MICHIEL ROOK DATABASE MIGRATIONS WITHOUT DOWN TIME

Transcription

1 MICHIEL ROOK DATABASE MIGRATIONS WITHOUT DOWN

2 Developer, consultant, trainer,

3 ABOUT DATABASE MIGRATIONS

4 ABOUT SCHEMA MIGRATIONS

5 SQL

6

7 UP

8 DOCTRINE class Version extends AbstractMigration { public function up(schema $schema) { $this->addsql('create TABLE addresses (id INT NOT NULL, street VARCHAR(255) NOT NULL, PRIMARY KEY(id))'); } public function down(schema $schema) { $this->addsql('drop TABLE addresses'); }

9 DOCTRINE mysql> select * from migration_versions; version row in set (0,00

10 FLYWAY V create_addresses_table.sql CREATE TABLE addresses (id INT NOT NULL, street VARCHAR(255) NOT NULL, PRIMARY

11 FLYWAY mysql> select * from schema_version; installed_rank version description type script << Flyway Baseline >> BASELINE << Flywa create addresses table SQL V rows in set (0,00 sec) checksum installed_by installed_on execution_time NULL migrations_ :27: migrations_ :27:21 16

12 TRANSACTIONS?

13 ROLLBACKS?

14 1 DESTRUCTIVE

15 1 LONG-LIVED LOCKS DESTRUCTIVE

16 1 LONG-LIVED LOCKS DESTRUCTIVE CHANGES

17 1 LONG-LIVED LOCKS DESTRUCTIVE CHANGES RENAMES

18 1 2 DESTRUCTIVE CHANGES IMPLICIT

19 1 2 3 DESTRUCTIVE CHANGES IMPLICIT COMMITS

20 DESTRUCTIVE CHANGES IMPLICIT COMMITS SHARDING MULTIPLE

21 ROLLBACKS

22 DOWNTIME?

23 CREATE

24 CREATE PACKAGE SHUT DOWN

25 CREATE PACKAGE SHUT DOWN APPLICATION RUN

26 CREATE PACKAGE SHUT DOWN APPLICATION DEPLOY PACKAGE RUN

27 CREATE PACKAGE RUN APPLICATION SHUT DOWN APPLICATION DEPLOY PACKAGE RUN

28 DOWNTIME?

29 DOWNTIME

30 NO MIGRATIONS!

31 DOWNTIME

32 ZERO DOWNTIME DEPLOYMENT LOAD BALANCER APP

33 ZERO DOWNTIME DEPLOYMENT LOAD BALANCER APP V1 APP

34 ZERO DOWNTIME DEPLOYMENT LOAD BALANCER APP

35 DATABASE STATE?

36 DATABASE VERSION LOAD BALANCER APP V1 expects v1 DATABASE

37 DATABASE VERSION LOAD BALANCER APP V1 expects v1 DATABASE

38 DATABASE VERSION LOAD BALANCER APP V1 APP V2 expects v1 expects v2 DATABASE

39 OLD APP SHOULD WORK WITH NEW STATE

40 DECOUPLE

41 MIGRATION DECOUPLE DEPLOYMENT

42 EXPAND - CONTRACT

43 BACKWARDS COMPATIBILITY

44 CLIENT CLIENT EXISTING API

45 CLIENT EXISTING API CLIENT CLIENT NEW

46 DEPRECATION

47 CLIENT EXISTING API CLIENT CLIENT NEW

48 CLIENT EXISTING API CLIENT CLIENT NEW

49 CLIENT EXISTING API CLIENT CLIENT NEW

50 CLIENT CLIENT NEW API

51 NON-DESTRUCTIVE CHANGES

52 ADDING

53 ADDING TABLES ADDING

54 ADDING TABLES ADDING COLUMNS CREATING

55 ADDING TABLES ADDING COLUMNS CREATING INDEXES

56 ONE DIFF BACK

57 EXAMPLE: RENAMING A COLUMN

58 1 CREATE COLUMN WITH NEW

59 1 2 CREATE COLUMN WITH NEW NAME WRITE TO OLD & NEW

60 1 2 3 CREATE COLUMN WITH NEW NAME WRITE TO OLD & NEW COLUMNS MIGRATE OLD

61 CREATE COLUMN WITH NEW NAME WRITE TO OLD & NEW COLUMNS MIGRATE OLD RECORDS READ FROM NEW

62 CREATE COLUMN WITH NEW NAME WRITE TO OLD & NEW COLUMNS MIGRATE OLD RECORDS READ FROM NEW COLUMN remove old column and

63

64 FEATURE TOGGLES

65 ENABLE/DISABLE

66 ENABLE/DISABLE FEATURES ALTERNATIVE CODE

67 ENABLE/DISABLE FEATURES ALTERNATIVE CODE PATHS AT

68

69 CREATE COLUMN WITH NEW NAME WRITE TO OLD & NEW COLUMNS MIGRATE OLD RECORDS READ FROM NEW COLUMN feature toggle feature

70 NOSQL

71 NO SCHEMA

72 MIGRATE DURING READ

73 BACKGROUND MIGRATION

74 NO DOWNTIME

75 LARGE DATASETS

76 LONG MIGRATIONS

77 LONG RUNNING QUERIES LONG MIGRATIONS

78 LONG MIGRATIONS LONG RUNNING QUERIES MEMORY USAGE

79 LONG MIGRATIONS FAILURES LONG RUNNING QUERIES MEMORY USAGE

80 LONG MIGRATIONS FAILURES RESTARTING, RESUMING LONG RUNNING QUERIES MEMORY USAGE

81 LOGGING & PROGRESS LONG MIGRATIONS FAILURES RESTARTING, RESUMING LONG RUNNING QUERIES MEMORY USAGE

82 QUEUES

83 UI queries DTOs messages Data Layer Queue Database messages

84 UI queries DTOs messages Data Layer Queue Database messages

85 CQRS

86 COMMAND QUERY RESPONSIBILITY SEGREGATION

87 SEPARATE READS FROM WRITES

88 UI queries DTOs updates Data Layer Commands Repository Database Database Event Handlers events

89 TOOLS

90 @michieltcs

91 RECAP

92 MULTIPLE STEPS

93 NO BREAKING CHANGES

94 LITERATURE databaserefactoring.com github.com/barsoom/devbook/

95 THANK / mrook@fourscouts.nl