发布日期: 2024-06-13
版本号: v20.0.0-rc1

Vitess v20.0.0版本发布，主要变更包括：删除已弃用的--vreplication_tablet_type标志、池容量相关标志及vitess/base和vitess/k8s Docker镜像，停止支持gh-ost迁移工具并移除相关测试。破坏性变更涉及VTOrc指标名称调整、VStream API中ENUM/SET类型数据改用字符串值返回、shutdown_grace_period默认值改为3秒、新增--unmanaged标志替代旧参数，以及Durabler接口方法重命名。查询兼容性增强，支持Vindex提示、带LIMIT的UPDATE、多表更新/删除、子查询删除、用户定义函数跟踪及INSERT行别名语法。标志变更包括pprof-http默认关闭、新增健康检查并发控制标志及查询日志采样功能。次要改进包含新增查询缓存命中统计、VTTablet字符处理统计、gRPC认证凭据通过SIGHUP重载，VTAdmin升级至Node v20并替换Highcharts为D3图表。此版本共合并410项拉取请求，详细日志可查阅GitHub发布页。

更新内容（中文）

Vitess v20.0.0 版本发布

概要

重大变更

删除项

`--vreplication_tablet_type` 标志

已删除此前弃用的 --vreplication_tablet_type 标志。

连接池容量标志

已删除此前弃用的 --queryserver-config-query-pool-waiter-cap、--queryserver-config-stream-pool-waiter-cap 和 --queryserver-config-txpool-waiter-cap 标志。

`vitess/base` 和 `vitess/k8s` Docker 镜像

由于已从 vitess/lite 镜像中移除 MySQL，现删除 vitess/base 和 vitess/k8s 镜像。

这些镜像不再有用，因为可将 vitess/lite 作为其他 Docker 镜像的基础（如 vitess/vtgate、vitess/vttablet 等）。

`gh-ost` 二进制文件及端到端测试

Vitess 20.0 停止支持 gh-ost DDL 策略。

vttablet 二进制文件不再嵌入 gh-ost。使用 gh-ost DDL 策略的用户需在 vttablet 主机或 pod 上提供 gh-ost 二进制文件。Vitess 将在系统 PATH 中查找 gh-ost；否则用户应指定 vttablet --gh-ost-path。

Vitess 端到端测试不再使用或测试 gh-ost 迁移。

遗留的 `EmergencyReparentShard` 统计项

以下 EmergencyReparentShard 统计项在 Vitess 18.0 中已弃用，现于 Vitess 20.0 中移除：

ers_counter
ers_success_counter
ers_failure_counter

这些计数器已被以下统计项替代（于 Vitess 18.0 引入）：

emergency_reparent_counts - EmergencyReparentShard 运行次数，按键空间、分片和操作结果细分。
planned_reparent_counts - PlannedReparentShard 运行次数，按键空间、分片和操作结果细分。

同时新增 reparent_shard_operation_timings 统计项以提供重新分片操作的各阶段耗时。

破坏性变更

VTOrc 指标名称变更

VTOrc 中以下指标名称已变更。旧指标在此版本中仍可通过 /debug/vars 获取，但将在后续版本中移除。新指标名称与旧指标名称在 Prometheus 中对应同一指标名称，故无实际变化。

旧指标名称	新指标名称	Prometheus 名称
`analysis.change.write`	`AnalysisChangeWrite`	`vtorc_analysis_change_write`
`audit.write`	`AuditWrite`	`vtorc_audit_write`
`discoveries.attempt`	`DiscoveriesAttempt`	`vtorc_discoveries_attempt`
`discoveries.fail`	`DiscoveriesFail`	`vtorc_discoveries_fail`
`discoveries.instance_poll_seconds_exceeded`	`DiscoveriesInstancePollSecondsExceeded`	`vtorc_discoveries_instance_poll_seconds_exceeded`
`discoveries.queue_length`	`DiscoveriesQueueLength`	`vtorc_discoveries_queue_length`
`discoveries.recent_count`	`DiscoveriesRecentCount`	`vtorc_discoveries_recent_count`
`instance.read`	`InstanceRead`	`vtorc_instance_read`
`instance.read_topology`	`InstanceReadTopology`	`vtorc_instance_read_topology`
`emergency_reparent_counts`	`EmergencyReparentCounts`	`vtorc_emergency_reparent_counts`
`planned_reparent_counts`	`PlannedReparentCounts`	`vtorc_planned_reparent_counts`
`reparent_shard_operation_timings`	`ReparentShardOperationTimings`	`vtorc_reparent_shard_operation_timings_bucket`

VTGate VStream API 中 ENUM 和 SET 列的处理

VTGate VStream API 现在在复制/快照阶段和流式阶段均以字符串值形式返回 ENUM 和 SET 列类型值（嵌入在 VEvent 消息的 RowChange 消息中）。此变更为使 VStream API 更友好直观，并确保两阶段行为一致。在此变更前，复制阶段中 ENUM 和 SET 列值为字符串，而流式阶段为整数（仅对 MySQL 有内部意义）。此不一致导致各 VStream 客户端/消费者（如 Debezium Vitess 连接器）处理困难。现行为统一为字符串值，因最终接收端通常非 MySQL，消费者需自行映射。为平稳过渡，FieldEvent 消息新增 EnumSetStringValues 布尔字段。当该字段为 false（Vitess v19 及更早版本）时，消费者需在流式阶段执行映射；为 true 时则无需映射。

示例表结构及数据变更前后的流输出对比详见原文档。

若使用 Debezium Vitess 连接器，应在升级至 Vitess v20.0.1 或更高版本前升级连接器至 2.7（将包含相关变更）。若使用 PlanetScale 连接器（AirByte、FiveTran 或 singer-tap）则无需操作。

自定义 VStream 客户端需使用 v20 binlogdata protos 构建新客户端以支持 Vitess v20.0.1 或更高版本。

`shutdown_grace_period` 默认值变更

--shutdown_grace_period 标志默认值从 0 秒 变更为 3 秒，以提高故障切换弹性并防止 PlannedReparentShard 超时。

若需保留旧行为，可设置该标志为 0 秒，但存在 PlannedReparentShard 超时风险。

新增 `unmanaged` 标志及弃用 `disable_active_reparents`

新增 --unmanaged 标志以标记非托管 tablet，并运行验证确保配置正确。vttablet、vtcombo 和 vttestserver 中的 --disable_active_reparents 标志已弃用，将在未来版本移除。指定 --unmanaged 时将同时禁用复制命令和修复。

自此版本起，所有非托管 tablet 应指定此标志。

弃用 `recovery-period-block-duration` 标志

VTOrc 中 --recovery-period-block-duration 标志已弃用，其值现被忽略，将在后续版本移除。VTOrc 不再在恢复完成后阻塞后续恢复，因获取分片锁后会刷新信息。

`mysqlctld` 的 `onterm_timeout` 默认值变更

mysqlctld 的 --onterm_timeout 标志默认值变更为足以等待 --shutdown-wait-time 默认值，确保 MySQL 在 TERM 信号下正常关闭。

`MoveTables` 默认移除分片键空间迁移表时自动递增子句

MoveTables create 子命令新增 --remove-sharded-auto-increment 标志并默认设为 true。该标志控制从非分片键空间迁移表至分片键空间时是否移除 MySQL auto_increment 子句。分片表通常不应使用 auto_increment，建议使用全局唯一标识或 Vitess 序列。如需保留，创建 workflow 时可设此标志为 false。

`Durabler` 接口方法重命名

Durabler 接口方法改为公共方法（首字母大写）以便外部包集成自定义耐久性策略（详见 RFC）。

变更：

promotionRule 重命名为 PromotionRule
semiSyncAckers 重命名为 SemiSyncAckers
isReplicaSemiSync 重命名为 IsReplicaSemiSync

查询兼容性

Vindex 提示

Vitess 现支持 Vindex 提示，允许用户通过指定应考虑或忽略的 vindex 影响查询分片路由，提升分片数据库查询效率。

示例：

SELECT * FROM user USE VINDEX (hash_user_id, secondary_vindex) WHERE user_id = 123;
SELECT * FROM order IGNORE VINDEX (range_order_id) WHERE order_date = '2021-01-01';

带 LIMIT 的 UPDATE 支持

新增分片表带 LIMIT 的 UPDATE 支持。

示例：update t1 set t1.foo = 'abc', t1.bar = 23 where t1.baz > 5 limit 1

多表 UPDATE 支持

新增分片表多表 JOIN 更新单目标表列的 UPDATE 支持。

示例：update t1 join t2 on t1.id = t2.id join t3 on t1.col = t3.col set t1.baz = 'abc', t1.apa = 23 where t3.foo = 5 and t2.bar = 7

多目标 UPDATE 支持

新增分片表多目标表 UPDATE 支持。

示例：update t1 join t2 on t1.id = t2.id set t1.foo = 'abc', t2.bar = 23

带子查询的 DELETE 支持

新增分片表带子查询的 DELETE 支持。

示例：delete from t1 where id in (select col from t2 where foo = 32 and bar = 43)

多目标 DELETE 支持

新增分片表多目标 DELETE 支持。

示例：delete t1, t3 from t1 join t2 on t1.id = t2.id join t3 on t1.col = t3.col

用户定义函数支持

VTGate 可追踪用户定义函数以优化查询计划。需在 VTGate 启用 --track-udfs 标志。未启用时 VTGate 不会感知需下推至 MySQL 的聚合 UDF。

INSERT 行别名支持

新增 INSERT 语句行别名以配合 on duplicate key update。

示例：

insert into user(id, name, email) values (100, 'Alice', 'alice@mail.com') as new on duplicate key update name = new.name, email = new.email
insert into user(id, name, email) values (100, 'Alice', 'alice@mail.com') as new(m, n, p) on duplicate key update name = n, email = p

查询超时

查询超时后，Vitess 现使用 kill query 代替 kill connection 以保留连接，减少连接波动。

标志变更

`pprof-http` 默认值变更

v19 引入的 --pprof-http 标志默认值从 true 变更为 false，使 HTTP pprof 端点变为需手动启用功能。如需启用，需显式

更新内容（原始）

Release of Vitess v20.0.0

Major Changes

Deletion

`--vreplication_tablet_type` flag

The previously deprecated flag --vreplication_tablet_type has been deleted.

Pool Capacity Flags

The previously deprecated flags --queryserver-config-query-pool-waiter-cap, --queryserver-config-stream-pool-waiter-cap and --queryserver-config-txpool-waiter-cap have been deleted.

`vitess/base` and `vitess/k8s` Docker images

Since we have deleted MySQL from our vitess/lite image, we are removing the vitess/base and vitess/k8s images.

These images are no longer useful since we can use vitess/lite as the base of many other Docker images (vitess/vtgate, vitess/vtgate, …).

`gh-ost` binary and endtoend tests

Vitess 20.0 drops support for gh-ost DDL strategy.

vttablet binary no longer embeds a gh-ost binary. Users of gh-ost DDL strategy will need to supply a gh-ost binary on the vttablet host or pod. Vitess will look for the gh-ost binary in the system PATH; otherwise the user should supply vttablet --gh-ost-path.

Vitess’ endtoend tests no longer use nor test gh-ost migrations.

Legacy `EmergencyReparentShard` stats

The following EmergencyReparentShard stats were deprecated in Vitess 18.0 and are removed in Vitess 20.0:

ers_counter
ers_success_counter
ers_failure_counter

These counters are replaced by the following stats (introduced in Vitess 18.0):

emergency_reparent_counts - Number of times EmergencyReparentShard has been run. It is further subdivided by the keyspace, shard and the result of the operation.
planned_reparent_counts - Number of times PlannedReparentShard has been run. It is further subdivided by the keyspace, shard and the result of the operation.

Also, the reparent_shard_operation_timings stat was added to provide per-operation timings of reparent operations.

Breaking Changes

Metric Name Changes in VTOrc

The following metric names have been changed in VTOrc. The old metrics are still available in /debug/vars for this release, but will be removed in later releases. The new metric names and the deprecated metric names resolve to the same metric name on prometheus, so there is no change there.

Old Metric Name	New Metric Name	Name in Prometheus
`analysis.change.write`	`AnalysisChangeWrite`	`vtorc_analysis_change_write`
`audit.write`	`AuditWrite`	`vtorc_audit_write`
`discoveries.attempt`	`DiscoveriesAttempt`	`vtorc_discoveries_attempt`
`discoveries.fail`	`DiscoveriesFail`	`vtorc_discoveries_fail`
`discoveries.instance_poll_seconds_exceeded`	`DiscoveriesInstancePollSecondsExceeded`	`vtorc_discoveries_instance_poll_seconds_exceeded`
`discoveries.queue_length`	`DiscoveriesQueueLength`	`vtorc_discoveries_queue_length`
`discoveries.recent_count`	`DiscoveriesRecentCount`	`vtorc_discoveries_recent_count`
`instance.read`	`InstanceRead`	`vtorc_instance_read`
`instance.read_topology`	`InstanceReadTopology`	`vtorc_instance_read_topology`
`emergency_reparent_counts`	`EmergencyReparentCounts`	`vtorc_emergency_reparent_counts`
`planned_reparent_counts`	`PlannedReparentCounts`	`vtorc_planned_reparent_counts`
`reparent_shard_operation_timings`	`ReparentShardOperationTimings`	`vtorc_reparent_shard_operation_timings_bucket`

ENUM and SET column handling in VTGate VStream API

The VTGate VStream API now returns ENUM and SET column type values in VEvent messages (in the embedded RowChange messages) as their string values instead of the integer based ones — in both the copy/snapshot phase and the streaming phase. This change was done to make the VStream API more user-friendly, intuitive, and to align the behavior across both phases. Before this change the values for ENUM and SET columns were string values in the copy phase but integer values (which only have an internal meaning to MySQL) in the streaming phase. This inconsistency led to various challenges and issues for each VStream client/consumer (e.g. the Debezium Vitess connector failed to properly perform a snapshot for tables containing these column types). Now the behavior is intuitive — clients need the string values as the eventual sink is often not MySQL so each consumer needed to perform the mappings themselves — and consistent. While this is a (potentially) breaking change, a new boolean field has been added to the FieldEvent message called EnumSetStringValues. When that field is false (in Vitess v19 and older) then the consumer will need to perform the mappings during streaming phase, but not during copy phase. When this field is true, then no mapping is required. This will help to ensure a smooth transition for all consumers over time. To demonstrate, let’s look at the textual output (printing the received VEvents as strings) when streaming a single enum_set_test table from the unsharded commerce keyspace so that we can see what the VStream looks like before and after when we start a new VStream in copy/snapshot mode and then transition to streaming mode for the following table:

CREATE TABLE `enum_set_test` (
  `id` int NOT NULL AUTO_INCREMENT,
  `name` varchar(120) DEFAULT NULL,
  `shirt_size` enum('small','medium','large','xlarge','xxlarge') DEFAULT NULL,
  `hobbies` set('knitting','cooking','pickleball','biking','hiking','motorcycle','video games','reading') DEFAULT NULL,
  PRIMARY KEY (`id`)
)

And with the table having this data when we start our VStream and begin the copy/snapshot phase:

mysql> select * from enum_set_test;
+----+-----------+------------+-------------------------+
| id | name      | shirt_size | hobbies                 |
+----+-----------+------------+-------------------------+
|  1 | Billy Bob | xlarge     | cooking,reading         |
|  2 | Sally Mae | medium     | knitting,cooking,hiking |
+----+-----------+------------+-------------------------+
2 rows in set (0.00 sec)

And finally we will perform the following inserts and updates to the table during the streaming phase:

insert into enum_set_test values (3, "Matt Lord", 'medium', 'pickleball,biking,hiking,motorcycle,video games,reading');
insert into enum_set_test values (4, "Jerry Badyellow", 'large', '');
update enum_set_test set shirt_size = 'small', hobbies = 'knitting,cooking,hiking,reading' where id = 2;

Vitess v19 and older:

[type:BEGIN keyspace:"commerce" shard:"0" type:FIELD field_event:{table_name:"commerce.enum_set_test" fields:{name:"id" type:INT32 table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"id" column_length:11 charset:63 flags:49667 column_type:"int"} fields:{name:"name" type:VARCHAR table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"name" column_length:480 charset:255 column_type:"varchar(120)"} fields:{name:"shirt_size" type:ENUM table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"shirt_size" column_length:28 charset:255 flags:256 column_type:"enum('small','medium','large','xlarge','xxlarge')"} fields:{name:"hobbies" type:SET table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"hobbies" column_length:288 charset:255 flags:2048 column_type:"set('knitting','cooking','pickleball','biking','hiking','motorcycle','video games','reading')"} keyspace:"commerce" shard:"0"} keyspace:"commerce" shard:"0"]
[type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/ce357206-0d49-11ef-8fd1-a74564279579:1-35"}} keyspace:"commerce" shard:"0"]
[type:ROW row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:9 lengths:6 lengths:15 values:"1Billy Bobxlargecooking,reading"}} keyspace:"commerce" shard:"0"} keyspace:"commerce" shard:"0" type:ROW row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:9 lengths:6 lengths:23 values:"2Sally Maemediumknitting,cooking,hiking"}} keyspace:"commerce" shard:"0"} keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/ce357206-0d49-11ef-8fd1-a74564279579:1-35" table_p_ks:{table_name:"enum_set_test" lastpk:{fields:{name:"id" type:INT32 charset:63 flags:49667} rows:{lengths:1 values:"2"}}}}} keyspace:"commerce" shard:"0" type:COMMIT keyspace:"commerce" shard:"0"]
[type:BEGIN keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/ce357206-0d49-11ef-8fd1-a74564279579:1-35"}} keyspace:"commerce" shard:"0" type:COMMIT keyspace:"commerce" shard:"0"]
[type:COPY_COMPLETED keyspace:"commerce" shard:"0" type:COPY_COMPLETED]
[type:BEGIN timestamp:1715179728 current_time:1715179728532658000 keyspace:"commerce" shard:"0" type:FIELD timestamp:1715179728 field_event:{table_name:"commerce.enum_set_test" fields:{name:"id" type:INT32 table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"id" column_length:11 charset:63 flags:49667 column_type:"int"} fields:{name:"name" type:VARCHAR table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"name" column_length:480 charset:255 column_type:"varchar(120)"} fields:{name:"shirt_size" type:ENUM table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"shirt_size" column_length:28 charset:255 flags:256 column_type:"enum('small','medium','large','xlarge','xxlarge')"} fields:{name:"hobbies" type:SET table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"hobbies" column_length:288 charset:255 flags:2048 column_type:"set('knitting','cooking','pickleball','biking','hiking','motorcycle','video games','reading')"} keyspace:"commerce" shard:"0"} current_time:1715179728535652000 keyspace:"commerce" shard:"0" type:ROW timestamp:1715179728 row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:9 lengths:1 lengths:3 values:"3Matt Lord2252"}} keyspace:"commerce" shard:"0" flags:1} current_time:1715179728535739000 keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/ce357206-0d49-11ef-8fd1-a74564279579:1-36"}} keyspace:"commerce" shard:"0" type:COMMIT timestamp:1715179728 current_time:1715179728535754000 keyspace:"commerce" shard:"0"]
[type:BEGIN timestamp:1715179735 current_time:1715179735538607000 keyspace:"commerce" shard:"0" type:ROW timestamp:1715179735 row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:15 lengths:1 lengths:1 values:"4Jerry Badyellow30"}} keyspace:"commerce" shard:"0" flags:1} current_time:1715179735538659000 keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/ce357206-0d49-11ef-8fd1-a74564279579:1-37"}} keyspace:"commerce" shard:"0" type:COMMIT timestamp:1715179735 current_time:1715179735538672000 keyspace:"commerce" shard:"0"]
[type:BEGIN timestamp:1715179741 current_time:1715179741728690000 keyspace:"commerce" shard:"0" type:ROW timestamp:1715179741 row_event:{table_name:"commerce.enum_set_test" row_changes:{before:{lengths:1 lengths:9 lengths:1 lengths:2 values:"2Sally Mae219"} after:{lengths:1 lengths:9 lengths:1 lengths:3 values:"2Sally Mae1147"}} keyspace:"commerce" shard:"0" flags:1} current_time:1715179741728730000 keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/ce357206-0d49-11ef-8fd1-a74564279579:1-38"}} keyspace:"commerce" shard:"0" type:COMMIT timestamp:1715179741 current_time:1715179741728744000 keyspace:"commerce" shard:"0"]

Vitess v20 and newer:

[type:BEGIN keyspace:"commerce" shard:"0" type:FIELD field_event:{table_name:"commerce.enum_set_test" fields:{name:"id" type:INT32 table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"id" column_length:11 charset:63 flags:49667 column_type:"int"} fields:{name:"name" type:VARCHAR table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"name" column_length:480 charset:255 column_type:"varchar(120)"} fields:{name:"shirt_size" type:ENUM table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"shirt_size" column_length:28 charset:255 flags:256 column_type:"enum('small','medium','large','xlarge','xxlarge')"} fields:{name:"hobbies" type:SET table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"hobbies" column_length:288 charset:255 flags:2048 column_type:"set('knitting','cooking','pickleball','biking','hiking','motorcycle','video games','reading')"} keyspace:"commerce" shard:"0" enum_set_string_values:true} keyspace:"commerce" shard:"0"]
[type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/156f702a-0d47-11ef-8723-653d045ab990:1-50"}} keyspace:"commerce" shard:"0"]
[type:ROW row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:9 lengths:6 lengths:15 values:"1Billy Bobxlargecooking,reading"}} keyspace:"commerce" shard:"0"} keyspace:"commerce" shard:"0" type:ROW row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:9 lengths:6 lengths:23 values:"2Sally Maemediumknitting,cooking,hiking"}} keyspace:"commerce" shard:"0"} keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/156f702a-0d47-11ef-8723-653d045ab990:1-50" table_p_ks:{table_name:"enum_set_test" lastpk:{fields:{name:"id" type:INT32 charset:63 flags:49667} rows:{lengths:1 values:"2"}}}}} keyspace:"commerce" shard:"0" type:COMMIT keyspace:"commerce" shard:"0"]
[type:BEGIN keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/156f702a-0d47-11ef-8723-653d045ab990:1-50"}} keyspace:"commerce" shard:"0" type:COMMIT keyspace:"commerce" shard:"0"]
[type:COPY_COMPLETED keyspace:"commerce" shard:"0" type:COPY_COMPLETED]
[type:BEGIN timestamp:1715179399 current_time:1715179399817221000 keyspace:"commerce" shard:"0" type:FIELD timestamp:1715179399 field_event:{table_name:"commerce.enum_set_test" fields:{name:"id" type:INT32 table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"id" column_length:11 charset:63 flags:49667 column_type:"int"} fields:{name:"name" type:VARCHAR table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"name" column_length:480 charset:255 column_type:"varchar(120)"} fields:{name:"shirt_size" type:ENUM table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"shirt_size" column_length:28 charset:255 flags:256 column_type:"enum('small','medium','large','xlarge','xxlarge')"} fields:{name:"hobbies" type:SET table:"enum_set_test" org_table:"enum_set_test" database:"vt_commerce" org_name:"hobbies" column_length:288 charset:255 flags:2048 column_type:"set('knitting','cooking','pickleball','biking','hiking','motorcycle','video games','reading')"} keyspace:"commerce" shard:"0" enum_set_string_values:true} current_time:1715179399821735000 keyspace:"commerce" shard:"0" type:ROW timestamp:1715179399 row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:9 lengths:6 lengths:55 values:"3Matt Lordmediumpickleball,biking,hiking,motorcycle,video games,reading"}} keyspace:"commerce" shard:"0" flags:1} current_time:1715179399821762000 keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/156f702a-0d47-11ef-8723-653d045ab990:1-51"}} keyspace:"commerce" shard:"0" type:COMMIT timestamp:1715179399 current_time:1715179399821801000 keyspace:"commerce" shard:"0"]
[type:BEGIN timestamp:1715179399 current_time:1715179399822310000 keyspace:"commerce" shard:"0" type:ROW timestamp:1715179399 row_event:{table_name:"commerce.enum_set_test" row_changes:{after:{lengths:1 lengths:15 lengths:5 lengths:0 values:"4Jerry Badyellowlarge"}} keyspace:"commerce" shard:"0" flags:1} current_time:1715179399822355000 keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/156f702a-0d47-11ef-8723-653d045ab990:1-52"}} keyspace:"commerce" shard:"0" type:COMMIT timestamp:1715179399 current_time:1715179399822360000 keyspace:"commerce" shard:"0"]
[type:BEGIN timestamp:1715179400 current_time:1715179400512056000 keyspace:"commerce" shard:"0" type:ROW timestamp:1715179400 row_event:{table_name:"commerce.enum_set_test" row_changes:{before:{lengths:1 lengths:9 lengths:6 lengths:23 values:"2Sally Maemediumknitting,cooking,hiking"} after:{lengths:1 lengths:9 lengths:5 lengths:31 values:"2Sally Maesmallknitting,cooking,hiking,reading"}} keyspace:"commerce" shard:"0" flags:1} current_time:1715179400512094000 keyspace:"commerce" shard:"0" type:VGTID vgtid:{shard_gtids:{keyspace:"commerce" shard:"0" gtid:"MySQL56/156f702a-0d47-11ef-8723-653d045ab990:1-53"}} keyspace:"commerce" shard:"0" type:COMMIT timestamp:1715179400 current_time:1715179400512108000 keyspace:"commerce" shard:"0"]

An example key difference there being that after:{lengths:1 lengths:9 lengths:1 lengths:3 values:"2Sally Mae1147"} from Vitess v19 and older becomes after:{lengths:1 lengths:9 lengths:5 lengths:31 values:"2Sally Maesmallknitting,cooking,hiking,reading"} from Vitess v20 and newer. So 1 -> small and 147 -> knitting,cooking,hiking,reading for the ENUM and SET column values respectively. This also demonstrates why this mapping is necessary in consumers/clients, as 147 has no logical meaning/value for this column outside of MySQL internals.

If you’re using the Debezium Vitess connector, you should upgrade your connector to 2.7 (the next release) — which should contain the relevant necessary changes — prior to upgrading Vitess to v20.0.1 or later. If you’re using any of the PlanetScale connectors (AirByte, FiveTran, or singer-tap) then no actions are required.

If you’re using a custom VStream client/consumer, then you will need to build a new client with the updated v20 binlogdata protos (source for which would be in main or the release-20.0 branch) before needing to support Vitess v20.0.1 or later. Your client will then be able to handle old and new messages, with older messages always having this new field set to false.

`shutdown_grace_period` Default Change

The --shutdown_grace_period flag, which was introduced in v2 with a default of 0 seconds, has now been changed to default to 3 seconds. This makes reparenting in Vitess resilient to client errors, and prevents PlannedReparentShard from timing out.

In order to preserve the old behaviour, the users can set the flag back to 0 seconds causing open transactions to never be shutdown, but in that case, they run the risk of PlannedReparentShard calls timing out.

New `unmanaged` Flag and `disable_active_reparents` deprecation

New flag --unmanaged has been introduced in this release to make it easier to flag unmanaged tablets. It also runs validations to make sure the unmanaged tablets are configured properly. --disable_active_reparents flag has been deprecated for vttablet, vtcombo and vttestserver binaries and will be removed in future releases. Specifying the --unmanaged flag will also block replication commands and replication repairs.

Starting this release, all unmanaged tablets should specify this flag.

`recovery-period-block-duration` Flag deprecation

The flag --recovery-period-block-duration has been deprecated in VTOrc from this release. Its value is now ignored and the flag will be removed in later releases. VTOrc no longer blocks recoveries for a certain duration after a previous recovery has completed. Since VTOrc refreshes the required information after acquiring a shard lock, blocking of recoveries is not required.

`mysqlctld` `onterm_timeout` Default Change

The --onterm_timeout flag default value has changed for mysqlctld. It now is by default long enough to be able to wait for the default --shutdown-wait-time when shutting down on a TERM signal.

This is necessary since otherwise MySQL would never shut down cleanly with the old defaults, since mysqlctld would shut down already after 10 seconds by default.

`MoveTables` now removes `auto_increment` clauses by default when moving tables from an unsharded keyspace to a sharded one

A new --remove-sharded-auto-increment flag has been added to the MoveTables create sub-command and it is set to true by default. This flag controls whether any MySQL auto_increment clauses should be removed from the table definitions when moving tables from an unsharded keyspace to a sharded one. This is now done by default as auto_increment clauses should not typically be used with sharded tables and you should instead rely on externally generated values such as a form of universally/globally unique identifiers or use Vitess sequences in order to ensure that each row has a unique identifier (Primary Key value) across all shards. If for some reason you want to retain them you can set this new flag to false when creating the workflow.

`Durabler` interface method renaming

The methods of the Durabler interface in go/vt/vtctl/reparentutil were renamed to be public (capitalized) methods to make it easier to integrate custom Durability Policies from external packages. See RFC for details.

Users of custom Durability Policies must rename private Durabler methods.

Changes:

The promotionRule method was renamed to PromotionRule
The semiSyncAckers method was renamed to SemiSyncAckers
The isReplicaSemiSync method was renamed to IsReplicaSemiSync

Query Compatibility

Vindex Hints

Vitess now supports Vindex hints that provide a way for users to influence the shard routing of queries in Vitess by specifying, which vindexes should be considered or ignored by the query planner. This feature enhances the control over query execution, allowing for potentially more efficient data access patterns in sharded databases.

Example:

   SELECT * FROM user USE VINDEX (hash_user_id, secondary_vindex) WHERE user_id = 123;
   SELECT * FROM order IGNORE VINDEX (range_order_id) WHERE order_date = '2021-01-01';

For more information about Vindex hints and its usage, please consult the documentation.

Update with Limit Support

Support is added for sharded update with limit.

Example: update t1 set t1.foo = 'abc', t1.bar = 23 where t1.baz > 5 limit 1

More details about how it works is available in MySQL Docs

Update with Multi Table Support

Support is added for sharded multi-table update with column update on single target table using multiple table join.

Example: update t1 join t2 on t1.id = t2.id join t3 on t1.col = t3.col set t1.baz = 'abc', t1.apa = 23 where t3.foo = 5 and t2.bar = 7

More details about how it works is available in MySQL Docs

Update with Multi Target Support

Support is added for sharded multi table target update.

Example: update t1 join t2 on t1.id = t2.id set t1.foo = 'abc', t2.bar = 23

More details about how it works is available in MySQL Docs

Delete with Subquery Support

Support is added for sharded table delete with subquery

Example: delete from t1 where id in (select col from t2 where foo = 32 and bar = 43)

Delete with Multi Target Support

Support is added for sharded multi table target delete.

Example: delete t1, t3 from t1 join t2 on t1.id = t2.id join t3 on t1.col = t3.col

More details about how it works is available in MySQL Docs

User Defined Functions Support

VTGate can track any user defined functions for better planning. User Defined Functions (UDFs) should be directly loaded in the underlying MySQL.

It should be enabled in VTGate with the --track-udfs flag. This will enable the tracking of UDFs in VTGate and will be used for planning. Without this flag, VTGate will not be aware that there might be aggregating user-defined functions in the query that need to be pushed down to MySQL.

More details about how to load UDFs is available in MySQL Docs

Insert Row Alias Support

Support is added to have row alias in Insert statement to be used with on duplicate key update.

Example:

insert into user(id, name, email) valies (100, 'Alice', 'alice@mail.com') as new on duplicate key update name = new.name, email = new.email
insert into user(id, name, email) valies (100, 'Alice', 'alice@mail.com') as new(m, n, p) on duplicate key update name = n, email = p

More details about how it works is available in MySQL Docs

Query Timeout

On a query timeout, Vitess closed the connection using the kill connection statement. This leads to connection churn which is not desirable in some cases. To avoid this, Vitess now uses the kill query statement to cancel the query. This will only cancel the query and does not terminate the connection.

Flag Changes

`pprof-http` Default Change

The --pprof-http flag, which was introduced in v19 with a default of true, has now been changed to default to false. This makes HTTP pprof endpoints now an opt-in feature, rather than opt-out. To continue enabling these endpoints, explicitly set --pprof-http when starting up Vitess components.

New `--healthcheck-dial-concurrency` flag

The new --healthcheck-dial-concurrency flag defines the maximum number of healthcheck connections that can open concurrently. This limit is to avoid hitting Go runtime panics on deployments watching enough tablets to hit the runtime’s maximum thread limit of 10000 due to blocking network syscalls. This flag applies to vtcombo, vtctld and vtgate only and a value less than the runtime max thread limit (10000) is recommended.

New minimum for `--buffer_min_time_between_failovers`

The --buffer_min_time_between_failovers vttablet flag now has a minimum value of 1s. This is because a value of 0 can cause issues with the buffering mechanics resulting in unexpected and unnecessary query errors — in particular during MoveTables SwitchTraffic operations. If you are currently specifying a value of 0 for this flag then you will need to update the config value to 1s prior to upgrading to v20 or later as vttablet will report an error and terminate if you attempt to start it with a value of 0.

New `--track-udfs` vtgate flag

The new --track-udfs flag enables VTGate to track user defined functions for better planning.

Help text fix for `--lock-timeout`

The help text for the flag --lock-timeout was incorrect. We were documenting it as a flag that controlled the duration for which the shard lock was acquired. It is actually the maximum duration for which we wait while attempting to acquire a lock from the topology server.

New `--querylog-sample-rate` flag

The new flag --querylog-sample-rate float adds support for sampling queries based on a float value between 0.0 (no logging) and 1.0 (all queries logged). If configured, this filtering is applied after the existing --querylog-filter-tag filter.

New `--tablet-filter-tags` flag

The new flag --tablet-filter-tags StringMap adds support to VTGate for filtering tablets by tablet tag key/values, specified as comma-separated list of key:values. The tags of a tablet are defined by the VTTablet flag --init_tags, which is also defined as a comma-separated list of key:values.

Minor Changes

New Stats

VTTablet Query Cache Hits and Misses

VTTablet exposes two new counter stats:

QueryCacheHits: Query engine query cache hits
QueryCacheMisses: Query engine query cache misses

VTTablet Query Text Characters Processed

VTGate and VTTablet expose a new counter stat QueryTextCharactersProcessed to reflect the number of query text characters processed.

VTGate groups this metric by Operation, Keyspace and TabletType. On VTTablet it is grouped by Table, Plan and optionally Workload.

`SIGHUP` reload of gRPC client static auth creds

The internal gRPC client now caches the static auth credentials and supports reloading via the SIGHUP signal. Previous to v20 the credentials were not cached. They were re-loaded from disk on every use.

VTAdmin

vtadmin-web updated to node v20.12.2 (LTS)

Building vtadmin-web now requires node >= v20.12.0 (LTS). Breaking changes from v18 to v20 can be found at https://nodejs.org/en/blog/release/v20.12.0 – with no known issues that apply to VTAdmin. Full details on the node v20.12.2 release can be found at https://nodejs.org/en/blog/release/v20.12.2.

Replaced highcharts with d3

The vtadmin-web UI no longer has a dependency on highcharts for licensing reasons. The tablet QPS, tablet VReplication QPS, and workflow streams lag charts have all been replaced by d3. We’ll be iteratively improving the d3 charts until they reach feature parity with the original highcharts charts.

The entire changelog for this release can be found here.

The release includes 410 merged Pull Requests.

Thanks to all our contributors: @Aoang, @GuptaManan100, @Its-Maniaco, @Maniktherana, @VaibhavMalik4187, @ajm188, @aparajon, @app/dependabot, @app/github-actions, @app/vitess-bot, @arthurschreiber, @bddicken, @beingnoble03, @brendar, @crazeteam, @dbussink, @deepthi, @demmer, @derekperkins, @ejortegau, @frouioui, @harshit-gangal, @mattlord, @maxenglander, @mdlayher, @notfelineit, @pavedroad, @rafer, @rohit-nayak-ps, @rvrangel, @shlomi-noach, @systay, @timvaillancourt, @tycol7, @vitess-bot, @vmg, @wangweicugw, @whuang8, @yoheimuta

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Vitess v20.0.0 版本发布

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Release of Vitess v20.0.0

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