Files
Tim Deeb-SwihartandGitHub be7b5514a5 Reconnect to SQL databases when connections fail (#5926)
## What changed?

Both our PostgreSQL and MySQL database backends will now automatically
reconnect to the database when certain errors occur: all errors chosen
have been experienced when testing this behavior through an AWS Aurora
RDS failover of either MySQL or PostgreSQL.

For both backends we will reconnect when we see:
- `ECONNRESET`
- `ECONNABORTED`
- `ECONNREFUSED`
- `io.EOF`
- `io.ErrUnexpectedEOF`
- `database/sql/driver.ErrBadConn`

for postgres we will also reconnect on the following SQLStates:
- `25006` read-only transaction
- `57P03` cannot connect now
- `0A000` feature not supported, but ONLY when the message is `cannot
set transaction read-write mode during recovery`

for mysql we will also reconnect when we see the following error codes:
- `1040` too many connections 
- `1792` read-only transaction (SQLstate `25006`)
- `1836` running in read-only mode

This logic is easily extensible should we discover more failure modes
over time

## Why?

We've had multiple community reports of Temporal problems during RDS
failover. One part of this is the fact that we wouldn't necessarily
reconnect; we were at the whims of our chosen SQL abstraction's
connection pooling logic.

## How did you test it?

I manually tested this functionality in the presence of repeated RDS
failovers: 

- [x] postgres12 plugin with pq driver
- [x] postgres12 plugin with pgx driver
- [x] mysql plugin

Automated testing will be added to our regular testing pipelines once
our infrastructure friends have added the support I need (it's in
progress)

## Potential risks

We're concerned there's a correctness issue in our PostgreSQL backend
that's related to our behavior during an RDS failover. If we merge this
before I figure out what's going on, we could hide the issue and make it
harder to reproduce.

## Documentation
N/A

## Is hotfix candidate?
Yes?
2024-05-17 16:59:15 -07:00

419 lines
12 KiB
Go

// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc. All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package tests
import (
"database/sql"
"testing"
"github.com/stretchr/testify/require"
"github.com/stretchr/testify/suite"
"go.temporal.io/server/common/persistence/sql/sqlplugin"
"go.temporal.io/server/common/primitives"
"go.temporal.io/server/common/shuffle"
"go.temporal.io/server/common/util"
)
const (
testNamespaceEncoding = "random encoding"
)
var (
testNamespaceName = "random namespace"
testNamespaceData = []byte("random namespace data")
)
type (
namespaceSuite struct {
suite.Suite
*require.Assertions
store sqlplugin.DB
}
)
func NewNamespaceSuite(
t *testing.T,
store sqlplugin.DB,
) *namespaceSuite {
return &namespaceSuite{
Assertions: require.New(t),
store: store,
}
}
func (s *namespaceSuite) SetupSuite() {
}
func (s *namespaceSuite) TearDownSuite() {
}
func (s *namespaceSuite) SetupTest() {
s.Assertions = require.New(s.T())
}
func (s *namespaceSuite) TearDownTest() {
}
func (s *namespaceSuite) TestInsert_Success() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
}
func (s *namespaceSuite) TestInsert_Fail_Duplicate() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
namespace = s.newRandomNamespaceRow(id, name, notificationVersion)
_, err = s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.Error(err) // TODO persistence layer should do proper error translation
namespace = s.newRandomNamespaceRow(id, shuffle.String(testNamespaceName), notificationVersion)
_, err = s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.Error(err) // TODO persistence layer should do proper error translation
namespace = s.newRandomNamespaceRow(primitives.NewUUID(), name, notificationVersion)
_, err = s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.Error(err) // TODO persistence layer should do proper error translation
}
func (s *namespaceSuite) TestInsertSelect() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
filter := sqlplugin.NamespaceFilter{
ID: &id,
}
rows, err := s.store.SelectFromNamespace(newExecutionContext(), filter)
s.NoError(err)
s.Equal([]sqlplugin.NamespaceRow{namespace}, rows)
filter = sqlplugin.NamespaceFilter{
Name: &name,
}
rows, err = s.store.SelectFromNamespace(newExecutionContext(), filter)
s.NoError(err)
s.Equal([]sqlplugin.NamespaceRow{namespace}, rows)
}
func (s *namespaceSuite) TestInsertUpdate_Success() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
namespace = s.newRandomNamespaceRow(id, name, notificationVersion)
result, err = s.store.UpdateNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err = result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
}
func (s *namespaceSuite) TestUpdate_Fail() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.UpdateNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(0, int(rowsAffected))
}
func (s *namespaceSuite) TestInsertUpdateSelect() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
namespace = s.newRandomNamespaceRow(id, name, notificationVersion)
result, err = s.store.UpdateNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err = result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
filter := sqlplugin.NamespaceFilter{
ID: &id,
}
rows, err := s.store.SelectFromNamespace(newExecutionContext(), filter)
s.NoError(err)
s.Equal([]sqlplugin.NamespaceRow{namespace}, rows)
filter = sqlplugin.NamespaceFilter{
Name: &name,
}
rows, err = s.store.SelectFromNamespace(newExecutionContext(), filter)
s.NoError(err)
s.Equal([]sqlplugin.NamespaceRow{namespace}, rows)
}
func (s *namespaceSuite) TestInsertDeleteSelect_ID() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
filter := sqlplugin.NamespaceFilter{
ID: &id,
}
result, err = s.store.DeleteFromNamespace(newExecutionContext(), filter)
s.NoError(err)
rowsAffected, err = result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
filter = sqlplugin.NamespaceFilter{
ID: &id,
}
_, err = s.store.SelectFromNamespace(newExecutionContext(), filter)
s.Error(err) // TODO persistence layer should do proper error translation
filter = sqlplugin.NamespaceFilter{
Name: &name,
}
_, err = s.store.SelectFromNamespace(newExecutionContext(), filter)
s.Error(err) // TODO persistence layer should do proper error translation
}
func (s *namespaceSuite) TestInsertDeleteSelect_Name() {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
filter := sqlplugin.NamespaceFilter{
Name: &name,
}
result, err = s.store.DeleteFromNamespace(newExecutionContext(), filter)
s.NoError(err)
rowsAffected, err = result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
filter = sqlplugin.NamespaceFilter{
ID: &id,
}
_, err = s.store.SelectFromNamespace(newExecutionContext(), filter)
s.Error(err) // TODO persistence layer should do proper error translation
filter = sqlplugin.NamespaceFilter{
Name: &name,
}
_, err = s.store.SelectFromNamespace(newExecutionContext(), filter)
s.Error(err) // TODO persistence layer should do proper error translation
}
func (s *namespaceSuite) TestInsertSelect_Pagination() {
// cleanup the namespace for pagination test
rowsPerPage, err := s.store.SelectFromNamespace(newExecutionContext(), sqlplugin.NamespaceFilter{
GreaterThanID: nil,
PageSize: util.Ptr(1000000),
})
switch err {
case nil:
for _, row := range rowsPerPage {
_, err := s.store.DeleteFromNamespace(newExecutionContext(), sqlplugin.NamespaceFilter{
ID: &row.ID,
})
s.NoError(err)
}
case sql.ErrNoRows:
// noop
default:
s.NoError(err)
}
namespaces := map[string]*sqlplugin.NamespaceRow{}
numNamespace := 2
numNamespacePerPage := 1
for i := 0; i < numNamespace; i++ {
id := primitives.NewUUID()
name := shuffle.String(testNamespaceName)
notificationVersion := int64(1)
namespace := s.newRandomNamespaceRow(id, name, notificationVersion)
result, err := s.store.InsertIntoNamespace(newExecutionContext(), &namespace)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
namespaces[namespace.ID.String()] = &namespace
}
rows := map[string]*sqlplugin.NamespaceRow{}
filter := sqlplugin.NamespaceFilter{
GreaterThanID: nil,
PageSize: util.Ptr(numNamespacePerPage),
}
for doContinue := true; doContinue; doContinue = filter.GreaterThanID != nil {
rowsPerPage, err := s.store.SelectFromNamespace(newExecutionContext(), filter)
switch err {
case nil:
for _, row := range rowsPerPage {
rows[row.ID.String()] = &row
}
length := len(rowsPerPage)
if length == 0 {
filter.GreaterThanID = nil
} else {
filter.GreaterThanID = &rowsPerPage[len(rowsPerPage)-1].ID
}
case sql.ErrNoRows:
filter.GreaterThanID = nil
default:
s.NoError(err)
}
}
s.Equal(namespaces, rows)
}
func (s *namespaceSuite) TestSelectLockMetadata() {
row, err := s.store.SelectFromNamespaceMetadata(newExecutionContext())
s.NoError(err)
tx, err := s.store.BeginTx(newExecutionContext())
s.NoError(err)
metadata, err := tx.LockNamespaceMetadata(newExecutionContext())
s.NoError(err)
s.Equal(row, metadata)
s.NoError(tx.Commit())
}
func (s *namespaceSuite) TestSelectUpdateSelectMetadata_Success() {
row, err := s.store.SelectFromNamespaceMetadata(newExecutionContext())
s.NoError(err)
originalVersion := row.NotificationVersion
result, err := s.store.UpdateNamespaceMetadata(newExecutionContext(), row)
s.NoError(err)
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(1, int(rowsAffected))
row, err = s.store.SelectFromNamespaceMetadata(newExecutionContext())
s.NoError(err)
s.Equal(originalVersion+1, row.NotificationVersion)
}
func (s *namespaceSuite) TestSelectUpdateSelectMetadata_Fail() {
row, err := s.store.SelectFromNamespaceMetadata(newExecutionContext())
s.NoError(err)
originalVersion := row.NotificationVersion
namespaceMetadata := s.newRandomNamespaceMetadataRow(row.NotificationVersion + 1000)
result, err := s.store.UpdateNamespaceMetadata(newExecutionContext(), &namespaceMetadata)
s.NoError(err) // TODO persistence layer should do proper error translation
rowsAffected, err := result.RowsAffected()
s.NoError(err)
s.Equal(0, int(rowsAffected))
row, err = s.store.SelectFromNamespaceMetadata(newExecutionContext())
s.NoError(err)
s.Equal(originalVersion, row.NotificationVersion)
}
func (s *namespaceSuite) newRandomNamespaceRow(
id primitives.UUID,
name string,
notificationVersion int64,
) sqlplugin.NamespaceRow {
return sqlplugin.NamespaceRow{
ID: id,
Name: name,
Data: shuffle.Bytes(testNamespaceData),
DataEncoding: testNamespaceEncoding,
IsGlobal: true,
NotificationVersion: notificationVersion,
}
}
func (s *namespaceSuite) newRandomNamespaceMetadataRow(
notificationVersion int64,
) sqlplugin.NamespaceMetadataRow {
return sqlplugin.NamespaceMetadataRow{
NotificationVersion: notificationVersion,
}
}