1 / 20

Chapter 6: Accessing large amount of data i.e. Big Data

Chapter 6: Accessing large amount of data i.e. Big Data. Objectives. Be able to describe the concepts of: Channel subsystems Control Units DASD RAID Multiple allegiance/ Parallel Access Volumes (PAV) Random access to data Databases Data sharing DFSMS. Introduction.

fann
Download Presentation

Chapter 6: Accessing large amount of data i.e. Big Data

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 6: Accessing large amount of data i.e. Big Data

  2. Objectives Be able to describe the concepts of: • Channel subsystems • Control Units • DASD • RAID • Multiple allegiance/ Parallel Access Volumes (PAV) • Random access to data • Databases • Data sharing • DFSMS

  3. Introduction The core function of a large-scale computing environment is to process corporate data. ESCON is an optical fiber, half-duplex, serial interface FICON has replaced ESCON in current deployments because of FICON's technical superiority (especially its higher performance) and lower cost. FICON is a network of Fibre Channel devices which allows many-to-many communication, device name lookup, security, and redundancy

  4. I/O Connectivity

  5. Channel Subsystem and System Assist Processors (SAP)

  6. Control units • To execute channel commands • Protocol : CCW • CCW Chain : an operation that consist of more than 1 CCW • Allow functionality beyond the power of the early mainframe processors... minimize interrupts • Beginning : 1 device to 1 control unit • Now : 1 device can connect to > 1 control unit

  7. Direct Access Storage Device (DASD) Architecture

  8. DASD Architecture (Cont...)

  9. Mapping for access to devices • UCBUnit Control Block • UCWUnit Control Word • CUCB Control unit control block The Channel SubSystem uses the UCW to find the CUCBs and decides which is the best channel/control unit pair to use for the operation. “What's the best path”

  10. Mapping for access to devices (Cont...)

  11. DASD Subsystem A control unit may be connected to several channels, a device may be connected to several control units. The reason is availibility andresilience. Between the control unit and the IBM System z an ESCON or FICON-Director can be connected in addition. That will increase the systems stability and scalability.

  12. Redundant array of independent disk (RAID) There is a variety of common and insignificant RAID-level. RAID-5 has a high I/O rate and a medium data rate. (N+1 plus distributed Check Char) RAID-5 is used by the IBM DS8000 controller arrays in the majority of configurations.

  13. Reducing the number of logical volumes • Amount of Data problem : to manage logical volumes solution : DFSMS • Larger Volumes problem : more I/O to each volume solution : RAID BUT... Is not enough...

  14. Multiple allegiance(MA) / Parallel access volume(PAV) MA PAV

  15. Random access to data • RAID : First slow, as of next high-speed retrieval • Predictive loading : load the data into the CONTROL UNIT CACHE

  16. Databases • likely relational databases • a single large server controlling all data request  not on mainframe (clients & server on different machines): • Good data integrity • Poor processor utilization  on mainframe (clients & server on same machine) : • Good data integrity • Good processor utilization

  17. Data Sharing The ability to share data for both reading and updating, from multiple programs that can be running on different physical machines. • Parallel Sysplex is required • with structures in the Coupling Facility (CF) providing the necessary mechanisms

  18. Data Facility Storage Management System • Object Access Method (OAM) • OAM uses database/DASD, tape, and optical technologies to manage the storage and retrieval of objects. • OAM uses a hierarchy: • DASD • Tape volumes with a tape library device • Optical volumes inside a library device

  19. Data placement and management • Performance • Space • Backup • Migration

  20. Summary The New Mainframe and access large amounts of data: • Access large amounts data is required for a variety of applications • Requires a high processor utilization • High levels of reliability are needed • Tape media : high capacity, low cost, but slow and sequential • Quick data transfer rates are need

More Related