Table of Contents

Deploying SNMP on Content Delivery Networks

Deploying SNMP on Content Delivery Networks

This appendix contains information on deploying SNMP for use with the Cisco CDN product, including detailed information on the CISCO-CONTENT-NETWORK-MIB.

The chapter contains the following sections:

• Defining a Device as an SNMP Agent
  
  
• CISCO-CONTENT-NETWORK-MIB
  
  
• Using SNMP to Monitor CDN Devices
  
  

Defining a Device as an SNMP Agent

Before defining a device as an SNMP agent, you must configure the SNMP manager so that it recognizes the CDN devices.

Refer to your SNMP manager documentation for further information on configuring your SNMP manager.

See the "Adding and Removing SNMP Managers" section for information on registering your SNMP managers with Cisco Internet CDN Software.

CISCO-CONTENT-NETWORK-MIB

The contents of the CISCO-CONTENT-NETWORK-MIB follow. The end of the MIB is marked END. See the sections that follow for instructions on obtaining an online copy of the MIB from Cisco and on implementing the SNMP traps defined in the MIB.

Note   If you have questions regarding the MIB or implementing SNMP on your CDN, e-mail Cisco's content network MIB support desk at content-network-mib@cisco.com, or see the "Obtaining Technical Assistance" section for instructions on contacting the Cisco Technical Assistance Center.

*****************************************************************

CISCO-CONTENT-NETWORK-MIB.my

Cisco Content Network Management Information Base

Copyright (c) 2001 by Cisco Systems, Inc.

All rights reserved.

*****************************************************************

CISCO-CONTENT-NETWORK-MIB DEFINITIONS ::= BEGIN

IMPORTS

MODULE-IDENTITY,

OBJECT-TYPE,

NOTIFICATION-TYPE,

Gauge32

FROM SNMPv2-SMI

ZeroBasedCounter32

FROM RMON2-MIB

NOTIFICATION-GROUP,

OBJECT-GROUP,

MODULE-COMPLIANCE

FROM SNMPv2-CONF

ciscoMgmt

FROM CISCO-SMI;

ciscoContentNetworkMIB MODULE-IDENTITY

LAST-UPDATED "200109101459Z"

ORGANIZATION "Cisco Systems, Inc."

CONTACT-INFO

"Cisco Systems Customer Service

Postal: 170 W Tasman Drive

San Jose, CA 95134-1706 USA

Tel: +1 800 553-NETS

E-mail: content-network-mib@cisco.com"

DESCRIPTION

"This MIB module defines objects for Content Network devices. A Content Network is a collection of devices that optimizes the delivery of Internet content (such as HTML documents and MPEG files) by caching content near clients, by pushing content into those caches, and by routing each client request to the best device available at that moment to serve the particular content requested.

Content Network devices include Content Engines (CEs) for serving content, Content Routers (CRs) for routing client requests, and Content Distribution Managers (CDMs) for administering the network."

REVISION "200109101459Z"

DESCRIPTION

"Deprecated:

ccnNotifServerStart

ccnNotifServerStop

Added:

ccnNotifOffline

ccnNotifNeedsAttention

ccnNotifWaitingForCdm

ccnNotifOnline"

REVISION "200105232134Z"

DESCRIPTION

"Initial version of this MIB module."

::= { ciscoMgmt 216 }

ciscoContentNetworkMIBObjects

OBJECT IDENTIFIER ::= { ciscoContentNetworkMIB 1 }

—Application groups

ccnReport

OBJECT IDENTIFIER ::= { ciscoContentNetworkMIBObjects 1 }

-- Categories for the report group.

ccnReportDns OBJECT IDENTIFIER ::= { ccnReport 1 }

ccnReportAcct OBJECT IDENTIFIER ::= { ccnReport 2 }

—Objects for the ccnReportDns category.

ccnReportDnsRequestRate OBJECT-TYPE

SYNTAX Gauge32

UNITS "requests-per-second"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Number of DNS requests per second."

::= { ccnReportDns 1 }

ccnReportDnsClientCount OBJECT-TYPE

SYNTAX ZeroBasedCounter32

UNITS "clients"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Total number of DNS clients that have contacted this device since the DNS server last started."

::= { ccnReportDns 2 }

ccnReportDnsRequests OBJECT-TYPE

SYNTAX ZeroBasedCounter32

UNITS "requests"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Total number of DNS requests since the DNS server last started."

::= { ccnReportDns 3 }

—Objects for the ccnReportAcct category.

ccnReportAcctBytesServed OBJECT-TYPE

SYNTAX ZeroBasedCounter32

UNITS "bytes"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Total number of bytes of content served to clients from this device since the servers on this device last started."

::= { ccnReportAcct 1 }

ccnReportAcctObjectsCached OBJECT-TYPE

SYNTAX Gauge32

UNITS "objects"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Total number of objects in the content cache."

::= { ccnReportAcct 2 }

ccnReportAcctCacheHitRate OBJECT-TYPE

SYNTAX Gauge32

UNITS "objects-per-minute"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Number of cache hits per minute."

::= { ccnReportAcct 3 }

ccnReportAcctCacheMissRate OBJECT-TYPE

SYNTAX Gauge32

UNITS "objects-per-minute"

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Number of cache misses per minute."

::= { ccnReportAcct 4 }

—Notification Events

ciscoContentNetworkMIBNotif

OBJECT IDENTIFIER ::= { ciscoContentNetworkMIB 2 }

ccnNotifications

OBJECT IDENTIFIER ::= { ciscoContentNetworkMIBNotif 0 }

ccnNotifServerStart NOTIFICATION-TYPE

STATUS deprecated — See ccnNotifOnline.

DESCRIPTION

"The servers on this device are being started."

::= { ccnNotifications 1 }

ccnNotifServerStop NOTIFICATION-TYPE

STATUS deprecated — See ccnNotifOffline,

-— ccnNotifNeedsAttention, and

-— ccnNotifWaitingForCdm.

DESCRIPTION

"The servers on this device are being stopped."

::= { ccnNotifications 2 }

ccnNotifOffline NOTIFICATION-TYPE

STATUS current

DESCRIPTION

"The device is about to disconnect from the network."

::= { ccnNotifications 3 }

ccnNotifNeedsAttention NOTIFICATION-TYPE

STATUS current

DESCRIPTION

"The device is on the network, but is unregistered (not associated with any CDN) or needs some other adjustment that cannot be done through the CDM administrator interface (such as repairing a disk, completing a software upgrade, or configuring the CDM database)."

::= { ccnNotifications 4 }

ccnNotifWaitingForCdm NOTIFICATION-TYPE

STATUS current

DESCRIPTION

"The device (CE or CR) is waiting for configuration information from the CDM. The device is on the network and is either failing to communicate with the CDM or is being told explicate by the CDM to continue waiting pending activation by the CDN administrator."

::= { ccnNotifications 5 }

ccnNotifOnline NOTIFICATION-TYPE

STATUS current

DESCRIPTION

"The device is operational and ready to participate in the CDN."

::= { ccnNotifications 6 }

—compliance specification

ccnMIBConformance

OBJECT IDENTIFIER ::= { ciscoContentNetworkMIB 3 }

ccnMIBCompliances

OBJECT IDENTIFIER ::= { ccnMIBConformance 1 }

ccnMIBGroups

OBJECT IDENTIFIER ::= { ccnMIBConformance 2 }

—Conformance

ccnMIBCompliance MODULE-COMPLIANCE

STATUS deprecated —See ccnMIBComplianceRev1.

DESCRIPTION

"The compliance statement for Cisco Systems entities that implement the Content Network applications."

MODULE — this module

MANDATORY-GROUPS {

ccnReportingGroup,

ccnNotifGroup

}

::= { ccnMIBCompliances 1 }

ccnMIBComplianceRev1 MODULE-COMPLIANCE

STATUS current

DESCRIPTION

"The compliance statement for Cisco Systems entities that implement the Content Network applications."

MODULE — this module

MANDATORY-GROUPS {

ccnReportingGroup,

ccnNotifGroupRev1

}

::= { ccnMIBCompliances 2 }

—Units of Conformance

ccnReportingGroup OBJECT-GROUP

OBJECTS {

ccnReportDnsRequestRate,

ccnReportDnsClientCount,

ccnReportDnsRequests,

ccnReportAcctBytesServed,

ccnReportAcctObjectsCached,

ccnReportAcctCacheHitRate,

ccnReportAcctCacheMissRate

}

STATUS current

DESCRIPTION

"DNS and Accounting with low capacity Counter32 and Gauge32 objects."

::= { ccnMIBGroups 1 }

ccnNotifGroup NOTIFICATION-GROUP

NOTIFICATIONS {

ccnNotifServerStart,

ccnNotifServerStop

}

STATUS deprecated -- See ccnNotifGroupRev1.

DESCRIPTION

"Notifications for the Cisco Content Network."

::= { ccnMIBGroups 2 }

ccnNotifGroupRev1 NOTIFICATION-GROUP

NOTIFICATIONS {

ccnNotifOffline,

ccnNotifNeedsAttention,

ccnNotifWaitingForCdm,

ccnNotifOnline

}

STATUS current

DESCRIPTION

"Notifications for the Cisco Content Network."

::= { ccnMIBGroups 3 }

END

Obtaining the CISCO-CONTENT-NETWORK-MIB

You can find the definition of the CISCO-CONTENT-NETWORK-MIB at ftp://ftp.cisco.com/pub/mibs/v2/CISCO-CONTENT-NETWORK-MIB.my.

CISCO-CONTENT-NETWORK-MIB Variables

Table B-1 describes variables in the CISCO-NETWORK-MIB.

CISCO-CONTENT-NETWORK-MIB SNMP Traps

The SNMP agent on a Cisco Internet CDN device sends an unsolicited notification to the SNMP manager if any of the events described in Table B-2 occurs on the device. This message is called a trap. You can configure your trap host (most likely your SNMP management station) to perform a specified action when a trap is detected.

Using SNMP to Monitor CDN Devices

SNMP can be used to monitor CDN devices, as described in the following sections;

Monitoring Content Routers

The following variables provide information about Content Routers:

ccnReportDnsRequestRate—Number of DNS requests per second.

ccnReportDnsClientCount—Total number of DNS clients that have contacted this device since the DNS server last started.

ccnReportDnsRequests—Total number of DNS requests since the DNS server last started.

If the values of all three of the preceding variables for a Content Router are greater than 0, then the router is working. You will not see the values incrementing in real time, because the SNMP agent collects this information at 15-minute intervals.

Monitoring Content Engines

The following variables provide information about Content Engines:

ccnReportAcctBytesServed—Total number of bytes of content served to clients from this device since the servers on this device last started.

ccnReportAcctObjectsCached—Total number of objects in the content cache.

ccnReportAcctCacheHitRate—Number of cache hits per minute.

CcnReportAcctCacheMissRate—Number of cache misses per minute.

If the values of the preceding variables for a Content Engine are greater than 0, then the Content Engine is serving content.

Note   Monitoring the Content Engine-specific variables does not enable you to detect when a Content Engine is about to reach its serving threshold. When a Content Engine reaches its serving capacity, further requests sent to it will not be fulfilled. If a Content Engine cannot serve further content and is part of a cluster, the request will be served by another Content Engine within the cluster that is hosting the same content.

Identifying Overburdened Devices

The following conditions indicate overload or maximum CPU utilization on CDN devices.

• A device that generates the ccnNotifOffline, ccnNotifNeedsAttention, or ccnNotifWaitingForCdm traps needs attention.
  
  
• A device that frequently generates the ccnNotifOnline and ccnNotifServerStart traps needs attention.
  
  
• A device that shows sustained high levels of CPU utilization (between 80 and 90 percent) indicates overload. If your devices show 100 percent utilization for more than 5 minutes, you should consider either adding more Content Engines to your CDN or reducing the content load.
  
  

Also consider the following device-specific indicators.

Content Router

If the ccnReportDnsRequestRate variable approaches a value of 5000 requests per second, the potential exists for an overload of the Content Router.

Note   Even if your system does approach this figure, the CDN will tolerate overload of individual Content Routers. As the response time slows and packets are dropped, clients will switch to other, more reliable servers.

Content Engine

The combined value of the ccnReportAcctCacheHitRate and ccnReportAcctCacheMissRate is a good measure of HTTP load on a Content Engine. However, there is no defined threshold for this load, because the threshold depends on the content mix served by the Content Engine.