Files
tasks/common/persistence/sql/sqlplugin/mysql/cluster_metadata.go
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

272 lines
8.4 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 mysql
import (
"context"
"database/sql"
"strings"
p "go.temporal.io/server/common/persistence"
"go.temporal.io/server/common/persistence/sql/sqlplugin"
)
const constMetadataPartition = 0
const constMembershipPartition = 0
const (
// ****** CLUSTER_METADATA_INFO TABLE ******
insertClusterMetadataQry = `INSERT INTO cluster_metadata_info (metadata_partition, cluster_name, data, data_encoding, version) VALUES(?, ?, ?, ?, ?)`
updateClusterMetadataQry = `UPDATE cluster_metadata_info SET data = ?, data_encoding = ?, version = ? WHERE metadata_partition = ? AND cluster_name = ?`
getClusterMetadataBase = `SELECT data, data_encoding, version FROM cluster_metadata_info `
listClusterMetadataQry = getClusterMetadataBase + `WHERE metadata_partition = ? ORDER BY cluster_name LIMIT ?`
listClusterMetadataRangeQry = getClusterMetadataBase + `WHERE metadata_partition = ? AND cluster_name > ? ORDER BY cluster_name LIMIT ?`
getClusterMetadataQry = getClusterMetadataBase + `WHERE metadata_partition = ? AND cluster_name = ?`
writeLockGetClusterMetadataQry = getClusterMetadataQry + ` FOR UPDATE`
deleteClusterMetadataQry = `DELETE FROM cluster_metadata_info WHERE metadata_partition = ? AND cluster_name = ?`
// ****** CLUSTER_MEMBERSHIP TABLE ******
templateUpsertActiveClusterMembership = `INSERT INTO
cluster_membership (membership_partition, host_id, rpc_address, rpc_port, role, session_start, last_heartbeat, record_expiry)
VALUES(?, ?, ?, ?, ?, ?, ?, ?)
ON DUPLICATE KEY UPDATE
session_start=VALUES(session_start), last_heartbeat=VALUES(last_heartbeat), record_expiry=VALUES(record_expiry)`
templatePruneStaleClusterMembership = `DELETE FROM
cluster_membership
WHERE membership_partition = ? AND record_expiry < ?`
templateGetClusterMembership = `SELECT host_id, rpc_address, rpc_port, role, session_start, last_heartbeat, record_expiry FROM
cluster_membership WHERE membership_partition = ?`
// ClusterMembership WHERE Suffixes
templateWithRoleSuffix = ` AND role = ?`
templateWithHeartbeatSinceSuffix = ` AND last_heartbeat > ?`
templateWithRecordExpirySuffix = ` AND record_expiry > ?`
templateWithRPCAddressSuffix = ` AND rpc_address = ?`
templateWithHostIDSuffix = ` AND host_id = ?`
templateWithHostIDGreaterSuffix = ` AND host_id > ?`
templateWithSessionStartSuffix = ` AND session_start >= ?`
// Generic SELECT Suffixes
templateWithLimitSuffix = ` LIMIT ?`
templateWithOrderBySessionStartSuffix = ` ORDER BY membership_partition ASC, host_id ASC`
)
func (mdb *db) SaveClusterMetadata(
ctx context.Context,
row *sqlplugin.ClusterMetadataRow,
) (sql.Result, error) {
if row.Version == 0 {
return mdb.ExecContext(ctx,
insertClusterMetadataQry,
constMetadataPartition,
row.ClusterName,
row.Data,
row.DataEncoding,
1,
)
}
return mdb.ExecContext(ctx,
updateClusterMetadataQry,
row.Data,
row.DataEncoding,
row.Version+1,
constMetadataPartition,
row.ClusterName,
)
}
func (mdb *db) ListClusterMetadata(
ctx context.Context,
filter *sqlplugin.ClusterMetadataFilter,
) ([]sqlplugin.ClusterMetadataRow, error) {
var err error
var rows []sqlplugin.ClusterMetadataRow
switch {
case len(filter.ClusterName) != 0:
err = mdb.SelectContext(ctx,
&rows,
listClusterMetadataRangeQry,
constMetadataPartition,
filter.ClusterName,
filter.PageSize,
)
default:
err = mdb.SelectContext(ctx,
&rows,
listClusterMetadataQry,
constMetadataPartition,
filter.PageSize,
)
}
return rows, err
}
func (mdb *db) GetClusterMetadata(
ctx context.Context,
filter *sqlplugin.ClusterMetadataFilter,
) (*sqlplugin.ClusterMetadataRow, error) {
var row sqlplugin.ClusterMetadataRow
err := mdb.GetContext(ctx,
&row,
getClusterMetadataQry,
constMetadataPartition,
filter.ClusterName,
)
if err != nil {
return nil, err
}
return &row, err
}
func (mdb *db) DeleteClusterMetadata(
ctx context.Context,
filter *sqlplugin.ClusterMetadataFilter,
) (sql.Result, error) {
return mdb.ExecContext(ctx,
deleteClusterMetadataQry,
constMetadataPartition,
filter.ClusterName,
)
}
func (mdb *db) WriteLockGetClusterMetadata(
ctx context.Context,
filter *sqlplugin.ClusterMetadataFilter,
) (*sqlplugin.ClusterMetadataRow, error) {
var row sqlplugin.ClusterMetadataRow
err := mdb.GetContext(ctx,
&row,
writeLockGetClusterMetadataQry,
constMetadataPartition,
filter.ClusterName,
)
if err != nil {
return nil, err
}
return &row, err
}
func (mdb *db) UpsertClusterMembership(
ctx context.Context,
row *sqlplugin.ClusterMembershipRow,
) (sql.Result, error) {
return mdb.ExecContext(ctx,
templateUpsertActiveClusterMembership,
constMembershipPartition,
row.HostID,
row.RPCAddress,
row.RPCPort,
row.Role,
mdb.converter.ToMySQLDateTime(row.SessionStart),
mdb.converter.ToMySQLDateTime(row.LastHeartbeat),
mdb.converter.ToMySQLDateTime(row.RecordExpiry))
}
func (mdb *db) GetClusterMembers(
ctx context.Context,
filter *sqlplugin.ClusterMembershipFilter,
) ([]sqlplugin.ClusterMembershipRow, error) {
var queryString strings.Builder
var operands []interface{}
queryString.WriteString(templateGetClusterMembership)
operands = append(operands, constMembershipPartition)
if filter.HostIDEquals != nil {
queryString.WriteString(templateWithHostIDSuffix)
operands = append(operands, filter.HostIDEquals)
}
if filter.RPCAddressEquals != "" {
queryString.WriteString(templateWithRPCAddressSuffix)
operands = append(operands, filter.RPCAddressEquals)
}
if filter.RoleEquals != p.All {
queryString.WriteString(templateWithRoleSuffix)
operands = append(operands, filter.RoleEquals)
}
if !filter.LastHeartbeatAfter.IsZero() {
queryString.WriteString(templateWithHeartbeatSinceSuffix)
operands = append(operands, filter.LastHeartbeatAfter)
}
if !filter.RecordExpiryAfter.IsZero() {
queryString.WriteString(templateWithRecordExpirySuffix)
operands = append(operands, filter.RecordExpiryAfter)
}
if !filter.SessionStartedAfter.IsZero() {
queryString.WriteString(templateWithSessionStartSuffix)
operands = append(operands, filter.SessionStartedAfter)
}
if filter.HostIDGreaterThan != nil {
queryString.WriteString(templateWithHostIDGreaterSuffix)
operands = append(operands, filter.HostIDGreaterThan)
}
queryString.WriteString(templateWithOrderBySessionStartSuffix)
if filter.MaxRecordCount > 0 {
queryString.WriteString(templateWithLimitSuffix)
operands = append(operands, filter.MaxRecordCount)
}
compiledQryString := queryString.String()
var rows []sqlplugin.ClusterMembershipRow
if err := mdb.SelectContext(ctx,
&rows,
compiledQryString,
operands...,
); err != nil {
return nil, err
}
for i := range rows {
rows[i].SessionStart = mdb.converter.FromMySQLDateTime(rows[i].SessionStart)
rows[i].LastHeartbeat = mdb.converter.FromMySQLDateTime(rows[i].LastHeartbeat)
rows[i].RecordExpiry = mdb.converter.FromMySQLDateTime(rows[i].RecordExpiry)
}
return rows, nil
}
func (mdb *db) PruneClusterMembership(
ctx context.Context,
filter *sqlplugin.PruneClusterMembershipFilter,
) (sql.Result, error) {
return mdb.ExecContext(ctx,
templatePruneStaleClusterMembership,
constMembershipPartition,
mdb.converter.ToMySQLDateTime(filter.PruneRecordsBefore),
)
}