PolarDB:PolarProxy release notes

Database proxy 2.x.x release notes

• 2.9.17 (Released on: 2025-11-07)

  Category	Description
  Performance optimizations	Optimized routing for Multi-master Cluster (Limitless) Edition. Requests for SHOW TABLE STATUS from db_name statements are routed to a specified read/write (RW) node to ensure data consistency when table status information is retrieved. Optimized the read-only transaction processing mechanism. If a node that is locked by a read-only transaction becomes abnormal, the business session remains connected. This improves cluster high availability and business continuity during node failures. Optimized the binary logging (binlog) pull performance for a global database network (GDN). This resolves the issue of slow binlog pulling from the cluster endpoint of a secondary cluster. Note This optimization is disabled by default. If you need this feature, submit a ticket to have it enabled.
  Bug fixes	Fixed an issue where read-only transactions could cause a cluster to crash in specific scenarios. This enhances overall cluster stability. Fixed an issue where the SQL firewall feature could cause a cluster to crash when it processed certain special SQL statements. This improves cluster stability when the SQL firewall is enabled. Fixed an issue where data could not be decrypted after a database proxy upgrade to a specific version (2.9.12 to 2.9.16) on clusters that are configured with PolarDB Always-confidential encryption rules.

• 2.9.16 (Released on: 2025-09-17)

  Category	Description
  Performance optimizations	Optimized the error message that is returned when routing fails with the /*FORCE_IMCI_NODES*/ hint. Optimized the rule matching logic for the dynamic data masking feature.
  Bug fixes	Fixed a routing issue with SELECT … FOR SHARE statements. Fixed an issue where the SQL parser could not recognize CHARACTER SET when parsing CAST. Fixed an issue where routing binary PREPARE statements in a Multi-master Cluster (Limitless) Edition could cause unexpected disconnections in specific scenarios. Fixed a routing issue with the advanced transaction splitting feature when processing multi-statement scenarios. Fixed an issue where the overload protection feature could cause unexpected disconnections in some scenarios. Fixed an issue where persistent connections could cause errors in XA requests.

• 2.9.15 (Released on: 2025-07-17)

  Category	Description
  New features	Added support for configuring global consistency separately on read-only endpoints where the Load Balancing Policy is set to Load Balancing Based On The Number Of Active Requests.
  Performance optimizations	Improved diagnostics capabilities. Added an error code prefix to requests that are rerouted to columnstore index read-only nodes to facilitate quick problem identification and location. Optimized the logic for automatic request distribution among row store and column store nodes. This improves the efficiency and accuracy of request distribution in hybrid transactional and analytical processing (HTAP) scenarios.
  Bug fixes	Fixed an issue in global consistency (high-performance mode) where the client might receive an error. This occurred when the timeout configuration was changed from 0, Send The Request To The Primary Node (default) to 2, Timeout And Downgrade. If A Global Consistency Read Times Out, The Query Is Automatically Downgraded To A Regular Request, And The Client Does Not Receive An Error Message. Fixed an issue where a slow query in a PREPARE statement with a /*FORCE_MASTER*/ hint was not correctly routed to a columnstore index read-only node for execution. Fixed an issue of high query response time (RT) in low-concurrency scenarios under global consistency (traditional mode). This improves system performance in such scenarios. Fixed an issue in a Multi-master Cluster (Limitless) Edition where concurrently executing CREATE DATABASE statements to create a database with the same name on multiple nodes could cause command execution to fail due to conflicts. Fixed an issue in a Multi-master Cluster (Limitless) Edition where the MySQL parser could cause a service crash when processing CREATE TABLE statements. This enhances system stability.

• 2.9.13 (Released on: 2025-05-22)

  Category	Description
  Bug fixes	Fixed an issue where the CPU utilization monitoring results were inaccurate.

• 2.9.12 (Released on: 2025-05-15)

  Category	Description
  New features and performance optimizations	Optimized global consistency (high-performance mode). The consistency level is adjusted from the system level to the connection level. You can configure it separately for each PolarProxy endpoint. Optimized the persistent connection switching process. Optimized SQL parsing. Optimized the transaction-level connection pool. Optimized statistical metrics.
  Bug fixes	Fixed an issue with OrcaScan command node binding and an issue of unexpected disconnections due to wait timeout. Fixed an issue where on-demand connection establishment was disconnected by the last_used command. Fixed a routing error in Multi-master Clusters when `Set AutoCommit=0/1` was used in multi-statement transactions. Fixed a compatibility issue between the transaction-level connection pool and HTAP. Fixed an issue where read-only transactions did not meet consistency requirements. Fixed compatibility issues with some drivers.

• 2.9.10 (Released on: 2025-02-14)

  Category

  Description

  Bug fixes

  Fixed a query routing error for temporary tables created with the CREATE TEMPORARY TABLE * AS SELECT * FROM * statement. Fixed an execution error for XA transactions on read-only endpoints configured with load balancing based on the number of active requests. Fixed a routing error for XA transactions in Multi-master Clusters. Fixed a table creation error in some scenarios for Multi-master Clusters. Fixed an error that occurred on read-only endpoints configured with load balancing based on the number of active requests. The error was caused using the primary node with force_master/force_node hints. Fixed an issue where a session was unexpectedly disconnected after the wait_timeout period expired when pulling binary logs from a cluster endpoint.

• 2.9.8 (Released on: 2024-11-25)

  Category	Description
  New features and performance optimizations	Added support for routing requests that contain built-in GIS functions, such as ST_Distance_Sphere, to read-only nodes. Added support for configuring timeout policies for high-performance strong consistency: forward to the primary node, report an error, or downgrade. Added support for global consistency in Multi-master Cluster scenarios. Added support for selecting specific primary nodes for custom endpoints. Optimized the load balancing capability for read-only nodes in Multi-master Cluster scenarios.
  Bug fixes	Fixed an issue that could cause a proxy out-of-memory (OOM) error in high-concurrency data read scenarios. Fixed an issue where transaction resumable upload failed in some scenarios. Fixed an issue where accounts using caching_sha2_password did not support the pymysql driver. Fixed an issue where the force_node hint became invalid during a primary/secondary failover. Fixed a crash issue caused by proxy exceptions in some Multi-master Cluster scenarios. Fixed an issue where the Standby role was incorrectly identified in some Multi-master Cluster scenarios. Fixed an issue where a primary/secondary failover could cause connection reuse to use the wrong database after the transaction-level connection pool was enabled.

• 2.9.4 (Released on: 2024-08-29)

  Category	Description
  New features and performance optimizations	Always-confidential encryption now supports key updates.
  Bug fixes	Fixed an issue where accessing a temporary table created in a stored procedure failed. Fixed an issue where CREATE TABLE LIKE and RENAME TABLE statements failed to execute in a Multi-master Cluster. Fixed an issue of slow request responses in high-concurrency scenarios for PolarDB for AI. Fixed proxy blocking and restart issues in some scenarios.

• 2.9.2 (Released on: 2024-07-29)

  Category	Description
  New features and performance optimizations	Added support for MySQL 8.0 caching_sha2_password authentication. Added support for using wildcard characters in encryption rules. Optimized the routing policy for statements related to global transaction identifiers (GTIDs). Added support for the ->> and -> JSON syntax.
  Bug fixes	Fixed an issue where thread ID rotation and overwriting in short-lived connection scenarios occasionally caused connection establishment to fail. Fixed an error with nested transactions in multi-statement queries. Fixed a proxy exception caused by parsing failures for some specific SQL statements.

• 2.8.47 (Released on: 2024-12-02)

  Category	Description
  New features and performance optimizations	Added support for routing requests that contain built-in GIS functions, such as ST_Distance_Sphere, to read-only nodes.
  Bug fixes	Fixed an issue that could cause a proxy out-of-memory (OOM) error in high-concurrency data read scenarios. Fixed an issue where transaction resumable upload failed in some scenarios. Fixed an issue where a primary/secondary failover could cause connection reuse to use the wrong database after the transaction-level connection pool was enabled.

• 2.8.46 (Released on: 2024-09-13)

  Category	Description
  New features and performance optimizations	Optimized the downstream throughput for access across regions or in extreme network conditions. Optimized the routing for select information_schema.processlist. In the new version, it is routed to the primary node by default to prevent gh-ost lock-free DDL failures.
  Bug fixes	Fixed an issue of slow requests when a read-only Endpoint was attached to only one AP (read-only) node. Fixed an issue where incorrect routing of a user variable caused an Illegal mix of collations error in the application.

• 2.8.45 (Released on: 2024-07-19)

  Category	Description
  New features and performance optimizations	Optimized read-after-write splitting for transactions in some scenarios. Optimized persistent connections in some scenarios. Optimized the handling of non-business data messages for data masking or encryption.
  Bug fixes	Fixed connection establishment failures for on-demand connection establishment in some scenarios. Fixed a compatibility issue between on-demand connection establishment and automatic traffic redirection. Fixed incorrect request routing for automatic traffic redirection in some scenarios. Fixed an issue where the proxy unexpectedly restarted during data masking or encryption scenarios. Fixed an issue where overload protection did not recover promptly in specific scenarios, causing slow request responses. Fixed an issue of unexpected disconnection when executing binlog dump on a cluster endpoint. Fixed incorrect request routing for multi-statement queries that use temporary tables. Fixed a compatibility issue with read-only endpoints that use connection-based load balancing in some scenarios. Fixed an issue of incorrect connection reuse in the transaction-level connection pool in `COM_RESET_CONNECTION` scenarios. Fixed an issue where requests were unexpectedly routed to the primary database under global consistency. Fixed a potential proxy connection leak issue when kill connection was frequently used. Fixed an issue that could cause connection blocking in some scenarios.

• 2.8.35 (Released on: 2024-02-26)

  Category	Description
  New features and performance optimizations	Added support for on-demand connection establishment. Added support for configuring a timeout period for session consistency.
  Bug fixes	Fixed a disconnection issue with binlog_dump when BINLOG_DUMP_NON_BLOCK is enabled. Fixed an issue where some connections to the database were blocked for a long time in some scenarios when automatic traffic redirection was enabled. Fixed a potential error when using SET OPTION with the session-level connection pool. Fixed an issue that could cause connection blocking in some scenarios when using STMT_SEND_LONG_DATA. Fixed an issue where some persistent connections did not exit as expected. Fixed an issue where some monitoring metrics were inaccurate in certain scenarios. Fixed exceptions on some proxy nodes.

• 2.8.28 (Released on: 2024-01-08)

  Category	Description
  New features and performance optimizations	Added support for intra-transaction traffic distribution when automatic traffic redirection is configured, the Read/Write Mode of the cluster endpoint is set to Read-only, and the Load Balancing Policy of the cluster endpoint is set to Load Balancing Based On The Number Of Active Requests. In automatic traffic redirection mode, deleting an AP node now takes effect on existing connections. Added support for configuring server weights at the Endpoint granularity. Optimized some persistent connection scenarios. SSL now supports only TLS 1.2.
  Bug fixes	Fixed an issue where the client received a 9000 error code when using automatic traffic redirection with PolarDB for MySQL 8.0.2. Fixed an issue where the client received a 9000 error code because the SQL statement contained special syntax during an automatic traffic redirection operation. Fixed a failure when executing the EXPLAIN SELECT operation in some scenarios. Fixed an issue where user requests were briefly blocked when a read-only node was deleted in some scenarios. Fixed an issue where using the transaction-level connection pool could cause connections to become unresponsive in some scenarios. Fixed exceptions on some proxy nodes. Fixed an issue where using automatic traffic redirection caused proxy exceptions or unresponsive connections in some scenarios after the Consistency Level of the cluster endpoint was set to Session Consistency or Global Consistency. Fixed a routing error caused using a temporary table in an SQL statement.

• 2.8.25 (Released on: 2023-08-30)

  Category	Description
  New features and performance optimizations	Optimized persistent connection scenarios.
  Bug fixes	Fixed an issue where internal keepalive or large messages could cause user sessions to hang. Fixed an issue where `select` statements with custom variables were routed to the primary database. Fixed an issue where multi-statement queries with comments were routed to read-only nodes.

• 2.8.24 (Released on: 2023-08-08)

  Category	Description
  New features and performance optimizations	Optimized the logic of the internal monitor detection template.
  Bug fixes	Fixed an issue where `show warnings` timed out and failed on read-only endpoints. Fixed a proxy exception that could occur in some scenarios when the transaction-level connection pool was enabled.

• 2.8.21 (Released on: 2023-06-25)

  Category	Description
  New features and performance optimizations	Optimized the performance of some internal modules. Added support for routing `explain select` statements to read-only nodes. Added support for routing `show status` statements to the previous node. Added support for the query encryption feature.
  Bug fixes	Fixed a session hang issue that could occur when an AP node restarted while automatic traffic redirection was enabled. Fixed a session hang issue that could occur when a node restarted while parallel query was enabled. Fixed an issue where `Optimize` was routed to a read-only node in some scenarios. Fixed an issue where parsing errors in some `with select` scenarios caused requests to be routed to the primary node. Fixed an issue where users could see the unexpected database `polar_proxy_encode`. Fixed an issue where request RT jittered when a read-only node was added. Fixed an issue where the dynamic data masking mask did not take effect. Fixed exceptions on some proxy nodes.

• 2.8.12 (Released on: 2023-03-01)

  Category	Description
  New features and performance optimizations	Improved the performance of short-lived connections by 10%.
  Bug fixes	Fixed an issue where `row_number` was routed to the primary node. Fixed proxy exceptions in some scenarios. Fixed an issue where a read-only node exception caused a proxy monitor detection exception, leading to user disconnection. Fixed a failure when using `prepare exec` with automatic traffic redirection for row store. Fixed an issue where the dynamic data masking mask did not take effect.

• 2.8.11 (Released on: 2023-02-22)

  Category	Description
  New features and performance optimizations	Configuring automatic request distribution among row store and column store nodes now supports transaction, session, and global consistency.
  Bug fixes	Fixed a routing error for SQL statements that are longer than 64 KB and contain temporary tables. Fixed an issue where the transaction resolution was lost during transaction splitting, causing transient disconnections in PHP 8.0. Fixed an authentication failure on read-only Endpoints in specific scenarios. Fixed a connection establishment failure when using the session pool in specific scenarios.

• 2.8.8 (Released on: 2022-12-15)

  Category	Description
  New features and performance optimizations	Read/write splitting now supports weight-based dynamic load balancing. For more information, see Weight-based dynamic load balancing. Read-only Endpoints now support request-level load balancing. HTAP automatic request distribution among row store and column store nodes now supports routing transactional processing (TP) requests to AP nodes. When you enable or disable elastic parallel query, the change can take effect on existing connections.
  Bug fixes	Fixed an issue where connections were disconnected in specific scenarios.

• 2.8.3 (Released on: 2022-11-04)

  Category	Description
  New features and performance optimizations	Added support for the overload protection feature. Added support for the readable hot replica feature.
  Bug fixes	Fixed an unexpected disconnection issue with multi-statement queries in HTAP automatic traffic redirection. Fixed several internal exceptions that caused RT jitter.

• 2.7.9 (Released on: 2022-08-01)

  Category	Description
  New features and performance optimizations	The SQL firewall feature now supports `show` syntax. Read/write cluster endpoints now support Elastic Parallel Processing (EPP) and single-node parallel query (PQ). The `force hint` syntax now supports `prepare` syntax.
  Bug fixes	Fixed an issue where environment variables were lost on newly added database nodes in the session-level connection pool, leading to inconsistent states. Fixed an incorrect routing issue for `update` when a read-only transaction was enabled in a multi-statement scenario. Fixed an incorrect routing issue for `COM_STMT_FETCH` in consistency scenarios.

• 2.7.5 (Released on: 2022-07-15)

  Category	Description
  New features and performance optimizations	The SQL firewall feature now supports `show` syntax. Read/write cluster endpoints are now supported.
  Bug fixes	Fixed an issue where the Accept Reads on Primary Node feature did not take effect on old connections. Fixed several internal exceptions.

• 2.4.35 (Released on: 2022-07-05)

  Category	Description
  Bug fixes	Fixed a session exception that occurred when a `SET` request was received during an RW node restart with persistent connections enabled. Fixed several issues with inaccurate internal monitoring and diagnostic tools.

• 2.4.33 (Released on: 2022-05-07)

  Category

  Description

  Bug fixes

  Fixed an issue where environment variables in the transaction-level connection pool were not replayed, causing incorrect connection reuse in sessions. Fixed an error when executing prepare exec with HTAP automatic load balancing. Fixed an issue where the transaction resolution in the message status was lost due to transaction splitting (this might affect PHP 8.0). Fixed proxy exceptions in specific scenarios.

• 2.4.30 (Released on: 2022-03-08)

  Category	Description
  New features and performance optimizations	Optimized the session consistency level.
  Bug fixes	Fixed some incorrect routing issues with the HTAP automatic traffic redirection feature. Fixed a proxy exception that occurred when the PolarProxy specifications exceeded 32 cores. Fixed a proxy crash in specific scenarios. Fixed an incorrect routing issue with `prepare select for update` in specific scenarios.

• 2.4.27 (Released on: 2021-12-30)

  Category	Description
  New features and performance optimizations	Added support for automatic traffic redirection between row store and column store.
  Bug fixes	Fixed a `kill session` failure. Fixed a `COM_STMT_EXECUTE` failure that occurred when parameter types were frequently modified. Fixed an issue where read requests were routed to a read-only node after `Select for update` was executed within a transaction. Fixed a failure to insert special utf8mb4 characters for connections newly created during a primary node restart. Fixed an issue where the latest committed data could not be read after a transaction with session consistency was committed.

• 2.4.22 (Released on: 2021-09-10)

  Category	Description
  Bug fixes	Fixed an issue where PolarProxy did not properly close `prepare`, leading to high database memory usage. Fixed a persistent connection failure in specific scenarios. Fixed a proxy exception that occurred when the default cluster endpoint was changed to read-only mode. Fixed a proxy crash in specific scenarios.

• 2.4.18 (Released on: 2021-08-12)

  Category	Description
  Bug fixes	Fixed an issue of garbled text that occurred when a JDBC application did not specify a font set, and a database node restarted or an account authentication failed. Fixed a connection failure for Flink clients. Fixed some temporary table routing errors.

• 2.4.17 (Released on: 2021-07-14)

  Category	Description
  New features and performance optimizations	PolarDB for MySQL 5.7 now supports persistent transaction connections during failover scenarios. Added internal monitoring metrics.
  Bug fixes	Optimized the long RT response issue caused by MySQL account authentication failures. Optimized the issue where new connections quickly skipped an abnormal read-only node. Fixed a connection failure that occurred after parallel computing was enabled on a read-only Endpoint. Fixed a routing error for `current timestamp`. Fixed an incorrect routing issue with `for update parse`. Fixed a routing error caused by incorrect syntax analysis of `@a` in a `join` clause. Fixed an authentication failure for MySQL 8.0 clients with empty passwords. Fixed a failure to execute some `name prepare` statements.

• 2.4.12 (Released on: 2021-05-20)

  Category	Description
  New features and performance optimizations	Added support for dynamic data masking.
  Bug fixes	Fixed proxy exceptions in specific scenarios.

• 2.4.7 (Released on: 2021-03-15)

  Category	Description
  New features and performance optimizations	Added support for persistent connections.
  Bug fixes	Fixed an incorrect routing issue with `lock in shared mode`.

Database Proxy 1.x.x release notess

• 1.13.42 (Released on: 2022-12-15)

  Category	Description
  Bug fixes	Fixed a connection failure caused by too many database connections. Fixed RT jitter caused by internal scheduled tasks.

• 1.13.39 (Released on: 2022-07-20)

  Category	Description
  New features and performance optimizations	Optimized the performance of PolarProxy in scenarios with many incorrect authentications. Optimized the identity verification feature. When there are incorrect account authentications, the rate limiting granularity is changed from global to account-level.
  Bug fixes	Fixed an issue where the transaction resolution was lost during transaction splitting. Fixed an issue where environment variables were not replayed in the transaction-level connection pool. Fixed a failure to close `prepare` in XA transactions. Fixed several internal exceptions.

• 1.13.34 (Released on: 2022-03-03)

  Category	Description
  New features and performance optimizations	Added support for the MySQL utf8mb3 encoding format. Optimized the session consistency level.
  Bug fixes	Fixed an incorrect routing issue with `select for update` caused by too many `prepare stmt` parameters.

• 1.13.30 (Released on: 2021-12-30)

  Category	Description
  Bug fixes	Fixed an issue where the latest committed data could not be read after a transaction with session consistency was committed.

• 1.13.27 (Released on: 2021-11-16)

  Category	Description
  Bug fixes	Fixed SSL compatibility issues with some clients. Optimized the performance of proxy parsing for `insert` statements.

• 1.13.25 (Released on: 2021-08-18)

  Category	Description
  Bug fixes	Fixed a proxy memory leak issue caused by MySQL account authentication failures. Fixed a proxy crash that could occur in multi-Endpoint scenarios.

• 1.13.22 (Released on: 2021-07-21)

  Category	Description
  New features and performance optimizations	Added support for `select last_insert_id()` after the transaction-level connection pool is enabled. Added support for the `FOUND_ROWS` function after the transaction-level connection pool is enabled. Added support for routing the `COM_STATISTICS` protocol to read-only nodes. Optimized the transaction-level connection pool. Optimized global consistency: Requests can be routed to a read-only node as long as one read-only node meets the consistency requirements. Added support for routing `geo` functions to read-only nodes. Added some internal monitoring metrics.
  Bug fixes	Fixed routing errors caused by incorrect parsing of some SQL statements. Fixed an issue where `stmt_exec()` failed after `stmt_long_data()` was executed in specific scenarios. Fixed a `load data infile` execution failure.

• 1.13.5 (Released on: 2020-12-01)

  Category	Description
  New features and performance optimizations	Eventual consistency now supports transaction splitting. Added support for the following HINT syntax: force node connection /*force_proxy_internal*/set force_node = 'pi-aaaaaaaaa'; All subsequent requests on this connection are sent only to the node `pi-aaaaaaaaa`. If this node is unhealthy, the error message set force node 'pi-aaaaaaaaa' is not found, please check. is reported. force node query /*force_node='pi-aaaaaaaa'*/ show processlist; This request is executed only on the `pi-aaaaaaaa` node. If this node is unhealthy, the error message 'force hint server node is not found, please check.' is reported. Added some internal monitoring metrics.
  Bug fixes	Fixed an issue where the select type, status, mode, where gtx_id = '4' FOR UPDATE; statement was routed to a read-only node because it contained the `mode` keyword. Fixed a load imbalance issue under specific conditions. Fixed a potential `stmt_close` failure in `prepare` scenarios.

• 1.12.10 (Released on: 2020-10-19)

  Category	Description
  Bug fixes	Fixed a connection establishment exception with SSL encryption for MySQL 8.0. Fixed an exception when PolarProxy loaded new requests to a database node after its status changed from DOWN to RUNNING.

• 1.12.7 (Released on: 2020-08-06)

  Category	Description
  New features and performance optimizations	Added support for `show full processlist` syntax. Added support for XA transaction syntax.
  Bug fixes	Fixed several issues with the transaction-level connection pool. Fixed issues with accessing read-only nodes in a GDN. Fixed an error when executing the `show processlist` command in MySQL 8.0. Fixed several connection establishment failures.

• 1.11.12 (Released on: 2020-06-22)

  Category	Description
  New features and performance optimizations	Added support for the transaction-level connection pool. Read-only Endpoints for PolarDB for MySQL 8.0 now support parallel query.

• 1.10.7 (Released on: 2020-03-18)

  Category	Description
  New features and performance optimizations	Added support for the global consistency feature.
  Bug fixes	Fixed an exception when initializing system environment variables in the session-level connection pool.

• 1.9.23 (Released on: 2020-02-21)

  Category	Description
  New features and performance optimizations	Added support for connecting to a cluster with a root account. Added support for SSL Certificate encryption.
  Bug fixes	Fixed a `change user` failure. Fixed a `load file` failure. Fixed an issue where the application reported an Exception: Packets out of order error because it received a message with an incorrect sequence. Fixed an issue where the read-only Endpoint was disconnected when the primary node was abnormal.

• 1.9.14 (Released on: 2019-12-24)

  Category	Description
  New features and performance optimizations	You can use HINTs, such as /*FORCE_SLAVE*/ and /*FORCE_MASTER*/. Added support for accepting read requests on the primary database.
  Bug fixes	Fixed an issue of garbled text caused by an incorrect default charset value. Fixed an issue where an incorrect MySQL version string was returned.