Oracle Cloud Computing

What is a database Cloud Computing?

This looks like the million dollar question; what we know for sure is that it is a quite recent technology and different people identify the Cloud Architecture by different key features (On-Demand, Broad Network Access, Resource Pooling, Rapid Elasticity, Measured Service). There are two main categories: Private and Public Cloud, which identifies respectively in house and outsourced Cloud installation. Focusing on Oracle Database technology the Private Cloud is a clustered infrastructure hosted on the company?s data center, therefore the IT department is responsible of the installation, maintenance and life cycle of all hardware and software components. In case of Public Cloud the company demands the management of the databases to a third party, which owns the infrastructure used to manage the databases of different customers.

Beyond the different marketing definitions of database cloud computing, Oracle provides a reach set of features to realize this kind of setup. The main component of this architecture is the Grid Infrastructure, which provides the cluster and storage foundation of Oracle Cloud Computing. On top of the Grid Infrastructure we have the RDBMS which enables RAC, RAC One Node and stand-alone database setups.

At this point, anyone can say that with the exception of the name, there is almost nothing new compared to the earlier version of Oracle Real Application Cluster (RAC). But Oracle Cloud Computing is much more than a simple multi-node RAC which hosts several databases; the introduction of features like Quality of Service Management (QoS), Server Pool, Instance Caging (extension of Resource Manager) and the enhancement of the existing ones, allow to consolidate all the environments guaranteeing to each application: the performance expected, the scalability for future needs, the availability to respect the Service Level Agreement (SLA), the best time to market, the governance of the entire platform and last but not least cost saving.

Obviously Oracle provides all the instruments to reach such great result, but it is up to the single organization to define and implement the most appropriate modus operandi in terms of OM, Life Cycle, Capacity planning and management, to obtain the result promised by this great technology.

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Oracle Resource Manager

 

#############################################################
##    How to implement Oracle Resource Manager granting    ##
##    CONSUMER GROUPS to Clusterware services              ##
#############################################################

--Create a service for OLTP sessions
srvctl add service -d dbrac10 -s DBRAC10_OLTP -r dbrac11,dbrac12,dbrac13
srvctl start service -d dbrac10 -s DBRAC10_OLTP

--Create a service for BATCH sessions
srvctl add service -d dbrac10 -s DBRAC10_BATCH -r dbrac11,dbrac12,dbrac13
srvctl start service -d dbrac10 -s DBRAC10_BATCH


###################################################################
## Resource Plan Design:
## MGMT_P1=75% SYS_GROUP,  MGMT_P2=80% OLTP, MGMT_P2=10% BATCH, MGMT_P2=5%
## ORA$AUTOTASK_SUB_PLAN,  MGMT_P2=5% ORA$DIAGNOSTICS, MGMT_P3=70% OTHER_GROUPS           
###################################################################       

## Resource Plan Implementation:
BEGIN
DBMS_RESOURCE_MANAGER.CREATE_PENDING_AREA();
DBMS_RESOURCE_MANAGER.CREATE_PLAN(PLAN => 'REAL_TIME_PLAN', COMMENT => 'Respurce Plan for OLTP database');
DBMS_RESOURCE_MANAGER.CREATE_CONSUMER_GROUP (CONSUMER_GROUP => 'OLTP',CATEGORY => 'INTERACTIVE', COMMENT => 'OLTP sessions');
DBMS_RESOURCE_MANAGER.CREATE_CONSUMER_GROUP (CONSUMER_GROUP => 'BATCH', CATEGORY => 'BATCH', COMMENT => 'BATCH sessions');
DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE (PLAN => 'REAL_TIME_PLAN', GROUP_OR_SUBPLAN => 'OLTP', COMMENT => 'OLTP group', MGMT_P2 => 80);
DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE (PLAN => 'REAL_TIME_PLAN', GROUP_OR_SUBPLAN => 'BATCH', COMMENT => 'BATCH group',
MGMT_P3 => 70, PARALLEL_DEGREE_LIMIT_P1 => 6, ACTIVE_SESS_POOL_P1 => 4, MAX_IDLE_TIME => 240);
DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE (PLAN => 'REAL_TIME_PLAN', GROUP_OR_SUBPLAN => 'SYS_GROUP', COMMENT => 'SYS group', MGMT_P1 => 70);
DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE (PLAN => 'REAL_TIME_PLAN', GROUP_OR_SUBPLAN => 'OTHER_GROUPS', COMMENT => 'OTHER group', MGMT_P4 => 50);
DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE (PLAN => 'REAL_TIME_PLAN',GROUP_OR_SUBPLAN => 'ORA$AUTOTASK_SUB_PLAN', COMMENT => 'ORA$AUTOTASK_SUB_PLAN group', MGMT_P3 => 20);
DBMS_RESOURCE_MANAGER.CREATE_PLAN_DIRECTIVE (PLAN => 'REAL_TIME_PLAN', GROUP_OR_SUBPLAN => 'ORA$DIAGNOSTICS', COMMENT => 'ORA$DIAGNOSTICS group', MGMT_P3 => 10);
DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING (DBMS_RESOURCE_MANAGER.SERVICE_NAME, 'DBRAC10_OLTP', 'OLTP');
DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING(DBMS_RESOURCE_MANAGER.SERVICE_NAME, 'DBRAC10_BATCH', 'BATCH');
DBMS_RESOURCE_MANAGER.VALIDATE_PENDING_AREA();
DBMS_RESOURCE_MANAGER.SUBMIT_PENDING_AREA();
DBMS_RESOURCE_MANAGER.CLEAR_PENDING_AREA();
END;
/

###################################################################


## Grant the Switch to the Users
BEGIN
DBMS_RESOURCE_MANAGER.CREATE_PENDING_AREA();    
dbms_resource_manager_privs.grant_switch_consumer_group ('PERF_TEST','OLTP',FALSE); 
dbms_resource_manager_privs.grant_switch_consumer_group ('PERF_TEST','BATCH',FALSE); 
DBMS_RESOURCE_MANAGER.VALIDATE_PENDING_AREA();
DBMS_RESOURCE_MANAGER.SUBMIT_PENDING_AREA();
DBMS_RESOURCE_MANAGER.CLEAR_PENDING_AREA();
END;
/

###################################################################       
## Enable the Resource plan with the FORCE Option to avoid the Scheduler window to
## activate a different plan during the job execution.
ALTER SYSTEM SET RESOURCE_MANAGER_PLAN = 'FORCE:REAL_TIME_PLAN';
###################################################################       

## Example of Group and Plan Deletion:

BEGIN
DBMS_RESOURCE_MANAGER.DELETE_PLAN (PLAN => 'REAL_TIME_PLAN');
END;
/

BEGIN
DBMS_RESOURCE_MANAGER.DELETE_CONSUMER_GROUP(CONSUMER_GROUP => 'OLTP');
END;
/

BEGIN
DBMS_RESOURCE_MANAGER.DELETE_CONSUMER_GROUP(CONSUMER_GROUP => 'BATCH');
END;
/


###################################################################
## SQL Queries for monitoring Resource Manager  utilization:
###################################################################

## Check the service name used by each session
select inst_id, username, SERVICE_NAME, count(*) from gv$session 
where SERVICE_NAME <>'SYS$BACKGROUND'
group by inst_id, username, SERVICE_NAME order by  order by 2,3,1;


## List the Active Resource Consumer Groups:
select INST_ID, NAME, ACTIVE_SESSIONS, EXECUTION_WAITERS, REQUESTS, 
CPU_WAIT_TIME, CPU_WAITS, CONSUMED_CPU_TIME, YIELDS, QUEUE_LENGTH, 
ACTIVE_SESSION_LIMIT_HIT from gV$RSRC_CONSUMER_GROUP where name in 
('SYS_GROUP','BATCH','OLTP','OTHER_GROUPS') order by 2,1;