SNMPD to use cache and shared database based on MIB Classification
draft-haresh-sushrut-mib-classification-01

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INTERNET-DRAFT                     Haresh Khandelwal & Sushrut Deshpande
Intended Status: Experimental                              Cisco Systems
Expires:                                                      March 2012

  SNMPD to use cache and shared database based on MIB Classification 
               draft-haresh-sushrut-mib-classification-01

Abstract

   This memo defines classification of SNMP MIBs to either use SNMP
   cache database and shared database (SDB) mechanism to reduce high CPU
   usage while SNMP GET REQUEST, GETNEXT REQUEST, GETBULK REQUEST are
   continuously performed from network management system (NMS)/SNMP
   manager/SNMP MIB browser to managed device.

Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

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Copyright and License Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
 

Haresh,Sushrut                Experimental                      [Page 1]
INTERNET DRAFT             MIB classification              February 2012

   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1  Terminology . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  MIB classification . . . . . . . . . . . . . . . . . . . . . .  3
     2.1 How CPU usage goes high  . . . . . . . . . . . . . . . . . .  3
     2.2 MIB Classification . . . . . . . . . . . . . . . . . . . . .  4
     2.3 How SNMP CACHE and SHARED DATABASE works . . . . . . . . . .  4
     2.4 How CPU usage reduced  . . . . . . . . . . . . . . . . . . .  4
   3  Security Considerations . . . . . . . . . . . . . . . . . . . .  6
   4  IANA Considerations . . . . . . . . . . . . . . . . . . . . . .  6
   5  References  . . . . . . . . . . . . . . . . . . . . . . . . . .  6
     5.1  Normative References  . . . . . . . . . . . . . . . . . . .  6
     5.2  Informative References  . . . . . . . . . . . . . . . . . .  6
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .  6

 

Haresh,Sushrut                Experimental                      [Page 2]
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1  Introduction

   Continuous GET REQUEST, GETNEXT REQUEST, GETBULK REQUEST on managed
   device results into high CPU usage. High CPU usage is result of high
   process interactions between SNMP process and requested OID's process
   when OID came from GET REQUEST, GETNEXT REQUEST, GETBULK REQUEST.
   This draft suggests the way to reduce these process interactions in
   order to reduce CPU usage. This approach also suggests way to reduce
   high CPU usage with accurate OID values.

1.1  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.  MIB classification 

2.1 How CPU usage goes high

   When SNMP protocol data units (SNMP PDU) are received by SNMPD
   running on managed device (router, switch etc...), SNMPD de capsulate
   PDU and retrieves requested ODI from PDU. After getting OIDs, SNMPD
   interacts with process under whom requested OIDs and its value
   reside.

   For example, NMS sends SNMP GET REQUEST with seeking of interface
   operational status whose OID is .1.3.6.1.2.1.2.2.1.8. This GET
   REQUEST PDU is received at managed device's SNMPD which in turn de
   capsulated PDU and find out that "ifOperStatus" is requested from