v20.0.0-rc2
版本发布时间: 2024-06-20 13:03:47
vitessio/vitess最新发布版本:v21.0.0-rc2(2024-10-23 13:13:47)
Release of Vitess v20.0.0
Summary
Table of Contents
-
- Deletions
-
Breaking changes
- Metric Name Changes in VTOrc
- ENUM and SET column handling in VTGate VStream API
-
shutdown_grace_period
Default Change -
New
unmanaged
Flag anddisable_active_reparents
deprecation -
recovery-period-block-duration
Flag deprecation -
mysqlctld
onterm-timeout
Default Change -
MoveTables
now removesauto_increment
clauses by default when moving tables from an unsharded keyspace to a sharded one -
Durabler
interface method renaming
- Query Compatibility
- Query Timeout
- Flag changes
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 timesEmergencyReparentShard
has been run. It is further subdivided by the keyspace, shard and the result of the operation. -
planned_reparent_counts
- Number of timesPlannedReparentShard
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 toPromotionRule
- The
semiSyncAckers
method was renamed toSemiSyncAckers
- The
isReplicaSemiSync
method was renamed toIsReplicaSemiSync
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 441 merged Pull Requests.
Thanks to all our contributors: @Aoang, @Ari1009, @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
1、 vitess-20.0.0-rc2-4af99b5.tar.gz 578.12MB
2、 vitess-20.0.0_rc2-4af99b5.x86_64.rpm 577.47MB
3、 vitess_20.0.0-rc2-4af99b5_amd64.deb 578.77MB