Vitess v23.0.0-rc1

Release of Vitess v23.0.0

Summary

Table of Contents

• Major Changes
  • New default versions
    • Upgrade to MySQL 8.4
• Minor Changes
  • Deprecations
    • Metrics
  • Deletions
    • Metrics
  • New Metrics
    • VTGate
    • VTOrc
  • Topology
    • --consul_auth_static_file requires 1 or more credentials
  • VTOrc
    • Aggregated Discovery Metrics HTTP API removed
    • Dynamic control of EmergencyReparentShard-based recoveries
    • Recovery stats to include keyspace/shard
    • /api/replication-analysis HTTP API deprecation
  • VTTablet
    • API Changes
    • CLI Flags
    • Managed MySQL configuration defaults to caching-sha2-password
    • MySQL timezone environment propagation
    • gRPC tabletmanager client error changes
  • Docker

Major Changes

New default versions

Upgrade to MySQL 8.4

The default major MySQL version used by our vitess/lite:latest image is going from 8.0.40 to 8.4.6.
This change was merged in #18569.

VTGate also advertises MySQL version 8.4.6 by default instead of 8.0.40. If that is not what you are running, you can set the mysql_server_version flag to advertise the desired version.

⚠️ Upgrading to this release with vitess-operator:

If you are using the vitess-operator, considering that we are bumping the MySQL version from 8.0.40 to 8.4.6, you will have to manually upgrade:

1. Add innodb_fast_shutdown=0 to your extra cnf in your YAML file.
2. Apply this file.
3. Wait for all the pods to be healthy.
4. Then change your YAML file to use the new Docker Images (vitess/lite:v23.0.0).
5. Remove innodb_fast_shutdown=0 from your extra cnf in your YAML file.
6. Apply this file.

This is only needed once when going from the latest 8.0.x to 8.4.x. Once you're on 8.4.x, it is possible to upgrade and downgrade between 8.4.x versions without needing to run innodb_fast_shutdown=0.

Minor Changes

Deprecations

Metrics

Component	Metric Name	Notes	Deprecation PR
vtorc	DiscoverInstanceTimings	Replaced by DiscoveryInstanceTimings	#18406

Deletions

Metrics

Component	Metric Name	Was Deprecated In	Deprecation PR
vtgate	QueriesProcessed	v22.0.0	#17727
vtgate	QueriesRouted	v22.0.0	#17727
vtgate	QueriesProcessedByTable	v22.0.0	#17727
vtgate	QueriesRoutedByTable	v22.0.0	#17727

New Metrics

VTGate

Name	Dimensions	Description	PR
TransactionsProcessed	Shard, Type	Counts transactions processed at VTGate by shard distribution and transaction type.	#18171

VTOrc

Name	Dimensions	Description	PR
SkippedRecoveries	RecoveryName, Keyspace, Shard, Reason	Count of the different skipped recoveries processed.	#17985

Topology

--consul_auth_static_file requires 1 or more credentials

The --consul_auth_static_file flag used in several components now requires that 1 or more credentials can be loaded from the provided json file.

VTOrc

Aggregated Discovery Metrics HTTP API removed

VTOrc's undocumented /api/aggregated-discovery-metrics HTTP API endpoint was removed. The list of documented VTOrc APIs can be found here.

We recommend using the standard VTOrc metrics to gather the same metrics. If you find that a metric is missing in standard metrics, please open an issue or PR to address this.

Dynamic control of EmergencyReparentShard-based recoveries

Note: disabling EmergencyReparentShard-based recoveries introduces availability risks; please use with extreme caution! If you rely on this functionality often, for example in automation, this may be signs of an anti-pattern. If so, please open an issue to discuss supporting your use case natively in VTOrc.

The new vtctldclient RPC SetVtorcEmergencyReparent was introduced to allow VTOrc recoveries involving EmergencyReparentShard actions to be disabled on a per-keyspace and/or per-shard basis. Previous to this version, disabling EmergencyReparentShard-based recoveries was only possible globally/per-VTOrc-instance. VTOrc will now consider this keyspace/shard-level setting that is refreshed from the topo on each recovery. The disabled state is determined by first checking if the keyspace, and then the shard state. Removing a keyspace-level override does not remove per-shard overrides.

To provide observability of keyspace/shards with EmergencyReparentShard-based VTOrc recoveries disabled, the EmergencyReparentShardDisabled metric was added. This metric label can be used to create alerting to ensure EmergencyReparentShard-based recoveries are not disabled for an undesired period of time.

Recovery stats to include keyspace/shard

The following recovery-related stats now include labels for keyspaces and shards:

1. FailedRecoveries
2. PendingRecoveries
3. RecoveriesCount
4. SuccessfulRecoveries

Previous to this release, only the recovery "type" was included in labels.

/api/replication-analysis HTTP API deprecation

The /api/replication-analysis HTTP API endpoint is now deprecated and is replaced with /api/detection-analysis, which currently returns the same response format.

VTTablet

API Changes

• Added RestartReplication method to TabletManagerClient interface. This new RPC allows stopping and restarting MySQL replication with semi-sync configuration in a single call, providing a convenient alternative to separate StopReplication and StartReplication calls.

CLI Flags

• skip-user-metrics flag if enabled, replaces the username label with "UserLabelDisabled" to prevent metric explosion in environments with many unique users.

Managed MySQL configuration defaults to caching-sha2-password

The default authentication plugin for MySQL 8.0.26 and later is now caching_sha2_password instead of mysql_native_password. This change is made because mysql_native_password is deprecated and removed in future MySQL versions. mysql_native_password is still enabled for backwards compatibility.

This change specifically affects the replication user. If you have a user configured with an explicit password, it is recommended to make sure to upgrade this user after upgrading to v23 with a statement like the following:

ALTER USER 'vt_repl'@'%' IDENTIFIED WITH caching_sha2_password BY 'your-existing-password';

In future Vitess versions, the mysql_native_password authentication plugin will be disabled for managed MySQL instances.

MySQL timezone environment propagation

Fixed a bug where environment variables like TZ were not propagated from mysqlctl to the mysqld process.
As a result, timezone settings from the environment were previously ignored. Now mysqld correctly inherits environment variables.
⚠️ Deployments that relied on the old behav...

Vitess v22.0.1

Release of Vitess v22.0.1

The entire changelog for this release can be found here.

The release includes 19 merged Pull Requests.

Thanks to all our contributors: @GuptaManan100, @app/vitess-bot, @vitess-bot

Vitess v21.0.5

Release of Vitess v21.0.5

The entire changelog for this release can be found here.

The release includes 14 merged Pull Requests.

Thanks to all our contributors: @GuptaManan100, @app/vitess-bot, @frouioui, @harshit-gangal, @systay, @vitess-bot

Vitess v20.0.8

Release of Vitess v20.0.8

The entire changelog for this release can be found here.

The release includes 11 merged Pull Requests.

Thanks to all our contributors: @GuptaManan100, @app/vitess-bot, @frouioui

Vitess v22.0.0

Release of Vitess v22.0.0

Summary

Table of Contents

• Major Changes
  • Deprecations
    • Metrics
    • CLI Flags
  • Deletions
    • Metrics
    • CLI Flags
    • gh-ost and pt-osc Online DDL strategies
  • New Metrics
    • VTGate
    • VTTablet
  • Config File Changes
    • VTOrc
    • VTGate
  • VTOrc
    • Stalled Disk Recovery
    • KeyRanges in --clusters_to_watch
  • New Default Versions
    • MySQL 8.0.40
    • Docker vitess/lite images with Debian Bookworm
  • New Support
    • More Efficient JSON Replication
    • LAST_INSERT_ID(x)
    • Maximum Idle Connections in the Pool
    • Filtering Query logs on Error
    • MultiQuery RPC in vtgate
    • Unsharded CREATE PROCEDURE support
  • Optimization
    • Prepared Statement
  • New VtctldServer RPC
  • Prefer not promoting a replica that is currently taking a backup
  • Semi-sync monitor in vttablet
  • Wrapped fatal transaction errors
• Minor Changes
  • Topology read concurrency behaviour changes
  • VTTablet
    • CLI Flags
    • ACL enforcement and reloading
  • VTAdmin
    • Updated to node v22.13.1

Major Changes

Deprecations

Metrics

Component	Metric Name	Deprecation PR
vtgate	QueriesProcessed	#17727
vtgate	QueriesRouted	#17727
vtgate	QueriesProcessedByTable	#17727
vtgate	QueriesRoutedByTable	#17727

CLI Flags

Component	Flag Name	Notes	Deprecation PR
vttablet	twopc_enable	Usage of TwoPC commit will be determined by the transaction_mode set on VTGate via flag or session variable.	#17279
vtgate	grpc-send-session-in-streaming	Session will always be sent as part of the response from the StreamExecute RPC.	#17907

---

Deletions

Metrics

Component	Metric Name	Was Deprecated In	Deletion PR
vttablet	QueryCacheLength	v21.0.0	#16289
vttablet	QueryCacheSize	v21.0.0	#16289
vttablet	QueryCacheCapacity	v21.0.0	#16289
vttablet	QueryCacheEvictions	v21.0.0	#16289
vttablet	QueryCacheHits	v21.0.0	#16289
vttablet	QueryCacheMisses	v21.0.0	#16289

CLI Flags

Component	Flag Name	Was Deprecated In	Deletion PR
vttablet	queryserver-enable-settings-pool	v21.0.0	#16280
vttablet	remove-sharded-auto-increment	v21.0.0	#16860
vttablet	disable_active_reparents	v20.0.0	#14871
vtgate, vtcombo, vtctld	healthcheck-dial-concurrency	v21.0.0	#16378

gh-ost and pt-osc Online DDL strategies

Vitess no longer recognizes the gh-ost and pt-osc (pt-online-schema-change) Online DDL strategies. The vitess strategy is the recommended way to make schema changes at scale. mysql and direct strategies continue to be supported.

These vttablet flags have been removed:

• --gh-ost-path
• --pt-osc-path

Attempting to use gh-ost or pt-osc as --ddl-strategy will yield an error:

$ vtctldclient ApplySchema --ddl-strategy="gh-ost" ...
$ vtctldclient ApplySchema --ddl-strategy="pt-osc" ...

---

New Metrics

VTGate

Name	Dimensions	Description	PR
QueryExecutions	Query, Plan, Tablet	Number of queries executed.	#17727
QueryRoutes	Query, Plan, Tablet	Number of vttablets the query was executed on.	#17727
QueryExecutionsByTable	Query, Table	Queries executed by vtgate, with counts recorded per table.	#17727
VStreamsCount	Keyspace, ShardName, TabletType	Number of active vstreams.	#17858
VStreamsEventsStreamed	Keyspace, ShardName, TabletType	Number of events sent across all vstreams.	#17858
VStreamsEndedWithErrors	Keyspace, ShardName, TabletType	Number of vstreams that ended with errors.	#17858
CommitModeTimings	Mode	Timing metrics for commit (Single, Multi, TwoPC).	#16939
CommitUnresolved	N/A	Counter for 2PC transaction failures after Prepare.	#16939

The work done in #17727 introduces new metrics for queries. Via this work we have deprecated several vtgate metrics, please see the Deprecated Metrics section. Here is an example of how the new metrics are calculated:

Query: select t1.a, t2.b from t1 join t2 on t1.id = t2.id
Shards: 2
Sharding Key: id for both tables

Metrics Published:
1. QueryExecutions – {select, scatter, primary}, 1
2. QueryRoutes – {select, scatter, primary}, 2
3. QueryExecutionsByTable – {select, t1}, 1 and {select, t2}, 1

VTTablet

Name	Dimensions	Description	PR
TableRows	Table	Estimated number of rows in the table.	#17570
TableClusteredIndexSize	Table	Byte size of the clustered index (i.e. row data).	#17570
IndexCardinality	Table, Index	Estimated number of unique values in the index	#17570
IndexBytes	Table, Index	Byte size of the index.	#17570
UnresolvedTransaction	ManagerType	Current number of unresolved transactions.	#16939
...

Vitess v22.0.0-rc3

Release of Vitess v22.0.0

Summary

Table of Contents

• Major Changes
  • Deprecations
    • Metrics
    • CLI Flags
  • Deletions
    • Metrics
    • CLI Flags
    • gh-ost and pt-osc Online DDL strategies
  • New Metrics
    • VTGate
    • VTTablet
  • Config File Changes
    • VTOrc
    • VTGate
  • VTOrc
    • Stalled Disk Recovery
    • KeyRanges in --clusters_to_watch
  • New Default Versions
    • MySQL 8.0.40
    • Docker vitess/lite images with Debian Bookworm
  • New Support
    • More Efficient JSON Replication
    • LAST_INSERT_ID(x)
    • Maximum Idle Connections in the Pool
    • Filtering Query logs on Error
    • MultiQuery RPC in vtgate
    • Unsharded CREATE PROCEDURE support
  • Optimization
    • Prepared Statement
  • New VtctldServer RPC
  • Prefer not promoting a replica that is currently taking a backup
  • Semi-sync monitor in vttablet
  • Wrapped fatal transaction errors
• Minor Changes
  • Topology read concurrency behaviour changes
  • VTTablet
    • CLI Flags
    • ACL enforcement and reloading
  • VTAdmin
    • Updated to node v22.13.1

Major Changes

Deprecations

Metrics

Component	Metric Name	Deprecation PR
vtgate	QueriesProcessed	#17727
vtgate	QueriesRouted	#17727
vtgate	QueriesProcessedByTable	#17727
vtgate	QueriesRoutedByTable	#17727

CLI Flags

Component	Flag Name	Notes	Deprecation PR
vttablet	twopc_enable	Usage of TwoPC commit will be determined by the transaction_mode set on VTGate via flag or session variable.	#17279
vtgate	grpc-send-session-in-streaming	Session will always be sent as part of the response from the StreamExecute RPC.	#17907

---

Deletions

Metrics

Component	Metric Name	Was Deprecated In	Deletion PR
vttablet	QueryCacheLength	v21.0.0	#16289
vttablet	QueryCacheSize	v21.0.0	#16289
vttablet	QueryCacheCapacity	v21.0.0	#16289
vttablet	QueryCacheEvictions	v21.0.0	#16289
vttablet	QueryCacheHits	v21.0.0	#16289
vttablet	QueryCacheMisses	v21.0.0	#16289

CLI Flags

Component	Flag Name	Was Deprecated In	Deletion PR
vttablet	queryserver-enable-settings-pool	v21.0.0	#16280
vttablet	remove-sharded-auto-increment	v21.0.0	#16860
vttablet	disable_active_reparents	v20.0.0	#14871
vtgate, vtcombo, vtctld	healthcheck-dial-concurrency	v21.0.0	#16378

gh-ost and pt-osc Online DDL strategies

Vitess no longer recognizes the gh-ost and pt-osc (pt-online-schema-change) Online DDL strategies. The vitess strategy is the recommended way to make schema changes at scale. mysql and direct strategies continue to be supported.

These vttablet flags have been removed:

• --gh-ost-path
• --pt-osc-path

Attempting to use gh-ost or pt-osc as --ddl-strategy will yield an error:

$ vtctldclient ApplySchema --ddl-strategy="gh-ost" ...
$ vtctldclient ApplySchema --ddl-strategy="pt-osc" ...

---

New Metrics

VTGate

Name	Dimensions	Description	PR
QueryExecutions	Query, Plan, Tablet	Number of queries executed.	#17727
QueryRoutes	Query, Plan, Tablet	Number of vttablets the query was executed on.	#17727
QueryExecutionsByTable	Query, Table	Queries executed by vtgate, with counts recorded per table.	#17727
VStreamsCount	Keyspace, ShardName, TabletType	Number of active vstreams.	#17858
VStreamsEventsStreamed	Keyspace, ShardName, TabletType	Number of events sent across all vstreams.	#17858
VStreamsEndedWithErrors	Keyspace, ShardName, TabletType	Number of vstreams that ended with errors.	#17858
CommitModeTimings	Mode	Timing metrics for commit (Single, Multi, TwoPC).	#16939
CommitUnresolved	N/A	Counter for 2PC transaction failures after Prepare.	#16939

The work done in #17727 introduces new metrics for queries. Via this work we have deprecated several vtgate metrics, please see the Deprecated Metrics section. Here is an example of how the new metrics are calculated:

Query: select t1.a, t2.b from t1 join t2 on t1.id = t2.id
Shards: 2
Sharding Key: id for both tables

Metrics Published:
1. QueryExecutions – {select, scatter, primary}, 1
2. QueryRoutes – {select, scatter, primary}, 2
3. QueryExecutionsByTable – {select, t1}, 1 and {select, t2}, 1

VTTablet

Name	Dimensions	Description	PR
TableRows	Table	Estimated number of rows in the table.	#17570
TableClusteredIndexSize	Table	Byte size of the clustered index (i.e. row data).	#17570
IndexCardinality	Table, Index	Estimated number of unique values in the index	#17570
IndexBytes	Table, Index	Byte size of the index.	#17570
UnresolvedTransaction	ManagerType	Current number of unresolved transactions.	#16939
...

Vitess v22.0.0-rc2

Release of Vitess v22.0.0

Summary

Table of Contents

• Major Changes
  • Deprecations
    • Metrics
    • CLI Flags
  • Deletions
    • Metrics
    • CLI Flags
    • gh-ost and pt-osc Online DDL strategies
  • New Metrics
    • VTGate
    • VTTablet
  • Config File Changes
    • VTOrc
    • VTGate
  • VTOrc
    • Stalled Disk Recovery
    • KeyRanges in --clusters_to_watch
  • New Default Versions
    • MySQL 8.0.40
    • Docker vitess/lite images with Debian Bookworm
  • New Support
    • More Efficient JSON Replication
    • LAST_INSERT_ID(x)
    • Maximum Idle Connections in the Pool
    • Filtering Query logs on Error
    • MultiQuery RPC in vtgate
    • Unsharded CREATE PROCEDURE support
  • Optimization
    • Prepared Statement
  • RPC Changes
  • Prefer not promoting a replica that is currently taking a backup
  • Semi-sync monitor in vttablet
  • Wrapped fatal transaction errors
• Minor Changes
  • Topology read concurrency behaviour changes
  • VTTablet
    • CLI Flags
    • ACL enforcement and reloading
  • VTAdmin
    • Updated to node v22.13.1

Major Changes

Deprecations

Metrics

Component	Metric Name	Deprecation PR
vtgate	QueriesProcessed	#17727
vtgate	QueriesRouted	#17727
vtgate	QueriesProcessedByTable	#17727
vtgate	QueriesRoutedByTable	#17727

CLI Flags

Component	Flag Name	Notes	Deprecation PR
vttablet	twopc_enable	Usage of TwoPC commit will be determined by the transaction_mode set on VTGate via flag or session variable.	#17279
vtgate	grpc-send-session-in-streaming	Session will be sent as part of response on StreamExecute API call.	#17907

---

Deletions

Metrics

Component	Metric Name	Was Deprecated In	Deprecation PR
vttablet	QueryCacheLength	v21.0.0	#16289
vttablet	QueryCacheSize	v21.0.0	#16289
vttablet	QueryCacheCapacity	v21.0.0	#16289
vttablet	QueryCacheEvictions	v21.0.0	#16289
vttablet	QueryCacheHits	v21.0.0	#16289
vttablet	QueryCacheMisses	v21.0.0	#16289

CLI Flags

Component	Flag Name	Was Deprecated In	Deprecation PR
vttablet	queryserver-enable-settings-pool	v21.0.0	#16280
vttablet	remove-sharded-auto-increment	v21.0.0	#16860
vttablet	disable_active_reparents	v20.0.0	#14871
vtgate, vtcombo, vtctld	healthcheck-dial-concurrency	v21.0.0	#16378

gh-ost and pt-osc Online DDL strategies

Vitess no longer recognizes the gh-ost and pt-osc (pt-online-schema-change) Online DDL strategies. The vitess strategy is the recommended way to make schema changes at scale. mysql and direct strategies continue to be supported.

These vttablet flags have been removed:

• --gh-ost-path
• --pt-osc-path

The use of gh-ost and pt-osc as strategies as follows, yields an error:

$ vtctldclient ApplySchema --ddl-strategy="gh-ost" ...
$ vtctldclient ApplySchema --ddl-strategy="pt-osc" ...

---

New Metrics

VTGate

Name	Dimensions	Description	PR
QueryExecutions	Query, Plan, Tablet	Number of queries executed.	#17727
QueryRoutes	Query, Plan, Tablet	Number of vttablets the query was executed on.	#17727
QueryExecutionsByTable	Query, Table	Queries executed at vtgate, with counts recorded per table.	#17727
VStreamsCount	Keyspace, ShardName, TabletType	Number of active vstream.	#17858
VStreamsEventsStreamed	Keyspace, ShardName, TabletType	Number of events sent across all vstreams.	#17858
VStreamsEndedWithErrors	Keyspace, ShardName, TabletType	Number of vstreams that ended with errors.	#17858
CommitModeTimings	Mode	Timing metrics for commit (Single, Multi, TwoPC).	#16939
CommitUnresolved	N/A	Counter for failure after Prepare.	#16939

The work done in #17727 introduces new metrics for queries. Via this work we have deprecated several vtgate metrics, please see the Deprecated Metrics section. Here is an example on how to use them:

Query: select t1.a, t2.b from t1 join t2 on t1.id = t2.id
Shards: 2
Sharding Key: id for both tables

Metrics Published:
1. QueryExecutions – {select, scatter, primary}, 1
2. QueryRoutes – {select, scatter, primary}, 2
3. QueryExecutionsByTable – {select, t1}, 1 and {select, t2}, 1

VTTablet

Name	Dimensions	Description	PR
TableRows	Table	Estimated number of rows in the table.	#17570
TableClusteredIndexSize	Table	Byte size of the clustered index (i.e. row data).	#17570
IndexCardinality	Table, Index	Estimated number of unique values in the index	#17570
IndexBytes	Table, Index	Byte size of the index.	#17570
UnresolvedTransaction	ManagerType	Number of events sent across all vstreams.	#16939
CommitPreparedFail	`...

Vitess v21.0.4

Release of Vitess v21.0.4

The entire changelog for this release can be found here.

The release includes 35 merged Pull Requests.

Thanks to all our contributors: @app/vitess-bot, @dbussink, @frouioui, @harshit-gangal, @mattlord, @systay, @vitess-bot

Vitess v20.0.7

Release of Vitess v20.0.7

The entire changelog for this release can be found here.

The release includes 27 merged Pull Requests.

Thanks to all our contributors: @app/vitess-bot, @dbussink, @harshit-gangal, @systay, @vitess-bot

Vitess v22.0.0-rc1

Release of Vitess v22.0.0

Summary

Table of Contents

• Major Changes
  • Deprecations
    • Metrics
    • CLI Flags
  • Deletions
    • Metrics
    • CLI Flags
    • gh-ost and pt-osc Online DDL strategies
  • New Metrics
    • VTGate
    • VTTablet
  • Config File Changes
    • VTOrc
    • VTGate
  • VTOrc
    • Stalled Disk Recovery
    • KeyRanges in --clusters_to_watch
  • New Default Versions
    • MySQL 8.0.40
    • Docker vitess/lite images with Debian Bookworm
  • New Support
    • More Efficient JSON Replication
    • LAST_INSERT_ID(x)
    • Maximum Idle Connections in the Pool
    • Filtering Query logs on Error
  • Optimization
    • Prepared Statement
  • RPC Changes
  • Prefer not promoting a replica that is currently taking a backup
  • Semi-sync monitor in vttablet
  • Wrapped fatal transaction errors
• Minor Changes
  • Topology read concurrency behaviour changes
  • VTTablet
    • CLI Flags
    • ACL enforcement and reloading
  • VTAdmin
    • Updated to node v22.13.1

Major Changes

Deprecations

Metrics

Component	Metric Name	Deprecation PR
vtgate	QueriesProcessed	#17727
vtgate	QueriesRouted	#17727
vtgate	QueriesProcessedByTable	#17727
vtgate	QueriesRoutedByTable	#17727

CLI Flags

Component	Flag Name	Notes	Deprecation PR
vttablet	twopc_enable	Usage of TwoPC commit will be determined by the transaction_mode set on VTGate via flag or session variable.	#17279
vtgate	grpc-send-session-in-streaming	Session will be sent as part of response on StreamExecute API call.	#17907

---

Deletions

Metrics

Component	Metric Name	Was Deprecated In	Deprecation PR
vttablet	QueryCacheLength	v21.0.0	#16289
vttablet	QueryCacheSize	v21.0.0	#16289
vttablet	QueryCacheCapacity	v21.0.0	#16289
vttablet	QueryCacheEvictions	v21.0.0	#16289
vttablet	QueryCacheHits	v21.0.0	#16289
vttablet	QueryCacheMisses	v21.0.0	#16289

CLI Flags

Component	Flag Name	Was Deprecated In	Deprecation PR
vttablet	queryserver-enable-settings-pool	v21.0.0	#16280
vttablet	remove-sharded-auto-increment	v21.0.0	#16860
vttablet	disable_active_reparents	v20.0.0	#14871
vtgate, vtcombo, vtctld	healthcheck-dial-concurrency	v21.0.0	#16378

gh-ost and pt-osc Online DDL strategies

Vitess no longer recognizes the gh-ost and pt-osc (pt-online-schema-change) Online DDL strategies. The vitess strategy is the recommended way to make schema changes at scale. mysql and direct strategies continue to be supported.

These vttablet flags have been removed:

• --gh-ost-path
• --pt-osc-path

The use of gh-ost and pt-osc as strategies as follows, yields an error:

$ vtctldclient ApplySchema --ddl-strategy="gh-ost" ...
$ vtctldclient ApplySchema --ddl-strategy="pt-osc" ...

---

New Metrics

VTGate

Name	Dimensions	Description	PR
QueryExecutions	Query, Plan, Tablet	Number of queries executed.	#17727
QueryRoutes	Query, Plan, Tablet	Number of vttablets the query was executed on.	#17727
QueryExecutionsByTable	Query, Table	Queries executed at vtgate, with counts recorded per table.	#17727
VStreamsCount	Keyspace, ShardName, TabletType	Number of active vstream.	#17858
VStreamsEventsStreamed	Keyspace, ShardName, TabletType	Number of events sent across all vstreams.	#17858
VStreamsEndedWithErrors	Keyspace, ShardName, TabletType	Number of vstreams that ended with errors.	#17858
CommitModeTimings	Mode	Timing metrics for commit (Single, Multi, TwoPC).	#16939
CommitUnresolved	N/A	Counter for failure after Prepare.	#16939

The work done in #17727 introduces new metrics for queries. Via this work we have deprecated several vtgate metrics, please see the Deprecated Metrics section. Here is an example on how to use them:

Query: select t1.a, t2.b from t1 join t2 on t1.id = t2.id
Shards: 2
Sharding Key: id for both tables

Metrics Published:
1. QueryExecutions – {select, scatter, primary}, 1
2. QueryRoutes – {select, scatter, primary}, 2
3. QueryExecutionsByTable – {select, t1}, 1 and {select, t2}, 1

VTTablet

Name	Dimensions	Description	PR
TableRows	Table	Estimated number of rows in the table.	#17570
TableClusteredIndexSize	Table	Byte size of the clustered index (i.e. row data).	#17570
IndexCardinality	Table, Index	Estimated number of unique values in the index	#17570
IndexBytes	Table, Index	Byte size of the index.	#17570
UnresolvedTransaction	ManagerType	Number of events sent across all vstreams.	#16939
CommitPreparedFail	FailureType	Number of vstreams that ended with errors.	[#16939](https://github.com/vitessio/vit...