Data Collection

Data collection is at the heart of Capacity Advisor and a task is created during configuration to automatically collect utilization data from all licensed VSE resources added to HP SIM. (See “First Data Collection (or the Automated Nightly Collection)”.)

HP recommends that once you have become familiar with using Capacity Advisor, you should review this scheduled task to understand what it is doing and make sure that it fits your needs. This automated data collection task gathers historical data from all your systems so that the data is available when you need it for analysis.

Data Collection Infrastructure

In the data collection infrastructure, each component plays a role, as shown in Figure 2-1. It all begins with data collection.

Figure 2-1 Capacity Advisor Data Collection Infrastructure

1	The Agentless Data Collector Service runs on Microsoft Windows managed systems only.
2	Agentless data collected by the Agentless Data Collector Service is made available to the Capacity Advisor Data Collector.
3	The Utilization Provider enables the operation of the Capacity Advisor Data Collector.
4	Microsoft Virtual Machine Manager (VMM) data is made available to the Capacity Advisor Data Collector.
5	VSE data collected by the Utilization Provider is made available to the Capacity Advisor Data Collector.
6	The Data Collector gathers data from the VSE database and includes it in the historical database.
7	You can import data (HP OVPA and HP PMP) into the historical database for analysis.
8	Automatic data conversion occurs when importing data into the Capacity Advisor database.
9	Historical data is stored for use in Capacity Advisor.
10	The Utilization Calculator uses historical data collected over time to create reports.
11	Scenario data is stored automatically for continued use in the Scenario Editor.
12	Use the Scenario Editor to manipulate the collected data associated with workloads and systems.
13	Use the Profile Viewer to examine a graphical display of the utilization of a specific resource for a specific workload or system.
14	Use the Report Generator to create reports to examine.
15	Use the web browser to work with Capacity Advisor and exploit its features.

Collecting Data for a Workload with a HP Serviceguard Package

Starting with VSE Management Software version 3.0, you can associate a VSE-monitored workload with a Serviceguard package. This association will allow VSE Virtualization Manager to show workloads moving from one system to another within minutes of the Serviceguard migration. It will also allow Capacity Advisor to show an uninterrupted history of utilization data for a workload across these migrations.

Associating VSE monitored workloads and Serviceguard packages requires that Virtual Vault has been installed on the Central Management Server (CMS) and that the corresponding version of the Utilization Provider has been installed on all member systems of the Serviceguard cluster. All nodes of the cluster must be running the appropriate version of the Utilization Provider. For specific version information, see the HP Systems Insight Manager screen: Help About HP Systems Insight Manager.

Comparison of Agentless and UP Data Collection

This help topic compares the potential benefits and possible drawbacks that accompany the use of agentless data collection versus using the Utilization Provider (UP) to collect data from systems licensed for Capacity Advisor.

Table 2-1 A Comparison of Agentless Versus Utilization Provider Data Collection

Utilization Provider (UP)	Agentless Configuration File
Available for HP-UX, Linux, OpenVMS, and Microsoft® Windows® systems	Available for Windows systems only
Equally useful in data quality, accuracy, and richness.
Requires hosting and updating the UP agent	Leverages existing data on the system; no additional agent hosting or update required.
Not susceptible to downtime in the network or the CMS. Collected data is held for a maximum of 30 days by the UP for transfer to the database on the CMS. By default, UP data is transferred once each day.	Susceptible to network or CMS downtime as data is continuously collected (every five minutes by default) by the CMS across the network from each managed system.
No additional load on CPU or memory resources incurred on the CMS.	Small additional load on CPU and memory resources incurred by the agentless data collection service running on the CMS.




	Collection Precedence: When a system is listed in the agentless data configuration file and also is running the Utilization Provider, the data collection function in Capacity Advisor will store the set of agentless data rather than the Utilization Provider data. Where you have decided that agentless data collection is your preferred collection method, you may want to remove the Utilization Provider from those systems. If you remove systems from the agentless configuration file and install the Utilization Provider on those systems, the data collected in the current day via agentless means may be lost. Should this occur, you can expect to see a gap when viewing reports that include the day on which the switch was made.

HP PMP Data Differs from Utilization Provider Data

Differences in data imported from HP Performance Management Pack (HP PMP) affects how you should interpret resulting analysis and scenarios as compared to data collected from the Utilization Provider.

Differences in Memory Data

Capacity Advisor normally measures memory collected from the Utilization Provider, which returns the sum of memory allocated to the processes on the system.

HP PMP collection provides the total memory less the zeroed, free, and standby memory.

This means that HP PMP counts memory used by the operating system, whereas the Utilization Provider does not. The memory use reported by HP PMP is about 20% higher than memory use reported by the Utilization Provider.

Because Capacity Advisor assumes a different memory amount than HP PMP provides, Capacity Advisor may overestimate the memory needed when using HP PMP data to analyze stacking several application instances in a system running a single instance of an operating system.

While either the Utilization Provider data or the HP PMP data can be used to plan memory size in a new configuration, you should not use a mix of HP PMP and Utilization Provider data when looking for a trend in memory utilization.

Differences in Network Data

HP PMP does not report the correct network IO when network interface cards (NICs) are being teamed for network fault tolerance (for example, by using HP Network Config utility).

That is, for a system with 2 NICs teamed as one single logical NIC, Utilization Provider reports the addition of TX and RX Mbps for the teamed NIC.

HP PMP adds the metrics from the 2 NICS, ignoring that they are working as a teamed NIC.

For a teamed configuration, the HP PMP network utilization curve will be always twice that of the Utilization Provider data.

If you know you have teamed NICs, or if you suspect your imported network data is twice as high as it should be, you will want to instruct Capacity Advisor to ignore the imported data. When logged in as a user authorized to use the Capacity Advisor toolbox on the CMS, you will be able to mark data as invalid. You can do this from the Profile Viewer, or by using the capprofile(1M) command.

Data Collection

Technical documentation

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