To guarantee Quality of Service (QoS) in large scale data virtualization deployments, in general, we can distinguish between two main types of
workloads with different QoS requirements:
- Informational workloads: these workloads are common in reporting applications that are characterized
by the need to handle high volumes of data. There is usually no need for low
latency because users are not typically on-line waiting for results.
- Operational / Transactional workloads: these scenarios are typical in operational applications
(e.g. Single Customer View application) and are associated with high concurrency levels of queries
handling small dataset sizes. These processes need immediate responses.
In an enterprise-level Virtual DataPort(VDP) deployment, both operational and informational workloads can be in place
since VDP can be used across many different use cases. In this section, we are going to see how to access
the Resource Manager and how to create Rules and Plans. It will allow you to classify queries based on the attributes of the session,
and to allocate resources to that query in a way that optimizes resources utilization for your application environment.
In summary, the Resource Manager introduces two main concepts:
- Plans: restrictions assigned to a user session (e.g. limiting the rows returned from a query)
- Rules: assigns a plan to the session of a user if a certain
condition is met (e.g. when the source IP address is 10.0.20.80)
Accesssing Resource Manager
To open the Resource Manager, click the
Administration > Resource Manager option in the top menu.
Once the tool is opened, you can add Rules and Plans. Plans have to be created first because later, in the rule configuration
window, you will have to associate the plan to a rule. Let's see how to create a plan:
- Click on the Plans tab.
- Click on New to create a new plan.
- Click on New restriction.
- In this dialog you have to select two things: when to execute the plan and what actions have to be performed.
- When: Always or when the CPU usage goes over a certain percentage
- Actions: Stop query, set priority of threads,
switch query to other plan or set the number of concurrent
requests, among others.
- Click Ok to save the restriction.
- Click Ok again to save the plan.
Now, we can create a new rule and associate the previously created plan. Let's see how:
- Click on the Rules tab.
- Click on New to create a new rule.
- Enter a name and a description for the new rule.
- In this dialog you have to select if the rule will be applied
to all the user sessions (
Always) or only to some of them (
- In this case yo have to add a condition based on the attributes of the session: client IP,
access interface (JDBC, ODBC, WS-REST, ...), authentication (LOCAL, LDAP, Kerberos), ...
- Select the plan that will be applied to the user when the condition is met.
- Click Ok to save the rule.
How it works
The Resource Manager acts when a user session is opened against Virtual DataPort server. The management procedure is the following:
- A user opens a connection to Virtual DataPort server.
- The Resource Manager evaluates the condition of the first rule.
- If the condition is not met, it evaluates the condition of the second rule.
- If this second condition is not met, it evaluates the condition of the next rule, and so on.
- When it finds a rule that meets the condition, it assigns the plan of the rule to the user session and stops evaluating more rules.
Do you need an example?
It's your lucky day! The following section will show you some Resource Manager examples of Rules/Plans.