{"id":7427,"date":"2016-03-20T21:14:53","date_gmt":"2016-03-20T20:14:53","guid":{"rendered":"https:\/\/www.dbi-services.com\/blog\/rac-to-ron-then-ron-to-rac-and-singleton-service\/"},"modified":"2016-03-20T21:14:53","modified_gmt":"2016-03-20T20:14:53","slug":"rac-to-ron-then-ron-to-rac-and-singleton-service","status":"publish","type":"post","link":"https:\/\/www.dbi-services.com\/blog\/rac-to-ron-then-ron-to-rac-and-singleton-service\/","title":{"rendered":"RAC to RON then RON to RAC and singleton service"},"content":{"rendered":"

By Franck Pachot<\/h2>\n

.
\nYou will probably never do it, but let’s imagine you have a RAC database, policy managed, with singleton service. Then you convert it to RAC One Node and you change your mind and convert it back to RAC. Be careful, the singleton services are converted to uniform ones when converting to RAC<\/p>\n

My RACDB database is running on two nodes:<\/p>\n

[oracle@racp1vm1 ~]$ srvctl status database -db racdb\nInstance RACDB_1 is running on node racp1vm1\nInstance RACDB_2 is running on node racp1vm2<\/code><\/pre>\n
it is policy managed and in a server pool of two servers:<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl config database -db racdb | grep pool\nServer pools: pool1\n[oracle@racp1vm1 ~]$ srvctl status srvpool -serverpool pool1\nServer pool name: pool1\nActive servers count: 2\n<\/code><\/pre>\n
I’m in RAC and have the singleton service ‘S’ running on first node<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl config service -db racdb -service S\nService name: s\nServer pool: pool1\nCardinality: UNIFORM\nDisconnect: false\nService role: PRIMARY\nManagement policy: AUTOMATIC\n...\n<\/code><\/pre>\n
I want to go to RAC One Node so I need to have only one instance running<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl stop instance -db racdb -instance RACDB_2 -f\n<\/code><\/pre>\n
and then convert<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl convert database -db racdb -dbtype RACONENODE\n<\/code><\/pre>\n
Then I check the service:<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl status service -db racdb -service s\nService s is running on nodes: racp1vm1\n<\/code><\/pre>\n
still running on one node of course, and still defined as SINGLETON<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl  config service -db racdb -service s\nService name: s\nServer pool: pool1\nCardinality: SINGLETON\nDisconnect: false\nService role: PRIMARY\nManagement policy: AUTOMATIC\n<\/code><\/pre>\n
Let’s now convert back to RAC<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl convert database -db racdb -dbtype RAC\n<\/code><\/pre>\n
and check the service:<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl status service -db racdb -service s\nService s is running on nodes: racp1vm1,racp1vm2\n<\/code><\/pre>\n
Ouch. My service that was a singleton is now running on all nodes.<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl config service -db racdb -service s\nService name: s\nServer pool: pool1\nCardinality: UNIFORM\nDisconnect: false\nService role: PRIMARY\nManagement policy: AUTOMATIC\n<\/code><\/pre>\n
It seems that the conversion from RAC One Node to RAC has modified all service cardinality to be UNIFORM.<\/p>\n
You have to set it back to SINGLETON:<\/p>\n
\n[oracle@racp1vm1 ~]$ srvctl modify service -db racdb -cardinality singleton -service s -f\n<\/code><\/pre>\n
Be careful with that.
\nA service for which the application has not be designed to be load balanced across several nodes may have horrible performance. It’s always a good idea to check the service config and where they are running.<\/p>\n","protected":false},"excerpt":{"rendered":"
By Franck Pachot . You will probably never do it, but let’s imagine you have a RAC database, policy managed, with singleton service. Then you convert it to RAC One Node and you change your mind and convert it back to RAC. Be careful, the singleton services are converted to uniform ones when converting to… <\/p>\n","protected":false},"author":27,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","neve_meta_reading_time":"","_themeisle_gutenberg_block_has_review":false,"footnotes":""},"categories":[4133],"tags":[535],"class_list":["post-7427","post","type-post","status-publish","format-standard","hentry","category-database","tag-rac"],"yoast_head":"\nRAC to RON then RON to RAC and singleton service - dbi services | Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.dbi-services.com\/blog\/rac-to-ron-then-ron-to-rac-and-singleton-service\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"RAC to RON then RON to RAC and singleton service\" \/>\n<meta property=\"og:description\" content=\"By Franck Pachot . You will probably never do it, but let’s imagine you have a RAC database, policy managed, with singleton service. Then you convert it to RAC One Node and you change your mind and convert it back to RAC. 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