How to correctly manage the operational performance of DB2 For z/OS or OS/390

Today, we will focus on the description of the actual operational performance of correctly managing DB2 For z/OS or OS/390. Today, major organizations are facing major problems, it mainly aims to make their applications run very well and maintain high efficiency.

This will be an endless task, and you will have to repeat multiple times to collect, analyze, and check performance-related statistics. When a DBMS system, such as DB2, is included in your application system, performance management will be more difficult.

In fact, performance optimization is one of the biggest problems facing all database administrators. They hear and face similar complaints from customers about low performance all day, because no users like to wait, when they use an application, if the response time is too long, you will get endless complaints and dissatisfaction from users.

The response time of the application caused by the reasons is too long, which is not easy to answer and solve. Many DBAs work overtime, but can only solve some performance problems. In this article, we will focus on the basic sections of performance management and optimization, and gradually go deep into the way to adjust the performance of DB2 databases and applications.

Each database application consists of the operating system, database, and application. Therefore, DBAs need to monitor and adjust the performance of the entire system from these three aspects.

I. Adjust the system

The beginning of DB2 performance management is system adjustment. The system mentioned here is composed of operating system software and hardware, which provides services for applications. From the hardware point of view, it mainly includes the host itself, as well as the corresponding disk subsystem, network connection and all peripheral devices. From the software perspective, the most important thing is to include the operating system, file subsystem, data management subsystem, network protocol and related middleware, such as the transaction processor and Message Queue Manager.

To ensure stable system performance, the database administrator must be able to monitor all these software and hardware resources and manage and optimize these different software and hardware components for mutual cooperation. For example: for memory allocation and storage management as well as Zheng He DBMS and other system software, it is correct to use database log and so on. In addition, the database administrator must be able to properly configure system installation, port and upgrade database software. The system is the cornerstone of an application. If the system cannot run well, all applications based on the system will run slowly and even cause program errors.

To manage DB2 system performance, DBA's first task is to ensure that all independent and interconnected address spaces can communicate with each other correctly, and each address space can run well. For example, CICS, IMS, TSO, WebSphere and DB2 Connect. If these subroutines are not properly cultivated, all these subroutines and subsystems may affect the performance of DB2 applications.

For example, when the database data is accessed by the CICS program, multiple threads will work synchronously, enabling many users to synchronously access the data in DB2 through the CICS program. Using CICS Attach Facility through this mechanism, CICS connects to DB2) You can connect each CICS region to a DB2 system. In this way, multiple DB2 systems can be connected to multiple CICS region in the same layout through configuration, and DB2 provides data services for CICS.

Execute SQL data operations through the TCB of MVS. These TCB are stored in the CICS address space and use cross-memory commands to call the DB2 Data Service DSNDBM1 ).

In addition, the resource control table (RDBMS) must be properly standby for use by DB2 programs. The RDBMS runs in the CICS space and only applies to CICS accessing DB2 data. It defines how CICS transactions use DB2 resources. It defines a Plan for each CICS transaction and uses this Plan to access DB2, it also defines detailed parameters and types for some application plans to access DB2.

DB2 data administrators need to pay special attention to the configuration of DB2 system parameters, whether through the DB2 command or DSNZPARMs. For performance optimization, the most important thing is the memory usage. DB2 needs to allocate memory for Buffer, EDM, RID, and sort cache. The amount of memory is limited, how these memories can be effectively utilized is crucial to the efficient performance of DB2.

DB2 data administrators need to pay special attention to the configuration of DB2 system parameters, whether through the DB2 command or DSNZPARMs. For performance optimization, the most important thing is the memory usage. DB2 needs to allocate memory for Buffer, EDM, RID, and sort cache. The amount of memory is limited, how these memories can be effectively utilized is crucial to the efficient performance of DB2.

References:

Moulder, Tom, Performance Management of a Data Warehouse, BMC Software white paper, 2001.

Mullins, Craig S., DB2 Developers Guide, 4th edition, indianapois, IN (2000) SAMS

Publishing, ISBN 0-672-31828-8

Mullins, Craig S., A DB2 for z/OS Performance Road Map, eServer Magazine, Mainframe

Edition, limit l 2002.

The above content is an introduction to the performance of managing DB2 For z/OS or OS/390. I hope you will gain some benefits.