Files
threshold/internal/db/db_test.go
T
Hugo VieiraandJeff Mitchell bed6e1a0ff feat(server): Reload database on SIGHUP
If the database url is updated on Boundary's config and then a SIGHUP
triggered, we now connect to the new database, ensure it's OK to use
and use that one going forwards instead.

This allows a controller to be deployed in a more dynamic infrastructure
where, for example, database credentials could change, without having
to restart the controller. In this case only a database url config
change and a SIGHUP signal to all controllers would be required.

This uses an atomic.Pointer to store wrapped DB objects. This allows
atomically swapping to the new object. A timeout is introduced so that
if the object is swapped after the existing one has been looked up it
isn't immediately invalidated. The timeout is a maximum; a ticker once a
second that looks at stats to determine how many database connections
are still in use and then closes the driver as soon as none are in use.

This could be done with mutexes to avoid checking stats in a loop, but
that carries its own risk: if a write lock is attempted to be acquired
while a query is holding a read lock, the write lock will block, and any
subsequent read locks will also block since write locks take priority.
As a result, if a query is long-running or timing out, all other queries
in the system will become blocked. Our default user request timeout is
90 seconds and some jobs have no timeout at all, so this is not a purely
theoretical concern, even if it's unlikely.

Refs: #2435
Co-authored-by: Jeff Mitchell <jeffrey.mitchell@gmail.com>
2022-09-12 17:55:32 +01:00

177 lines
3.5 KiB
Go

package db
import (
"context"
"sync/atomic"
"testing"
"github.com/hashicorp/boundary/testing/dbtest"
"github.com/hashicorp/go-dbw"
"github.com/stretchr/testify/require"
)
func TestOpen(t *testing.T) {
ctx := context.Background()
cleanup, url, _, err := dbtest.StartUsingTemplate(dbtest.Postgres)
if err != nil {
t.Fatal(err)
}
defer func() {
if err := cleanup(); err != nil {
t.Error(err)
}
}()
type args struct {
dbType DbType
connectionUrl string
opt []Option
}
tests := []struct {
name string
args args
wantErr bool
}{
{
name: "valid",
args: args{
dbType: Postgres,
connectionUrl: url,
},
wantErr: false,
},
{
name: "invalid",
args: args{
dbType: Postgres,
connectionUrl: "",
},
wantErr: true,
},
{
name: "invalid - max_open_connections set to 3",
args: args{
dbType: Postgres,
connectionUrl: "",
opt: []Option{WithMaxOpenConnections(3)},
},
wantErr: true,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got, err := Open(ctx, tt.args.dbType, tt.args.connectionUrl)
defer func() {
if err == nil {
sqlDB, err := got.SqlDB(ctx)
require.NoError(t, err)
err = sqlDB.Close()
require.NoError(t, err)
}
}()
if (err != nil) != tt.wantErr {
t.Errorf("Open() error = %v, wantErr %v", err, tt.wantErr)
return
}
if tt.wantErr && got != nil {
t.Error("Open() wanted error and got != nil")
}
})
}
}
func TestSwap(t *testing.T) {
tests := []struct {
name string
db func() *DB
newDB func() *DB
expErr bool
expErrStr string
}{
{
name: "nilNewDB",
db: func() *DB {
ret := &DB{wrapped: new(atomic.Pointer[dbw.DB])}
return ret
},
newDB: nil,
expErr: true,
expErrStr: "no new db object present",
},
{
name: "nilNewDBWrapped",
db: func() *DB {
ret := &DB{wrapped: new(atomic.Pointer[dbw.DB])}
return ret
},
newDB: func() *DB {
ret := &DB{}
return ret
},
expErr: true,
expErrStr: "no new db object present",
},
{
name: "nilCurrentDBWrapped",
db: func() *DB {
ret := &DB{}
return ret
},
newDB: func() *DB {
db, _ := dbw.TestSetupWithMock(t)
ret := &DB{wrapped: new(atomic.Pointer[dbw.DB])}
ret.wrapped.Store(db)
return ret
},
expErr: true,
expErrStr: "no current db is present to swap, aborting",
},
{
name: "dbReplace",
db: func() *DB {
db, _ := dbw.TestSetupWithMock(t)
ret := &DB{wrapped: new(atomic.Pointer[dbw.DB])}
ret.wrapped.Store(db)
return ret
},
newDB: func() *DB {
db, _ := dbw.TestSetupWithMock(t)
ret := &DB{wrapped: new(atomic.Pointer[dbw.DB])}
ret.wrapped.Store(db)
return ret
},
expErr: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
var oldDb, newDb *DB
if tt.db != nil {
oldDb = tt.db()
}
if tt.newDB != nil {
newDb = tt.newDB()
}
var oldWrappedVal dbw.DB
if !tt.expErr {
oldWrappedVal = *oldDb.wrapped.Load()
}
ctx := context.Background()
closeFn, err := oldDb.Swap(ctx, newDb)
if tt.expErr {
require.EqualError(t, err, tt.expErrStr)
require.Nil(t, closeFn)
return
}
dbw.TestSetupWithMock(t)
require.NoError(t, err)
require.NotNil(t, closeFn)
require.NotEqual(t, oldWrappedVal, oldDb.wrapped.Load())
require.EqualValues(t, newDb.wrapped.Load(), oldDb.wrapped.Load()) // For pointer values, require tests the underlying values' equality.
})
}
}