17985549
An approach to decentralized computer systems
The technology for distributed computing is available. However, it is argued that decentralized systems will always require more careful design, planning, and management than their centralized counterparts. The rationale for and against decentralization is given, and a technical approach to decentralized systems is sketched. This approach contrasts with the popular concept of a distributed integrated database which transparently provides remote IO against single system image. Rather, it proposes that functions be distributed as `servers' which abstract data as high-level operations on objects and communicate with `requestors' via a standard message protocol. This requestor-server approach has the advantages of modularity and performance.
215936012
Evolution of Data Management
Society has made great strides in capturing, storing, managing, analyzing, and visualizing data. These tasks are generically called data management, and this article sketches its evolution through ...
25154953
Queues Are Databases
Message-oriented-middleware (MOM) has become an small industry. MOM offers queued transaction processing as an advance over pure client-server transaction processing. This note makes four points: Queued transaction processing is less general than direct transaction processing. Queued systems are built on top of direct systems. You cannot build a direct system atop a queued system. It is difficult to build direct, conversational, or distributed transactions atop a queued system. Queues are interesting databases with interesting concurrency control. It is best to build these mechanisms into a standard database system so other applications can use these interesting features. Queue systems need DBMS functionality. Queues need security, configuration, performance monitoring, recovery, and reorganization utilities. Database systems already have these features. A full-function MOM system duplicates these database features. Queue managers are simple TP-monitors managing server pools driven by queues. Database systems are encompassing many server pool features as they evolve to TP-lite systems.
40830661
Greetings from a Filesystem User
9663368
Parallel database systems: the future of database processing or a passing fad?
The concept of parallel database machines consisting of exotic hardware has been replaced by a fairly conventional shared-nothing hardware base along with a highly parallel dataflow software architecture. Such a design provides speedup and scaleup in processing relational database queries. This paper reviews the techniques used by such systems, and surveys current commercial and research systems.
31301873
Parity Striping of Disk Arrays: Low-Cost Reliable Storage with Acceptable Throughput
An analysis of mirrored discs and of RAID5 shows that mirrors have considerably better throughput, measured as requests/second on random requests of arbitrary size (up to 1MB). Mirrors have comparable or better response time for requests of reasonable size (less than 100KB). But mirrors have a 100% storage penalty: storing the data twice. Parity striping is a data layout that stripes the parity across the discs, but does not stripe the data. Parity striping has throughput almost as good as mirrors, and has cost/GB comparable to RAID5 designs -combing the advantages of both for high-traffic disc resident data. Parity striping has additional fault containment and software benefits as well. Parity striping sacrifices the high data transfer rates of RAID designs for high throughput. It is argued that response time and throughput are preferable performance metrics. Outline Introduction Why Striping and RAID Are Inappropriate for OLTP Systems Parity Striping: Cheap Reliable Storage Plus High Throughput An Analysis of Mirrors, RAID5, and Parity Stripe Performance Mirrored Discs Parity Stripe Discs RAID5 Discs Applying the Analysis to a 10+2 array The Read-Only Case The Write-Only Case Analyzing a High-Performance Disc Other Benefits of Parity Striping Summary Acknowledgments References Appendix: Spreadsheets Corresponding to the Graphs
40167878
Why do Computer Stop and What Can be About it?
10364748
Why Do Computers Stop and What Can Be Done About It?
An analysis of the failure statistics of a commercially available fault-tolerant system shows that administration and software are the major contributors to failure. Various approaches to software fault-tolerance are then discussed -- notably process-pairs, transactions and reliable storage. It is pointed out that faults in production software are often soft (transient) and that a transaction mechanism combined with persistent processpairs provides fault-tolerant execution -- the key to software fault-tolerance.
10432009
Increasing the Effectiveness of OS Research
13482322
Triumphs, Sins, and Challenges of Database Benchmarking
35790813
Mobile technologies for the world's children
In this panel, academic, non-profit, and industry professionals will discuss their global perspectives on mobile technologies for the world's children. Panelists will explore such issues concerning children's access to mobile devices, the decreasing age that children have access to these technologies, mobile innovations for learning, and challenges/opportunities in diverse countries. This interactive session will begin with each panelist giving a short summary of their work-to-date with children and various mobile applications. Then the panelists will be asked questions by children from different countries via pre-recorded video. Audience members will be invited to offer their thoughts and comments as well as the panelists during the video question period. Audience members will also be able to ask further questions throughout the panel discussion.