VReplication: Support automatically replacing auto_inc cols with sequences

[mattlord]

Description

Since #15679 we automatically strip any MySQL auto_increment clauses on tables that are being moved (using the MoveTables command) from an unsharded keyspace to a sharded one. And since #13656 we support initializing any sequences in the target keyspace on SwitchTraffic.

In this PR, we build upon both of those items of work to support automatically creating a Vitess Sequence for each if those tables that HAD an auto_increment clause if one does not already exist. This requires the use of two flags:

1. When creating the workflow, specify:
   - That we want to replace any removed MySQL auto_increment clauses with vschema AutoIncrement definitions using --sharded-auto-increment-handling=replace
   - An unsharded keyspace in --global-keyspace that we can then later use to create the sequence tables in if they don't already exist (they don't in the manual test below)
2. When switching traffic, specify the --initialize-target-sequences flag, which will create a missing sequence table when possible

Manual test

alias vtctldclient='command vtctldclient --server=localhost:15999'

./101_initial_cluster.sh; mysql < ../common/insert_commerce_data.sql; ./201_customer_tablets.sh; ./202_move_tables.sh; ./203_switch_reads.sh; ./204_switch_writes.sh; ./205_clean_commerce.sh; ./301_customer_sharded.sh; ./302_new_shards.sh; ./303_reshard.sh; ./304_switch_reads.sh; ./305_switch_writes.sh; ./306_down_shard_0.sh; ./307_delete_shard_0.sh

vtctldclient ApplySchema --sql "alter table product drop primary key, add product_id int unsigned not null auto_increment primary key" commerce

vtctldclient ApplyVSchema --vschema='
{
  "sharded": true,
  "vindexes": {
    "hash": {
      "type": "hash"
    },
    "unicode_loose_xxhash": {
      "type": "unicode_loose_xxhash"
    }
  },
  "tables": {
    "corder": {
      "column_vindexes": [
        {
          "column": "customer_id",
          "name": "hash"
        }
      ],
      "auto_increment": {
        "column": "order_id",
        "sequence": "order_seq"
      }
    },
    "customer": {
      "column_vindexes": [
        {
          "column": "customer_id",
          "name": "hash"
        }
      ],
      "auto_increment": {
        "column": "customer_id",
        "sequence": "customer_seq"
      }
    },
    "product": {
      "column_vindexes": [
        {
          "column": "sku",
          "name": "unicode_loose_xxhash"
        }
      ]
    }
  }
}
' customer

sleep 5

vtctldclient MoveTables --workflow commerce2customer --target-keyspace customer create --source-keyspace commerce --tables product --sharded-auto-increment-handling=replace --global-keyspace commerce

vtctldclient GetVSchema customer --compact

mysql commerce -e "insert into product (sku, description, price) values ('SKU-1003', 'Mouse', 5)"

sleep 5

vtctldclient MoveTables --workflow commerce2customer --target-keyspace customer switchtraffic --initialize-target-sequences

vtctldclient GetVSchema customer --compact

mysql commerce -e "show tables"

mysql commerce -e "select * from product order by product_id"

mysql commerce -e "select * from product_seq"

mysql commerce -e "insert into product (sku, description, price) values ('SKU-1004', 'Table', 199), ('SKU-1005', 'Chair', 99)"

mysql commerce -e "select * from product order by product_id"

mysql commerce -e "select * from product_seq"

Results:

{
  "sharded": true,
  "vindexes": {
    "hash": {
      "type": "hash"
    }
  },
  "tables": {
    "corder": {
      "column_vindexes": [
        {
          "column": "customer_id",
          "name": "hash"
        }
      ],
      "auto_increment": {
        "column": "order_id",
        "sequence": "order_seq"
      }
    },
    "customer": {
      "column_vindexes": [
        {
          "column": "customer_id",
          "name": "hash"
        }
      ],
      "auto_increment": {
        "column": "customer_id",
        "sequence": "customer_seq"
      }
    },
    "product": {
      "column_vindexes": [
        {
          "column": "product_id",
          "name": "hash"
        }
      ],
      "auto_increment": {
        "column": "product_id",
        "sequence": "product_seq"
      }
    }
  }
}
+--------------------+
| Tables_in_commerce |
+--------------------+
| customer_seq       |
| order_seq          |
| product            |
| product_seq        |
+--------------------+
+----------+-------------+-------+------------+
+----------+-------------+-------+------------+
| sku      | description | price | product_id |
+----------+-------------+-------+------------+
| SKU-1001 | Monitor     |   100 |          1 |
| SKU-1002 | Keyboard    |    30 |          2 |
| SKU-1003 | Mouse       |     5 |          3 |
+----------+-------------+-------+------------+
+----+---------+-------+
| id | next_id | cache |
+----+---------+-------+
|  0 |       4 |  1000 |
+----+---------+-------+
+----------+-------------+-------+------------+
| sku      | description | price | product_id |
+----------+-------------+-------+------------+
| SKU-1001 | Monitor     |   100 |          1 |
| SKU-1002 | Keyboard    |    30 |          2 |
| SKU-1003 | Mouse       |     5 |          3 |
| SKU-1004 | Table       |   199 |          4 |
| SKU-1005 | Chair       |    99 |          5 |
+----------+-------------+-------+------------+
+----+---------+-------+
| id | next_id | cache |
+----+---------+-------+
|  0 |    1004 |  1000 |
+----+---------+-------+

The strip_sharded_auto_increment field was renamed to sharded_auto_increment_handling — which is upgrade/downgrade safe with protobufs as field indexes are used — and the type of the proto field was changed from bool to an enum/int32 to support the new REPLACE option. This is upgrade/downgrade safe because the wire format for bool is a varint with 0 being false and 1 being true — with the deserialization ending up 0 = false > 0 = true. To demonstrate:

git checkout vrepl_replace_auto_inc && make build 
cp bin/vtctldclient /tmp

git checkout main && make build
cd examples/local
./101_initial_cluster.sh; mysql < ../common/insert_commerce_data.sql; ./201_customer_tablets.sh

❯ vtctldclient MoveTables --workflow commerce2customer --target-keyspace customer create --source-keyspace commerce --tables product --remove-sharded-auto-increment=REPLACE --global-keyspace commerce
E0930 17:51:16.473295   29269 main.go:56] invalid argument "REPLACE" for "--remove-sharded-auto-increment" flag: strconv.ParseBool: parsing "REPLACE": invalid syntax

❯ /tmp/vtctldclient --server=localhost:15999  MoveTables --workflow commerce2customer --target-keyspace customer create --source-keyspace commerce --tables product --sharded-auto-increment-handling=REPLACE --global-keyspace commerce
The following vreplication streams exist for workflow customer.commerce2customer:

id=1 on customer/zone1-200: Status: Copying. VStream has not started.

Traffic State: Reads Not Switched. Writes Not Switched

❯ command mysql -u root --socket ${VTDATAROOT}/vt_0000000$(vtctldclient GetTablets --keyspace customer --tablet-type primary --shard "0" | awk '{print $1}' | cut -d- -f2 | bc)/mysql.sock vt_customer -e "select * from _vt.vreplication\G"
*************************** 1. row ***************************
                   id: 1
             workflow: commerce2customer
               source: keyspace:"commerce" shard:"0" filter:{rules:{match:"product" filter:"select * from product"}}
                  pos: MySQL56/9fec34ea-7f75-11ef-8280-bf546605e365:1-45
             stop_pos: NULL
              max_tps: 0
  max_replication_lag: 0
                 cell: zone1
         tablet_types: replica,primary
         time_updated: 1727733136
transaction_timestamp: 0
                state: Running
              message:
              db_name: vt_customer
          rows_copied: 0
                 tags:
       time_heartbeat: 1727733136
        workflow_type: 1
       time_throttled: 0
  component_throttled:
     reason_throttled:
    workflow_sub_type: 0
 defer_secondary_keys: 0
              options: {"strip_sharded_auto_increment": true}

And using the manual test case from above but using binaries built on main with a vtctldclient binary from the PR branch:

...

❯ /tmp/vtctldclient --server :15999 MoveTables --workflow commerce2customer --target-keyspace customer create --source-keyspace commerce --tables product --sharded-auto-increment-handling=replace --global-keyspace commerce
The following vreplication streams exist for workflow customer.commerce2customer:

id=2 on customer/zone1-300: Status: Copying. VStream has not started.
id=2 on customer/zone1-401: Status: Copying. VStream has not started.

Traffic State: Reads Not Switched. Writes Not Switched

❯ mysql commerce/0 -e "show create table product\G"
*************************** 1. row ***************************
       Table: product
Create Table: CREATE TABLE `product` (
  `sku` varbinary(128) NOT NULL,
  `description` varbinary(128) DEFAULT NULL,
  `price` bigint DEFAULT NULL,
  `product_id` int unsigned NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`product_id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

❯ mysql customer/-80 -e "show create table product\G"
*************************** 1. row ***************************
       Table: product
Create Table: CREATE TABLE `product` (
  `sku` varbinary(128) NOT NULL,
  `description` varbinary(128) DEFAULT NULL,
  `price` bigint DEFAULT NULL,
  `product_id` int unsigned NOT NULL,
  PRIMARY KEY (`product_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

So we can see that the auto_increment clauses were still removed.

Related Issue(s)

• Fixes: Feature Request: MoveTables support for auto replacing auto_inc cols with sequences #16864

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
• If this change is to be back-ported to previous releases, a justification is included in the PR description
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on CI?
• Documentation: Add docs for MoveTables auto increment handling website#1859

[vitess-bot]

Review Checklist

Hello reviewers! 👋 Please follow this checklist when reviewing this Pull Request.

General

• Ensure that the Pull Request has a descriptive title.
• Ensure there is a link to an issue (except for internal cleanup and flaky test fixes), new features should have an RFC that documents use cases and test cases.

Tests

• Bug fixes should have at least one unit or end-to-end test, enhancement and new features should have a sufficient number of tests.

Documentation

• Apply the release notes (needs details) label if users need to know about this change.
• New features should be documented.
• There should be some code comments as to why things are implemented the way they are.
• There should be a comment at the top of each new or modified test to explain what the test does.

New flags

• Is this flag really necessary?
• Flag names must be clear and intuitive, use dashes (-), and have a clear help text.

If a workflow is added or modified:

• Each item in Jobs should be named in order to mark it as required.
• If the workflow needs to be marked as required, the maintainer team must be notified.

Backward compatibility

• Protobuf changes should be wire-compatible.
• Changes to _vt tables and RPCs need to be backward compatible.
• RPC changes should be compatible with vitess-operator
• If a flag is removed, then it should also be removed from vitess-operator and arewefastyet, if used there.
• vtctl command output order should be stable and awk-able.

[codecov]

Codecov Report

Attention: Patch coverage is 68.27586% with 46 lines in your changes missing coverage. Please review.

Project coverage is 69.43%. Comparing base (945124a) to head (1d8601a).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
go/vt/vtctl/workflow/traffic_switcher.go	56.41%	34 Missing ⚠️
...ldclient/command/vreplication/movetables/create.go	0.00%	7 Missing ⚠️
go/vt/vtctl/workflow/server.go	81.81%	2 Missing ⚠️
go/vt/vtctl/workflow/utils.go	60.00%	2 Missing ⚠️
go/vt/vtctl/workflow/materializer.go	96.15%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #16860    +/-   ##
========================================
  Coverage   69.42%   69.43%            
========================================
  Files        1571     1571            
  Lines      203304   203433   +129     
========================================
+ Hits       141148   141249   +101     
- Misses      62156    62184    +28     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[deepthi]

We'll run the website docs update for the vtctld command reference once before release.

[deepthi]

Was adding </a> to every section heading done by your editor? Seems unnecessary.

[mattlord]

I did it as w/o it the content is messed up in some readers (the preview one I use). It’s proper to end it.

[deepthi]

This is too verbose for a summary. Can you please condense it into a short paragraph? No need to give all the background, just describe the feature briefly.

[mattlord]

In my mind if we add something to the summary we think it’s worth highlighting. At a minimum we should then describe what the thing is that we’re highlighting and explain why we think it’s worth highlighting. Which to me includes the context for what it is, what it is, why it’s important, when you'd use it, and how to use it. Two paragraphs is not a lot IMO and if you look at this and previous summary docs multiple paragraphs is quite common (just look at the one right above this). That being said, I will try and condense it and eliminate some content that isn’t strictly necessary for the stated objectives.

[mattlord]

I created a docs PR for this: vitessio/website#1859

Once that's merged this can become a short paragraph that links to this for additional details: https://deploy-preview-1859--vitess.netlify.app/docs/21.0/reference/vreplication/movetables/#auto-increment-handling

[mattlord]

Updated in 3ceb253 Thanks!