Release notes for ApsaraDB for Redis Enhanced Edition (Tair) minor versions - Tair (Redis® OSS-Compatible)

Alibaba Cloud releases minor versions of Tair from time to time to provide new features, fix known issues, and improve user experience. This topic describes the release notes for minor versions of Tair. We recommend that you update minor versions of instances during off-peak hours.

View or update the minor version of an instance

You can view the current minor version of an instance in the console. For information about the update operations and usage notes, see Update the minor version of an instance.

Important

The system automatically detects the minor version of an instance. If the instance is of the latest minor version, the Minor Version Update button is not displayed or is dimmed.
Minor version updates may differ from region to region. The minor version of an instance displayed in the console prevails.

Introduction to ApsaraDB for Redis Enhanced Edition (Tair)

The rapid development of the Internet makes business scenarios more diverse and complex. To meet the changing requirements, ApsaraDB for Redis Enhanced Edition (Tair), as a high-availability and high-performance NoSQL database service, provides multiple series types of instances based on storage mediums such as DRAM, NVM, and ESSDs. These series types are developed to meet your requirements for low-latency access, data persistence, and reduced overall costs, and provide higher performance, more data structures, and more flexible storage methods. This helps you meet business requirements in different scenarios.

Tair instance series are compatible with multiple open source Redis versions.

Tair DRAM-based instances that are compatible with Redis 7.0: Redis 7.0 and earlier. In addition, this instance series supports the extended data structures of Tair.
Tair DRAM-based instances that are compatible with Redis 6.0: Redis 6.2 and earlier. In addition, this instance series supports the extended data structures of Tair.
Tair DRAM-based instances that are compatible with Redis 5.0: Redis 5.0 and earlier. In addition, this instance series supports the extended data structures of Tair.
Tair persistent memory-optimized instances: Redis 6.0 and earlier. This instance series has limits on specific commands. For more information, see Limits on commands supported by Tair.
Tair ESSD/SSD-based instances: Redis 6.0 and earlier. This instance series has limits on specific commands. For more information, see Limits on commands supported by Tair.

Update levels

LOW: regular updates. LOW-level updates include routine feature updates, such as adding a feature.
MEDIUM: recommended updates. MEDIUM-level updates include optimization of features and modules. LOW-level updates are also included in MEDIUM-level updates.
HIGH: major updates. HIGH-level updates include major updates that ensure stability or security, such as fixing a vulnerability or defect. LOW-level and MEDIUM-level updates are also included in HIGH-level updates.

Tair DRAM-based instances

Redis 7.0-compatible DRAM-based instances

Minor version	Update level	Release date	Category	Description
24.7.0.0	LOW	2024-07-22	New feature	DRAM-based instances of minor version 24.7.0.0 are available. These instances are compatible with Redis 7.0 and support all self-developed data structures of Tair.

Redis 6.0-compatible DRAM-based instances

Minor version	Update level	Release date	Category	Description
24.7.0.0	LOW	2024-07-22	Feature optimization	TairVector supports the use of Hierarchical Navigable Small World (HNSW) indexes in sparse vectors. The ts-auto-del-empty-skey-enable parameter is added to control the expiration behavior of skeys in TairTS. The default value of this parameter is yes, which indicates that an skey is deleted when all data points in the skey expire. Stability is enhanced.
24.6.1.1	LOW	2024-07-09	Feature optimization	The stability of TairSearch is enhanced.
24.6.1.0	LOW	2024-07-05	New feature	The JSON.MERGE command is supported for TairDoc.
24.6.1.0	LOW	2024-07-05	Feature optimization	The stability of TairVector is enhanced.
24.6.0.0	LOW	2024-07-02	Feature optimization	The stability of data synchronization between master and replica nodes in high-volume traffic scenarios is enhanced.
24.5.1.0	MEDIUM	2024-06-06	Feature optimization	The usage limits on the COMMAND GETKEYS command are removed. The memory usage of FLAT vector indexes in TairVector is optimized to reduce the memory waste of small indexes. Inverted indexes such as Within and Condition in TairVector are optimized, and the TVS.KNNSEARCHFIELD and TVS.MINDEXKNNSEARCHFIELD commands are added. The field_type field is added to the returned aux_info information when the TFT.MSEARCH command in TairSearch sorts data by index field.
24.5.1.0	MEDIUM	2024-06-06	Fixed issue	The write performance issue of TairVector is fixed. This issue is introduced in 24.3.2.2. Starting from 24.3.2.2, the write performance of TairVector begins to degrade. We recommend that you update the minor version of your instance to 24.5.1.0 or later. Specific issues related to TairSearch are fixed to enhance stability.
24.5.0.0	MEDIUM	2024-05-22	Feature optimization	Cross-slot command synchronization in master-replica mode is optimized. The BGREWRITE command can be run in the background more quickly for large instances. The INFO command returns the CPU utilization, queries per second (QPS), and traffic information on a per-command basis.
24.5.0.0	MEDIUM	2024-05-22	Fixed issue	Stability is enhanced.
24.4.1.0	MEDIUM	2024-04-22	Feature optimization	Arbitrary rollback to previous synchronization points is supported after a Data Transmission Service (DTS) task is restarted. If your instance consistently requires DTS tasks for data synchronization, we recommend that you update the minor version of the instance to 24.4.1.0.
24.4.0.0	MEDIUM	2024-04-16	Feature optimization	The memory footprint of core data structures is optimized to reduce memory usage when a small number of complex structural elements exist. The performance of TairVector in combined full-text and scalar search is optimized. As with single-index searches, TairVector can now return non-vector fields during multi-index searches.
24.4.0.0	MEDIUM	2024-04-16	Fixed issue	Stability is enhanced.
24.3.2.2	MEDIUM	2024-03-21	Feature optimization	The engine metadata overhead on standard master-replica instances is reduced.
24.3.2.2	MEDIUM	2024-03-21	Fixed issue	Stability is enhanced.
24.3.2.1	MEDIUM	2024-03-18	Feature optimization	The capability of TairVector to perform scalar filtering before vector similarity search is enhanced. The way in which scalar indexes are stored in TairVector is optimized. This optimization allows TairVector to handle duplicate scalar index values in a more efficient manner. In addition, the maximum length of index values is increased to 32 KB. TairVector is also optimized to return results for queries that use inverted indexes to match scalar values.
24.3.2.1	MEDIUM	2024-03-18	Fixed issue	The following issue is fixed: The attribute_data_size and index_data_size statistics calculated by the TVS.GETINDEX interface in TairVector are incorrect. The following issue is fixed: The output of the XINFO command includes an extra level of indentation. The following issue is fixed: The number of keys returned by the SCAN command may be significantly greater than the provided Count value. This issue is introduced in 24.3.0.0.
24.3.1.0	LOW	2024-03-11	Feature optimization	Metadata is not immediately created after the SELECT command for switching between multiple databases is run. Databases and their metadata are created when data is read from or written to the databases. This optimization aims to prevent metadata bloat caused by Redis management tools that iterate through all databases. The efficiency of expiration check on an instance that has multiple databases is improved. The system proportionally distributes tasks to delete expired data across the databases based on the amount of expired data in each database.
24.3.0.0	MEDIUM	2024-03-07	Feature optimization	An instance can be rolled back within seconds when the configurations of the instance fail to be changed. This prevents the instance from becoming unavailable due to a failed configuration change. Note However, metadata consumes a large amount of memory when a large number of logical databases are used. If this issue occurs, update the minor version of your instance to 24.3.2.2 or later. This issue is fixed in these minor versions. The SWAPDB, COPY, and MOVE commands can be run on a cluster instance to manage data across different databases in the instance.
24.3.0.0	MEDIUM	2024-03-07	Fixed issue	The following issue is fixed: If the LIMIT option in the ZRANGEBYSCORE command is set to an excessively large value, an out of memory (OOM) error may occur due to the pre-allocation of a large amount of memory in the database.
24.1.0.0	MEDIUM	2024-01-23	Feature optimization	TairVector allows you to create inverted indexes for scalar data such as tag attributes, and provides the k-nearest neighbor (KNN) search feature. During retrieval, TairVector filters the dataset based on the scalar attributes and then applies the KNN algorithm for vector search on the filtered results.
24.1.0.0	MEDIUM	2024-01-23	Fixed issue	The following issue is fixed: An instance may stop responding when the GETDEL command does not run as expected. The following issue is fixed: The last-entry information is incorrect in the output of the XINFO STREAM command. Specific issues related to TairVector are fixed to enhance stability.
23.12.2.0	LOW	2023-12-26	New feature	The semi-synchronous replication mode (semisync) is supported. You can use the #no_loose_tsync-repl-mode parameter to enable or disable this feature. The feature is in the proof of concept (POC) stage. Exercise caution when you enable the feature in a production environment.
23.12.1.2	MEDIUM	2023-12-21	Feature optimization	Improvements are made to enhance write performance in specific scenarios. We recommend that you update your instance to this minor version. The EXPAINSCORE command is supported for TairSearch.
23.12.1.2	MEDIUM	2023-12-21	Fixed issue	Multiple Common Vulnerabilities and Exposures (CVE) fixes related to Lua scripts from the Redis community are incorporated. Specific issues related to TairSearch and TairVector are fixed. Several stability issues are addressed. We recommend that you update your instance to this minor version.
23.8.1.2	MEDIUM	2023-08-22	Feature optimization	Tair is optimized to reduce the CPU utilization of instances during idle periods and improve the baseline performance of instances. The CPU utilization metric in CloudDBA is standardized. Statistics about master-replica replication traffic can be separately displayed in the output of the INFO STATS command.
23.8.1.2	MEDIUM	2023-08-22	Fixed issue	Specific issues related to TairVector are fixed.
23.8.0.0	MEDIUM	2023-08-03	New feature	TLS encryption is fully supported for Tair. TairVector allows you to set a time-to-live (TTL) for keys within indexes, perform vector nearest-neighbor queries on specified keys, and perform full-text search. TairVector also supports hybrid search that combines vector search and full-text search.
			Feature optimization	The overall performance of Tair is optimized to enhance stability. The EXZRANKBYSCORE command is supported for TairZset. The commands of TairDoc are optimized to match the commands in the official TairDoc documentation. The performance of the GETBIT, BITPOS, and BITCOUNT commands is optimized.
			Fixed issue	Specific issues related to TairSearch and TairVector are fixed.
6.2.8.4	MEDIUM	2023-07-13	Fixed issue	The following issue is fixed: TairVector filters have a low probability of causing instance crashes.
6.2.8.3	MEDIUM	2023-07-12	Feature optimization	The performance of TairVector filters is optimized to reduce the execution time.
6.2.8.2	MEDIUM	2023-07-04	Feature optimization	The stability of automatic memory space reclamation of HNSW indexes in TairVector is enhanced.
6.2.8.1	MEDIUM	2023-07-02	Fixed issue	The following issue is fixed: The replica node crashes because the involved key has expired when the RENAME command that is run on the master node is synchronized to the replica node.
6.2.8.0	MEDIUM	2023-07-01	New feature	The automatic memory space reclamation of HNSW indexes is supported for TairVector.
6.2.8.0	MEDIUM	2023-07-01	Fixed issue	The issue concerning the WAIT command that may cause crashes in cluster instances is fixed. The following issue is fixed: The NOSCRIPT error occasionally occurs when the EVALSHA command is run from different clients following the SCRIPT LOAD command.
6.2.7.3	MEDIUM	2023-06-12	Feature optimization	The performance of the backup processes that run in the background is optimized to improve the backup speed.
6.2.7.2	MEDIUM	2023-06-12	New feature	Documents of the ARRAY data type and the similarity ranking algorithm Okapi BM25 are supported for TairSearch.
			Feature optimization	The memory usage of the dictionary data structure is optimized.
			Fixed issue	The issue concerning the word matching of the pattern tokenizer in TairSearch is fixed to enhance the stability of the tokenizer.
6.2.6.9	LOW	2023-05-09	Feature optimization	Stability is enhanced.
6.2.6.8	MEDIUM	2023-04-28	Fixed issue	The issue concerning scale-out tasks that cannot end as expected in specific conditions is fixed.
6.2.6.7	LOW	2023-04-22	Feature optimization	The ROLE command can be run by a standard user.
6.2.6.6	LOW	2023-04-20	Feature optimization	The stability of TairSearch is enhanced.
6.2.6.5	MEDIUM	2023-04-17	Feature optimization	The logic and stability of TairSearch are optimized.
6.2.6.5	MEDIUM	2023-04-17	Fixed issue	The issue concerning incorrect listen addresses that are displayed in a client list is fixed.
6.2.6.2	HIGH	2023-04-12	Security hardening	The minor version is integrated with the open source Redis version that has recent CVEs fixed. The security and stability are enhanced.
6.2.5.3	LOW	2023-03-20	Fixed issue	The issue concerning storage exceptions in TairSearch is fixed.
6.2.5.2	LOW	2023-03-17	Feature optimization	The master-replica synchronization logic is optimized in exceptional scenarios where TairSearch is used.
6.2.5.2	LOW	2023-03-17	Fixed issue	The issue that integers are not supported for DOUBLE-type fields in TairSearch is fixed.
6.2.5.0	HIGH	2023-03-14	Feature optimization	TairString is optimized to reduce the memory usage of a key by 8 bytes. TairSearch is optimized to store compressed documents and support the TFT.ANALYZER command that is used to view the effects of analyzers.
6.2.5.0	HIGH	2023-03-14	Fixed issue	The issue that causes TairSearch to produce inaccurate statistics about memory is fixed. The issue that may cause wake-up failures on the blocked clients is fixed. The issue that may cause the XINFO command to return incompatible outputs in specific cases is fixed.
6.2.4.7	HIGH	2023-03-03	Fixed issue	The high-availability performance is optimized when pipelined requests accumulate.
6.2.4.6	LOW	2023-03-02	Feature optimization	Read replicas can be specified to handle read-only requests such as `EVAL` and `EVALSHA` by using the readonly_lua_route_ronode_enable parameter.
6.2.4.3	HIGH	2023-02-14	Feature optimization	TairString is optimized to use the latest encoding format to save memory.
6.2.4.3	HIGH	2023-02-14	Fixed issue	The following issue is fixed: Synchronization of probabilistic data does not end when you change the number of data shards for a cluster instance.
6.2.4.1	LOW	2023-02-07	New feature	TairSearch is supported. The full JSONPath syntax is supported for the JSON.GET command in TairDoc.
6.2.3.2	HIGH	2023-01-13	Fixed issue	The issue concerning slow deletion of expired data from cluster instances after the number of data shards is changed is fixed.
6.2.3.1	LOW	2023-01-04	Feature optimization	The stability and high availability of read/write splitting instances are enhanced.
6.2.3.0	LOW	2022-12-26	Feature optimization	TairVector is supported for cluster instances in proxy mode. In addition, the FLOAT16 data type and queries with multiple vector indexes are supported.
6.2.2.0	LOW	2022-11-22	Feature optimization	The Jaccard distance formula is supported for TairVector. The `index_data_size` and `attribute_data_size` parameters can be used in TairVector to calculate the memory usage of each index.
6.2.1.5	LOW	2022-11-14	Feature optimization	The issues related to the use of blocking APIs are fixed to enhance service stability.
6.2.1.3	LOW	2022-10-28	Feature optimization	The stability of TairVector is enhanced.
6.2.1.2	LOW	2022-10-14	Feature optimization	The stability of TairVector is enhanced.
6.2.1.1	LOW	2022-10-13	First release	DRAM-based instances of minor version 6.2.1.1 are available. These instances are compatible with Redis 6.2 and self-developed data modules of Tair (except for TairSearch). Slow queries that involve the KEYS, SMEMBERS, HGETALL, or EXHGETALL command can be identified and isolated. Performance is optimized. Compared with commands that run on Redis Open-Source Edition instances, such as Pub/Sub commands and Lua commands, commands that run on Tair DRAM-based instances of version 6.2.1.1 and have the same specifications provide twice the performance. TairVector is released. TairVector is a self-developed vector search data module that supports the HNSW and Flat Search indexing algorithms. The module provides high-performance real-time vector database service that combines storage and search capabilities.

Redis 5.0-compatible DRAM-based instances

Minor version	Update level	Release date	Category	Description
5.0.52	LOW	2024-06-25	Feature optimization	The execution efficiency of Pub/Sub commands is optimized to prevent stuttering that occurs when a large number of users unsubscribe from channels at the same time. The client polling mechanism is optimized to prevent a failure to promptly collect memory statistics and reclaim unused memory for long-lived connections. The method used by child processes to save Redis Database (RDB) files and append-only files (AOFs) to disks is optimized.
5.0.51	LOW	2024-05-28	Feature optimization	Stability is enhanced.
5.0.50	LOW	2024-05-28	Feature optimization	Monitoring of watched or blocked connections is enhanced. Rehashing-related metrics are added. The real-time hotkey statistics feature is upgraded in several aspects. For example, the exact queries per second (QPS) of a hotkey can be displayed, and statistics about up to 50 hotkeys can be collected at the same time.
5.0.50	LOW	2024-05-28	Fixed issue	The following issue is fixed: Collected QPS statistics are incorrect due to the use of shared objects. Shared objects are no longer used after the real-time hotkey statistics feature is enabled.
5.0.49	MEDIUM	2024-04-24	Feature optimization	The INFO STATS command is optimized to include statistics about disconnections caused by exceeding client buffer limits: client_query_buffer_limit_disconnections client_output_buffer_limit_disconnections The threshold for real-time collection of statistics about large keys is added. The default value is 2000. For example, if a key of the STRING type is 2,000 characters in length, the key is considered a large key. If the number of elements in a key of the LIST, SET, or HASH type exceeds 2,000, the key is considered a large key.
5.0.49	MEDIUM	2024-04-24	Fixed issue	The issue that the EXZRANKBYSCORE and EXZREVRANKBYSCORE commands in exZset cause crashes is fixed by adding checks for the Score dimension.
5.0.48	LOW	2024-01-09	Feature optimization	The efficiency of active expiration is optimized. The pubsub_clients metric is added to the INFO CLIENTS command. The EXPAINSCORE command is supported for TairSearch. The stability of TairSearch is enhanced.
5.0.48	LOW	2024-01-09	Fixed issue	Memory bloat issues that are caused by TairSearch analyzers are fixed.
5.0.47	LOW	2023-10-18	Feature optimization	The issue that the CPU utilization reaches 100% in extreme scenarios is optimized.
5.0.46	LOW	2023-10-10	Feature optimization	Lua scripts in cluster instances are optimized to handle different connection types (TCP or TLS).
5.0.45	MEDIUM	2023-09-20	Feature optimization	The performance of CLUSTER SLOTS and CLUSTER NODES is optimized.
5.0.45	MEDIUM	2023-09-20	Fixed issue	The issue that TairHash occasionally crashes is fixed.
5.0.44	MEDIUM	2023-08-24	Feature optimization	Traffic can be split into data traffic and replication traffic.
5.0.44	MEDIUM	2023-08-24	Fixed issue	The CVE-2022-24834 security vulnerability is fixed.
5.0.41	LOW	2023-07-21	Feature optimization	The stability of TairSearch is enhanced.
5.0.35	LOW	2023-06-12	New feature	The similarity ranking algorithm Okapi BM25 is supported for TairSearch.
5.0.34	LOW	2023-05-22	Feature optimization	The stability of imperceptible scaling is enhanced.
5.0.33	LOW	2023-04-23	New feature	Documents of the ARRAY data type are supported for TairSearch. The stability of TairSearch is enhanced.
5.0.32	LOW	2023-03-31	Feature optimization	The TFT.EXPLAINCOST command is supported for TairSearch.
5.0.30	LOW	2023-03-20	Feature optimization	Stability is enhanced.
5.0.29	LOW	2023-03-16	Feature optimization	Stability is enhanced.
5.0.28	LOW	2023-03-15	Feature optimization	TairSearch is optimized to store compressed documents and support the TFT.ANALYZER command that is used to view the effects of analyzers.
5.0.27	HIGH	2023-02-15	Feature optimization	Statistics about hotkeys are regularly recorded in audit logs.
5.0.27	HIGH	2023-02-15	Fixed issue	The following issue is fixed: Cluster instances may crash during scaling operations after Global Distributed Cache is enabled.
5.0.25	LOW	2023-01-13	Feature optimization	Tokenizers are supported in TairSearch. For more information, see Search analyzers. The lowercase parameter is supported for term and terms queries in TairSearch.
5.0.22	MEDIUM	2022-11-02	Feature optimization	The IK and pattern tokenizers are supported for TairSearch. Stability is enhanced.
5.0.21	LOW	2022-11-02	Feature optimization	Stability is enhanced.
5.0.18	LOW	2022-09-29	Feature optimization	The stability of data parsing and persistence in TairSearch is enhanced. Query builder client pipelines are supported for TairSearch.
5.0.15	LOW	2022-08-29	Feature optimization	The MSEARCH feature is available for TairSearch. The stability of multi-threaded writes is enhanced for TairSearch. The stability of cluster instances is enhanced.
5.0.10	LOW	2022-07-28	Feature optimization	Stability is enhanced.
5.0.9	LOW	2022-07-27	Feature optimization	The stability of scaling child instances for a distributed instance is enhanced. The `sort` efficiency of TairSearch is improved. The sparse document query efficiency of TairSearch is improved. The account names are case-sensitive. Query optimizations for the KEYS command are removed to prevent unexpected behavior.
1.9.11	MEDIUM	2024-01-03	Fixed issue	The issues that TairTS fails to provide expected output under specific conditions is fixed.
1.9.9	MEDIUM	2023-03-23	Fixed issue	The issue that may cause incorrect data types in the output of the TR.GETBIT command in TairRoaring is fixed.
1.9.8	LOW	2023-03-16	Feature optimization	Stability is enhanced.
1.9.7	LOW	2022-12-26	Feature optimization	The stability of TairSearch is enhanced.
1.9.6	LOW	2022-11-02	Feature optimization	The stability of TairTS is enhanced.
1.9.4	LOW	2022-08-24	Feature optimization	The process of starting a cluster instance is optimized.
1.8.9	LOW	2022-06-07	Feature optimization	The service stability is improved for instances in direct connection mode.
1.8.8	LOW	2022-06-01	Feature optimization	TairSearch is updated to improve the efficiency of JOIN queries.
1.8.5	HIGH	2022-05-24	Security hardening	The configuration change stability is improved for cluster instances in the direct connection mode. The aggregation feature is supported in TairSearch to improve document write efficiency.
1.8.4	LOW	2022-05-17	Feature optimization	The stability and execution efficiency of TairSearch are improved.
1.8.3	LOW	2022-04-28	Feature optimization	The stability of TairTS is enhanced.
1.8.2	HIGH	2022-04-22	Security hardening	The following issue is fixed: The migration of large keys may fail during configuration changes of cluster instances in direct connection mode.
1.8.2	HIGH	2022-04-22	Feature optimization	The query efficiency of TairSearch is optimized.
1.8.1	LOW	2022-04-20	Feature optimization	TairRoaring V2.2 is released.
1.7.28	LOW	2022-03-24	Feature optimization	Statistics about Tair module commands can be collected and presented in latency histograms.
1.7.27	LOW	2022-03-11	Feature optimization	TairRoaring V2 is released. TairSearch is released.
1.7.20	MEDIUM	2022-01-04	Feature optimization	The performance of TairRoaring is optimized.
1.7.17	LOW	2021-11-29	Feature optimization	The following issue is fixed: Cluster instances may not be able to restart in specific scenarios. Note This feature optimization is supported only for DRAM-based cluster instances that use cloud disks.
1.7.16	LOW	2021-11-24	Feature optimization	The following issue is fixed: Statistics about the SPOP command are not collected when the real-time key analysis feature is enabled.
1.7.12	MEDIUM	2021-10-26	Feature optimization	The following issue is fixed to enhance stability: An excessive number of slow query logs are generated during configuration changes of cluster instances.
1.7.11	MEDIUM	2021-10-15	Feature optimization	TDE information can be included in the output of the INFO command. Stability is enhanced.
1.7.9	LOW	2021-10-13	Feature optimization	The autonomy capabilities in implementing imperceptible slot migration during configuration changes of cluster instances are enhanced.
1.7.8	MEDIUM	2021-09-26	Feature optimization	The ray casting algorithm is optimized for the TairGIS data structure to yield more precise search results when you run the GIS.CONTAINS command.
1.7.7	MEDIUM	2021-09-13	Feature optimization	TairRoaring is released. Stability is enhanced.
1.7.6	MEDIUM	2021-08-30	Feature optimization	Memory leaks that may occur during AOF rewrites are fixed. Statistics about QPS are classified. Three types of QPS can be calculated: read QPS, write QPS, and other QPS.
1.7.5	MEDIUM	2021-08-16	Feature optimization	The reliability and stability of imperceptible slot migration are enhanced.
1.7.4	HIGH	2021-08-11	Fixed issue	The following issue is fixed: Configuration changes may fail when the direct connection mode is enabled for cluster instances.
1.7.2	MEDIUM	2021-07-27	Feature optimization	Stability is enhanced.
1.7.1	MEDIUM	2021-07-20	New feature	TDE can be used to perform real-time I/O encryption and decryption on RDB files.
1.7.1	MEDIUM	2021-07-20	Feature optimization	The memory usage of TairHash is optimized.
1.6.15	MEDIUM	2021-07-12	Feature optimization	Stability is enhanced.
1.6.9	LOW	2021-06-22	New feature	Latency histograms are supported.
1.6.6	MEDIUM	2021-06-08	Feature optimization	Stability is enhanced.
1.6.3	LOW	2021-05-17	New feature	Specific functions of keys can be retained based on keys or key patterns when data is cleared. This feature can be used in the following scenarios: Restore specific keys or key patterns when point-in-time data restoration is performed by using the data flashback feature. Delete or retain the keyspace content based on keys or key patterns.
1.6.2	MEDIUM	2021-04-25	Feature optimization	The performance and migration speed during imperceptible scaling operations are optimized. Virtual IP addresses (VIPs) can be obtained over the Internet. This provides better support for clients that use the direct connection mode. The format of large keys is optimized.
1.6.1	MEDIUM	2021-04-08	New feature	By default, statistics about large keys are collected. The GT parameter is supported for TairString.
1.6.1	MEDIUM	2021-04-08	Feature optimization	The capability to migrate slots and implement imperceptible scaling is improved.
1.5.1	HIGH	2021-03-15	Fixed issue	The following issue is fixed: The real-time statistics about large keys become inaccurate when keys with the same name are written.
1.5.0	MEDIUM	2021-02-22	New feature	Statistics about large keys can be collected in real time.
1.5.0	MEDIUM	2021-02-22	Feature optimization	The failure detection capability of high-availability systems is improved when you call fork() in memory-intensive scenarios. This prevents long pauses that may occur.
1.4.16	HIGH	2021-01-11	New feature	Metadata can be cleared after an active geo-redundancy link becomes available. The link is built based on Global Distributed Cache or DTS. This accelerates subsequent synchronization operations.
1.4.16	HIGH	2021-01-11	Fixed issue	The following issue is fixed: Memory leaks may occur when the FLUSHALL command is frequently run in scenarios where TairHash is used.
1.4.13	LOW	2020-11-27	New feature	When the `illegal address` error message is returned, Tair includes the IP address of the client in the error message. An IP address whitelist can be configured for an instance based on the IP address prompt. Figure 1. IP address prompt
1.4.12	MEDIUM	2020-11-26	New feature	Flags such as FLAGS can be used in the syntax of TairString. This syntax is compatible with the Memcached semantics.
1.4.12	MEDIUM	2020-11-26	Feature optimization	The failure detection capability of high-availability systems is improved. Note We recommend that you update the minor version to 1.5.0 or later for the latest optimization of this feature.
1.4.9	HIGH	2020-10-22	Fixed issue	Correct binary logs can be generated when TairString data expires. This prevents data inconsistency between the master and replica nodes. The abnormal switchover of high-availability systems is fixed. This issue occurs when TairHash still uses the active expire algorithm in read-only scenarios. The following issue is fixed: The system may not respond when an instance that was forcefully stopped is restarted. The following issue is fixed: Expired keys are deleted when RDB files are loaded to instances for which the data flashback feature is enabled.
1.4.8	HIGH	2020-10-14	Fixed issue	Memory leaks that may occur when specific modules are loading are fixed.
1.4.7	MEDIUM	2020-10-12	Feature optimization	The output of the CLUSTER NODES command can be stored in the cache. This accelerates the command execution.
1.4.6	MEDIUM	2020-09-28	Feature optimization	The processing capabilities of specific modules are improved in specific scenarios.
1.4.1	MEDIUM	2020-09-08	New feature	The IP addresses of clients can be passed through to operational logs and audit logs by proxy nodes. This helps you interpret logs and identify clients that have issues.
1.4.1	MEDIUM	2020-09-08	Feature optimization	The data collection capability is improved to minimize the impact on data shards when a large number of connections are queued up and I/O threads are busy.
1.3.17	MEDIUM	2020-08-04	Feature optimization	The latency is reduced when DTS is used to perform two-way data synchronization.
1.3.16	HIGH	2020-07-19	New feature	The security group feature provided by Elastic Compute Service (ECS) is supported to simplify O&M. To allow ECS instances to access a Tair instance, you can add the security groups to which the ECS instances belong to the instance. You do not need to manually add the IP addresses of the ECS instances to the whitelists of the instance. The TairString module is updated to support more API operations (flags) that are compatible with the Memcached semantics.
1.3.16	HIGH	2020-07-19	Fixed issue	The following issue is fixed: The BGREWRITEAOF command is interrupted when you use the data flashback feature to restore data to a point in time. Latency flag bits in audit logs are modified to help identify these bits in master and replica audit logs.
1.3.9	MEDIUM	2020-06-19	Feature optimization	Saved point metadata can be automatically cleared when data is cleared. This way, replicators can be quickly restored in scenarios where multi-way data synchronization is implemented based on Global Distributed Cache or DTS.
1.3.7	LOW	2020-05-19	New feature	Role information such as `role:master` can be displayed in the Replication part of the INFO command output. This allows Redisson clients to call the role information in specific scenarios.
1.3.6	MEDIUM	2020-05-19	New feature	Statistics about hotkeys are regularly recorded in logs. The data statistics feature is supported for performance metrics. This feature allows the system to differentiate the QPS statistics that are generated in read, write, and read/write synchronization operations. This improves the accuracy of the statistics.
1.3.6	MEDIUM	2020-05-19	Feature optimization	The capability of the engine to restore data to a point in time by using data flashback is optimized. This simplifies data restoration. Commands such as AUTH, ADMINAUTH, and CONFIG do not record sensitive information when these commands are used. This improves data security.
1.3.5	HIGH	2020-04-22	Fixed issue	The issue that deadlocks may occur when multi-threaded engines asynchronously close client connections is fixed. The issue that file descriptors in engines cannot linearly expand is fixed.
1.3.3	HIGH	2020-04-22	New feature	The 64-bit hash algorithm can be applied to TairBloom. The final memory usage of TairBloom can be estimated, which allows the system to record more accurate memory statistics. The exhgetAll2 interface can be used in TairHash to revise command output formats.
1.3.3	HIGH	2020-04-22	Fixed issue	The error message that is returned by instances when a whitelist is improperly configured is changed from `(error) ERR invalid password` to `(error) ERR illegal address`. Memory leaks that may occur when you use TairGIS to manage multiple polygons are fixed. The issue that the default path of TairDoc is incorrect is fixed. The issue that Pub and Sub commands may compete for resources on multi-threaded engines is fixed.
1.3.1	HIGH	2020-04-03	New feature	The data flashback feature is supported. This feature allows you to restore Tair instance data to a point in time within the previous seven days. This prevents data loss caused by accidental operations, simplifies O&M, and protects databases in real time. TairGIS is compatible with Redis GEO commands. TairBloom can be used in capacity security validation for the BFRESERVE interface. TairHash supports the following new features: The NOACTIVE parameter is added to commands such as EXHSET, EXHEXPIRE, EXHINCRBY, and EXHINCRBYFLOAT. This parameter can reduce memory overheads in specific scenarios. The MAX and MIN parameters are added to the EXHINCRBY command to define the upper and lower boundaries of the value range. The noexp parameter is added to the EXHLEN command to return the true length of the EXHLEN command. The HINCRBY and HINCRBYFLOAT commands are supported for the hash structure. The transaction processing capability of these commands can be used to increase or decrease different fields that constitute a key at the same time.
			Feature optimization	The use of data modules is optimized. The performance is enhanced when the JedisCluster client runs the MGET or MSET command on cluster instances.
			Fixed issue	The following issue is fixed: Binary logs take up more space than can be provided by an instance. The issue that the system may not respond when hotkeys are evicted is fixed. The issue that the system may not respond due to double deallocation in TairHash is fixed. The issue that the system may not respond due to use-after-free (UAF) is fixed. This issue occurs when the audit log feature is disabled.
1.0.10	LOW	2020-02-19	New feature	The BITFIELD_RO command is added. This command significantly optimizes the performance of the BITFIELD command in read/write splitting scenarios. Note If the BITFIELD command contains only the get parameter, proxy nodes convert the command into the BITFIELD_RO command and forward the new command to multiple backend data shards.
1.0.9	HIGH	2020-02-19	Fixed issue	The following issue is fixed: The replication process stops when specific complex commands in Lua scripts are run.
1.0.8	HIGH	2020-02-10	Feature optimization	The algorithm and performance related to throttling are improved.
1.0.8	HIGH	2020-02-10	Fixed issue	The issue that the service stops because the congestion of client output buffers triggers server overload protection is fixed.
1.0.5	HIGH	2020-02-01	New feature	Global Distributed Cache is supported. Global Distributed Cache is an active geo-redundancy database system developed in-house by Alibaba Cloud. Global Distributed Cache supports business scenarios in which multiple sites in different regions provide services at the same time. This system also helps enterprises replicate the active geo-redundancy architecture of Alibaba. Binary logs and their protocols are available to support capabilities such as active geo-redundancy.
1.0.5	HIGH	2020-02-01	Fixed issue	The issue that the output of the INFO command can contain the `cluster_enabled` information when the direct connection mode is used is fixed. This allows specific SDKs to automatically negotiate to enter the cluster mode. The issue that the number of clients that are being managed is calculated inaccurately is fixed. The issue that the system may not respond when a client is released is fixed. The issue that the system may not respond when a pipeline contains complex commands is fixed.
0.2.9	HIGH	2020-01-06	Feature optimization	The memory usage of TairHash is optimized.
0.2.9	HIGH	2020-01-06	Fixed issue	The issue that the system may not respond during throttling is fixed.
0.2.7	HIGH	2019-12-23	New feature	The direct connection mode is supported. Clients can bypass proxy nodes to connect to instances by using private endpoints. This is similar to the connection to open source Redis clusters. The direct connection mode can reduce communication overheads and further improve the response speed. The identification logic for hotkeys is supported to accurately identify hotkeys. The memory usage of hotkeys is also optimized. The EXCAS command is supported in optimistic locking scenarios.
0.2.7	HIGH	2019-12-23	Fixed issue	The issue that core dump may occur when pipelines are used is fixed.
0.2.3	LOW	2019-12-03	First release	DRAM-based instances of Tair (Enterprise Edition) are suitable for business scenarios that require high concurrency, high performance, and a large number of read and write operations on hot data. Compared with Redis Open-Source Edition instances, DRAM-based instances have the following advantages: DRAM-based instances use the multi-threading model. A DRAM-based instance provides read and write performance approximately three times that of a Redis Open-Source Edition instance with the same specifications. DRAM-based instances provide multiple enhanced data modules, such as TairString (including CAS and CAD commands), TairHash, TairGIS, TairBloom, and TairDoc. These modules help simplify code, improve business performance, and allow you to focus on innovation.

Tair persistent memory-optimized instances

Minor version	Update level	Release date	Category	Description
1.2.7	HIGH	2024-07-10	New feature	The pubsub_clients metric is added to the INFO CLIENTS command. Traffic can be split into data traffic and replication traffic.
			Feature optimization	The efficiency of active expiration is optimized. The performance of CLUSTER SLOTS and CLUSTER NODES is optimized. The accuracy of memory usage statistics is improved to prevent false memory threshold alerts. Statistics about hotkeys are regularly recorded in audit logs.
			Fixed issue	The CVE-2022-24834 security vulnerability is fixed. The issue that TairHash occasionally crashes is fixed. Hotkey information is logged on a regular basis to ensure that historical hotkey records are complete and accurate. The stability of cluster instance scaling is enhanced. The stability of semi-synchronous data replication is enhanced.
1.2.6.4	LOW	2023-10-13	Fixed issue	The stability of semi-synchronous data replication is enhanced.
1.2.6.3	MEDIUM	2023-08-03	Fixed issue	The issue that exceptions may occur during TTL configuration in special scenarios is fixed. Stability is enhanced.
1.2.6.2	LOW	2022-12-09	Fixed issue	Stability is enhanced.
1.2.6.1	LOW	2022-11-14	Fixed issue	Stability is enhanced.
1.2.6	LOW	2022-11-02	New feature	TairHash is supported.
1.2.6	LOW	2022-11-02	Feature optimization	The performance of request execution is optimized. Stability is enhanced.
1.2.5.1	LOW	2022-09-21	Fixed issue	The vulnerabilities in TairCpc V1.2.5 that may cause instance exceptions are fixed. Note We recommend that you update instances that use TairCpc V1.2.5 to this version. Stability is enhanced.
1.2.5	MEDIUM	2022-08-31	Feature optimization	The extension policies for primary hash tables are optimized. The performance of FLUSHALL and FLUSHDB commands is optimized. The performance of the rehashing function is optimized. Stability is enhanced.
1.2.4.1	LOW	2022-07-28	Fixed issue	The issue that the GETBIT command may cause instance exceptions in V1.2.4 is fixed. Note We recommend that you update your instance to this minor version.
1.2.4	LOW	2022-07-18	Feature optimization	The RENAME and MOVE commands are supported by using the pena_rename_move_compatible_enabled parameter. The time complexity of the two commands is O(n) in Tair. This is different from the time complexity of the two commands in open source Redis. The stability of cluster instance scaling is enhanced. The performance of specific commands is improved to address slow execution issues on large keys. The commands include SETBIT, SETRANGE, APPEND, and BITFIELD.
1.2.3.4	LOW	2022-07-14	Fixed issue	The Errorstats - Selected field returned by the INFO command can be deleted. Latency histograms are optimized. The stability of semi-synchronous data replication is enhanced. The following issue is fixed: An error may be returned when commands such as ZUNIONSTORE or ZINTERSTORE are run on cluster instances in proxy mode. The following issue is fixed: The SORT command may cause inaccurate calculation of persistent memory usage in specific scenarios.
1.2.3.4	LOW	2022-07-14	Feature optimization	The redis_version value is changed to 6.0.9 in the INFO command output.
1.2.3.3	LOW	2022-05-12	New feature	TairCpc is released.
1.2.3.2	HIGH	2022-04-24	Fixed issue	The following issue is fixed: The key eviction order is abnormal when the MAXMEMORY_VOLATILE_TTL policy is specified for key eviction. The process of adding or removing nodes to or from a cluster instance is optimized. The stability of semi-synchronous data replication is enhanced.
1.2.3.1	LOW	2022-03-31	Feature optimization	The following issue is fixed: CAS commands cannot be persisted. The following issue is fixed: Client IP addresses cannot be displayed in slow query logs and audit logs of cluster instances. Stability is enhanced.
1.2.3	MEDIUM	2022-03-03	New feature	TairString is released. Streams are supported. Intset encoding is supported for the SET data structure to reduce memory overheads. Data eviction policies are supported. Service performance and stability are enhanced.
1.2.3	MEDIUM	2022-03-03	Fixed issue	The following issue is fixed: Statistics about the SPOP command are not collected when the real-time key analysis feature is enabled.
1.2.2.4	LOW	2022-01-21	Feature optimization	Storage space occupied by large values is optimized to reduce used persistent storage.
1.2.2.3	HIGH	2021-12-30	Feature optimization	Tail latency during data writes is optimized. Stability is enhanced.
1.2.2.2	HIGH	2021-12-14	Fixed issue	The following issue is fixed: In specific scenarios, the usage of lists and hashes cannot be correctly calculated.
1.2.2.1	LOW	2021-10-21	Feature optimization	Stability is enhanced.
1.2.2	HIGH	2021-10-20	Feature update	The speed at which cluster instances are scaled can be adaptively controlled. Note During scaling operations, the speed at which historical data is cleared is well adapted to instance loads. For example, more CPU cores are used for clearance in low-load scenarios to increase the clearance speed. This feature maintains the CPU utilization at a high level during scaling operations but does not affect service availability. The performance of commands such as CLUSTER NODES is optimized for large cluster instances.
1.2.2	HIGH	2021-10-20	Fixed issue	The issue that abnormal slow query logs are generated during scaling of cluster instances is fixed. Stability is enhanced.
1.2.0	LOW	2021-09-21	Feature update	The storage of the LIST, HASH, SET, and ZSET data structures is optimized to reduce their usage of memory and persistent memory.
1.1.8	LOW	2021-08-17	Feature update	Persistent memory can be fully used when memory is exhausted in specific scenarios. Stability is enhanced.
1.1.7	LOW	2021-08-02	New feature	The semi-synchronous replication mode is supported. By default, this mode is disabled. Note If this feature is enabled, logs are transmitted from a master node to a replica node after the data update that is initiated by the client is complete on the master node. After the replica node receives all logs, the master node returns the log transmission information to the client. If a replica node is unavailable or communication between a master node and a replica node is abnormal, semi-synchronous replication degrades to asynchronous replication. In the output of the INFO command, the redis_version value is changed to 4.9.9 and the pena_version parameter is added to indicate the minor version.
1.1.6.1	MEDIUM	2021-06-10	Feature update	Stability is enhanced.
1.1.6	MEDIUM	2021-05-08	New feature	Imperceptible scaling operations are supported. This allows slots to be migrated without perceptible impacts on your business.
1.1.6	MEDIUM	2021-05-08	Feature optimization	Ziplist encoding is supported in HASH and ZSET data structures to reduce memory overheads. The failure detection capability of high-availability systems is improved. Data migration of large cluster instances is optimized. Large cluster instances are instances that have a large number of data shards. The scaling stability of the cluster architecture is enhanced.
1.1.5	MEDIUM	2021-01-15	New feature	Cluster instances are supported. These instances eliminate performance bottlenecks caused by the single-threading model of open source Redis. You can use cluster instances in high-performance and large-capacity scenarios. The minor version of an instance can be used as the redis_version value in the output of the INFO command.
1.1.5	MEDIUM	2021-01-15	Feature optimization	Stability is enhanced.
1.1.4	MEDIUM	2020-10-28	New feature	The usage of persistent memory can be included in the command output when you run the INFO command by using a standard account.
1.1.4	MEDIUM	2020-10-28	Feature optimization	The space occupied by embstr encoding is decreased to reduce memory overheads. Stability is enhanced.
1.1.3	LOW	2020-09-16	First release	Persistent memory-optimized instances of Tair (Enterprise Edition) provide in-memory database services based on persistent memory (PMEM). These instances are compatible with open source Redis and provide large capacity. Persistent memory-optimized instances have the following advantages: A persistent memory-optimized instance costs about 30% less than a Redis Open-Source Edition instance. In scenarios where advanced memory specifications are used, persistent memory-optimized instances resolve issues such as high latency, high network jitter, and slow service data loading during fork operations triggered by AOF rewrites. You do not need to choose between performance and persistence. Persistent memory-optimized instances support command-level persistence. A response is returned after data persistence is completed for each write operation. Persistent memory-optimized instances are compatible with most of the data structures and interfaces of open source Redis. The persistence of data structures except for STREAM is supported.

Tair ESSD/SSD-based instances

Minor version	Update level	Release date	Category	Description
2.5.3	HIGH	2024-07-05	New feature	The GEO series of commands are supported. The RENAME and RENAMENX commands are supported, with a constraint on the maximum size of keys that can be renamed. The limit is defined by the max-rename-commit-size parameter, which is set to 16 MB by default. The ZPOPMIN, ZPOPMAX, BZPOPMIN, and BZPOPMAX commands are supported. The LPOS command is supported. The encoding of the LIST data structure is optimized to better align with the CPU complexity of the LIST data structure for DRAM-based instances.
2.5.3	HIGH	2024-07-05	Fixed issue	The String Rewrite interface is fixed to ensure compatibility with earlier versions of Redis. When you use DTS for data migration, the destination database can be a Redis instance of an earlier version. The Redis version number returned by the INFO command is changed from 4.0 to 6.0. Stability is enhanced.
2.5.2	HIGH	2024-01-22	New feature	ESSD/SSD-based instances of this minor version can serve as the source databases for data migration and synchronization tasks managed by DTS, and support resumable transmission. After the client is disconnected, Tair preemptively terminates the running commands that may cause slow queries, such as SUNION, SUNIONSTORE, SINTER, SINTERCARD, SINTERSTORE, SDIFF, SDIFFSTORE, and ZUNIONSTORE, to reduce resource consumption. In this case, the execution of write commands may not be successful.
			Feature optimization	The lock granularity for background garbage collection is optimized.
			Fixed issue	The stability of version upgrade under high disk usage is improved. The issue that data statistics may be inflated is fixed. The stability of specific commands is enhanced. The overall stability of instances is improved.
2.4.2.5	HIGH	2023-12-20	Fixed issue	Stability is enhanced.
2.4.2.4	HIGH	2023-11-06	Fixed issue	The stability of garbage collection is enhanced.
2.4.2.3	HIGH	2023-11-01	Feature optimization	The background garbage collection process can delete large keys in small and incremental batches. The default size of each batch is 1 MB.
2.4.2.2	HIGH	2023-09-04	Fixed issue	The stability of the FLUSHALL command and backup interface is improved.
2.4.2.2	HIGH	2023-09-04	Feature optimization	The execution speed of the FLUSHDB command is improved. The logic for limiting the speed of background writes to disks is added.
2.4.2.1	HIGH	2023-08-23	Feature optimization	The stability of iterating through the HASH, SET, LIST, and ZSET data structures is enhanced when a large amount of junk data exists.
2.4.1.3	HIGH	2023-07-14	Fixed issue	The issue that causes the SSCAN command to return unexpected or incorrect results in specific scenarios is fixed.
2.4.1.2	HIGH	2023-07-11	Fixed issue	Stability is enhanced.
2.4.1.1	HIGH	2023-07-10	Fixed issue	Stability is enhanced.
2.4.1	HIGH	2023-07-04	Feature optimization	The read and write performance of instances in extreme scenarios is optimized. The memory usage of logs is optimized.
2.3.3	HIGH	2023-04-20	Fixed issue	The issue that may cause wake-up failures on the blocked clients is fixed.
2.3.2	HIGH	2022-12-22	Fixed issue	The following issue is fixed: The system may crash when the BRPOP, BLPOP, or BRPOPLPUSH command is run.
2.3.1	MEDIUM	2022-09-14	New feature	The transaction feature is supported. The MULTI and EXEC commands can be used in transactions. You can use the `txn-isolation-lock` parameter to manage this feature. The Lua scripting feature is supported. The EVAL, EVALSHA, and SCRIPT commands can be used to manage Lua scripts. You can use the `txn-isolation-lock` and `#no_loose_lua-strict-mode` parameters to manage this feature. The following commands that manage bitmaps are supported: BITCOUNT, BITFIELD, BITOP, BITPOS, GETBIT, and SETBIT.
2.3.1	MEDIUM	2022-09-14	Feature optimization	The stability of data synchronization between master and replica nodes is optimized.
2.2.22	MEDIUM	2022-08-10	Feature optimization	The continuous read and write performance of instances that contain terabytes of data is optimized.
2.2.15	HIGH	2022-06-06	Fixed issue	Stability is enhanced.
2.1.13	LOW	2022-05-05	Feature optimization	The stability of data synchronization between master and replica nodes is optimized.
2.1.12	LOW	2022-04-26	Feature optimization	The stability of data synchronization between master and replica nodes is optimized.
2.1.10	LOW	2022-04-14	Feature optimization	The efficiency of synchronization between master and replica nodes is optimized to provide higher throughput and lower latency. The resource usage of compact operations that are generated when a large number of large keys concurrently expire is optimized.
2.1.7	LOW	2021-08-12	Feature optimization	The speed of master-replica switchover is optimized to improve stability. Master-replica switchover is also known as proactive HA.
2.1.5	HIGH	2021-07-13	Fixed issue	The issue that binary logs occupy a large amount of space is fixed.
2.1.4	MEDIUM	2021-07-07	Feature optimization	The storage parameters of ESSD/SSD-based instances that have terabytes of capacity are optimized to improve performance. Stability is enhanced.
2.1.0	LOW	2021-05-26	New feature	The canary release of the transaction feature is supported. The MULTI and EXEC commands can be used in transactions. The canary release of the Lua scripting feature is supported. The EVAL, EVALSHA, and SCRIPT commands can be used to manage Lua scripts.
2.0.13	LOW	2021-04-24	New feature	Notifications about keyspace events can be sent.
1.2.17	HIGH	2021-02-04	Fixed issue	The following issue is fixed: In specific cases, the FLUSHALL command may cause data inconsistency between master and replica nodes.
1.2.16	HIGH	2021-01-29	Fixed issue	The following issue is fixed to ensure data consistency between master and replica nodes: In specific cases, a master node and a replica node cannot be automatically reconnected after a disconnection.
1.2.15	MEDIUM	2021-01-20	New feature	The cmd_slowlog_count metric is added to collect historical statistics about slow query logs.
1.2.15	MEDIUM	2021-01-20	Feature optimization	Protection capabilities are improved in scenarios where disk space is fully occupied.
1.2.14	LOW	2020-12-31	New feature	Data verification for master and replica nodes is added.
1.2.13	HIGH	2020-12-31	Fixed issue	The issues that occur on the RESTORE command in specific scenarios are fixed.
1.2.12	MEDIUM	2020-12-23	Feature optimization	The FLUSHALL and FLUSHDB commands are optimized to limit serial execution.
1.2.11	MEDIUM	2020-12-10	Feature optimization	Memory management is optimized.
1.2.10	LOW	2020-12-04	New feature	Password-free access over a virtual private cloud (VPC) is supported. To prevent OOM errors caused by large transactions, the size of a single transaction can be limited by using the max-write-batch-size parameter.
1.2.9	MEDIUM	2020-11-27	Feature optimization	The redis_version parameter is added to the output of the INFO command.
1.2.8	HIGH	2020-11-20	Fixed issue	The issue that the number of connections is incorrectly calculated is fixed. The issue that the number of keys is incorrectly calculated when the RESTORE command is run is fixed.
1.2.7	HIGH	2020-10-28	Fixed issue	The issue that unexpected quits occur when the SETRANGE command is run is fixed. The issue that exceptions occur when keys are empty strings is fixed.
1.2.6	HIGH	2020-09-28	Fixed issue	The following issue is fixed: Connection management logs rapidly increase.
1.2.5	HIGH	2020-09-27	Fixed issue	The following issue is fixed: Operational logs rapidly increase.
1.2.4	HIGH	2020-09-27	Feature optimization	The stability of data synchronization between master and replica nodes is improved. The scanning performance for members of complex data structures is optimized.
1.2.4	HIGH	2020-09-27	Fixed issue	The following issue is fixed: The ZADD and ZINCR commands do not behave as expected according to their native behavior in Redis. In this case, semantic errors may occur when multiple duplicate members are managed. The following issue is fixed: `nil` is returned for empty strings when the MGET command is run.
1.2.3	LOW	2020-09-27	First release	ESSD-based instances of Tair (Enterprise Edition) are independently developed based on the TairDB key-value storage engine and use ESSDs to store data. These instances provide high-capacity, low-cost, and persistent database services. ESSD-based instances have the following advantages: ESSD-based instances store data in cloud disks to implement data persistence at a cost that can be as low as 15% that of Redis Open-Source Edition instances. ESSD-based instances use multiple I/O threads and worker nodes to improve throughput on each server and support replication of binary logs between master and replica nodes. ESSD-based instances are compatible with most of the open source Redis commands. ESSD-based instances reduce the amount of memory that is reserved for the forks of open source Redis.