Statistics policies
Overview
You can configure the following policy types for statistics collection:
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accounting policy—specifies the accounting record type and collection interval
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file policy—specifies the storage criteria for accounting statistics files on NEs
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statistics policy—specifies the storage criteria for statistics in the NFM-P
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MIB statistics policy—specifies the collection of MIB-based statistics counters from managed NEs, and is one of the following:
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server performance statistics policy—specifies the collection criteria for statistics related to NFM-P server performance
Table 2-2: Statistics policies per statistic type
|
Statistics type |
Policy | ||||
|---|---|---|---|---|---|
|
Accounting |
File |
Statistics |
MIB statistics |
Server performance statistics | |
|
Accounting |
✓ |
✓ |
✓ |
— |
— |
|
Performance |
— |
— |
✓ |
✓ |
— |
|
Server performance |
— |
— |
✓ |
— |
✓ |
Accounting policies
NEs collect accounting statistics using an accounting policy and an associated file policy that are assigned to a SAP, SDP, network port, or subscriber profile.
An accounting policy specifies an accounting statistics record type, a collection interval, an administrative state, and a file policy.
The NFM-P supports the following accounting policy types:
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service accounting policies—apply to SAPs, and specify the accounting records to collect for services
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network accounting policies—apply to network ports and SDPs, and specify the accounting records to collect for network resources
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subscriber accounting policies—apply to subscriber profiles and specify the accounting records to collect for residential subscribers
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AA accounting policies—apply to applications, application groups, and protocols, and specify the accounting records to collect for flows
An NE collects accounting statistics based on a specified collection interval and writes the statistics data in XML format to a file on the NE. After the rollover period specified in a file policy, the NE closes and compresses the file. The NE notifies the NFM-P that a new file is ready for processing, the NFM-P uses FTP or SCP to obtain the file from the NE, and adds the file contents to the NFM-P database. A third-party application can gather the statistics data and process it according to your specifications.
Note: To conserve NE and NFM-P resources, Nokia recommends that you disable an accounting policy on an object when statistics for the object are not required.
When an accounting policy is administratively disabled, accounting statistics data is not written to a file on the NE. When the accounting policy is re-enabled, the new accounting data represents traffic activity since the re-enabling of the policy. Because the statistics data accumulates in rolling counters, no information is lost.
You can customize the record in a service, subscriber, or AA accounting policy by specifying the counters that are collected and the data thresholds for collection. See Chapter 4, Accounting statistics for more information.
Changes to an accounting policy that is disabled apply immediately to all objects to which the policy is applied. Changes to an accounting policy that is enabled take effect at the beginning of the next collection period.
Consider the following before you configure an accounting policy.
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An accounting policy requires a file policy. If you deploy an accounting policy in the absence of a file policy, a default file policy is automatically created.
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For service and network accounting policies, there can be one default policy. Default accounting policies are not in effect until they are distributed to the NEs by the NFM-P operator.
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There is a one-to-many relationship between accounting policies and accounting objects. For example, one service accounting policy can apply to many SAPs, but a SAP can have only one service accounting policy.
Note: When you configure an accounting policy, Nokia recommends that you specify the same value for the Collection Interval parameter in the accounting policy and the Rollover parameter in the file policy. Failure to align these values may result in resource contention when a file rollover occurs.
File policies
A file policy specifies the relative size, storage location, and backup location of the files on the NE that contain accounting statistics data. An NE collects accounting statistics based on the collection interval specified for a SAP, network port, or subscriber in an accounting policy, and writes the statistics data in XML format to a file on the NE. After the rollover period specified in a file policy, the NE closes and compresses the file. The NE then notifies the NFM-P that a new file is ready for processing.
One file policy can be defined as a default policy and is automatically associated with an accounting policy if no file policy is specified.
Note: When configuring both an Accounting Policy and a File Policy, Nokia recommends that the intervals for both policies are aligned. Failure to align these intervals may result in a resource contention at the file Rollover time.
Statistics policies
A statistics policy specifies a retention period and alarm thresholds for a statistics record. The retention period defines how long the NFM-P database retains the statistics record after collection, which affects the database storage requirements.
When statistics collection is enabled, the oldest statistics records are periodically removed from the database. When the collection interval is short and the retention period is long, more disk space is required to store the statistics data.
Note: You can configure the length of time that the NFM-P database globally retains accounting statistics data. See the NSP System Administrator Guide for information about configuring the accounting statistics data retention period.
MIB statistics policies
The collection of performance statistics from NEs is controlled by MIB statistics polices that specify an administrative state, polling synchronization start time, and collection interval. There are two types of MIB statistics policies:
Each type of MIB statistics policy contains a list of MIB entry policies. A MIB entry policy defines the collection criteria for a specific MIB row. In an NE MIB policy, a MIB entry policy applies to all objects on the NE that use the MIB entry. In a specific MIB policy, the MIB entry policy applies only to the specified objects on the NE. For example, the sapEgrQosPlcyQueueStatsEntry MIB entry applies to L2 and L3 SAPs. In an NE MIB statistics policy, selecting this MIB entry enables collection of the entry on all L2 and L3 SAPs on the NE. In a specific MIB statistics policy, selecting this MIB entry enables collection only on the selected L2 or L3 SAPs.
If the statistics collection time required for a MIB entry exceeds the collection interval specified in the MIB statistics policy, the NFM-P raises an alarm. An NFM-P operator can change the polling interval for a statistics class to prevent this. See Chapter 3, Performance statistics collection for information about modifying polling criteria.
The collection of MIB statistics counters is disabled by default. See Chapter 3, Performance statistics collection for information about enabling performance statistics collection.
Note: To view statistics on the NFM-P GUI, you must set the Administrative State parameter of the MIB policy to UP and the Polling Admin State parameter must be set to UP.
NE MIB statistics policies
An NE MIB statistics policy defines the global collection of specific statistics on specific NEs, for example, the port statistics from all ports in a group of NEs. In such a collection scenario, configuring NE MIB policies rather than specific MIB policies is more efficient and uses fewer collection resources. Nokia recommends using NE MIB policies for general performance statistics collection on groups of NEs, and specific policies to enable or disable collection for specific NE objects.
After an NE MIB statistics policy is applied to an NE, statistics are collected for all objects on the NE, except for objects that have a specific MIB statistics policy. This prevents statistics from being collected twice—once by the NE MIB policy and once by the specific MIB policy.
Each NE requires an NE MIB statistics policy. The NFM-P has a default policy that it applies to an NE automatically when no NE MIB statistics policy is specified. The collection interval for each counter in the default policy is 15 min, and collection is disabled by default to conserve NE resources.
Specific MIB statistics policies
A specific MIB statistics policy defines the collection of selected performance statistics from specific objects on specific NEs to achieve a high statistics-collection granularity. For example, to collect port statistics at one rate for access ports and another rate for network ports, you can configure two policies that specify different collection intervals, and explicitly specify the access or network ports to which each policy applies. When a new access or network port is enabled, an NFM-P operator can add the port to the specific MIB statistics policy to enable statistics collection on the port.
The settings in a specific MIB statistics policy override the settings in an NE MIB statistics policy, and can be used to disable statistics collection for specific objects. For example, you enable statistics collection globally for an NE using an NE MIB statistics policy, and then disable the collection of specific statistics using a specific MIB statistics policy.
Distributing the collection of performance statistics
You can distribute the polling load on the NFM-P by creating multiple MIB statistics policies to define the collection of performance statistics across the network. This allows you to configure the Polling Synchronization Time parameter in each MIB statistic policy to have a different start time and to have the policy only poll for statistics from one NE type. For example, you can create two policies: one policy polling 7750 SR NEs at 00:00, and the second policy polling 7705 SAR NEs at 01:00.
Server performance statistics policies
Server performance statistics provide information about NFM-P server performance. You can specify the type of server statistics that are collected and the collection interval for each type.
Each type of server performance statistic has the following: