Connector/JでMaster/Slave Replication構成のMySQLに接続する #mysql_casual_fukuoka /connector-j-master-slave-replication

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1. Connector/JͰ Master/Slave Replicationߏ੒ͷ MySQLʹ઀ଓ͢Δ MySQL Casual Talks in Fukuoka vol.7

   2018/08/09 @matsumana

2. ࣗݾ঺հ • ໊લɿ দ࡚ ֶ • ॴଐɿ LINE Fukuokaגࣜձࣾ
 ։ൃ3ࣨ

   • Roleɿ SRE • Twitterɿ @matsumana

3. ΞδΣϯμ • Connector/JͷMaster/Slave Replication઀ଓػೳͷ঺հ • Spring BootΞϓϦ͔Β࢖ͬͯΈΔ

4. ࠓճ࢖༻ͨ͠όʔδϣϯ • MySQL: 5.7.22 • Spring Boot: 2.0.3 • Flyway:

   5.0.7 • HikariCP: 2.7.9 • MySQL Connector/J: 5.1.46
 Oracleࣾ͸8.0΁ͷҠߦΛڧ͘ਪ঑͍ͯ͠·͢
 Spring Bootͷmasterϒϥϯν͸8.0.11ʹҠߦࡁͳͷͰɺSpring Boot 2.1ͰҠߦ͢ΔΈ͍ͨͰ͢
 Spring Boot͸bugfixόʔδϣϯ࣌ʹґଘϥΠϒϥϦͷbugfix͔͠औΓࠐ·ͳ͍ϙϦγʔͰ͢ • MyBatis Spring Boot Starter: 1.3.2 • MyBatis: 3.4.6

5. Connector/Jͷ Master/Slave Replication઀ଓػೳ ͷ঺հ

6. Connector/JͷMulti-Host Connections͸͍͔ͭ͋͘Δ • Failover
 
 • Load Balancing
 
 •

   Master/Slave Replication ← ࠓ೔͸͜Ε͚ͩ
 https://dev.mysql.com/doc/connector-j/5.1/en/connector-j-multi-host-connections.html

7. Master/Slave Replicationͷಛ௃ • ҎԼͷΑ͏ͳ઀ଓURLΛઃఆ͓ͯ͘͠ͱɺconnection͕ReadOnlyͩͬͨ৔߹SQLΛSlaveʹ౤͛ͯ͘ΕΔ
 
 • Slave͸ෳ਺ࢦఆՄೳͰɺϩʔυόϥϯε͞ΕΔ • Multiple-Master ReplicatonରԠ


   • ެࣜυΩϡϝϯτʹγϯϓϧͳαϯϓϧιʔε͕͋Γ·͢
 https://dev.mysql.com/doc/connector-j/5.1/en/connector-j-master-slave-replication-connection.html

8. Spring BootΞϓϦ͔Β ࢖ͬͯΈΔ

9. αϯϓϧιʔε • source repo (CLIΞϓϦ):
 https://github.com/matsumana/mysql-jdbc-replication-demo • Application software stack:

   • Docker (MySQLͷMaster/SlaveϨϓϦέʔγϣϯ؀ڥΛϩʔΧϧʹߏங) • Spring Boot • HikariCP • MyBatis • MySQL Connector/J • Flyway

10. ServiceΫϥε @Service @Transactional(readOnly = true) class TodoService(val repository: TodoRepository) {

    @Transactional(readOnly = false) fun insert(todo: Todo) { repository.insert(todo) } 
 fun selectFromSlave(): Todo { return repository.select() } }

11. RepositoryΠϯλϑΣʔε (MyBatis) @Mapper interface TodoRepository { 
 @Insert(""" INSERT INTO

    `todo` (`title`, `detail`, `finished`)
 VALUES
 (#{title}, #{detail}, #{finished}) """) @Options(useGeneratedKeys = true) fun insert(todo: Todo) // Ambiguous Groups @Select(""" SELECT MAX(`id`) AS `id`, `title`, `detail`, `finished` FROM `todo` """) fun select(): Todo }

12. σϞ ͦͷ1 TransactionalΞϊςʔγϣϯͷreadOnlyଐੑʹΑͬͯ SQL͕MasterͱSlaveʹ౤͛෼͚ΒΕΔ༷ࢠΛݟͯΈΔ • long_query_time=0 ʹઃఆ͍ͯ͠ΔͷͰશͯͷSQL͕slow logʹग़ྗ͞ΕΔ • ࠓճͷαϯϓϧΞϓϦͰ͸slow

    logϑΝΠϧΛϗετOS͔Β֬ೝͰ͖Δ • ./docker-volumes/mysql/master/slow-log/slow.log • ./docker-volumes/mysql/slave/slow-log/slow.log • HikariCPͷconnectionInitSqlʹ "kamipo TRADITIONAL" Λઃఆ͍ͯ͠·͢ • http://www.songmu.jp/riji/entry/2015-07-08-kamipo-traditional.html

13. Master • ϓʔϧ͞Ε͍ͯΔConnectionຖʹHikariCPͷconnectionInitSql͕࣮ߦ͞Ε͍ͯΔ
 → ૝ఆͲ͓Γͷڍಈ • INSERT͸࣮ߦ͞Ε͍ͯΔ͕ɺSELECT͸࣮ߦ͞Ε͍ͯͳ͍
 → ૝ఆͲ͓Γͷڍಈ

14. Slave • HikariCPͷconnectionInitSql͕શ࣮͘ߦ͞Ε͍ͯͳ͍
 → ? • SELECT͸࣮ߦ͞Ε͍ͯΔ͕ɺINSERT͸࣮ߦ͞Ε͍ͯͳ͍
 → ૝ఆͲ͓Γͷڍಈ

15. ͳͥSlaveʹରͯ͠ HikariCPͷconnectionInitSql͕ ࣮ߦ͞Ε͍ͯͳ͍ͷ͔ʁ

16. HikariCPͱConnector/JͷιʔεΛಡΜͰΈͨ • HikariCPͷ֘౰Օॴ
 https://github.com/brettwooldridge/HikariCP/blob/HikariCP-2.7.9/src/main/java/com/zaxxer/hikari/pool/PoolBase.java#L426 • connectionInitSql͸Master/Slave ReplicationΛҙ࣮ࣝͨ͠૷ʹ͸ͳ͍ͬͯͳ͍ͷͰ
 connectionInitSql͸Masterʹରͯ͠ͷΈ࣮ߦ͍ͯ͠Δ • Connector/JͰSQL࣮ߦର৅ϊʔυ͕ܾఆ͞ΕΔͷͰɺ


    HikariCPͷϨΠϠʔͰશͯͷϊʔυʹରͯ͠connectionInitSqlΛ
 ࿙Εͳ࣮͘ߦ͢Δͷ͸೉͍͠ͱࢥΘΕ·͢ • Connector/Jͷ֘౰Օॴ
 https://github.com/mysql/mysql-connector-j/blob/5.1.46/src/com/mysql/jdbc/ReplicationConnectionProxy.java#L49 • ReplicationConnectionProxyͷreadOnlyσϑΥϧτ஋͸false

17. σϞ1ͷ·ͱΊ • Master/Slave Replication઀ଓͰHikariCPͷconnectionInitSqlΛ࢖͏৔߹͸஫ҙ͕ඞཁ • connectionInitSqlʹઃఆͨ͠SQL͸Masterʹ͔࣮͠ߦ͞Εͳ͍ • sql_modeΛઃఆ͍ͨ͠৔߹͸ɺ
 HikariCPͷconnectionInitSqlͰ͸ͳ͘MySQLαʔόͷmy.cnfͰ΍Γ·͠ΐ͏ •

    ิ଍ɿΞϯϏΪϡΞεάϧʔϓʢᐆດͳάϧʔϓʣ
 SQLΞϯνύλʔϯ - ։ൃऀΛ଴ͪड͚Δ25ͷམͱ݀͠ (֦େ൛)
 https://www.slideshare.net/t_wada/sql-antipatterns-digest/59

18. σϞ ͦͷ2 HikariCPͰϓʔϧ͞Ε͍ͯΔConnection਺ͱ MasterͱSalveͦΕͧΕͷ࣮ࡍͷConnection਺Λ֬ೝͯ͠ΈΔ

19. • HikariCPͷmaximumPoolSizeσϑΥϧτ஋͸10 ϓʔϧ͞Ε͍ͯΔConnection਺ͷϝτϦΫε

20. Master

21. Slave

22. σϞ2ͷ·ͱΊ • ྫ͑͹ɺHikariCPͷϝτϦΫεͰɺϓʔϧ͍ͯ͠Δ઀ଓ਺͕10ͱͳ͍ͬͯΔঢ়ଶͩͱɺ Master/Slaveͷશϊʔυʹରͯ͠10ͣͭ઀ଓ͕ுΒΕ͍ͯΔ • େ͖ͳ໰୊͸͋Γ·ͤΜ͕ɺҰԠ͓֮͑ͯ͘ํ͕ྑͦ͞͏Ͱ͢

23. σϞ2ͷٙ໰఺ • ϓʔϧ͞Ε͍ͯΔશͯͷConnection1ͭ1͕ͭMaster/Slaveશϊʔυ΁
 ઀ଓ͍ͯ͠Δͱ͍͏ࣄʹͳΔ͕ɺ࣮૷͸Ͳ͏ͳ͍ͬͯΔʁ

24. ࠶ͼιʔεΛಡΜͰΈͨ

25. σϞ2ͷٙ໰఺ (݁࿦) • SQLΛ࣮ߦ͢Δ౓ʹTransactionΞϊςʔγϣϯͷreadOnlyଐੑΛ࢖ͬͯ
 SQLͷ࣮ߦઌΛ”౎౓”ܾఆ͍ͯ͠Δ • SQL࣮ߦઌͷ੾Γସ͑ϩδοΫ͕࣮૷͞Ε͍ͯΔͷ͸ɺ
 Connector/JͷReplicationConnectionProxy#setReadOnly

26. Ϋϥεਤ

27. • HikariCPͷProxyConnection#setReadOnlyܦ༝ͰReadOnlyϑϥά͕ηοτ͞ΕΔ • ͍͔ͭ͘ͷܧঝͱҕৡΛܦͯɺConnector/JͷReplicationConnectionProxy#setReadOnly ͕ݺ͹ΕɺcorrentConnectionϑΟʔϧυͱͯ͠อ͍࣋ͯ͠ΔSQL࣮ߦઌ͕੾ΓସΘΔ ֓ཁ

28. ͍ͭͰʹɺSpring͕HikariCPͷ ProxyConnection#setReadOnly ΛݺͿͱ͜Ζͷιʔε΋ ಡΜͰΈͨ

29. େ͖̎ͭ͘ʹ෼͚ͯઆ໌͠·͢ • TransactionΞϊςʔγϣϯ৘ใऩू • ServiceΫϥεͷϝιουݺͼग़͠ޙɺ
 HikariCPͷProxyConnection#setReadOnly͕ݺ͹ΕΔ·Ͱ

30. 1. TransactionΞϊςʔγϣϯ৘ใऩू

31. 1. ΞϓϦέʔγϣϯىಈ 2. Beanੜ੒ 2-1. AOPॲཧ 2-1-1. TransactionΞϊςʔγϣϯ৘ใऩू
 SpringTransactionAnnotationParser#parseTransactionAnnotation 2-1-2.

    ͦͷଞͷAOPॲཧ ॲཧͷྲྀΕ (֓ཁ)

32. 2. ServiceΫϥεͷϝιουݺͼग़͠ޙ HikariCPͷ ProxyConnection#setReadOnly͕
 ݺ͹ΕΔ·Ͱ

33. 1. CGLIBͰΤϯϋϯε͞ΕͨService ProxyΫϥεͷϝιου͕࣮ߦ͞ΕΔ 2. TransactionInterceptor͕ݺ͹ΕΔ 3. DataSource͔ΒίωΫγϣϯऔಘ & τϥϯβΫγϣϯ։࢝
 DataSourceTransactionManager#doBegin

    4. Ξϊςʔγϣϯ͔Βऩूͨ͠ReadOnlyଐੑΛConnectionͷReadOnlyʹઃఆ
 DataSourceUtils#prepareConnectionForTransaction ॲཧͷྲྀΕ (֓ཁ)

34. 5. ServiceΫϥεͷϝιου࣮ߦ 6. Commit or Rollback 7. Connectionͷঢ়ଶΛϦηοτ (ReadOnly=falseʹ໭͢)
 DataSourceUtils#resetConnectionAfterTransaction

    ॲཧͷྲྀΕ (֓ཁ)

35. ·ͱΊ • Connector/JͷMaster/Slave Replication઀ଓػೳΛ͝঺հ͠·ͨ͠ • Master/Slave Replication઀ଓͰ͸ɺHikariCPͷconnectionInitSql͸Masterʹ͔͠
 ࣮ߦ͞Εͳ͍ࣄ͕Θ͔Γ·ͨ͠ • Connector/J͕Ͳ͏΍ͬͯMaster/SlaveΛ੾Γସ͍͑ͯΔ͔ௐ΂·ͨ͠

    • SpringͷServiceΫϥεʹઃఆͨ͠TransactionΞϊςʔγϣϯͷreadOnlyଐੑ͕ͲͷΑ͏ ʹͯ͠ConnectionͷreadOnlyଐੑʹηοτ͞ΕΔͷ͔ௐ΂·ͨ͠

36. Thank you :)