cluster_database_instances less than actual number of instance, any harm?
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From: charles on 18 Jun 2010 08:50 All, We are trying to add one node to our RAC system (10.2.0.4) on linux. Our cluster_database_instances is set at 2, and we do not want to bounce our production database. We plan to keep it as 2 for a few month until we upgrade our Oracle. According to Oracle document, cluster_database_instances does not have to be the same as the actual number of instance. As long as it is the same across the nodes, it is OK. Our test also show that setting cluster_database_instances at 2 for a three nodes cluster does not seem to have any issue. Is there any harm to run three node cluster while setting cluster_database_instances at 2, say for 3 month? Thanks for your help.
From: Vladimir M. Zakharychev on 19 Jun 2010 03:46
On Jun 18, 4:50 pm, charles <dshprope...(a)gmail.com> wrote: > All, > > We are trying to add one node to our RAC system (10.2.0.4) on linux. > Our cluster_database_instances is set at 2, and we do not want to > bounce our production database. We plan to keep it as 2 for a few > month until we upgrade our Oracle. > > According to Oracle document, cluster_database_instances does not have > to be the same as the actual number of instance. As long as it is the > same across the nodes, it is OK. Our test also show that setting > cluster_database_instances at 2 for a three nodes cluster does not > seem to have any issue. > > Is there any harm to run three node cluster while setting > cluster_database_instances at 2, say for 3 month? > > Thanks for your help. If you've read the docs, you should've noticed that this parameter is only used to compute the default value for LARGE_POOL_SIZE and only when PARALLEL_AUTOMATIC_TUNING is set to TRUE (and that this last parameter is deprecated since 10g.) So it's pretty safe to have it at any value as long as it's the same across all nodes. And you can safely override any defaults Oracle might derive from this parameter. Regards, Vladimir M. Zakharychev N-Networks, makers of Dynamic PSP(tm) http://www.dynamicpsp.com |