{"id":2202,"date":"2023-07-14T16:51:28","date_gmt":"2023-07-14T14:51:28","guid":{"rendered":"https:\/\/www.ludovicocaldara.net\/dba\/?p=2202"},"modified":"2023-07-14T16:51:28","modified_gmt":"2023-07-14T14:51:28","slug":"trust-oracle-with-oracle","status":"publish","type":"post","link":"https:\/\/www.ludovicocaldara.net\/dba\/trust-oracle-with-oracle\/","title":{"rendered":"When it comes to using Oracle, trust Oracle…"},"content":{"rendered":"

A month ago, I saw this article published on the AWS architecture blog:<\/p>\n

Disaster Recovery for Oracle Database on Amazon EC2 with Fast-Start Failover<\/a><\/p>\n

I love seeing people suggesting Oracle Data Guard Fast-Start Failover for high availability. Nevertheless, there are a few problems with the architecture and steps proposed in the article.<\/p>\n

I sent my comments via Disqus on the AWS blogging platform, but after a month, my comment was rejected, and the blog content hasn’t changed.<\/p>\n

For this reason, I don’t have other places to post my comment but here…<\/p>\n

    \n
  1. The link to the setup procedure is from 2009.
    \nWe have official documentation that we keep up to date. The Fast-Start Failover part:
    \n    https:\/\/docs.oracle.com\/en\/database\/oracle\/oracle-database\/19\/dgbkr\/using-data-guard-broker-to-manage-switchovers-failovers.html#GUID-D26D79F2-0093-4C0E-98CD-224A5C8CBFA4<\/a>
    \nand the Best Practices guide:
    \n    https:\/\/docs.oracle.com\/en\/database\/oracle\/oracle-database\/19\/haovw\/oracle-data-guard-best-practices.html#GUID-C3A78B07-6584-4380-8D53-E5B831A5894C<\/a><\/li>\n
  2. The part about cascading standbys references a step-by-step guide from an external blog written many years ago for 11gR2.<\/li>\n
  3. The DBMS_SERVICE doc is from 12cR1, while other links are from 21c doc or 19c doc. As of today, most implement 19c. That’s probably the version to use.
    \n    https:\/\/docs.oracle.com\/en\/database\/oracle\/oracle-database\/19\/arpls\/DBMS_SERVICE.html#GUID-C11449DC-EEDE-4BB8-9D2C-0A45198C1928<\/a><\/li>\n
  4. The steps used to create the database service do not include any HA property, which will make most efforts useless. (see Table 153-6 in the link above).<\/li>\n
  5. The article talks about TAF, but no steps exist to configure it. We don’t recommend TAF since 12c anyway. Today (19c), the recommendation is TAC (Transparent Application Continuity).
    \n    https:\/\/www.oracle.com\/docs\/tech\/application-checklist-for-continuous-availability-for-maa.pdf<\/a><\/li>\n
  6. But, most important, TAF (or Oracle connectivity in general) does NOT require a host IP change! There is no need to change the DNS when using the recommended connection string with multiple address_lists.<\/li>\n
  7. Some RedoRoutes examples are not correct. In this video I explain how they work and how to set them up:
    \n    https:\/\/www.youtube.com\/watch?v=huG8JPu_s4Q<\/a><\/li>\n
  8. The diagram shows the master observer together with the standby database, which is a bad practice. I explain why and how here:
    \n    https:\/\/www.youtube.com\/watch?v=e81UPLfnLi0<\/a><\/li>\n<\/ol>\n

    The central message is:<\/p>\n

    If you need to implement a complex architecture using a software solution, pay attention that the practices suggested by the partner\/integrator\/3rd party match the ones from the software vendor. In the case of Oracle Data Guard, Oracle knows better \ud83d\ude09<\/p>\n

    Cheers<\/p>\n

    —<\/p>\n

    Ludovico<\/p>\n

     <\/p>\n","protected":false},"excerpt":{"rendered":"

    A month ago, I saw this article published on the AWS architecture blog: Disaster Recovery for Oracle Database on Amazon EC2 with Fast-Start Failover I love seeing people suggesting Oracle Data Guard Fast-Start Failover for high availability. Nevertheless, there are … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[326,329,315],"tags":[353],"class_list":["post-2202","post","type-post","status-publish","format-standard","hentry","category-oracle","category-oracle-dg","category-oracle-database-19c","tag-fsfo"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/posts\/2202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/comments?post=2202"}],"version-history":[{"count":1,"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/posts\/2202\/revisions"}],"predecessor-version":[{"id":2203,"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/posts\/2202\/revisions\/2203"}],"wp:attachment":[{"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/media?parent=2202"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/categories?post=2202"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ludovicocaldara.net\/dba\/wp-json\/wp\/v2\/tags?post=2202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}