Product Functions

This section describes main functions of DCS. You can check if a certain function is available in a region on the console.

Backup and Restoration

Data in DCS instances can be backed up to Object Storage Service (OBS). If a DCS instance becomes faulty, data in the instance can be restored from the backup, so that service continuity is not affected.

Both automatic backup and manual backup are supported. For details, see Backing Up or Restoring Instance Data.

Only the data of master/standby, cluster, and read/write splitting DCS Redis instances can be backed up and restored, while those of single-node instances cannot.

Run Logs

You can create run log files on the DCS console to collect run logs of DCS Redis 4.0 and later instances within a specified time range. After the logs are collected, you can download the log files to view the logs. For details, see Viewing Redis Run Logs.

Cache Analysis

By performing big key analysis and hot key analysis, you will have a picture of keys that occupy a large space and those that are frequently accessed. For details, see Querying Big Keys and Hot Keys in a DCS Redis Instance.

DCS provides the expired key scan function. The entire keyspace of an instance can be traversed and expired keys can be scanned and released. For details, see Scanning and Deleting Expired Keys in a DCS Redis Instance.

Slow Queries

Redis logs queries that exceed a specified execution time. You can view slow query logs on the DCS console to identify performance issues. For details, see Viewing Slow Queries of a DCS Redis Instance.

Instance Diagnosis

If a fault or performance issue occurs, you can use DCS to diagnose your instance to learn about the cause and impact of the issue and how to handle it. For details, see Diagnosing a DCS Redis Instance.

Public Access

You can access a DCS instance over a public network using the instance public IP address. DCS has the following restrictions on public access:

Only password-protected DCS Redis 3.0 instances support public access. You can enable or disable SSL for public access. You are advised to download a CA certificate in advance and use it to verify the certificate of a DCS instance for security purposes. For more information, see Public Access to a DCS Redis 3.0 Instance (Discontinued).

DCS Redis 4.0 or later instances do not support direct public network binding. Instead, single-node, master/standby, read/write splitting, and Proxy Cluster password-protected instances support public access through ELB. Redis Cluster instances do not support public access. For details, see Enabling Public Access to Redis and Obtaining the Access Addresses.

Security Groups and Whitelists

You can use security groups or whitelists to control access to your DCS instances. Only clients that meet the requirements can access your DCS instances.

DCS helps you control access to your DCS instances in the following ways, depending on the deployment mode:

To control access to DCS Redis 3.0 and 6.0 enterprise edition instances, you can use security groups. Whitelists are not supported. For details, see How Do I Configure a Security Group?.
To control access to DCS Redis 4.0 and later basic edition instances, you can use whitelists. Security groups are not supported. For details, see Configuring DCS Redis Access Whitelist.

Modifying Specifications

You can modify the specifications of a DCS Redis instance to meet changing service requirements. In addition to the cache capacity, you can also change the instance type of some instances.

For example, you can change a master/standby DCS Redis 5.0 instance to a Proxy Cluster instance with another cache size. For details, see Modifying DCS Instance Specifications.

Adjusting Instance Bandwidth

When instance bandwidth is insufficient, you can adjust it on the console. For details, see Adjusting DCS Instance Bandwidth.

Renaming Critical Commands

Certain critical commands can be modified for DCS Redis instances. Once a command is modified, it is only known to the modifier. Running the original command by other users is blocked. For details, see Renaming Critical Commands for DCS Instances.

Read/Write Splitting

Huawei Cloud DCS for Redis provides read/write splitting to meet high-concurrency read/write requirements. Learn whether read/write splitting is supported for an instance, see Does DCS for Redis Support Read/Write Splitting?. To implement read/write splitting, you are advised to use a read/write splitting instance to free your client from any configuration.

Cross-Region Multi-Active

Currently, DCS does not support cross-region multi-active because Redis does not have a mature active-active solution. Active-active is different from disaster recovery or master/standby high availability.

Redis active-active across clouds or regions cannot be achieved because the customized REdis Serialization Protocols (RESP) are not unified. If active-active is required, it can be implemented through dual-write on the application end. For details, see Disaster Recovery and Multi-Active Solution.

Data Migration Guide

DCS for Redis provides the following two migration modes:

Importing data from backup files: Download the source Redis data and then upload the data to an OBS bucket in the same region as the destination DCS Redis instance. DCS will read the backup data from the OBS bucket and migrate the data into the destination instance. This migration mode can be used for migrating data from other Redis vendors or self-hosted Redis to HUAWEI CLOUD DCS for Redis.
Migrating data online: If the source and destination instances are interconnected and the SYNC and PSYNC commands are supported in the source instance, data can be migrated online in full or incrementally from the source to the destination.

For details, see Migrating Instance Data.

Monitoring

Monitoring is key to ensuring DCS instance reliability, availability, and performance, and determining instance resource usage. Cloud Eye is a monitoring service that can capture the running status of your DCS instances. You can use Cloud Eye to automatically monitor DCS instances in real time and manage alarms and notifications, so that you can keep track of DCS performance metrics. For details, see Viewing Monitoring Metrics and Configuring Alarms.

Auditing

Cloud Trace Service (CTS) records operations on your cloud resources, allowing you to query, audit, and backtrack resource operation requests initiated from the console or open APIs as well as responses to these requests. For details, see Viewing DCS Audit Logs.