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Mainframe
- 1. Mainframe OS Kanika Kapoor 8 th semester 061047
- 7. We will be studying the basics of Mainframe OS
- 8. Mainframe workloads: Batch and online transaction processing
- 16. Parallel Sysplex with 3 z/OS images 3 nodes
- 18. Basic shared DASD DASD
- 20. Clustering with CTC rings
- 21. Mainframe Strength : high availability, scalability So, perform hardware and software maintenance and installation in a non-disruptive manner Clustering
- 29. Mainframe computer a self-contained computing environment , or one part of the puzzle in distributed computing ??
- 30. The answer is both…
- 35. Address spaces in a z/OS system
- 39. Two-phase commit
- 49. z/os interrupts indicates a problem with the server hardware occur when the program issues an SVC instruction. An SVC is a request for a particular system service. indicate any of several events, such as a time interval expires or the CP receives a signal from another CP. an I/O operation completes, an error occurs, or an I/O device (such as a printer) becomes ready occur when the operator selects the restart function at the console time period expiring an error or other event has occurred in a program Restart Machine check Program check I/O SVC External
- 56. Thank you Any Queries
- 57. 128-bit PSW
- 60. Nearly all mainframes have the ability to run (or "host") multiple operating systems and thereby operate not as a single computer but as a number of virtual machines. In this role, a single mainframe can replace dozens or even hundreds of smaller servers, reducing management and administrative costs while providing greatly improved scalability and reliability. IBM/360
- 61. Address space The common areas provide a way to communicate between address spaces. Each program is loaded into its own private address space Address space = The virtual storage available to a program
- 64. To balance throughput with response and turnaround time, WLM does the following: Monitors the use of resources by the various address spaces. Monitors the system-wide use of resources to determine whether they are fully utilized. Determines which address spaces to swap out, and when. Inhibits the creation of new address spaces or steals pages when certain shortages of main storage exist. Changes the dispatching priority of address spaces, which controls the rate at which the address spaces are allowed to consume system resources. Selects the devices to be allocated, if a choice of devices exists, in order to balance the use of I/O devices Other z/OS components, transaction managers, and database managers can communicate to WLM a change in status for a particular address space (or for the system as a whole), or to invoke WLM's decision-making power. For example, WLM is notified when: main storage is configured into or out of the system. An address space is to be created. An address space is deleted. A swap-out starts or completes. Allocation routines can choose the devices to be allocated to a request. The processor capacity of a IBM System z server has changed via the Capacity on Demand capability. WLM is particularly well-suited to a sysplex environment.
Notes de l'éditeur
- The system can recover from a failed component without impacting the rest of the running system
- z/Os (64-bit)
- Job=process
- 1. At night, numerous batch jobs running programs and utilities are processed. These jobs consolidate the results of the online transactions that take place during the day. 2. The batch jobs generate reports of business statistics. 3. Backups of critical files and databases are made before and after the batch window. 4. Reports with business statistics are sent to a specific area for analysis the next day. 5. Reports with exceptions are sent to the branch offices. 6. Monthly account balance reports are generated and sent to all bank customers. 7. Reports with processing summaries are sent to the partner credit card company. 8. A credit card transaction report is received from the partner company. 9. In the production control department, the operations area is monitoring the messages on the system console and the execution of the jobs. 10. Jobs and transactions are reading or updating the database
- 1. A customer uses an ATM, which presents a user-friendly interface for various functions: Withdrawal, query account balance, deposit, transfer, or cash advance from a credit card account. 2. Elsewhere in the same private network, a bank employee in a branch office performs operations such as consulting, fund applications, and money ordering. 3. At the bank’s central office, business analysts tune transactions for improved performance. Other staff use specialized online systems for office automation to perform customer relationship management, budget planning, and stock control. 4. All requests are directed to the mainframe computer for processing. 5. Programs running on the mainframe computer perform updates and inquiries to the database management system (for example, DB2®). 6. Specialized disk storage systems store the database files.
- Jobs with similar needs are batched togrther
- A coupling facility is a mainframe processor, with memory and special channels, and a built-in operating system. It has no I/O devices, other than the special channels, and the operating system is very small. The ability to partition a large system into multiple smaller systems, called logical partitions or LPARs The ability to partition a large system into multiple smaller systems, called logical partitions or LPARs. A coupling facility is a mainframe processor, with memory and special channels, and a built-in operating system. It has no I/O devices, other than the special channels, and the operating system is very small. The ability to partition a large system into multiple smaller systems, called logical partitions or LPARs. A coupling facility is a mainframe processor, with memory and special channels, and a built-in operating system. It has no I/O devices, other than the special channels, and the operating system is very small. The ability to partition a large system into multiple smaller systems, called logical partitions or LPARs. A coupling facility is a mainframe processor, with memory and special channels, and a built-in operating system. It has no I/O devices, other than the special channels, and the operating system is very small. The ability to partition a large system into multiple smaller systems, called logical partitions or LPARs. A coupling facility is a mainframe processor, with memory and special channels, and a built-in operating system. It has no I/O devices, other than the special channels, and the operating system is very small. The ability to partition a large system into multiple smaller systems, called logical partitions or LPARs.
- Availability= system can recover from a failed component without impacting the rest of the running system….. Scalability=capability of a system to increase performance under an increased load when resources are added
- Channel path identifiers
- Virtual Machine=a process has its own processor with its own VM Each process is provided with a copy of underlying computer Each VM/c is isolated from other VM/s & don’t share resources=>security
- Monolithic kernel software -Device driver software- device controller hardware- device hardware (keyboard)
- While batch processing is possible on distributed systems, it is not as commonplace as on mainframes, because distributed systems often lack the following elements: Sufficient data storage, Available processor capacity ( cycles ), I/O bandwidth, Sysplex-wide management of system resources and job scheduling
- When data is changed, does the Data retention may be required by law. When data is changed, does the owning system or the updating system create a copy?
- Workstation Terminal In a distributed system, each processor has its own local memory. So, u must update data in each local memory
- Client server computing = distributed computing if several programs were to update the same data at the same time, the data could be corrupted (also referred to as a loss of data integrity).
- Follows ENFORCED ISOLATION
- DB 2 is the relational DB by IBM that runs on z/OS ,Linux etc
- If unauthorized users cannot log into the operating system, they cannot access the data. Address space=memory subset threads share memory Program=passive entity(contents of file stored on disk Process=active entity (Program counter, program stack data section); 4 states; represented by a PCB
- resource manager Participates in the unit of recovery an opportunity to vote on whether its part of the UR is in a consistent state and can be committed. If all participants vote yes, the sync point manager instructs all the resource managers to commit the changes. If any participants vote no, the sync point manager instructs them to back out the changes.
- Secondary storage devices-magnetic tapes, DASD (disks)
- Capacity=store, process very large volumes of corporate data
- RAIDs are inexpensive N disks treated as 1 disk Each of the n disks participate in R/W access Same no of R/W accesses, but each access can read n times the data
- Reliability=The system’s hardware components have extensive self-checking and self-recovery capabilities Reliability increased via redundancy Performance increased via parallelism RAID is not tolerant of user error, and it is far from tolerant enough to take the kind of software/game/freeware/pirated software abuse hurled at the average home PC. Newer versions of Microsoft Windows - like XP Pro - even supported completely software controlled RAID (under certain conditions)
- Loss of data integrity – concurrent updates on same data
- 4 necessary conditions: Mutual exclusion, Hold & Wait, No Preemption , Circular wait
- Data integrity- concerned with accidental damage & recovery
- When a process is to be executed, its pages are loaded into available frames from backing store Program is not constrained by amt of phy mem available
- Multiprogrammed-better CPU utilization by putting many jobs in memory if several programs were to update the same data at the same time, the data could be corrupted (also referred to as a loss of data integrity).
- Availability= system can recover from a failed component without impacting the rest of the running system….. Scalability=capability of a system to increase performance under an increased load when resources are added