicas
- Parameter Management
- Backup and Restoration
-
Data Migration
- Switching IP
- Creating a Backup Import Task
- Listing Migration Tasks
- Deleting Data Migration Tasks
- Querying Details of a Data Migration Task
- Configuring Auto-Reconnect for Migration Tasks
- Stopping a Data Migration Task
- Querying the Progress of an Online Migration Task
- Creating an Online Data Migration Task
- Configuring an Online Data Migration Task
- Stopping Data Migration Tasks
- Stopping Synchronization of a Data Migration Task
- Querying the Migration Log List
- Restarting Online Migration Tasks in Batches
- Tag Management
-
Cache Analysis
- Querying Expired Key Scan Records
- Scanning for Expired Keys Immediately
- Creating a Big Key Analysis Task
- Listing Big Key Analysis Tasks
- Querying Big Key Analysis Details
- Deleting a Big Key Analysis Task
- Configuring Automatic Big Key Analysis
- Querying the Configurations of Automatic Big Key Analysis
- Creating a Hot Key Analysis Task
- Listing Hot Key Analysis Tasks
- Querying Hot Key Analysis Details
- Deleting a Hot Key Analysis Task
- Configuring Automatic Hot Key Analysis
- Querying the Configurations of Automatic Hot Key Analysis
- Creating an Expired Key Scan Task
- Querying Automatic Scanning Configuration
- Modifying Automatic Scanning Configuration
- Log Management
- Account Management
- Network Security
- Background Task Management
- Instance Diagnosis
- Template Management
- Other APIs
- Session Management
- Permissions Policies and Supported Actions
- Appendix
- Out-of-Date APIs (Unavailable Soon)
- SDK Reference
-
FAQs
- Instance Types/Versions
-
Feature
- What Are the CPU Specifications of DCS Instances?
- What Are Shard and Replica Quantities?
- Do DCS Redis Instances Limit the Size of a Key or Value?
- Can I Obtain the Addresses of the Nodes in a Cluster DCS Redis Instance?
- Does DCS for Redis Support Redis Clusters?
- What Are Redis Data Eviction Policies?
- Does DCS for Redis Support Read/Write Splitting?
- Does DCS for Redis Support Multi-DB?
- Does DCS Support External Extensions, Plug-ins, or Modules?
- Do DCS Redis Instances Support Data Persistence? What Is the Impact of Persistence?
- Do DCS Redis Instances Limite Data Quantity?
-
Security
- How Do I Configure a Security Group?
- Why Can't Security Groups Be Configured for DCS Redis 4.0/5.0/6.0 Basic Edition Instances?
- How Can I Secure My DCS Redis Instances?
- Does DCS for Redis Support SSL Encrypted Transmission?
- How Do I Enable or Disable SSL for Public Access to a DCS Redis 3.0 Instance?
- Does DCS Support Cross-AZ Deployment?
- Is a Password Required for Accessing an Instance? How Do I Set a Password?
- Sentinel Principle
- Does DCS Support Sentinels?
-
Client and Network Connection
- Does DCS Support Public Access?
- Troubleshooting Redis Connection Failures
- Does DCS Support Cross-VPC Access?
- Will I Be Charged for the EIP Used for Public Access to a DCS Redis Instance?
- Why Is "(error) NOAUTH Authentication required" Displayed When I Access a DCS Redis Instance?
- What Should I Do If Access to DCS Fails After Server Disconnects?
- Why Do Requests Sometimes Time Out in Clients?
- What Should I Do If an Error Is Returned When I Use the Jedis Connection Pool?
- How Do I Access a DCS Redis Instance Through Redis Desktop Manager?
- What If "ERR Unsupported CONFIG subcommand" is Displayed in SpringCloud?
- What Can I Do If I Fail to Access a DCS Instance Using Its Domain Name Address?
- Can I Access DCS Instances in a Local Environment?
- What Should Be Noted When Using Redis for Pub/Sub?
- Why Is Public Access of My DCS Redis 3.0 Instance Unintentionally Disabled?
- What Can I Do If Error "Cannot assign requested address" Is Returned When I Access Redis Using connect?
- Connection Pool Selection and Recommended Jedis Parameter Settings
- What Can I Do If a Lettuce 6.x Client Is Incompatible with My DCS Instance?
- Should I Use a Domain Name or an IP Address to Connect to a DCS Redis Instance?
- Is the Read-only Address of a Master/Standby Instance Connected to the Master or Standby Node?
-
Redis Usage
- Can I Change the CPU Architecture?
- Can I Change the AZ for an Instance?
- Can I Change the VPC and Subnet for a DCS Redis Instance?
- Can I Customize or Change the Port for Accessing a DCS Instance?
- Can I Modify the Connection Addresses for Accessing a DCS Instance?
- Why Do I Fail to Delete an Instance?
- Why Does It Take a Long Time to Start a Cluster DCS Instance?
- What Should I Do If an Error Occurs in redis_exporter?
- What Is Reserved Memory? How Do I Configure Reserved Memory?
- Why Is Available Memory Smaller Than Instance Cache Size?
- Why Is Redisson Distributed Lock Not Supported by DCS Proxy Cluster Redis 3.0 Instances?
- Does DCS for Redis Provide Backend Management Software?
- Can I Recover Deleted Data of a DCS Instance?
- Why Is Available Memory of Unused DCS Instances Less Than Total Memory and Why Is Memory Usage of Unused DCS Instances Greater Than Zero?
- How Do I Check Redis Memory Usage?
- Why Is the Capacity or Performance of a Shard of a Redis Cluster Instance Overloaded When That of the Instance Is Still Below the Bottleneck?
- Why Does an OOM Error Occur During a Redis Connection?
- What Clients Can I Use for Redis Cluster in Different Programming Languages?
- Why Do I Need to Configure Timeout for Redis Cluster?
- Why Am I Seeing a Timeout Error When Reading Data from Redis?
- Explaining and Using Hash Tags
- Why Does a Key Disappear in Redis?
- Will Cached Data Be Retained After an Instance Is Restarted?
- How Do I Know Whether an Instance Is Single-DB or Multi-DB?
- Notes and Procedure for Enabling Multi-DB for Proxy Cluster Instances
- How Do I Create a Multi-DB Proxy Cluster Instance?
-
Instance Scaling and Upgrade
- Can I Upgrade Version for a DCS Redis Instance, for Example, from Redis 4.0 to Redis 5.0?
- Upgrading a Redis 3.0 Instance
- Are Services Interrupted If Maintenance is Performed During the Maintenance Time Window?
- Are DCS Instances Stopped or Restarted During Specification Modification?
- What DCS Instance Type Changes Are Supported?
- Are Services Interrupted During Specification Modification?
- Why Do I Fail to Modify the Specifications for a DCS Instance?
- How Do I Reduce the Capacity of a DCS Instance?
- How Do I Add Shards to a Cluster DCS Redis Instance Without Changing the Memory?
- How Do I Handle an Error When I Use Lettuce to Connect to a Redis Cluster Instance After Specification Modification?
- Can I Expand a Single Shard of a Cluster Instance (Scale-Up)?
-
Data Backup, Export, and Migration
- Can I Migrate Data from a Lower Redis Version to a Higher One?
- What Should I Consider When Transferring or Operating Data Between Different OSs?
- Can I Migrate Data from a Multi-DB Source Redis Instance to a Cluster DCS Redis Instance?
- What Are the Constraints and Precautions for Migrating Redis Data to a Cluster Instance?
- What Should I Consider for Online Migration?
- Can I Perform Online Migration Without Any Service Interruption?
- What If "Disconnecting timedout slave" and "overcoming of output buffer limits" Are Reported on the Source Instance During Online Migration?
- How Do I Export DCS Redis Instance Data?
- Why Is Memory of a DCS Redis Instance Unchanged After Data Migration Using Rump, Even If No Error Message Is Returned?
- Can I Export Backup Data of DCS Redis Instances to RDB Files on the Console?
- Where Are DCS Instance Backup Files Stored? How Many of Them Can Be Stored?
- Is All Data in a DCS Redis Instance Migrated During Online Migration?
- When Will AOF Rewrites Be Triggered?
- What Are the Common Causes of Redis Migration Failures?
- Can I Migrate Data to Multiple Target Instances in One Migration Task?
- How Do I Enable the SYNC and PSYNC Commands?
- Will the Same Keys Be Overwritten During Data Migration or Backup Import?
- Why Does Redis Cluster Migration Fail If It Uses Built-in Keys and Cross-Slot Lua Scripts?
- Handling Migration Errors
- Troubleshooting Data Migration Failures
- How Do I Migrate Memcached Data?
- Can I Migrate Data Between DCS Memcached and Redis Instances?
-
Big/Hot Key Analysis and Expired Key Scan
- What Are Big Keys and Hot Keys?
- What Is the Impact of Big Keys or Hot Keys?
- How Do I Avoid Big Keys and Hot Keys?
- How Do I Analyze the Hot Keys of a DCS Redis 3.0 Instance?
- How Do I Detect Big Keys and Hot Keys in Advance?
- How Does DCS Delete Expired Keys?
- How Long Are Keys Stored? How Do I Set Key Expiration?
- Why Does Memory Usage Decrease After Big Key Analysis Is Performed on Redis?
-
Redis Commands
- Does DCS for Redis Support Command Audits?
- How Do I Clear Redis Data?
- How Do I Find Specified Keys and Traverse All Keys?
- Why Do I Fail to Execute Some Redis Commands?
- Why is "permission denied" Returned When I Run the KEYS Command in Web CLI?
- How Do I Rename High-Risk Commands?
- Does DCS for Redis Support Pipelining?
- Does DCS for Redis Support the INCR and EXPIRE Commands?
- Why Does a Redis Command Fail to Take Effect?
- Is There a Time Limit on Executing Redis Commands? What Will Happen If a Command Times Out?
- Can I Configure Redis Keys to Be Case-Insensitive?
- Common Web CLI Errors
-
Monitoring and Alarm
- Why Is CPU Usage of a DCS Redis Instance 100%?
- How Do I View Current Concurrent Connections and Maximum Connections of a DCS Redis Instance?
- What Should I Do If the Monitoring Data of a DCS Redis Instance Is Abnormal?
- Why Is Used Memory Greater Than Available Memory?
- Why Does Bandwidth Usage Exceed 100%?
- Why Is the Rejected Connections Metric Displayed?
- Why Is Flow Control Triggered? How Do I Handle It?
- Master/Standby Switchover
- Instance Creation and Permissions
-
Memcached Usage
- Can I Dump DCS Memcached Instance Data for Analysis?
- What Memcached Version Is Compatible with DCS for Memcached?
- What Data Structures Does DCS for Memcached Support?
- Does DCS for Memcached Support Public Access?
- Can I Modify Configuration Parameters of DCS Memcached Instances?
- What Are the Differences Between DCS for Memcached and Self-Hosted Memcached?
- What Policies Does DCS for Memcached Use to Deal with Expired Data?
- How Should I Select AZs When Creating a DCS Memcached Instance?
- Troubleshooting
- Videos
-
More Documents
-
User Guide (ME-Abu Dhabi Region)
- Service Overview
- Getting Started
- Operation Guide
- Monitoring
- Auditing
-
FAQs
-
Client and Network Connection
- Security Group Configurations
- Does DCS Support Public Access?
- Does DCS Support Cross-VPC Access?
- What Should I Do If Access to DCS Fails After Server Disconnects?
- Why Do Requests Sometimes Time Out in Clients?
- What Should I Do If an Error Is Returned When I Use the Jedis Connection Pool?
- Why Is "ERR unknown command" Displayed When I Access a DCS Redis Instance Through a Redis Client?
- How Do I Access a DCS Redis Instance Through Redis Desktop Manager?
- What If "ERR Unsupported CONFIG subcommand" is Displayed in SpringCloud?
- How Do I Troubleshoot Redis Connection Failures?
- What Should Be Noted When Using Redis for Pub/Sub?
-
Redis Usage
- Why Is CPU Usage of a DCS Redis Instance 100%?
- Can I Change the VPC and Subnet for a DCS Redis Instance?
- Why Aren't Security Groups Configured for DCS Redis 4.0 and 5.0 Instances?
- Do DCS Redis Instances Limit the Size of a Key or Value?
- Can I Obtain the Addresses of the Nodes in a Cluster DCS Redis Instance?
- Why Is Available Memory of a DCS Redis 3.0 Instance Smaller Than Instance Cache Size?
- Does DCS for Redis Support Multiple Databases?
- Does DCS for Redis Support Redis Clusters?
- Does DCS for Redis Support Sentinel?
- What Is the Default Data Eviction Policy?
- What Should I Do If an Error Occurs in Redis Exporter?
- Why Is Memory Usage More Than 100%?
- Why Is Redisson Distributed Lock Not Supported by DCS Proxy Cluster Redis 3.0 Instances?
- Can I Customize or Change the Port for Accessing a DCS Instance?
- Can I Modify the Connection Addresses for Accessing a DCS Instance?
- Does DCS Support Cross-AZ Deployment?
- Why Does It Take a Long Time to Start a Cluster DCS Instance?
- What If Redis Commands Are Incompatible with DCS for Redis?
- Does DCS for Redis Provide Backend Management Software?
- Why Is Memory of a DCS Redis Instance Used Up by Just a Few Keys?
- Can I Recover Data from Deleted DCS Instances?
-
Redis Commands
- How Do I Clear Redis Data?
- How Do I Rename High-Risk Commands?
- Does DCS for Redis Support Pipelining?
- Does DCS for Redis Support the INCR and EXPIRE Commands?
- Why Do I Fail to Execute Some Redis Commands?
- Why Does a Redis Command Fail to Take Effect?
- Is There a Time Limit on Executing Redis Commands? What Will Happen If a Command Times Out?
-
Instance Scaling and Upgrade
- Can DCS Redis Instances Be Upgraded, for Example, from Redis 3.0 to Redis 4.0 or 5.0?
- Are Services Interrupted If Maintenance is Performed During the Maintenance Time Window?
- Are Instance Resources Affected During Specification Modification?
- Are Services Interrupted During Specification Modification?
- Why Do I Fail to Modify the Specifications for a DCS Redis Instance?
- Monitoring and Alarm
- Data Backup, Export, and Migration
- Master/Standby Switchover
-
Client and Network Connection
- Change History
- API Reference (ME-Abu Dhabi Region)
-
User Guide (Paris Region)
- Service Overview
- Getting Started
- Operation Guide
- Monitoring
- Auditing
-
FAQs
-
Client and Network Connection
- Security Group Configurations
- Does DCS Support Public Access?
- Does DCS Support Cross-VPC Access?
- What Should I Do If Access to DCS Fails After Server Disconnects?
- Why Do Requests Sometimes Time Out in Clients?
- What Should I Do If an Error Is Returned When I Use the Jedis Connection Pool?
- Why Is "ERR unknown command" Displayed When I Access a DCS Redis Instance Through a Redis Client?
- How Do I Access a DCS Redis Instance Through Redis Desktop Manager?
- What If "ERR Unsupported CONFIG subcommand" is Displayed in SpringCloud?
- How Do I Troubleshoot Redis Connection Failures?
- What Should Be Noted When Using Redis for Pub/Sub?
-
Redis Usage
- Why Is CPU Usage of a DCS Redis Instance 100%?
- Can I Change the VPC and Subnet for a DCS Redis Instance?
- Do DCS Redis Instances Limit the Size of a Key or Value?
- Why Is Available Memory of a DCS Redis 3.0 Instance Smaller Than Instance Cache Size?
- Does DCS for Redis Support Multiple Databases?
- Does DCS for Redis Support Redis Clusters?
- Does DCS for Redis Support Sentinel?
- What Is the Default Data Eviction Policy?
- What Should I Do If an Error Occurs in Redis Exporter?
- Why Is Memory Usage More Than 100%?
- Why Is Redisson Distributed Lock Not Supported by DCS Proxy Cluster Redis 3.0 Instances?
- Can I Customize or Change the Port for Accessing a DCS Instance?
- Can I Modify the Connection Addresses for Accessing a DCS Instance?
- Does DCS Support Cross-AZ Deployment?
- Why Does It Take a Long Time to Start a Cluster DCS Instance?
- Why Is Memory of a DCS Redis Instance Used Up by Just a Few Keys?
- Can I Recover Data from Deleted DCS Instances?
- Why Is "Error in execution" Returned When I Access Redis?
-
Redis Commands
- Why is "permission denied" Returned When I Run the Keys Command in Web CLI?
- How Do I Clear Redis Data?
- Does DCS for Redis Support the INCR and EXPIRE Commands?
- Why Do I Fail to Execute Some Redis Commands?
- Why Does a Redis Command Fail to Take Effect?
- Is There a Time Limit on Executing Redis Commands? What Will Happen If a Command Times Out?
-
Instance Scaling and Upgrade
- Can DCS Redis Instances Be Upgraded, for Example, from Redis 3.0 to Redis 4.0 or 5.0?
- Are Services Interrupted If Maintenance is Performed During the Maintenance Time Window?
- Are Instance Resources Affected During Specification Modification?
- Are Services Interrupted During Specification Modification?
- Why Do I Fail to Modify the Specifications for a DCS Redis or Memcached Instance?
- Data Backup, Export, and Migration
- Master/Standby Switchover
-
Memcached Usage
- Can I Dump DCS Memcached Instance Data for Analysis?
- What Memcached Version Is Compatible with DCS for Memcached?
- What Data Structures Does DCS for Memcached Support?
- Does DCS for Memcached Support Public Access?
- Can I Modify Configuration Parameters of DCS Memcached Instances?
- What Are the Differences Between DCS for Memcached and Self-Hosted Memcached?
- What Policies Does DCS for Memcached Use to Deal with Expired Data?
- How Should I Select AZs When Creating a DCS Memcached Instance?
-
Client and Network Connection
- Change History
-
API Reference (Paris Region)
- Before You Start
- API Overview
- Calling APIs
-
API V2
- Lifecycle Management
- Instance Management
- Shards and Replicas
- Parameter Management
- Backup and Restoration
-
Data Migration
- Creating a Backup Import Task
- Listing Migration Tasks
- Deleting Data Migration Tasks
- Querying Details of a Data Migration Task
- Configuring Auto-Reconnect for Migration Tasks
- Stopping a Data Migration Task
- Querying the Progress of an Online Migration Task
- Creating an Online Data Migration Task
- Configuring an Online Data Migration Task
- Stopping Data Migration Tasks
- Stopping Synchronization of a Data Migration Task
-
Cache Analysis
- Creating a Big Key Analysis Task
- Listing Big Key Analysis Tasks
- Querying Big Key Analysis Details
- Deleting a Big Key Analysis Task
- Configuring Automatic Big Key Analysis
- Querying the Configurations of Automatic Big Key Analysis
- Creating a Hot Key Analysis Task
- Listing Hot Key Analysis Tasks
- Querying Hot Key Analysis Details
- Deleting a Hot Key Analysis Task
- Configuring Automatic Hot Key Analysis
- Querying the Configurations of Automatic Hot Key Analysis
- Log Management
- Network Security
- Background Task Management
- Instance Diagnosis
- Template Management
- Other APIs
- Outdated APIs (V1)
- Permissions Policies and Supported Actions
- Appendix
- Change History
-
User Guide (Kuala Lumpur Region)
-
Service Overview
- What Is DCS?
- Application Scenarios
- DCS Instance Types
- DCS Instance Specifications
- Command Compatibility
- Disaster Recovery and Multi-Active Solution
- Comparing Redis Versions
- Comparing Redis and Memcached
- Comparing DCS and Open-Source Cache Services
- Notes and Constraints
- Basic Concepts
- Permissions
- Related Services
- Permissions Management
- Process of Using DCS
-
Getting Started
- Creating an Instance
-
Accessing an Instance
- Network Conditions for Accessing DCS Redis
- Accessing a DCS Redis Instance Through redis-cli
- Access in Different Languages
- Accessing a DCS Redis 4.0/5.0/6.0 Instance on the Console
- Accessing a DCS Memcached Instance (Discontinued)
- Viewing Details of a DCS Instance
- Operating DCS Instances
-
Managing DCS Instances
- Configuration Notice
- Modifying Configuration Parameters
- Modifying the Security Group
- Viewing Background Tasks
- Viewing Data Storage Statistics of a DCS Redis 3.0 Proxy Cluster Instance
- Managing Tags
- Managing Shards and Replicas
- Analyzing Big Keys and Hot Keys
- Managing IP Address Whitelist
- Viewing Redis Slow Queries
- Viewing Redis Run Logs
- Diagnosing an Instance
- Transmitting DCS Redis Data with Encryption Using SSL
- Backing Up and Restoring DCS Instances
- Migrating Data with DCS
- Managing Passwords
- Parameter Templates
- Monitoring
- Auditing
- Data Migration Guide
-
FAQs
- Instance Types/Versions
-
Client and Network Connection
- Security Group Configurations
- Does DCS Support Access over Public Networks?
- Does DCS Support Cross-VPC Access?
- Why Is "(error) NOAUTH Authentication required" Displayed When I Access a DCS Redis Instance?
- What Should I Do If Access to DCS Fails After Server Disconnects?
- Why Do Requests Sometimes Time Out in Clients?
- What Should I Do If an Error Is Returned When I Use the Jedis Connection Pool?
- Why Is "ERR unknown command" Displayed When I Access a DCS Redis Instance Through a Redis Client?
- How Do I Access a DCS Redis Instance Through Redis Desktop Manager?
- What If "ERR Unsupported CONFIG subcommand" is Displayed in SpringCloud?
- Is a Password Required for Accessing an Instance? How Do I Set a Password?
- What Should Be Noted When Using Redis for Pub/Sub?
- How Do I Troubleshoot Redis Connection Failures?
- What Can I Do If Error "Cannot assign requested address" Is Returned When I Access Redis Using connect?
- Connection Pool Selection and Recommended Jedis Parameter Settings
-
Redis Usage
- What Are Shard and Replica Quantities?
- Why Is CPU Usage of a DCS Redis Instance 100%?
- Can I Change the VPC and Subnet for a DCS Redis Instance?
- Why Aren't Security Groups Configured for DCS Redis 4.0/5.0/6.0 Instances?
- Do DCS Redis Instances Limit the Size of a Key or Value?
- Can I Obtain the Addresses of the Nodes in a Cluster DCS Redis Instance?
- Why Is Available Memory Smaller Than Instance Cache Size?
- Does DCS for Redis Support Read/Write Splitting?How Do I Configure Read/Write Splitting for a Redis Cluster Instance?
- Does DCS for Redis Support Multiple Databases?
- Does DCS for Redis Support Redis Clusters?
- What Is Sentinel?
- Does DCS for Redis Support Sentinel?
- What Is the Default Data Eviction Policy?
- What Should I Do If an Error Occurs in Redis Exporter?
- How Can I Secure My DCS Redis Instances?
- Why Is Redisson Distributed Lock Not Supported by DCS Proxy Cluster Redis 3.0 Instances?
- Can I Customize or Change the Port for Accessing a DCS Instance?
- Can I Modify the Connection Addresses for Accessing a DCS Instance?
- Why Do I Fail to Delete an Instance?
- Does DCS Support Cross-AZ Deployment?
- Why Does It Take a Long Time to Start a Cluster DCS Instance?
- Does DCS for Redis Provide Backend Management Software?
- Can I Recover Data from Deleted DCS Instances?
- Does DCS for Redis Support SSL Encrypted Transmission?
- Why Is Available Memory of Unused DCS Instances Less Than Total Memory and Why Is Memory Usage of Unused DCS Instances Greater Than Zero?
- How Do I Check Redis Memory Usage?
- Why Is the Capacity or Performance of a Shard of a Redis Cluster Instance Overloaded When That of the Instance Is Still Below the Bottleneck?
- Does DCS Support External Extensions, Plug-ins, or Modules?
- Why Is "Error in execution" Returned When I Access Redis?
- Why Does a Key Disappear in Redis?
- Why Does an OOM Error Occur During a Redis Connection?
- What Clients Can I Use for Redis Cluster in Different Programming Languages?
- Why Do I Need to Configure Timeout for Redis Cluster?
- Can I Change the AZ for an Instance?
- Explaining and Using Hash Tags
- Will Cached Data Be Retained After an Instance Is Restarted?
-
Redis Commands
- How Do I Clear Redis Data?
- How Do I Find Specified Keys and Traverse All Keys?
- Why is "permission denied" Returned When I Run the KEYS Command in Web CLI?
- How Do I Disable High-Risk Commands?
- Does DCS for Redis Support Pipelining?
- Does DCS for Redis Support the INCR and EXPIRE Commands?
- Why Do I Fail to Execute Some Redis Commands?
- Why Does a Redis Command Fail to Take Effect?
- Is There a Time Limit on Executing Redis Commands? What Will Happen If a Command Times Out?
- Can I Configure Redis Keys to Be Case-Insensitive?
- Can I View the Most Frequently Used Redis Commands?
- Common Web CLI Errors
-
Instance Scaling and Upgrade
- Can DCS Redis Instances Be Upgraded, for Example, from Redis 4.0 to 5.0?
- Are Services Interrupted If Maintenance is Performed During the Maintenance Time Window?
- Are Instances Stopped or Restarted During Specification Modification?
- Are Services Interrupted During Specification Modification?
- Why Can't I Modify Specifications for a DCS Redis/Memcached Instance?
- How Do I Reduce the Capacity of a DCS Instance?
- How Do I Handle an Error When I Use Lettuce to Connect to a Redis Cluster Instance After Specification Modification?
-
Monitoring and Alarm
- How Do I View Current Concurrent Connections and Maximum Connections of a DCS Redis Instance?
- Does Redis Support Command Audits?
- What Should I Do If the Monitoring Data of a DCS Redis Instance Is Abnormal?
- Why Is Available Memory of Unused DCS Instances Less Than Total Memory and Why Is Memory Usage of Unused DCS Instances Greater Than Zero?
- Why Is Used Memory Greater Than Available Memory?
- Why Does Bandwidth Usage Exceed 100%?
- Why Is the Rejected Connections Metric Displayed?
- Why Is Flow Control Triggered? How Do I Handle It?
-
Data Backup, Export, and Migration
- How Do I Export DCS Redis Instance Data?
- Can I Export Backup Data of DCS Redis Instances to RDB Files Using the Console?
- Why Are Processes Frequently Killed During Data Migration?
- Is All Data in a DCS Redis Instance Migrated During Online Migration?
- Do DCS Redis Instances Support Data Persistence? What Is the Impact of Persistence?
- When Will AOF Rewrites Be Triggered?
- Can I Migrate Data to Multiple Target Instances in One Migration Task?
- How Do I Enable the SYNC and PSYNC Commands?
- Will the Same Keys Be Overwritten During Data Migration or Backup Import?
- Online Migration with Rump
- What Should I Consider When Transferring or Operating Data Between Different OSs?
- Can I Migrate Data from a Multi-DB Source Redis Instance to a Cluster DCS Redis Instance?
- How Can I Migrate Partial Data?
- What Are the Constraints and Precautions for Migrating Redis Data to a Cluster Instance?
- What Should I Consider for Online Migration?
- Can I Perform Online Migration Without Any Service Interruption?
- What If "Disconnecting timedout slave" and "overcoming of output buffer limits" Are Reported on the Source Instance During Online Migration?
- Why Is Memory of a DCS Redis Instance Unchanged After Data Migration Using Rump, Even If No Error Message Is Returned?
- Can I Migrate Data from a Lower Redis Version to a Higher One?
- How Do I Migrate Memcached Data?
- Big/Hot Key Analysis
- Master/Standby Switchover
-
Memcached Usage
- Can I Dump DCS Memcached Instance Data for Analysis?
- What Memcached Version Is Compatible with DCS for Memcached?
- What Data Structures Does DCS for Memcached Support?
- Does DCS for Memcached Support Public Access?
- Can I Modify Configuration Parameters of DCS Memcached Instances?
- What Are the Differences Between DCS for Memcached and Self-Hosted Memcached?
- What Policies Does DCS for Memcached Use to Deal with Expired Data?
- How Should I Select AZs When Creating a DCS Memcached Instance?
- Troubleshooting
- Change History
-
Service Overview
- API Reference (Kuala Lumpur Region)
-
API Reference (Ankara Region)
- Before You Start
- API Overview
- Calling APIs
-
APIs V2 (Recommended)
- Lifecycle Management
- Instance Management
- Shards and Replicas
- Parameter Management
- Backup and Restoration
-
Data Migration
- Creating a Backup Import Task
- Listing Migration Tasks
- Deleting Data Migration Tasks
- Querying Details of a Data Migration Task
- Stopping a Data Migration Task
- Querying the Progress of an Online Migration Task
- Creating an Online Data Migration Task
- Configuring an Online Data Migration Task
- Stopping Data Migration Tasks
- Log Management
- Background Task Management
- Other APIs
- Outdated APIs (V1)
- Permissions Policies and Supported Actions
- Appendix
-
User Guide (Ankara Region)
- Service Overview
-
Getting Started
- Creating an Instance
-
Accessing an Instance
- Network Conditions for Accessing DCS Redis
- Accessing a DCS Redis Instance Through redis-cli
- Access in Different Languages
- Accessing a DCS Redis Instance on the Console
- Viewing Details of a DCS Instance
-
User Guide
- Permissions Management
- Operating DCS Instances
-
Managing DCS Instances
- Configuration Notice
- Modifying Configuration Parameters
- Modifying Maintenance Time Window
- Modifying the Security Group
- Viewing Background Tasks
- Viewing Data Storage Statistics of a DCS Redis 3.0 Proxy Cluster Instance
- Managing Shards and Replicas
- Analyzing Big Keys and Hot Keys
- Scanning and Deleting Expired Keys in a DCS Redis Instance
- Managing IP Address Whitelist
- Viewing Redis Run Logs
- Diagnosing an Instance
- Backing Up and Restoring DCS Instances
- Migrating Data with DCS
- Managing Passwords
- Monitoring
- Best Practices
-
FAQs
- Instance Types/Versions
-
Client and Network Connection
- Security Group Configurations
- Does DCS Support Access at EIPs?
- Does DCS Support Cross-VPC Access?
- What Should I Do If Access to DCS Fails After Server Disconnects?
- Why Do Requests Sometimes Time Out in Clients?
- What Should I Do If an Error Is Returned When I Use the Jedis Connection Pool?
- Why Is "ERR unknown command" Displayed When I Access a DCS Redis Instance Through a Redis Client?
- How Do I Access a DCS Redis Instance Through Redis Desktop Manager?
- What If "ERR Unsupported CONFIG subcommand" is Displayed in SpringCloud?
- How Do I Troubleshoot Redis Connection Failures?
- What Should Be Noted When Using Redis for Pub/Sub?
- Should I Use a Domain Name or an IP Address to Connect to a DCS Redis Instance?
-
Redis Usage
- Why Is CPU Usage of a DCS Redis Instance 100%?
- Can I Change the VPC and Subnet for a DCS Redis Instance?
- Why Aren't Security Groups Configured for DCS Redis 4.0 and Later Instances?
- Do DCS Redis Instances Limit the Size of a Key or Value?
- Can I Obtain the Addresses of the Nodes in a Cluster DCS Redis Instance?
- Why Is Available Memory Smaller Than Instance Cache Size?
- Does DCS for Redis Support Multiple Databases?
- Does DCS for Redis Support Redis Clusters?
- Does DCS for Redis Support Sentinel?
- What Is the Default Data Eviction Policy?
- What Should I Do If an Error Occurs in Redis Exporter?
- Why Is Redisson Distributed Lock Not Supported by DCS Proxy Cluster Redis 3.0 Instances?
- Can I Customize or Change the Port for Accessing a DCS Instance?
- Can I Modify the Connection Addresses for Accessing a DCS Instance?
- Does DCS Support Cross-AZ Deployment?
- Why Does It Take a Long Time to Start a Cluster DCS Instance?
- What If Redis Commands Are Incompatible with DCS for Redis?
- Does DCS for Redis Provide Backend Management Software?
- Why Is Memory of a DCS Redis Instance Used Up by Just a Few Keys?
- Can I Recover Data from Deleted DCS Instances?
- Why Is "Error in execution" Returned When I Access Redis?
-
Redis Commands
- How Do I Clear Redis Data?
- How Do I Disable High-Risk Commands?
- Does DCS for Redis Support Pipelining?
- Does DCS for Redis Support the INCR and EXPIRE Commands?
- Why Do I Fail to Execute Some Redis Commands?
- Why Does a Redis Command Fail to Take Effect?
- Is There a Time Limit on Executing Redis Commands? What Will Happen If a Command Times Out?
-
Instance Scaling and Upgrade
- Can DCS Redis Instances Be Upgraded, for Example, from Redis 4.0 to 5.0?
- Are Services Interrupted If Maintenance is Performed During the Maintenance Time Window?
- Are Instances Stopped or Restarted During Specification Modification?
- Are Services Interrupted During Specification Modification?
- Why Can't I Modify Specifications for a DCS Redis Instance?
-
Monitoring and Alarm
- Does Redis Support Command Audits?
- What Should I Do If the Monitoring Data of a DCS Redis Instance Is Abnormal?
- Why Is Available Memory of Unused DCS Instances Less Than Total Memory and Why Is Memory Usage of Unused DCS Instances Greater Than Zero?
- Why Is Used Memory Greater Than Available Memory?
- Why Is Flow Control Triggered? How Do I Handle It?
-
Data Backup, Export, and Migration
- How Do I Export DCS Redis Instance Data?
- Can I Export Backup Data of DCS Redis Instances to RDB Files Using the Console?
- Why Are Processes Frequently Killed During Data Migration?
- Is All Data in a DCS Redis Instance Migrated During Online Migration?
- Do DCS Redis Instances Support Data Persistence? What Is the Impact of Persistence?
- When Will AOF Rewrites Be Triggered?
- Online Migration with Rump
-
Big/Hot Key Analysis and Expired Key Scan
- What Are Big Keys and Hot Keys?
- What Is the Impact of Big Keys or Hot Keys?
- How Do I Avoid Big Keys and Hot Keys?
- How Do I Analyze the Hot Keys of a DCS Redis 3.0 Instance?
- How Do I Detect Big Keys and Hot Keys in Advance?
- How Does DCS Delete Expired Keys?
- How Long Are Keys Stored? How Do I Set Key Expiration?
- Master/Standby Switchover
-
User Guide (ME-Abu Dhabi Region)
- General Reference
Copied.
DCS Data Security
Security is a shared responsibility between Huawei Cloud and you. Huawei Cloud is responsible for the security of cloud services to provide a secure cloud. As a tenant, you should properly use the security capabilities provided by cloud services to protect data, and securely use the cloud. For details, see Shared Responsibilities.
This section provides actionable guidance for enhancing the overall security of using DCS. You can continuously evaluate the security status of your DCS resources, enhance their overall security defense by combining multiple security capabilities provided by DCS, and protect data stored in DCS from leakage and tampering both at rest and in transit.
Make security configurations from the following dimensions to meet your service needs.
- Protecting Data Through Access Control
- Encrypting Data Before Storage
- Data Restoration and Disaster Recovery
- Transmission Encryption with SSL
- Checking for Abnormal Data Access
- Using the Latest SDKs for Better Experience and Security
- Using Other Cloud Services for Additional Data Security
Protecting Data Through Access Control
Correctly use the access control capability provided by DCS to prevent your data from being stolen or damaged.
- Set only the minimum permissions for IAM users with different roles to prevent data leakage or misoperations caused by excessive permissions.
To better isolate and manage permissions, you are advised to configure an independent IAM administrator and grant them the permission to manage IAM policies. The IAM administrator can create different user groups based on your service requirements. User groups correspond to different data access scenarios. By adding users to user groups and binding IAM policies to user groups, the IAM administrator can grant different data access permissions to employees in different departments based on the principle of least privilege. For details, see Permissions Management.
- Configure a whitelist or security group to protect your data from abnormal reads or other operations.
By configuring an IP address whitelist or inbound and outbound security group rules, you can control the network range for connecting to your instance and prevent exposure to untrusted third parties.
DCS Redis 4.0/5.0/6.0 basic edition instances are controlled by whitelists. For details, see Managing IP Address Whitelist.
DCS Redis 6.0 professional instances are controlled by security group rules. For details, see How Do I Configure a Security Group? Do not set the source to 0.0.0.0/0 in the inbound rules of a security group.
- Do not use high-risk commands, to prevent attackers from directly damaging Redis.
You can rename high-risk commands to disable them if they are not used in your service. Learn more about disabled commands and commands that can be renamed.
- Use a non-default port to prevent scanning attacks.
The default listening port of the Redis server is 6379, which is vulnerable to scanning attacks. You can use a port in the range from 1 to 65535. For details, see Customizing a Port.
- Limit the maximum number of client connections to avoid resource exhaustion and DoS risks.
The maxclients parameter of Redis determines the maximum number of clients that can be concurrently connected to an instance. The default value is 10000, and the value can range from 1000 to 50000. Excess connection requests will be rejected.
Set a proper client connection limit based on your application scenario. For details about how to modify the maxclients parameter, see Modifying Configuration Parameters.
- Limit the idle time of Redis connections based on service requirements.
To prevent idle client connections from occupying resources for a long time, you can set the timeout parameter on the console. Client connections that remain idle for the period specified by this parameter will be closed. The default value of timeout is 0, indicating that the server does not proactively disconnect idle clients. The value ranges from 0 to 7200, in seconds.
You are not advised to set it to 0. For example, you can set it to 3,600 seconds. For details about how to modify the timeout parameter, see Modifying Configuration Parameters.
- Configure a password for accessing your DCS instance to prevent unauthorized clients from operating it by mistake. In this way, clients can be authenticated for access, improving instance security.
You can set a password when buying an instance, or reset the password of an existing instance.
- Use different DCS instances for different services to prevent instance faults from affecting multiple services.
Encrypting Data Before Storage
RDB and AOF persistent files in open-source Redis do not support encryption. Therefore, DCS does not support data encryption. If you have sensitive data, please encrypt it before writing it to DCS.
Data Restoration and Disaster Recovery
Build restoration and disaster recovery (DR) capabilities in advance to prevent data from being deleted or damaged by mistake in abnormal data processing scenarios.
- Enable automated instance backup to quickly restore data in abnormal scenarios.
DCS instances can be backed up automatically or manually. The automated backup function is disabled by default. After it is enabled, you can restore backup data to the instance. Backup data of an instance is stored for a maximum of 7 days. For details about automated backup, see Configuring a Backup Policy.
Manual backups are user-initiated full backups of instances. The backup data is stored in Huawei Cloud OBS buckets and removed upon deletion of the corresponding instance.
- Use cross-AZ replication for data DR.
A master/standby or cluster DCS instance can be deployed within an AZ or across multiple AZs for HA. For cross-AZ deployment, DCS initiates and maintains data synchronization. High availability is achieved by having a standby node take over in the event that a failure occurs on the master node. When operations are read-heavy, you can use DCS Redis 4.0 or later instances that support read/write splitting, or cluster instances that have multiple replicas. DCS maintains data synchronization between the master and replicas. You can connect to different addresses of an instance to isolate read and write operations.
For cross-AZ deployment, DCS initiates and maintains data synchronization. High availability is achieved by having a standby node take over in the event that a failure occurs on the master node.
Transmission Encryption with SSL
To prevent data from being stolen or damaged during transmission, use SSL encryption to access DCS.
Currently, only DCS for Redis 6.0 basic edition supports SSL encryption. You are advised to use DCS Redis 6.0 basic edition instances and enable SSL for them.
Checking for Abnormal Data Access
- Enable Cloud Trace Service (CTS) to record all DCS access operations for future audit.
CTS records operations on the cloud resources in your account. You can use the logs generated by CTS to perform security analysis, track resource changes, audit compliance, and locate faults.
After you enable CTS and configure a tracker, CTS can record management and data traces of DCS for auditing. For details, see Viewing DCS Audit Logs .
- Use Cloud Eye for real-time monitoring and alarm reporting on security events.
When using DCS, you may encounter error responses from the server. Huawei Cloud provides the Cloud Eye service to automatically monitor your DCS instances in real time, generate alarms, and send notifications, so that you can learn about the requests, traffic, and error responses of your DCS instances in real time.
Cloud Eye is enabled automatically after you create a DCS instance. For details, see DCS Metrics and Configuring DCS Monitoring and Alarms.
Using the Latest SDKs for Better Experience and Security
Upgrade SDKs to the latest version to better protect your data and DCS usage. Download the latest SDK in your desired language from SDK Overview.
Using Other Cloud Services for Additional Data Security
Ensuring DCS resource security using SecMaster
SecMaster provides you with built-in checks that are included in Cloud Security Compliance Check 1.0, DJCP 2.0 Level 3 Requirements, and Network Security, to check key configurations of DCS, generate alarms for configurations with security risks, and provide hardening suggestions and guidelines. You can use the resource management function of SecMaster to quickly learn about the DCS security status and locate security risks. For details, see Baseline Inspection Overview.
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot