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Revert migration lock upstream #156

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Revert migration lock upstream #156

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a5addab
Revert the migration advisory lock
claude Sep 13, 2026
5032b3b
Say why -p 1 is needed, and record that Connect migrates
claude Sep 13, 2026
b70fa37
Merge branch 'main' into revert-migration-lock-upstream
tire-fire Sep 14, 2026
92e43bd
Redo the db.go merge resolution
claude Sep 14, 2026
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43 changes: 4 additions & 39 deletions engine/db/db.go
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Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
package db

import (
"context"
"errors"
"fmt"
"log"
Expand All @@ -20,6 +19,9 @@ type DB struct {
db *gorm.DB
}

// Connect opens the connection pool and migrates. AutoMigrate reads the catalog
// and then creates, so it is not safe to run from two processes against the same
// database at once.
func Connect(connectURL string) *DB {
var err error

Expand Down Expand Up @@ -47,45 +49,8 @@ func Connect(connectURL string) *DB {
return db
}

// migrationLockID identifies the advisory lock that serializes schema
// migration. Any value works as long as every process agrees on it.
const migrationLockID int64 = 0x71756F74

// migrate applies the schema under an advisory lock.
//
// AutoMigrate and CREATE ... IF NOT EXISTS both read the catalog and then
// write, so two processes connecting at once can each decide a table is
// missing and issue CREATE TABLE. The loser gets "relation already exists" or
// a unique violation on pg_type. The lock makes the read-then-write pair
// exclusive; the second process runs its migration afterwards and finds
// nothing to do.
func (d *DB) migrate() {
sqlDB, err := d.db.DB()
if err != nil {
log.Fatalln("Failed to access database handle:", err)
}

// The lock is session scoped, so it has to be held on one pinned
// connection rather than borrowed from the pool per statement.
ctx := context.Background()
conn, err := sqlDB.Conn(ctx)
if err != nil {
log.Fatalln("Failed to acquire connection for migration lock:", err)
}
defer func() {
if _, err := conn.ExecContext(ctx, "SELECT pg_advisory_unlock($1)", migrationLockID); err != nil {
slog.Error("failed to release migration lock", "error", err)
}
if err := conn.Close(); err != nil {
slog.Error("failed to close migration lock connection", "error", err)
}
}()

if _, err := conn.ExecContext(ctx, "SELECT pg_advisory_lock($1)", migrationLockID); err != nil {
log.Fatalln("Failed to acquire migration lock:", err)
}

err = d.db.AutoMigrate(&AnnouncementSchema{},
err := d.db.AutoMigrate(&AnnouncementSchema{},
&TeamSchema{}, &RoundSchema{}, &ServiceCheckSchema{}, &SLASchema{}, &ManualAdjustmentSchema{},
&InjectSchema{}, &SubmissionSchema{}, &TeamServiceCheckSchema{},
// box schema must come first for automigrate to work
Expand Down