PolarDB：PolarProxy release notes

Release notes for PolarProxy 2.x.x

• 2.9.4 (Release date: August 29, 2024)

  Category	Description
  New feature and feature optimization	The PolarDB Always-confidential feature allows key update.
  Fixed issue	The following issue is fixed: Access to temporary tables created in a stored procedure fails. The following issue is fixed: The CREATE TABLE LIKE and RENAME TABLE statements fail to be executed on a cluster of Multi-master Cluster (Database/Table) edition. The following issue is fixed: Responses for queries are slow in PolarDB for AI high-concurrency scenarios. The following issue is fixed: PolarProxy is blocked and restarts in specific scenarios.

• 2.9.2 (Release date: July 29, 2024)

  Category	Description
  New feature and feature optimization	The caching_sha2_password authentication plug-in is supported. caching_sha2_password is the default authentication plug-in in MySQL 8.0. Wildcards can be used in encryption rules. The routing policies for statements related to global transaction identifiers (GTIDs) are optimized. The ->> and -> operators can be used in the JSON syntax.
  Fixed issue	The following issue is fixed: In short-lived connection scenarios, the frequent rerotation of thread IDs may lead to occasional connection failures. The following issue is fixed: An error occurs when a transaction that contains nested statements is executed. The following issue is fixed: An exception occurs on PolarProxy when specific SQL statements fail to be parsed.

• 2.8.46 (Release date: September 13, 2024)

  Category	Description
  New feature and feature optimization	The downlink access throughputs in cross-region or extreme network condition scenarios are optimized. The select information_schema.processlist queries are routed to the primary table by default, which reduces the risk of errors during schema modifications performed by using gh-ost.
  Fixed issue	The following issue is fixed: The requests are slow when a read-only endpoint is associated with only one read-only analytical processing (AP) node. The following issue is fixed: An Illegal mix of collations error occurs due to incorrect routing of user variables.

• 2.8.45 (Release date: July 19, 2024)

  Category	Description
  New feature and feature optimization	Read request splitting after a write request in transactions is optimized in specific scenarios. The persistent connection feature is optimized in specific scenarios. Processing of non-business data is optimized in data masking or encryption.
  Fixed issue	The following issue is fixed: On-demand connections may fail to be established in specific scenarios. The following issue is fixed: The on-demand connections feature is incompatible with the automatic request distribution between row store and column store nodes feature. The following issue is fixed: Specific requests may be incorrectly distributed when the automatic request distribution between column store and row store nodes feature is enabled. The following issue is fixed: PolarProxy may restart unexpectedly in scenarios in which data is being encrypted or decrypted. The following issue is fixed: Requests are inefficiently processed when PolarProxy fails to exit overload protection after the cluster recovers. The following issue is fixed: The connection to the cluster by using a cluster endpoint is unexpectedly interrupted when a binlog dump operation is performed by using the cluster endpoint. The following issue is fixed: Requests that use multiple statements and temporary tables are incorrectly routed. The following issue is fixed: A read-only endpoint may be incompatible with connections-based load balancing in specific scenarios. The following issue is fixed: After the COM_RESET_CONNECTION command is executed to reset a connection in a transaction-level connection pool, the connection cannot be reused as expected. The following issue is fixed: Requests are unexpectedly routed to the primary database when global consistency is enabled. The following issue is fixed: Resource leaks occur on Proxy connections when connections are frequently closed. The following issue is fixed: Connections are blocked in specific scenarios.

• 2.8.35 (Release date: February 26, 2024)

  Category	Description
  New feature and feature optimization	The on-demand connections feature is supported. You can specify the timeout period for session consistency.
  Fixed issue	The following issue is fixed: The binlog_dump connection is interrupted when BINLOG_DUMP_NON_BLOCK is enabled. The following issue is fixed: When the automatic request distribution between column store and row store nodes feature is enabled, several connections to databases may be blocked for an extended period of time. The following issue is fixed: An error may occur in the session-level connection pool when SET OPTION is used. The following issue is fixed: Connections may be blocked in specific scenarios when STMT_SEND_LONG_DATA is used. The following issue is fixed: Several connections do not exit properly when the persistent connections feature is used. The following issue is fixed: Specific monitoring metrics are inaccurate in several scenarios. The following issue is fixed: Specific PolarProxy nodes are abnormal.

• 2.8.28 (Release date: January 8, 2024)

  Category	Description
  New feature and feature optimization	If you set Read/Write Mode to read-only and Load Balancing Policy to Active Request-based Load Balancing when you configure the automatic request distribution between column store and row store nodes feature, request distribution within transactions is supported. When the automatic request distribution between column store and row store nodes feature is enabled, existing connections are affected when an AP node is deleted. Server weights can be configured based on endpoints. Specific persistent connection scenarios are optimized. Only TLS 1.2 is supported in the SSL feature.
  Fixed issue	The following issue is fixed: The 9000 error code is returned when you enable the automatic request distribution between column store and row store nodes feature for a PolarDB for MySQL 8.0.2 cluster. The following issue is fixed: The 9000 error code is returned when you execute a SQL statement that contains special clauses after you enable the automatic request distribution between column store and row store nodes feature. The following issue is fixed: The EXPLAIN SELECT statement cannot be executed in specific scenarios. The following issue is fixed: Requests are temporarily blocked in specific scenarios when you delete a read-only node. The following issue is fixed: If you use a transaction-level connection pool in specific scenarios, connections may become unresponsive. The following issue is fixed: Specific proxy nodes do not work as expected. The following issue is fixed: When Consistency Level is set to Session Consistency or Global Consistency and the automatic request distribution between column store and row store nodes feature is enabled, PolarProxy exceptions or unresponsive connections may occur. The following issue is fixed: Routing errors may occur when temporary tables are used in SQL statements.

• 2.8.25 (Release date: August 30, 2023)

  Category	Description
  New feature and feature optimization	The connection maintenance scenario is optimized.
  Fixed issue	The following issue is fixed: Session hangs may occur due to internal keepalive or large packets. The following issue is fixed: The SELECT statement that contains custom variables is routed to the primary node. The following issue is fixed: The multi-statements that contain comments are routed to read-only nodes.

• 2.8.24 (Release date: August 8, 2023)

  Category	Description
  New feature and feature optimization	The logic of the internal monitor detection template is optimized.
  Fixed issue	The following issue is fixed: The SHOW WARNINGS statement times out for read-only endpoints. The following issue is fixed: PolarProxy exceptions occur in specific scenarios when the transaction connection pool is enabled.

• 2.8.21 (Release date: June 25, 2023)

  Category	Description
  New feature and feature optimization	The performance of some internal modules is optimized. The EXPLAIN SELECT statement can be routed to read-only nodes. The SHOW STATUS statement can be routed to the previous node. The query encryption feature is supported.
  Fixed issue	The following issue is fixed: Session hangs may be caused by the restart of AP nodes when automatic request distribution between row store and column store nodes is enabled. The following issue is fixed: Session hangs may be caused by node restart when parallel query is enabled. The following issue is fixed: The OPTIMIZE statement is routed to read-only nodes in some scenarios. The following issue is fixed: The WITH SELECT statement is routed to the primary node due to a parsing error in some scenarios. The following issue is fixed: Users can query the polar_proxy_encode library unexpectedly. The following issue is fixed: RT jitters occur when read-only nodes are added. The following issue is fixed: The dynamic data masking feature does not take effect. The following issue is fixed: Specific PolarProxy nodes are abnormal.

• 2.8.12 (Release date: March 1, 2023)

  Category	Description
  New feature and feature optimization	The performance of short-lived connections is improved by 10%.
  Fixed issue	The following issue is fixed: Row_number is routed to the primary node. The following issue is fixed: PolarProxy exceptions occur in some scenarios. The following issue is fixed: The monitor detection is abnormal and users are disconnected due to read-only node exceptions. The following issue is fixed: The PREPARE EXEC statement fails when the automatic request distribution between row store and column store nodes feature is enabled. The following issue is fixed: The dynamic data masking feature does not take effect.

• 2.8.11 (Release date: February 22, 2023)

  Category	Description
  New feature and feature optimization	Transactions, session consistency, and global consistency are supported when the automatic request distribution between row store and column store nodes feature is enabled.
  Fixed issue	The following issue is fixed: A routing error occurs when an SQL statement that exceeds 64 KB in length involves temporary tables. The following issue is fixed: Transient connections occur in PHP 8.0 if the status of the transaction is lost after transaction splitting. The following issue is fixed: Read-only endpoint authentication fails in some scenarios. The following issue is fixed: The session pool fails to be connected in specific scenarios.

• 2.8.8 (Release date: December 15, 2022)

  Category	Description
  New feature and feature optimization	Weight-based load balancing is supported in the read/write splitting feature. For more information, see Weight-based load balancing. Read-only endpoints support SLB by request. Automatic request distribution allows TP requests to be routed to AP nodes. When you enable or disable the elastic parallel query feature, it takes effect for existing connections.
  Fixed issue	Connection failures in specific scenarios are fixed.

• 2.8.3 (Release date: November 4, 2022)

  Category	Description
  New feature and feature optimization	The overload protection feature is supported. Hot standby nodes can be read.
  Fixed issue	The following issue is fixed: A cluster is disconnected when automatic request distribution between column store and row store nodes is enabled for the cluster and multiple statements are used. The following issue is fixed: RT jitters occur due to several internal exceptions.

• 2.7.9 (Release date: August 1, 2022)

  Category	Description
  New feature and feature optimization	The SHOW statement is supported for the SQL firewall feature. Multi-node elastic parallel queries and single-node elastic parallel queries are supported by cluster endpoints in read and write mode. The force hints apply to the PREPARE statement.
  Fixed issue	The following issue is fixed: The state of a session-level connection pool is inconsistent due to the loss of environment variables on newly added nodes. The following issue is fixed: A routing error occurs for the FOR UPDATE clause when read-only transactions are enabled in multi-statement scenarios. The following issue is fixed: A routing error occurs for the COM_STMT_FETCH stored procedure in consistency scenarios.

• 2.7.5 (Release date: July 15, 2022)

  Category	Description
  New feature and feature optimization	The SHOW statement is supported for the SQL firewall feature. Cluster endpoints in the read and write mode are supported.
  Fixed issue	The following issue is fixed: The offload reads from the primary node feature does not take effect for existing connections. Several internal exceptions are fixed.

• 2.4.35 (Release date: July 5, 2022)

  Category	Description
  Fixed issue	The following issue is fixed: Exceptions may occur on sessions if SET requests are received and the primary node restarts when persistent connections are enabled. Several issuing concerning inaccurate internal monitoring metrics and diagnostic tools are fixed.

• 2.4.33 (Release date: May 7, 2022)

  Category

  Description

  Fixed issue

  The following issue is fixed: Sessions cannot reuse correct connections because environmental variables for the transaction-level connection pool are not replayed. The following issues are fixed: An error occurs when the PREPARE EXEC statement is executed for HTAP automatic load execution. The following issue is fixed: The status value of packets is lost when transaction splitting is performed, which may affect PHP 8.0. The following issue is fixed: PolarProxy exceptions occur in specific scenarios.

• 2.4.30 (Release date: March 8, 2022)

  Category	Description
  New feature and feature optimization	Session consistency is optimized.
  Fixed issue	The following issue is fixed: Some routes for HTAP automatic request distribution are incorrect. The following issue is fixed: An error occurs on PolarProxy with specifications higher than 32C. The following issue is fixed: PolarProxy does not respond in specific scenarios. The following issue is fixed: An error occurs while routing the PREPARE SELECT FOR UPDATE statement in specific scenarios.

• 2.4.27 (Release date: December 30, 2021)

  Category	Description
  New feature and feature optimization	Automatic request distribution between column store and row store nodes feature is supported.
  Fixed issue	The following issue is fixed: The kill session operation fails. The following issue is fixed: The COM_STMT_EXECUTE command fails when the parameter type is frequently modified. The following issue is fixed: Read requests are routed to read-only nodes after the SELECT FOR UPDATE statement is executed in transactions. The following issue is fixed: When the primary node restarts and a new connection is established, special characters of the utf8mb4 type cannot be inserted. The following issue is fixed: The latest committed data cannot be read after a session-consistent transaction is committed.

• 2.4.22 (Release date: September 10, 2021)

  Category

  Description

  Fixed issue

  The following issue is fixed: PolarProxy fails to terminate PREPARE statements, which causes high memory usage in databases. The following issue is fixed: Persistent connections fail in specific scenarios. The following issue is fixed: An error occurs on PolarProxy when the default cluster endpoint is changed to a read-only endpoint. The following issue is fixed: PolarProxy does not respond in specific scenarios.

• 2.4.18 (Release date: August 12, 2021)

  Category

  Description

  Fixed issue

  The following issue is fixed: If no character set is specified for a Java Database Connection (JDBC) application, the text of the application data is garbled when the database node connected to the application is restarted or when account authentication fails. The following issue is fixed: The database service fails to connect to Flink applications. Some requests that are supposed to be routed to a temporary table are routed to other tables.

• 2.4.17 (Release date: July 14, 2021)

  Category	Description
  New feature and feature optimization	PolarDB for MySQL 5.7 supports transaction connection retention in failover scenarios. Several internal metrics are added to monitor the cluster performance.
  Fixed issue	The following issue is fixed: The response time becomes longer due to a MySQL database account authentication failure. The following issue is fixed: When a read-only node becomes faulty, the system does not route new requests to the node. The following issue is fixed: Read-only endpoints cannot be accessed if the parallel query feature is enabled. The following issue is fixed: A routing error occurs when you query the current timestamp. The following issue is fixed: A routing error occurs when the FOR UPDATE clause is parsed. The following issue is fixed: A routing error occurs due to incorrect syntax analysis of the @a keyword in a JOIN clause. The following issue is fixed: The attempt to log on to a MySQL 8.0 client fails due to an authentication failure, because no password is provided. The following issues are fixed: Some PREPARE statements with the name parameter cannot be executed.

• 2.4.12 (Release date: May 20, 2021)

  Category	Description
  New feature and feature optimization	The dynamic data masking feature is supported. For more information, see Dynamic data masking.
  Fixed issue	PolarProxy exceptions occur in specific scenarios.

• 2.4.7 (Release date: March 15, 2021)

  Category	Description
  New feature and feature optimization	The persistent connections feature is supported.
  Fixed issue	The following issue is fixed: A routing error occurs when you execute a statement in which LOCK IN SHARED MODE is specified.

Release notes for PolarProxy 1.x.x

• 1.13.42 (Release date: December 15, 2022)

  Category	Description
  Fixed issue	The following issue is fixed: Connections to a database fail when a large number of connections are established. The following issue is fixed: RT jittering is caused by internal scheduled tasks.

• 1.13.39 (Release date: July 20, 2022)

  Category	Description
  New feature and feature optimization	PolarProxy performance is optimized in scenarios where tremendous authentication events with invalid accounts occur. The account authentication feature is optimized. When authentication events with invalid accounts occur, global throttling is changed to account throttling.
  Fixed issue	The following issue is fixed: The transaction status is lost when a transaction is split. The following issue is fixed: Environment variables in a transaction connection pool are not replayed. The following issue is fixed: The PREPARE statement cannot be terminated for XA transactions. Several internal exceptions are fixed.

• 1.13.34 (Release date: March 3, 2022)

  Category	Description
  New feature and feature optimization	MySQL utf8mb3 encoding is supported. Session consistency is optimized.
  Fixed issue	The following issue is fixed: A routing error occurs for the SELECT FOR UPDATE statement due to excessive prepare stmt parameters.

• 1.13.30 (Release date: December 30, 2021)

  Category	Description
  Fixed issue	The following issue is fixed: The latest committed data cannot be read after a session-consistent transaction is committed.

• 1.13.27 (Release date: November 16, 2021)

  Category	Description
  Fixed issue	The following issue is fixed: Some clients are incompatible with SSL. The performance of parsing INSERT statements when PolarProxy is used is improved.

• 1.13.25 (Release date: August 18, 2021)

  Category	Description
  Fixed issue	The following issue is fixed: A memory leak occurs on PolarProxy due to a MySQL database account authentication failure. PolarProxy does not respond when multiple endpoints are used to access a cluster.

• 1.13.22 (Release date: July 21, 2021)

  Category	Description
  New feature and feature optimization	The SELECT last_insert_id() statement can be executed after the transaction-level connection pool feature is enabled. The FOUND_ROWS function is supported after the transaction-level connection pool feature is enabled. The COM_STATISTICS command can be routed to read-only nodes. The transaction-level connection pool feature is optimized. The global consistency feature is optimized. Requests can be routed to a read-only node even if the node is the only read-only node that meets the consistency requirements. Queries that contain geo functions can be routed to read-only nodes. Several internal metrics are added to monitor the cluster performance.
  Fixed issue	The following issue is fixed: Routing errors occur due to incorrect parsing of several SQL statements. The following issue is fixed: In specific scenarios, the stmt_exec() command fails to run after the stmt_long_data() command is run. The LOAD DATA INFILE statement cannot be executed.

• 1.13.5 (Release date: December 1, 2020)

  Category	Description
  New feature and feature optimization	Eventual consistency is applicable to transaction splitting. The following hints are supported: force node connection /*force_proxy_internal*/set force_node = 'pi-aaaaaaaaa'; After you establish this connection, all requests are routed only to the pi-aaaaaaaaa node. If this node becomes faulty, the set force node 'pi-aaaaaaaaa' is not found, please check. error message is returned. force node query /*force_node='pi-aaaaaaaa'*/ show processlist; This statement can be executed only on the pi-aaaaaaaa node. If this node becomes faulty, the 'force hint server node is not found, please check.' error message is returned. Several internal metrics are added to monitor the cluster performance.
  Fixed issue	The following issue is fixed: If the mode keyword is included in the select type, status, mode, where gtx_id = '4' FOR UPDATE; statement, the statement is routed to read-only nodes. The following issue is fixed: In specific scenarios, loads are unbalanced among database nodes in a cluster. The stmt_close command fails to run after a PREPARE statement is executed.

• 1.12.10 (Release date: October 19, 2020)

  Category	Description
  Fixed issue	The following issue is fixed: PolarDB clusters that run MySQL 8.0 cannot be accessed after SSL encryption is enabled for the clusters. After the state of a database node changes from DOWN to RUNNING, PolarProxy fails to route subsequent requests to the database node.

• 1.12.7 (Release date: August 6, 2020)

  Category	Description
  New feature and feature optimization	The SHOW FULL PROCESSLIST statement is supported. XA transactions are supported.
  Fixed issue	Several issues of the transaction-level connection pool are fixed. Several issues that occur when you access read-only nodes in a global database network (GDN) are fixed. The following issue is fixed: An error occurs when you execute the SHOW PROCESSLIST statement on a cluster that runs MySQL 8.0. Several connections failed.

• 1.11.12 (Release date: June 22, 2020)

  Category	Description
  New feature and feature optimization	The transaction-level connection pool feature is supported. The parallel query feature is supported by read-only endpoints of PolarDB for MySQL clusters that run MySQL 8.0.

• 1.10.7 (Release date: March 18, 2020)

  Category	Description
  New feature and feature optimization	The global consistency feature is supported.
  Fixed issue	An error occurs when you initialize system environment variables for a session-level connection pool.

• 1.9.23 (Release date: February 21, 2020)

  Category	Description
  New feature and feature optimization	The root account can be used to connect to a cluster. SSL encryption is supported.
  Fixed issue	The following issue is fixed: The change user command fails. The following issue is fixed: The load file command fails. The following issue is fixed: When an application receives packets out of order, the application returns the Exception: Packets out of order error message. The following issue is fixed: Read-only endpoints are disconnected when the primary node becomes faulty.

• 1.9.14 (Release date: December 24, 2019)

  Category	Description
  New feature and feature optimization	The /*FORCE_SLAVE*/ and /*FORCE_MASTE*/ hints are supported. You can configure whether to offload read requests from the primary node to read-only nodes.
  Fixed issue	The following issue is fixed: Garbled text exists in the response if the default value of the charset parameter is invalid. The following issue is fixed: The returned string that indicates the MySQL engine version is incorrect.