vtgate: schema tracker panic on generated point column

[derekperkins]

Overview of the Issue

I triggered the same error as #17670 today with a generated point column. Here was the alter schema I ran, which successfully was processed through a vtgate connection, but then immediately brought down all vtgates.

alter table locations
add lat_long point as (
    point(
            geocode->>'$.geometry.location.lat',
            geocode->>'$.geometry.location.lng'
    )
)
SRID 4326 after geocodes;

I believe @dbussink already fixed the panic with #17659, but support still needs to be added

Related Issues:

• Bug Report: vtgates crash on start due to column_format compressed #17670

Reproduction Steps

CREATE TABLE `locations` (
  `location_id` mediumint unsigned NOT NULL AUTO_INCREMENT,
  `country_code` binary(2) NOT NULL,
  `type` varbinary(22) NOT NULL,
  `location` varbinary(85) NOT NULL,
  `name_no_context` varbinary(85) NOT NULL,
  `country_location_id` mediumint unsigned NOT NULL,
  `geocode` json DEFAULT NULL,
  `geocodes` json DEFAULT NULL,
  `lat_long` point GENERATED ALWAYS AS (point(json_unquote(json_extract(`geocode`,_utf8mb4'$.geometry.location.lat')),json_unquote(json_extract(`geocode`,_utf8mb4'$.geometry.location.lng')))) VIRTUAL /*!80003 SRID 4326 */,
  `time_zone` json DEFAULT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`location_id`),
  UNIQUE KEY `country_code__type__location__uq` (`country_code`,`type`,`location`),
  UNIQUE KEY `location_id__country_code__uq` (`location_id`,`country_code`),
  KEY `name_no_context__type` (`name_no_context`,`type`),
  KEY `type__name_no_context` (`type`,`name_no_context`),
  KEY `location__type` (`location`,`type`),
  KEY `type__location` (`type`,`location`),
  KEY `locations__country_location_id__location_id__fk` (`country_location_id`),
  CONSTRAINT `fk_Locations_Countries` FOREIGN KEY (`country_code`) REFERENCES `countries` (`country_code`),
  CONSTRAINT `locations__country_location_id__location_id__fk` FOREIGN KEY (`country_location_id`) REFERENCES `locations` (`location_id`)
) ENGINE=InnoDB AUTO_INCREMENT=314105 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

Binary Version

v21.0.1

Operating System and Environment details

GKE v1.31

Log Fragments

W0131 22:04:23.457072       1 parser.go:85] ignoring error parsing DDL syntax error at position 576 near 'SRID'
...
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x48 pc=0x1724e12]

goroutine 1 [running]:
vitess.io/vitess/go/exit.doRecover({0x1b80f40?, 0x378f650?}, 0x40?)
	vitess.io/vitess/go/exit/exit.go:92 +0x126
vitess.io/vitess/go/exit.Recover()
	vitess.io/vitess/go/exit/exit.go:69 +0x1f
panic({0x1b80f40?, 0x378f650?})
	runtime/panic.go:785 +0x132
vitess.io/vitess/go/vt/vtgate/schema.getTableCollation(0x19d0a2a?)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:413 +0x12
vitess.io/vitess/go/vt/vtgate/schema.getColumns(0x0)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:374 +0x2a
vitess.io/vitess/go/vt/vtgate/schema.(*Tracker).updateTables(0xc000dddc20, {0xc000bc031c, 0x9}, 0xc00134ccd0?)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:367 +0xf3
vitess.io/vitess/go/vt/vtgate/schema.(*Tracker).loadTables.func1(0xc00134ccd0)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:120 +0x38
vitess.io/vitess/go/vt/vttablet/grpctabletconn.(*gRPCQueryClient).GetSchema(0xc000921080, {0x2406a68?, 0x3846c20?}, 0xc0012de7e0, 0x1, {0x0, 0x0, 0x0}, 0xc001109640)
	vitess.io/vitess/go/vt/vttablet/grpctabletconn/conn.go:1141 +0x218
vitess.io/vitess/go/vt/vttablet/queryservice.(*wrappedService).GetSchema.func1({0x2406a68, 0x3846c20}, 0xc001139f38?, {0x242d050?, 0xc000921080?})
	vitess.io/vitess/go/vt/vttablet/queryservice/wrapped.go:345 +0x50
vitess.io/vitess/go/vt/vtgate.(*TabletGateway).withRetry(0xc0000f6700, {0x2406a68, 0x3846c20}, 0xc0012de7e0, {0xc000b636a0?, 0x410be5?}, {0x30?, 0x1cad6a0?}, 0x0, 0xc000c38750)
	vitess.io/vitess/go/vt/vtgate/tabletgateway.go:411 +0x872
vitess.io/vitess/go/vt/vttablet/queryservice.(*wrappedService).GetSchema(0xc000714618, {0x2406a68, 0x3846c20}, 0xc0012de7e0, 0x1, {0x0, 0x0, 0x0}, 0xc001109640)
	vitess.io/vitess/go/vt/vttablet/queryservice/wrapped.go:344 +0xf9
vitess.io/vitess/go/vt/vtgate/schema.(*Tracker).loadTables(0xc000dddc20, {0x242ce30, 0xc0000f6700}, 0xc0012de7e0)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:119 +0x1bb
vitess.io/vitess/go/vt/vtgate/schema.(*Tracker).LoadKeyspace(0xc000dddc20, {0x242ce30, 0xc0000f6700}, 0xc0012de7e0)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:86 +0x2b
vitess.io/vitess/go/vt/vtgate/schema.(*Tracker).AddNewKeyspace(0xc000dddc20, {0x242ce30, 0xc0000f6700}, 0xc0012de7e0)
	vitess.io/vitess/go/vt/vtgate/schema/tracker.go:482 +0x167
vitess.io/vitess/go/vt/vtgate.resolveAndLoadKeyspace({0x2406b50?, 0xc0002ca370?}, 0xc0002ca370?, 0xc000dddc20, 0xc0000f6700, {0xc000bc031c, 0x9})
	vitess.io/vitess/go/vt/vtgate/vtgate.go:415 +0x29f
vitess.io/vitess/go/vt/vtgate.addKeyspacesToTracker({0x2406b50, 0xc0002ca370}, 0xc000efba40, 0xc000dddc20, 0xc0000f6700)
	vitess.io/vitess/go/vt/vtgate/vtgate.go:396 +0x145
vitess.io/vitess/go/vt/vtgate.Init({0x2406b50, 0xc0002ca370}, 0xc0006e7b90, {0x0?, 0x0?}, {0x240c300, 0xc0004ce160}, {0x7ffc1b62cf10, 0xa}, {0xc000988188, ...}, ...)
	vitess.io/vitess/go/vt/vtgate/vtgate.go:315 +0x9ca