{"id":5365,"date":"2021-06-14T08:39:20","date_gmt":"2021-06-14T08:39:20","guid":{"rendered":"https:\/\/swiv.com.br\/enabling-fast-application-notification-taf-configuration\/"},"modified":"2026-05-27T20:02:31","modified_gmt":"2026-05-27T19:02:31","slug":"enabling-fast-application-notification-taf-configuration","status":"publish","type":"post","link":"https:\/\/swiv.com.br\/index.php\/2021\/06\/14\/enabling-fast-application-notification-taf-configuration\/","title":{"rendered":"Enabling Fast Application Notification (TAF) Configuration"},"content":{"rendered":"\n
Neste artigo, vamos explorar uma situa\u00e7\u00e3o de Falha Parcial, onde a camada de Banco de Dados \u00e9 afetada (apenas o banco Primary), e a camada de Aplica\u00e7\u00e3o (Client) consegue realizar o redirecionamento das conex\u00f5es (inclusive as vigentes) para o banco Standby. Esse recurso \u00e9 poss\u00edvel gra\u00e7as a implementa\u00e7\u00e3o de alguns pr\u00e9-requisitos:<\/p>\n\n\n\n
Database Services<\/li>
Data Broker com Fast-Start Failover (FSFO)<\/li>
Oracle Restart (para inst\u00e2ncias single, que \u00e9 o nosso caso)<\/li>
Configura\u00e7\u00e3o na camada client (que pode ser OCI, JDBC e ODP.Net)<\/li><\/ul>\n\n\n\n
Desse modo, quando o evento de falha \u00e9 identificado, o Relocate do Servi\u00e7o de Banco de Dados \u00e9 realizado, e o Broker envia uma notifica\u00e7\u00e3o FAN para a camada client, informando sobre a situa\u00e7\u00e3o. Como a camada client j\u00e1 estava com suas configura\u00e7\u00f5es realizadas previamente, ela consegue direcionar as conex\u00f5es para o novo banco Primary. Vamos iniciar o processo de prepara\u00e7\u00e3o:<\/p>\n\n\n\n
No ambiente Standby, vamos validar que o banco est\u00e1 up, e mudar a sua op\u00e7\u00e3o de startup (que est\u00e1 em mount) para OPEN. Assim, quando ligarmos o processo de Apply, o recurso de Real-Time Query estar\u00e1 habilitado:<\/p>\n\n\n
\n[oracle@fornix2 ~]$ srvctl status database -d cortexdr\nDatabase is running.\n[oracle@fornix2 ~]$ srvctl update database -db cortexdr -startoption OPEN\n<\/pre><\/div>\n\n\n
Ligando o processo de Redo Apply:<\/p>\n\n\n
\n[oracle@fornix2 ~]$ dgmgrl sys\/oracle@CORTEXDR as sysdba\nDGMGRL for Linux: Release 19.0.0.0.0 - Production on Sat Jun 14 05:04:17 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle and\/or its affiliates. All rights reserved.\n \nWelcome to DGMGRL, type "help" for information.\nConnected to "cortexDR"\nConnected as SYSDBA.\nDGMGRL> EDIT DATABASE CORTEXDR SET STATE=APPLY-ON;\nSucceeded.\n<\/pre><\/div>\n\n\n
Iniciando o processo do Observer:<\/p>\n\n\n
\n[oracle@fornix2 ~]$ dgmgrl sys\/oracle@CORTEXDR as sysdba\nDGMGRL for Linux: Release 19.0.0.0.0 - Production on Mon Jun 14 05:13:22 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle and\/or its affiliates. All rights reserved.\n \nWelcome to DGMGRL, type "help" for information.\nConnected to "cortexDR"\nConnected as SYSDBA.\nDGMGRL> START OBSERVER FILE='\/home\/oracle\/CORTEXDR.dat';\n[W000 2021-06-14T05:13:33.678-03:00] FSFO target standby is cortexdr\nObserver 'fornix2' started\n[W000 2021-06-14T05:13:33.832-03:00] Observer trace level is set to USER\n[W000 2021-06-14T05:13:33.832-03:00] Try to connect to the primary.\n[W000 2021-06-14T05:13:33.832-03:00] Try to connect to the primary cortex.\n[W000 2021-06-14T05:13:33.898-03:00] The standby cortexdr is ready to be a FSFO target\n[W000 2021-06-14T05:13:34.898-03:00] Connection to the primary restored!\n[W000 2021-06-14T05:13:36.899-03:00] Disconnecting from database cortex.\n<\/pre><\/div>\n\n\n<\/figure>\n\n\n\n
Agora podemos checar a configura\u00e7\u00e3o do nosso Data Guard atrav\u00e9s do Broker:<\/p>\n\n\n
\n[oracle@fornix1 ~]$ dgmgrl sys\/oracle@CORTEX as sysdba\nDGMGRL for Linux: Release 19.0.0.0.0 - Production on Mon Jun 14 05:15:35 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle and\/or its affiliates. All rights reserved.\n \nWelcome to DGMGRL, type "help" for information.\nConnected to "cortex"\nConnected as SYSDBA.\nDGMGRL> SHOW CONFIGURATION;\n \nConfiguration - cortex\n \n Protection Mode: MaxPerformance\n Members:\n cortex - Primary database\n cortexdr - (*) Physical standby database\n \nFast-Start Failover: Enabled in Potential Data Loss Mode\n \nConfiguration Status:\nSUCCESS (status updated 15 seconds ago)\n \nDGMGRL> SHOW DATABASE CORTEX;\n \nDatabase - cortex\n \n Role: PRIMARY\n Intended State: TRANSPORT-ON\n Instance(s):\n cortex\n \nDatabase Status:\nSUCCESS\n \nDGMGRL> SHOW DATABASE CORTEXDR;\n \nDatabase - cortexdr\n \n Role: PHYSICAL STANDBY\n Intended State: APPLY-ON\n Transport Lag: 0 seconds (computed 1 second ago)\n Apply Lag: 0 seconds (computed 1 second ago)\n Average Apply Rate: 0 Byte\/s\n Real Time Query: ON\n Instance(s):\n CORTEXDR\n \nDatabase Status:\nSUCCESS\n<\/pre><\/div>\n\n\n
Criando um novo Database Service no banco Primary e o iniciando:<\/p>\n\n\n
\n[oracle@fornix1 ~]$ sqlplus \/ as sysdba\n \nSQL*Plus: Release 19.0.0.0.0 - Production on Mon Jun 14 05:17:41 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle. All rights reserved.\n \n \nConnected to:\nOracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production\nVersion 19.3.0.0.0\n \nSQL> select name from dba_services ;\n \nNAME\n----------------------------------------------------------------\nSYS$BACKGROUND\nSYS$USERS\ncortex_CFG\nBSS\ncortexXDB\ncortex.localdomain\n \n6 rows selected.\n<\/pre><\/div>\n\n
\n[oracle@fornix2 ~]$ sqlplus \/ as sysdba\n \nSQL*Plus: Release 19.0.0.0.0 - Production on Mon Jun 14 05:18:09 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle. All rights reserved.\n \n \nConnected to:\nOracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production\nVersion 19.3.0.0.0\n \nSQL> select name from dba_services ;\n \nNAME\n----------------------------------------------------------------\nSYS$BACKGROUND\nSYS$USERS\ncortex_CFG\nBSS\ncortexXDB\ncortex.localdomain\n \n6 rows selected.\n<\/pre><\/div>\n\n\n
Para simular a camada Client, editei o arquivo “tnsnames.ora” do Oracle Client instalado em meu notebook pessoal, para acessar os ambientes:<\/p>\n\n\n\n<\/figure>\n\n\n\n
O teste de tnsping est\u00e1 OK:<\/p>\n\n\n\n<\/figure>\n\n\n\n
Realizando a conex\u00e3o com a \u00faltima STRING adicionada (que usa os recursos de Failover):<\/p>\n\n\n\n<\/figure>\n\n\n\n
Para completar essa camada, vamos adicionar ao arquivo sqlnet.ora a linha abaixo, no Oracle Client do meu notebook:<\/p>\n\n\n\n<\/figure>\n\n\n\n
Agora vem a parte legal do teste. Vamos disparar o comando abaixo de consulta atrav\u00e9s do meu Oracle Client, que demora alguns minutos para concluir, devido plano cartesiano gerado. Enquanto a consulta \u00e9 realizada, vamos abortar a inst\u00e2ncia do banco Primary. Isso provocar\u00e1 em nossa sess\u00e3o Client uma experi\u00eancia de congelamento. Uma vez identificado a indisponibilidade do Primary, o FSFO vai abrir o at\u00e9 ent\u00e3o Standby como Primary, mandar a FAN notification para o Client, que redirecionar\u00e1 a sess\u00e3o ativa para o novo Primary, e ent\u00e3o continuar a execu\u00e7\u00e3o do select. Importante citarmos que execu\u00e7\u00f5es de DML n\u00e3o possuem esse comportamento.<\/p>\n\n\n
\nselect x.employee_id from hr.employees x, hr.employees y, hr.employees z;\n<\/pre><\/div>\n\n\n<\/figure>\n\n\n
\n[oracle@fornix1 ~]$ sqlplus \/ as sysdba\n \nSQL*Plus: Release 19.0.0.0.0 - Production on Mon Jun 14 05:23:12 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle. All rights reserved.\n \n \nConnected to:\nOracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production\nVersion 19.3.0.0.0\n \nSQL> SHU ABORT;\nORACLE instance shut down.\n<\/pre><\/div>\n\n\n
Sess\u00e3o em Hang:<\/p>\n\n\n\n<\/figure>\n\n\n\n
FSFO identificando que o Primary est\u00e1 inacess\u00edvel e fazendo desse modo o Failover:<\/p>\n\n\n\n<\/figure>\n\n\n\n
Failover realizado:<\/p>\n\n\n
\n[S002 2021-06-14T05:24:09.628-03:00] Initiating Fast-start Failover.\nPerforming failover NOW, please wait...\nFailover succeeded, new primary is "cortexdr"\n<\/pre><\/div>\n\n\n<\/figure>\n\n\n\n
Nesse ponto, nossa sess\u00e3o contina o seu processamento de onde tinha parado, sem necessidade de interven\u00e7\u00e3o:<\/p>\n\n\n\n<\/figure>\n\n\n\n
E agora podemos constatar que a inst\u00e2ncia que estamos conectados \u00e9 o novo Primary:<\/p>\n\n\n\n<\/figure>\n\n\n\n
Vamos subir a antiga inst\u00e2ncia do Primary:<\/p>\n\n\n
\n[oracle@fornix1 ~]$ sqlplus \/ as sysdba\n \nSQL*Plus: Release 19.0.0.0.0 - Production on Mon Jun 14 05:29:21 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle. All rights reserved.\n \nConnected to an idle instance.\n \nSQL> startup;\nORACLE instance started.\n \nTotal System Global Area 2583690520 bytes\nFixed Size 8899864 bytes\nVariable Size 553648128 bytes\nDatabase Buffers 2013265920 bytes\nRedo Buffers 7876608 bytes\nDatabase mounted.\nDatabase opened.\n<\/pre><\/div>\n\n\n
Reinstate realizado automaticamente:<\/p>\n\n\n
\n[W000 2021-06-14T05:30:36.891-03:00] The standby cortex is ready to be a FSFO target\nReinstatement of database "cortex" succeeded\n2021-06-14T05:31:22.128-03:00\n[W000 2021-06-14T05:31:22.949-03:00] Successfully reinstated database cortex.\n<\/pre><\/div>\n\n\n<\/figure>\n\n\n\n
Realizando um Switchover para o Primary original:<\/p>\n\n\n
\n[oracle@fornix1 ~]$ dgmgrl sys\/oracle@CORTEX as sysdba DGMGRL for Linux: Release 19.0.0.0.0 - Production on Mon Jun 14 05:35:05 2021\nVersion 19.3.0.0.0\n \nCopyright (c) 1982, 2019, Oracle and\/or its affiliates. All rights reserved.\n \nWelcome to DGMGRL, type "help" for information.\nConnected to "cortex"\nConnected as SYSDBA.\nDGMGRL> SHOW CONFIGURATION;\n \nConfiguration - cortex\n \n Protection Mode: MaxPerformance\n Members:\n cortexdr - Primary database\n cortex - (*) Physical standby database\n \nFast-Start Failover: Enabled in Potential Data Loss Mode\n \nConfiguration Status:\nSUCCESS (status updated 47 seconds ago)\n \nDGMGRL> SWITCHOVER TO CORTEX;\nPerforming switchover NOW, please wait...\nNew primary database "cortex" is opening...\nOracle Clusterware is restarting database "cortexdr" ...\nConnected to an idle instance.\nConnected to an idle instance.\nConnected to an idle instance.\nConnected to an idle instance.\nConnected to an idle instance.\nConnected to "cortexDR"\nConnected to "cortexDR"\nSwitchover succeeded, new primary is "cortex"\nDGMGRL> SHOW CONFIGURATION;\n \nConfiguration - cortex\n \n Protection Mode: MaxPerformance\n Members:\n cortex - Primary database\n cortexdr - (*) Physical standby database\n \nFast-Start Failover: Enabled in Potential Data Loss Mode\n \nConfiguration Status:\nSUCCESS (status updated 43 seconds ago)\n \nDGMGRL>\n<\/pre><\/div>\n\n\n
Observer:<\/p>\n\n\n\n<\/figure>\n\n\n\n
\u00c9 poss\u00edvel ver que nossa sess\u00e3o agora alcan\u00e7a a inst\u00e2ncia do Primary original, de forma totalmente transparente:<\/p>\n\n\n\n<\/figure>\n\n\n\n
Obs: Este procedimento foi criado pelo senhor Ahmed Baraka (www.ahmedbaraka.com) e foi apenas reproduzido por mim em um laborat\u00f3rio pessoal para fins de aprendizado.<\/p>\n","protected":false},"excerpt":{"rendered":"
Neste artigo, vamos explorar uma situa\u00e7\u00e3o de Falha Parcial, onde a camada de Banco de Dados \u00e9 afetada (apenas o banco Primary), e a camada de Aplica\u00e7\u00e3o (Client) consegue realizar o redirecionamento das conex\u00f5es (inclusive as vigentes) para o banco Standby. Esse recurso \u00e9 poss\u00edvel gra\u00e7as a implementa\u00e7\u00e3o de alguns pr\u00e9-requisitos: Database Services Data Broker […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-5365","post","type-post","status-publish","format-standard","hentry","category-high-availability"],"_links":{"self":[{"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/posts\/5365","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/comments?post=5365"}],"version-history":[{"count":1,"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/posts\/5365\/revisions"}],"predecessor-version":[{"id":9104,"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/posts\/5365\/revisions\/9104"}],"wp:attachment":[{"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/media?parent=5365"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/categories?post=5365"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swiv.com.br\/index.php\/wp-json\/wp\/v2\/tags?post=5365"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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