DB2 9 System Administration for z/OS: Certification Study Guide: Exam 737 - Brossura

Nall, Judy H.

Brossura

ISBN 10: 1583470964 ISBN 13: 9781583470961

Casa editrice: Mc Pr Llc, 2010

Riassunto

Written with system administrators in mind, this reference offers information about both DB2 and z/OS operating systems as well as guidance for preparing for the IBM Certification Test 737. Helpful and thorough, this technical guide summarizes the new features of DB2 9 environments and provides essential system administration information, such as installation and maintenance procedures. With chapters on troubleshooting, performance and tuning, and securing and auditing, as well as practice questions, this reference is a one-stop shop for DB2 system administrators.

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Informazioni sull?autore

Judy H. Nall is an internationally recognized lecturer, consultant, writer, educator, and expert in DB2. She is the president of Computer Business International, Inc., a member of the IBM DB2 Gold Consultants Group, and the recipient of an IBM Data Champion award for contributions to the IBM Data Management community. She lives in Reno, Nevada.

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DB2 9 System Administration for z/OS

Certification Study Guide

By Judy H. Nall

MC Press

Copyright © 2010 Judy Nall
All rights reserved.

ISBN: 978-1-58347-096-1

Contents

Title Page, 
Copyright Page, 
Acknowledgments, 
CHAPTER 1 - Introduction to DB2 9 for z/OS, 
CHAPTER 2 - DB2 for z/OS Overview, 
CHAPTER 3 - Installation and Migration, 
CHAPTER 4 - Security and Auditing, 
CHAPTER 5 - System Backup and Recovery, 
CHAPTER 6 - Performance and Tuning, 
CHAPTER 7 - Systems Operations and Troubleshooting, 
APPENDIX A - DB2 Message Numbers, 
APPENDIX B - References, 
APPENDIX C - Answers to the Practice Questions, 

CHAPTER 1

Introduction to DB2 9 for z/OS

This chapter addresses the job responsibilities of the DB2 system administrator, describes what to expect on the IBM DB2 9 System Administrator for z/OS Exam (Test 000-737), and reviews the basic prerequisites assumed for the reader of this book.

Purpose of the Book

As the certification study guide for Test 737, this book guides you through the responsibilities, tasks, and methods used by a DB2 9 for z/OS system administrator. It covers all the objectives of the exam and provides sample exam questions and answers to test your knowledge.

The book provides a broad understanding of the responsibilities of a DB2 for z/OS system administrator, gives examples of day-to-day work requirements, describes techniques to assist you in your work, and provide details about how to develop your skill sets.

Test 737: DB2 9 System Administrator for z/OS

The system administrator exam certifies that the candidate has the skills, knowledge, and abilities to describe the architecture and administer the processes required to plan, install, manage, and tune secure DB2 for z/OS environments. To obtain this certification, you must pass two tests:

• Test 730: DB2 9 Family Fundamentals

• Test 737: DB2 9 System Administrator for z/OS

Test 737 is 90 minutes in duration and consists of 60 questions. The passing score is 62 percent. The exam consists of six sections, each of which includes questions and some scenarios for you to evaluate:

• Section 1: Installation and Migration (15 percent of the test) — Tests your knowledge of the installation and migration planning process, how to execute an installation/migration plan, and how to evaluate appropriate subsystem parameter (DSNZPARM) configuration settings (Chapter 3)

• Section 2: Security and Auditing (7 percent) — Assesses your understanding of how to protect DB2 resources, auditing techniques, and role-based security (Chapter 4)

• Section 3: System Operation and Maintenance (21.5 percent) — Deals with the management of DB2 components, commands, monitoring, and threads (Chapter 7)

• Section 4: Backup and Recovery (20 percent) — Tests your knowledge of the procedures for system-level backup, recovery from system failures, and disaster recovery processes (Chapter 5)

• Section 5: Performance and Tuning (21.5 percent) — Presents scenarios and asks you to analyze the performance; tests your knowledge of buffer pools, DSNZPARMs, statistics, traces and tools, efficient use of memory, and DB2 workload manager settings (Chapter 6)

• Section 6: Troubleshooting (15 percent) — Tests your problem-solving abilities, including your knowledge of operator commands and traces, how to identify contention problems, diagnostics in dealing with utilities, and resolving and identifying data sharing problems (Chapter 7)

Certification Web Site

The IBM Professional Certification Program Web site, http://www.ibm.com/certify, provides information that can help you prepare for the exam, including a sample test, a list of training resources to help you prepare for the exam, and information about testing centers worldwide. Take the time to visit this site and become familiar with the information it offers.

The sample assessment test is a good place to start. You can practice taking the exam and see how well you score on each section to evaluate your strengths and weaknesses. Remember, though, that passing the sample test does not result in credentials. For instructions about how to access the Web-based assessment test delivery tool, including registration and payment procedures, see the information page for Test 737.

DB2 System Administration Requirements

To work as a DB2 9 for z/OS system administrator, you need a strong background in DB2 for z/OS. For example, if you are currently a database administrator with a couple years of experience, or if you have several years as a DB2 advanced programming lead under your belt, you have the baseline to start working on your system administration skill set and certification.

Your understanding and background should include familiarity with the DB2 and System z architectures.

Knowledge of DB2

Your DB2 experience should include the following:

• DB2 catalog tables, DB2 directory, bootstrap data sets (BSDSs)

• DB2 active and archive logging

• DB2 virtual buffer pools (VBPs)

• SQL query writing, EXPLAIN, and troubleshooting

• Data Definition Language (DDL) and physical structures in DB2

• DB2 IBM administration tools and the Optimization Service Center (OSC)

• IBM or other vendor DB2 utilities (e.g., COPY, LOAD, RUNSTATS)

System z Architecture

Your z/OS skill set should include the following:

• How to write Job Control Language (JCL) to execute a job in z/OS

• How to use the Interactive System Productivity Facility (ISPF) and Program Development Facility (PDF) to display data set lists or define a data set

• How to use the System Display and Search Facility (SDSF) and/or the Interactive Output Facility (IOF) to find job execution information

• Familiarity with the System Modification Program/Extended (SMP/E) tool and its basic functions

• Knowledge of Workload Manager (WLM) and its basic functions

Familiarity with other software products, such as Customer Information Control System (CICS), WebSphere, and non-IBM vendor offerings is a plus. We will build on your DB2, z/OS, and product skills throughout this book.

To obtain more information about DB2 9 for z/OS, visit IBM's DB2 for z/OS Web site, http://www-01.ibm.com/software/data/db22/zos, where you will find downloads, product support, product documentation, and more.

CHAPTER 2

DB2 for z/OS Overview

This chapter reviews the tasks, services, structure, architecture, and components of DB2 9 for z/OS that constitute required knowledge for a DB2 system administrator.

CSECTs and Subcomponents

Let's begin with a short overview of how the DB2 code is structured internally:

• In DB2, each object module contains a single control section (CSECT).

• A CSECT typically performs one function, and the object module and CSECT have the same name.

• Member DSNWMODS in library SDSNSAMP contains the readable data set associated with a CSECT for DB2.

• CSECT names and message identifiers begin with the letters "DSN" in DB2.

• The fourth character of a DB2 CSECT name identifies a subcomponent. For example, the prefix DSNJ indicates the recovery log manager subcomponent, and these letters are used for the module and message prefixes related to that facility.

DB2 subcomponents are groups of closely related DB2 for z/OS modules that work together to provide a general function. There are three groups of subcomponents in DB2:

• System services

• Database services

• Distributed Data Facility (DDF) services

DB2 Resource Managers

The software that comprises the DB2 resource managers is usually responsible for managing a specific resource. The resource being managed can be physical or logical. DB2 usually has one subcomponent per resource manager, but exceptions exist. For example, the precompiler is not a resource manager, and the instrumentation facilities subcomponent contains two resource managers.

A resource manager identifier (RMID) identifies a resource manager. The RMID indicates the source of diagnostic output in your dumps. For your reference, the appendix at the end of this book provides a list of subcomponents and identifiers.

Address Spaces

In DB2, there are four major address spaces, some of which are known by several different acronyms:

• The main address space (DSN1MSTR), also known as the system services address space (SSAS) or the Data Systems Control Facility (DSCF)

• The data manager address space (DSN1DBM1), also known as the database services address space (DBAS or DSAS) or the Advanced Database Management Facility (ADMF)

• The Distributed Data Facility address space (DSN1DIST)

• The Internal Resource Lock Manager address space (IRLMPROC)

System Services

System services manage logs, agent services, and more by executing various subcomponents in the system services address space. This address space is also called the Data Systems Control Facility space.

Here are a few of the subcomponents that execute in the SSAS:

• System parameter manager

• Recovery manager

• Recovery log manager

• Group manager

• Distributed transaction manager

• Storage manager

• Agent services manager

• Message generator

• Initialization procedures

• Instrumentation facilities

• General command processor

• Subsystem support

Database Services

Database services use system services and z/OS to handle the actual database structures. The database services address space consists of three main components:

• Buffer manager

• Data manager (DM)

• Relational data system

The function of the DBAS is to manage the physical structures and data, execute SQL, and manage the buffers. Even though these are independent components, they work together to make a proper subsystem of z/OS. The database services address space is also referred to as the Advanced Database Management Facility address space.

Subcomponents of interest that execute in the DBAS are:

• LOB manager

• Service controller

• Stored procedures manager

• Data space manager

• Utilities (these work with associated code in an allied address space)

Distributed Data Facility Services

Running as an additional address space in DB2, the DDF services consist of one subcomponent called the Distributed Data Facility. DDF controls the connecting of distributed applications to DB2 for z/OS. The naming convention for this subsystem is xxxDIST.

Four resource managers are associated with DDF:

• Data Communications Resource Manager

• Distributed Data Interchange Services

• Distributed Relational Data System Manager

• Distributed Transaction Manager

These subcomponents execute in the DDF address space.

DB2 Distributed Relational Data Architecture (DRDA) subsystems and other relational databases can communicate with DDF by using Transmission Control Protocol/Internet Protocol (TCP/IP) or Virtual Telecommunications Access Method (VTAM) on the same network. DDF supports two network protocols, Systems Network Architecture (SNA) and TCP/IP, as well as the DRDA database communications protocol.

DRDA is set of database protocols that describe the architecture that allows connection and access to distributed relational data in multiple database systems. DRDA defines what must be exchanged and how it must be exchanged and then coordinates the communications between systems. Three components make up DRDA:

• Application requestor

• Application server

• Database server

Internal Resource Lock Manager

DB2 also requires the address space subsystem services of the Internal Resource Lock Manager (IRLM), which resides in its own address space. (Note that this "IRLM" is different from the Information Management System, or IMS, Resource Lock Manager.) The lock manager works with DB2 to serialize access to data. DB2 requests locks from IRLM to ensure data integrity when applications, utilities, and commands all attempt to access the same data.

In DB2 9, you must continue to specify the IRLM-related subsystem parameters PC and MAXCSA, but their values are no longer used. IBM has retained these parameters for compatibility reasons. Specific system site specifications now determine the amount of available storage for IRLM private control blocks, including locks. All IRLM locks are in the IRLM private address space; locks are no longer placed in the extended common service area (ECSA). IRLM control block structures are estimated at 540 bytes per lock and reside above the 2 GB bar. DXB, not DSN, is the prefix for IRLM.

Other Address Spaces

DB2 communicates with other address spaces, known as allied address spaces, in the z/OS environment. DB2 communicates with these "allied agents" to facilitate requests. Here is a list of allied agents with which DB2 communicates:

• Time Sharing Option (TSO) attachment facility

• Subsystem support

• Message generator, stand-alone only (DSN1SDMP)

• IMS attachment facility

• Call attachment facility

• Customer Information Control System (CICS) attachment facility

• Resource Recovery Services (RRF) attachment facility

• Utilities

Connections or threads to these allied agents are controlled through the subsystem parameter CTHREAD (which defaults to 200, has a maximum value of 2000, and is updatable online). The CTHREAD setting defines the number of concurrently allocated threads for local connections. If you find that you are waiting for a connection to access the DB2 subsystem, you might need to increase the number of allied connections specified through CTHREAD.

The CTHREAD setting, along with the MAXDBAT DSNZPARM, protects the virtual storage allocation. Be careful not to overcommit your virtual storage resources. If the number of remote threads is queued with work waiting, you might need to increase the MAXDBAT value.

Utilities use parallelism, so you will have one thread for each utility and an additional thread for each subtask. Thus, a single utility may be using many threads. You need to make sure to specify a CTHREAD value that will accommodate utility parallelism.

Non-allied address spaces do not communicate with DB2. Several subcomponents execute in non-allied address spaces:

• DB2 does not communicate with the DB2 precompiler (PRE), but the precompiler may require an allied address space, depending on the precompiler options you have selected.

• The full message generator for DB2 resides in the system services address space. The message generator can also run stand-alone in allied or non-allied address spaces.

• Portions of the instrumentation subcomponent run in a non-allied address space.

• DB2 stand-alone utilities run in non-allied address spaces.

Work Requests in DB2

DB2 tasks and agents are subcomponents that run in an allied address space. Each DB2 work request is represented by an agent. Several classes of agents exist: system agents, allied agents, and database access agents. DB2 tracks the agent (the work) using an agent control element (ACE). Each ACE is associated with one or more execution blocks (EBs).

A one-to-one relationship exists between a z/OS execution unit and an execution block. An EB is used to describe each unique unit of dispatch work, which can be dispatched in either task control block (TCB) or service request block (SRB) mode in z/OS. All allied agents to which the primary EB is related point to the user's home address TCB.

In the DB2 address space, when execution units are created in TCB mode, they are known as service tasks. Resource managers in DB2 can dynamically delete and create service tasks. When you initialize DB2, service tasks are created, and these usually exist until DB2 is stopped. The service tasks remain idle until their services are needed in DB2.

Examples of permanent service tasks include the following:

• System service tasks

• Log manager

• Recovery manager

• Database services tasks

• Buffer manager

• Data manager

• DDF tasks

• Distributed transaction manager

DB2 9 System Structure Basics

Figure 2.1 provides an overview of the DB2 subsystems.

DB2 uses several types of private address spaces, each requiring storage:

• DB2 system services address space (DSN1MSTR)

• DB2 database services address space (DSN1DBM1)

• DB2 DDF address space (DSN1DIST)

• IRLM address space (IRLMPROC)

• DB2 allied agent address spaces

• DB2 stored procedures address spaces (established by the Workload Manager, or WLM)

• DB2 administrative scheduler address space

When you start your DB2 subsystems, there is a recommended dispatching priority for these address spaces in z/OS: Without locking to protect your resources, you cannot begin, so IRLM is started first. Next, you start the DB2 performance monitors, then the DBM1 address space, and then the MSTR address space.

(Continues...)

Excerpted from DB2 9 System Administration for z/OS by Judy H. Nall. Copyright © 2010 Judy Nall. Excerpted by permission of MC Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Dettagli dell?edizione

• Editore: Mc Pr Llc
• Data di pubblicazione: 2010
• ISBN 10: 1583470964
• ISBN 13: 9781583470961
• Rilegatura: Copertina flessibile
• Lingua: Inglese
• Numero di pagine: 412
• Contatto del produttore: non disponibile