Search Results

Search found 659 results on 27 pages for 'safety'.

Page 15/27 | < Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >

• Stop external USB keyboard repeating key presses on Vista.

  - by dommer

  We have an infuriating problem with a (Vista/Dell) laptop. When an external (Logitech) USB keyboard is attached to it, it regularly starts repeating key presses. When the user recently deleted an Outlook message, it deleted them all! When typing a message, suddenly it will start repeating the last keypress about 30 times (it varies). It's not a mechanical issue. We've switched the keyboard out four times. Even tried a brand new one one. Every time it's the same. Also, the keyboard works fine on other machines. The problem doesn't arise when the laptop's own keyboard is used - even if the external USB keyboard is still attached. I'm stumped? Any ideas. Not using an external keyboard isn't an option due to our health and safety policy (...don't ask...).

  Read the article

• 2012 Oracle Fusion Middleware Innovation Awards for Oracle Exalogic

  - by Sanjeev Sharma

  Companies from around the world were honored for their innovative solutions using Oracle Fusion Middleware. This year’s 27 award winners, representing 11 countries and a wide span of industries, wowed the judges with a range of projects across eight product categories. 4 awards were given out to customers who demonstrated innovative application of Oracle Exalogic for their mission-critical applications.Below is an overview of the 4 businesses that won the Oracle Fusion Middleware Innovation Award for Oracle Exalogic this year. Company: Netshoes About: Leading online retailer of sporting goods in Latin America.Challenges: Rapid business growth resulted in frequent outages and poor response-time of online store-front Conventional ad-hoc approach to horizontal scaling resulted in high CAPEX and OPEX Poor performance and unavailability of online store-front resulted in revenue loss from purchase abandonment Solution: Consolidated ATG Commerce and Oracle WebLogic running on Oracle Exalogic.Business Impact:Reduced abandonment rates resulting in a two-digit increase in online conversion rates translating directly into revenue up-liftCompany: ClaroAbout: Leading communications services provider in Latin America.Challenges: Support business growth over the next 3  - 5 years while maximizing re-use of existing middleware and application investments with minimal effort and risk Solution: Consolidated Oracle Fusion Middleware components (Oracle WebLogic, Oracle SOA Suite, Oracle Tuxedo) and JAVA applications onto Oracle Exalogic and Oracle Exadata. Business Impact:Improved partner SLA’s 7x while improving throughput 5X and response-time 35x for  JAVA applicationsCompany: ULAbout: Leading safety testing and certification organization in the world.Challenges: Transition from being a non-profit to a profit oriented enterprise and grow from a $1B to $5B in annual revenues in the next 5 years Undertake a massive business transformation by aligning change strategy with execution Solution: Consolidated Oracle Applications (E-Business Suite, Siebel, BI, Hyperion) and Oracle Fusion Middleware (AIA, SOA Suite) on Oracle Exalogic and Oracle ExadataBusiness Impact:Reduced financial and operating risk in re-architecting IT services to support new business capabilities supporting 87,000 manufacturersCompany: Ingersoll RandAbout: Leading manufacturer of industrial, climate, residential and security solutions.Challenges: Business continuity risks due to complexity in enforcing consistent operational and financial controls; Re-active business decisions reduced ability to offer differentiation and compete Solution: Consolidated Oracle E-business Suite on Oracle Exalogic and Oracle ExadataBusiness Impact:Service differentiation with faster order provisioning and a shorter lead-to-cash cycle translating into higher customer satisfaction and quicker cash-conversionCheck out the winners of the Oracle Fusion Middleware Innovation awards in other categories here.

  Read the article

• Windows 7 x64 how to verify integrity of ALL files on an NTFS disk?

  - by kilves76

  Looking for a tool that would verify integrity of ALL files on a Windows 7 x64 NTFS disk reliably? This is for testing of experimental defrag software, so it really needs to be secure and foolproof. I know it will take a long time, there's millions of files on the disk, but safety just cannot be compromised in a situation like this. Freeware solution much preferred. Can be either Windows software (=inducing pitfalls about files changing due to booting Windows) or a stand alone boot (for example linux boot cd + usb key for storing chksum/metadata).

  Read the article

• Can I run a web site from my home network without jeapordizing other computers on my LAN?

  - by Alchemical

  I have a home LAN with 5 computers and a NAS, all connected to a Linksys router which is connected to my Cox cable modem. I'm interested in having one of my computers run an IIS-based web site and to have it be accessible to the internet with a static IP. However, I do not want o jeapordize the safety of the other computers on my home network! Is there anyway to do this safely, or as safe as possible? I may also like to run an FTP server from this computer. Finally, optionally I would like to allow remote access to this computer from the internet--but it seems to me that that may increase the security risk to the other computers substantially.

  Read the article

• BOEING, EA and UNDERWRITER LABS @ Oracle Open World 2012 General Session (GEN9504): Innovation Platform for Oracle Apps, including Oracle Fusion Applications

  - by Sanjeev Sharma

   What does it take to deliver social, mobile, cloud and business analytic      capabilities? Oracle Fusion Middleware is the leading innovation platform for today’s new    business  applications and the building-block of Oracle Fusion Applications.  Join Amit Zavery,  Vice President of Fusion Middleware Product Management discuss Oracle Fusion  Applications’ architecture and the strategy roadmap for Oracle Fusion Middleware. Underwriter Laboratories is the world’s leading provider of product safety and certification testing services.  To support its business growth from $1B to $5B in the next 5 years Underwriter Laboratories is undergoing a major business transformation. Underpinning Underwriter Laboratories's growth plans and associated business transformation is a major Datacenter Modernization effort to consolidate its existing Oracle Applications (E-Business Suite, Siebel CRM, BI etc.) and middleware components (Oracle SOA Suite, Oracle AIA etc.) on a standardized application platform. Underwriter Labs has identified Oracle Engineered Systems (Exalogic and Exadata) as the cornerstone of its Datacenter Modernization endeavor which will eventually support 10,000 employees, 87,000 manufactures and 600,000 catalog items.  Hear senior business leaders from Boeing, Electronic Arts and Underwriters  Laboratories discuss how their organizations are leveraging Oracle Fusion Middleware and  Oracle Applications to improve productivity, lower IT costs and lay a  foundation for business  innovation at the following general session at Oracle Open World 2012: Session:  GEN9504 - General Session: Innovation Platform for Oracle Apps, Including Oracle Fusion ApplicationsDate: Monday, 1 Oct, 2012Time: 10:45 am - 11:45 am (PST)Venue: Moscone West (3002 / 3004)

  Read the article

• Session state provider and atomic operations

  - by vtortola

  Hi, I've been thinking about this and it is blowing my mind... How does a session state provider properly works internally? I mean, I tried to write a custom session state provider based on Azure Tables or Blobs, but quickly I realized that because there is no way to ensure an atomic operation or establish a lock, race conditions are suitable to happen when several web servers do operation on that shared information. I know that there is a SQL Server Session State Provider (SQLS-SSP) and people is happy with it, so I guess that it's using some kind of transaction isolation level in order to accomplish some degree of concurrent safety, like checking is the data is lock (a simple column), locking it if not and returning the data in an atomic operation, but is that so? what does happen if the data is lock? does it returns an error? block the call for a while? returns it in read-only fashion? Cloud computing paradigms could be somehow new, but webfarms have been here for a while, so as I'm pretty new on it... do you recommend any good lecture about the topic? Thanks.

  Read the article

• DAO/Webservice Consumption in Web Application

  - by Gavin

  I am currently working on converting a "legacy" web-based (Coldfusion) application from single data source (MSSQL database) to multi-tier OOP. In my current system there is a read/write database with all the usual stuff and additional "read-only" databases that are exported daily/hourly from an Enterprise Resource Planning (ERP) system by SSIS jobs with business product/item and manufacturing/SCM planning data. The reason I have the opportunity and need to convert to multi-tier OOP is a newer more modern ERP system is being implemented business wide that will be a complete replacement. This newer ERP system offers several interfaces for third party applications like mine, from direct SQL access to either a dotNet web-service or a SOAP-like web-service. I have found several suitable frameworks I would be happy to use (Coldspring, FW/1) but I am not sure what design patterns apply to my data access object/component and how to manage the connection/session tokens, with this background, my question has the following three parts: Firstly I have concerns with moving from the relative safety of a SSIS job that protects me from downtime and speed of the ERP system to directly connecting with one of the web services which I note seem significantly slower than I expected (simple/small requests often take up to a whole second). Are there any design patterns I can investigate/use to cache/protect my data tier? It is my understanding data access objects (the component that connects directly with the web services and convert them into the data types I can then work with in my Domain Objects) should be singletons (and will act as an Adapter/Facade), am I correct? As part of the data access object I have to setup a connection by username/password (I could set up multiple users and/or connect multiple times with this) which responds with a session token that needs to be provided on every subsequent request. Do I do this once and share it across the whole application, do I setup a new "connection" for every user of my application and keep the token in their session scope (might quickly hit licensing limits), do I set the "connection" up per page request, or is there a design pattern I am missing that can manage multiple "connections" where a requests/access uses the first free "connection"? It is worth noting if the ERP system dies I will need to reset/invalidate all the connections and start from scratch, and depending on which web-service I use might need manually close the "connection/session"

  Read the article

• persistant data in tor browser bundle?

  - by Snesticle

  What sort of persistent data is generated by bundled Tor? I recently did an experiment using the Tor Browser Bundle for GNU-Linux. I created two directories, A and B, and placed an identical copy of Tor in each one. Next I placed a simple python script in directory A that both launched the vidalia package and, when exiting the network, deleted the entire contents of A with the exception of itself and rebuilt the bundle from the original archive. What surprises me is that after about ten hours of browsing each, A and B now show a distinct difference in startup time. Also curious is that I get a message in the log of B that never shows up in A: new control connection open which is a notice level advisory. This has nothing to do with what I was originally testing but now I'm interested in what exactly is going on. By the way I do not have to rely on Tor for my personal safety as many are forced to do so even if you just have a hunch I'd be interested in hearing it.

  Read the article

• HDD Carrier, like a soda carrier available at McDonalds?

  - by Jason Taylor

  We use external USB drives for backups, and they have to be stored offsite at the end of the week. Right now we have your standard external USB drive inside an enclosure. We were thinking about moving to a USB dock, and dock a bare HDD for backups, rather than having various sized and types of enclosures. If we were to do this, the drives need protection while being transported to/from the safety deposit box. Is there any kind of hard drive carrier that would let us slide two drives into it, and it would provide protection while the drives are carried around by non-technical people? I'm afraid such a product doesn't exist, but perhaps someone knows of something?

  Read the article

• Spotlight: How Scandinavia's Largest Nuclear Power Plant Increased Productivity and Reduced Costs wi

  - by [email protected]

  Ringhals nuclear power plant, which is part of the Vattenfall Group, is located about 60 km south-west of the beautiful coastal city of Gothenburg in Sweden. A deep concern to reduce environmental impact coupled with an effort to increase plant safety and operational efficiency have led to a recent surge in investments and initiatives around plant modification and plant optimization at Ringhals. A multitude of challenges were faced by the users in various groups that were involved in these projects. First, it was very difficult for users to easily access complex and layered asset and engineering information, which was critical to increased productivity and completing projects on time. Moreover, the 20 or so different solutions that were being used to view various document formats, not only resulted in collaboration complexity but also escalated IT administration costs and woes. Finally, there was a considerable non-engineering community comprising non-CAD specialists that needed easy access to plant data in an effort to minimize engineering disruption. Oracle's AutoVue significantly simplified the ability to efficiently view and use digital asset information by providing a standardized visualization solution for the enterprise. The key benefits achieved by Ringhals include: Increased productivity of plant optimization and plant modification by 3% Saved around $ 500 K annually Cut IT maintenance costs by 50% by using a single solution Reduced engineering disruption by allowing non-CAD users easy access to digital plant data The complete case-study can be found here

  Read the article

• Join the SOA and BPM Customer Insight Series

  - by Dain C. Hansen

  Summer is here! So put on your shades, kick back by the pool and watch the latest SOA and BPM customer insight series from Oracle. You’ll hear directly from some of Oracle’s most well respected customers across a range of deployments, industries, and use cases. You’ve heard us tell you the advantages of Oracle SOA and Oracle BPM. But this time, listen to what our customers are saying: See Rain Fletcher, VP of Application Development and Architecture at Choice Hotels, describe how they successfully made the transition from a complex legacy environment into a faster time-to-market shared services infrastructure as they implemented their event-driven Google API project. Listen to the County of San Joaquin, California discuss how they transformed to a services-oriented architecture and business process management platform to gain efficiency and greater visibility of mission critical information important to citizen public safety. Hear from Eaton, a global power management company, review innovative strategies for a successful application integration implementation, specifically the advantages of transitioning from TIBCO to using Oracle SOA and Oracle Fusion Applications.  Learn how Nets Denmark A/S implemented Oracle Unified Business Process Management Suite in just five months. Review the implementation overview from start to production, including integration with legacy systems. And finally, listen to Farmers Insurance share their SOA reference architecture as well as a timeline for how their services were deployed as well as the benefits for moving to an Oracle SOA-based application infrastructure.  Don’t miss the webcast series. Catch the first one on June 21st at 10AM PST with Rain Fletcher from Choice Hotels, and Bruce Tierney, Director Oracle SOA Suite. Register today!

  Read the article

• Presenting the Cloud in a Different Way

  - by BuckWoody

  I had the honor of presenting the Developers at the Portland PASS chapter, and decided to go a different way than just using PowerPoint Slides…. (click on any picture to enlarge) The point is that when you need to get a point across, it’s OK to change tactics to make sure the information sticks. In this case, I decided to make the audience the PowerPoint. I used a few props to show the various paradigms we use to describe what the industry uses for the word “cloud” First, we talked about Infrastructure as a Service. I picked a gentleman who didn’t quite fit the hard hat and safety vest I picked out for him. Notice our “user” as she accesses our “Server” (complete with tray and glass) which has been virtualized.    Software as a service comes next. In this case, the user and potentially even customers just access software (represented here as a Windows ME box…) remotely – everything is virtualized. Finally, Platform as a Service – Yup, Platform shoes as a necklace, and a tie-dye shirt to represent the 70’s – a decade when mainframes used stateless programming as well. Notice also the components of Windows Azure – Compute (Keyboard) Application Fabric (Toy Bus) and Storage (Bucket).   And at the end of the day, it’s all about serving those customers…

  Read the article

• Oracle OpenWorld Interactive Customer Panels

  - by kellsey.ruppel

  Oracle OpenWorld attendees regularly report that their interactions with fellow Oracle customers represent the most valuable aspect of the conference. This year, four customer panels will promote these valuable Oracle WebCenter interactions, including:  Building Next-Generation Portals: An Interactive Customer Panel Discussion  (Wednesday, October 3, 5:00 p.m., Moscone West 3000, session ID# CON8900) With panelists from Aramark, Canadian Partnership Against Cancer, Los Angeles Department of Building & Safety, Los Angeles Department of Water & Power and Siemens Healthcare Becoming a Social Business: Stories from the Front Lines of Change (Thursday, October 4, 11:15 a.m., Moscone West 3001, session ID# CON8899) Featuring University of Louisville Land Mines, Potholes, and Dirt Roads: Navigating the Way to Enterprise Content Management Nirvana  (Thursday, October 4, 12:45 p.m., Moscone West 3001, session ID# 8898) Including panelists from Critigen and Alberta, Canada's Department of Agricultural and Rural Development Using Web Experience Management to Drive Online Marketing Success (Thursday, October 4, 2:15 p.m., Moscone West 3001, session ID# CON8897)  Featuring panelists from Ancestry.com and Arbonne We hope you’ll join us to learn first-hand from Oracle WebCenter customers as they share best practices and lessons learned when implementing Oracle WebCenter. Looking for a guide of all the Oracle WebCenter sessions at Oracle OpenWorld? Be sure to download the Oracle WebCenter Focus OnGuide!

  Read the article

• Swap drive not operating correctly

  - by Blue Ice

  At first, I started seeing the warning signs. The halting pages. The molasses speed of the windows closing. The pictures not rendering. Then, I took action. Recently I added a swap drive to my computer. For a while, everything was good. Unicorns frolicked among the new bits and bytes resplendent on the shiny metal platter known as my swap drive. Today, I opened Chromium, and got on the 7th tab (start.csail.mit.edu) "He's dead, Jim!". This used to happen before I added my swap drive, but now I thought that it wouldn't happen because I added more memory. I fear for the safety of the unicorns. Please help me make my swap drive work again. As a side note, here is the result of cat /proc/swaps: Filename Type Size Used Priority /dev/sda5 partition 39075836 213896 -1 Result of free: total used free shared buffers cached Mem: 507472 330792 176680 0 6208 71252 -/+ buffers/cache: 253332 254140 Result of df -h: Filesystem Size Used Avail Use% Mounted on /dev/sdb1 147G 8.9G 130G 7% / none 4.0K 0 4.0K 0% /sys/fs/cgroup udev 240M 12K 240M 1% /dev tmpfs 50M 824K 49M 2% /run none 5.0M 0 5.0M 0% /run/lock none 248M 208K 248M 1% /run/shm none 100M 20K 100M 1% /run/user

  Read the article

• Does it make sense to write a build scripts in C++?

  - by Klaim

  I'm using CMake to generate my projects IDE/makefiles, but I still need to call custom "scripts" to manipulate my compiled files or even generate code. In previous projects I've been using Python and it was OK, but now I'm having serious trouble managing a lot of dependencies in two very big projects I'm working on so I want to minimize the dependencies everywhere. Someone suggested to me to use C++ to write my build scripts instead of adding a language dependency just for that. The projects themeselves already use C++ so there are several advantages that I can see: to build the whole project, only a C++ compiler and CMake would be necessary, nothing else (all the other dependencies are C or C++); C++ type safety (when using modern C++) makes everything easier to get "correct"; it's also the language I know the better so I'm more at ease with it even if I'm able to write some good Python code; potential gain in execution speed (but i don't think it will really be perceptible); However, I think there might be some drawbacks and I'm not sure of the real impact as I didn't try yet: might be longer to write the code (that said I'm not sure because I'm efficient enough in C++ to write something that work quickly, so maybe for this system it wouldn't be so long to write) (compilation time shouldn't be a problem for this case); I must assume that all the text files I'll read as input are in UTF-8, I'm not sure it can be easilly checked at runtime in C++ and the language will not check it for you; libraries in C++ are harder to manage than in scripting languages; I lack experience and forsight so maybe I'm missing advantages and drawbacks. So the question is: does it make sense to use C++ for this? do you have experiences to report and do you see advantages and disadvantages that might be important?

  Read the article

• Looking for suggestions: becoming a hireable, young programmer [closed]

  - by Dan

  I am a 17 year old Java programmer that has filled the last year with learning all of the ins and outs of Java - Using Eclipse, and the help of a friend of the family (a Java programming architect for some company), I have learned everything from serializing objects, basic networking, generics, reflection, multi-threading, code optimization and efficiency & some concurrency safety - built my own proxy class, and nowadays, I answer questions on Project Euler. I am seeking some suggestions though on where I go next, or where I go from here to get a job in programming. I dedicate at least an hour every day to coding, sometimes literally, the entire day, and I really have come to love the process. I just started reading Effective Java (v2), and learning Scala (as I see often, possibly the Java replacement) I will be going to college for Computer Science next year - and taking AP computer science this year (however, I took a practice exam and got an 87, only need a 60to70 to pass, so no need to study for it too much) -- I was wondering if getting the SE 7 OCA and OCP would help me in trying to get a programming job. I looked around and most people have said online that an OCA/OCP are practically useless, but, at my age do they make me any more credible? More or less, what would you recommend to get a job in programming these days - or distinguish yourself from the crowd? I have enough time and dedication to learn another language, or anything really. Thank you very much.

  Read the article

• One Does Like To Code: DevoxxUK

  - by Tori Wieldt

  What's happening at Devoxx UK? I'll be talking to Rock Star speakers, Community leaders, authors, JSR leads and more.  This video is a short introduction.   Check out these great sessions: Thursday, June 12Perchance to Stream with Java 8by Paul Sandoz13:40 - 14:30 | Room 1 Making the Internet-of-Things a Reality with Embedded Javaby Simon Ritter11:50 - 12:40 | Room 4 Java SE 8 Lambdas and Streams Labby Simon Ritter17:00 - 20:00 | Room Mezzanine Safety Not Guaranteed: Sun. Misc. Unsafe and the Quest for Safe Alternativesby Paul Sandoz18:45 - 19:45 | Room 3 Join the Java EvolutionHeather VanCuraPatrick Curran19:45 – 20:45 | Room 2  Glassfish is Here to StayDavid DelabasseeAntonio Goncalves19:45 – 20:45 | Room Expo Here is the full line-up of sessions. Devoxx UK includes a Hackergarten, where can devs work an Open Source project of their choice. The Adopt OpenJDK and Adopt a JSR Program folks will be there to help attendees contribute back to Java SE and Java EE itself!   Saturday includes a special Devoxx4Kids event in conjunction with the London Java Community. It's design to teach 10-16 year-olds simple programming concepts, robotics, electronics, and games making. Workshops include LEGO Mindstorms (robotic engineering), Greenfoot (programming), Arduino (electronics), Scratch (games making), Minecraft Modding (game hacking) and NAO (robotic programming). Small fee, you must register. If you can't attend Devoxx UK in person, stay tuned to the YouTube/Java channel. I'll be doing plenty of interviews so you can join the fun from around the world. 

  Read the article

• How to drastically improve code coverage?

  - by Peter Kofler

  I'm tasked with getting a legacy application under unit test. First some background about the application: It's a 600k LOC Java RCP code base with these major problems massive code duplication no encapsulation, most private data is accessible from outside, some of the business data also made singletons so it's not just changeable from outside but also from everywhere. no business model, business data is stored in Object[] and double[][], so no OO. There is a good regression test suite and an efficient QA team is testing and finding bugs. I know the techniques how to get it under test from classic books, e.g. Michael Feathers, but that's too slow. As there is a working regression test system I'm not afraid to aggressively refactor the system to allow unit tests to be written. How should I start to attack the problem to get some coverage quickly, so I'm able to show progress to management (and in fact to start earning from safety net of JUnit tests)? I do not want to employ tools to generate regression test suites, e.g. AgitarOne, because these tests do not test if something is correct.

  Read the article

• Bacula Director and Storage in LAN

  - by B14D3

  I have two networks LAN and DMZ.. Machines in DMZ are accesible from internet ( only over http). In LAN I have servers that see all LAN and all DMZ machines but machinse from DMZ don't see any LAN servers. Machines in LAN have access only to all LAN and DMZ, no direct access to internet and no access from internet. DMZ <------ LAN DMZ ----X--->LAN I'm planning to configure Bacula as major backup system. My plan is to install Bacula Director and Storage deamon on the same server in LAN for safety reasons. So my question is: Will this configuration work, is it posible for bacula director and storage deamon installed on server in LAN to makes backup servers that are in my DMZ? Or in this network configuration Bacula should be in DMZ? (If yes will I can backup with it servers in LAN ?)

  Read the article

• How to back up a network volume to my Time Capsule?

  - by Mike

  I have a Time Capsule that I'm using for my backups. I have a network volume (coincidentally on the same time capsule) that I'd like to back up as well. How can I tell Time Machine to back up network volumes in addition to my main laptop hard drive? PS: yes, I know this setup isn't ideal. It'll incur 2x network overhead when backing up the network volume, plus my data won't be safe in the event of a drive failure since both copies will be on the same disk. However, it will give me some small amount of safety in the event I accidentally delete files on the network volume, among other things.

  Read the article

• Click sound from computer when shut down

  - by user32569

  Hi, I build my new computer yesterday and I noticed, when computer is shut down, I mean the exact time its looses power from PSU, relativelly loud CLICK sound occurs. Please does anyone knows from where? I think MB, SSD, VGA, CPU nor coolers are not cousing this. I would guess maybe Samsung 1TB HDD (maybe when heads go back to LZ) or some hard safety switch or relay in PSU? Or just the MB speaker? (Yes, its actually installed). Do you have any experience with this? Thanks.

  Read the article

• UPS for hard drive protection

  - by dimi

  I am in a place where electricity is not ideal (old house, no ground), sometimes it occasionally shuts down and supposedly there are some spikes. I consider using UPS with the goal to increase safety of my personal data. My first priority is the health of my internal and external USB hard drives which can be damaged due to possible power instability. I do not care that much about possible losses of not-saved work, instead I just want to let my system have a minimum time to turn off without any risk of physical damaging my hard drives. Would a cheap offline UPS suit my neads? Or do i need a better one with automatic voltage regulator (AVR)? How critical is AVR for the hard drives? The external ones require their own power supplies and will be plugged directly into UPS.

  Read the article

• Disable disk caches in AWS EBS for PostgreSQL?

  - by Alexandr Kurilin

  It's my understanding that, without correctly disabling OS-level and drive-level caching, there is a chance that in case of system failure the Write-Ahead Log might not be saved correctly and in fact might get corrupted, possibly preventing data recovery. I've already made sure that wal_sync_method=fdatasync however I was unable to make any configuration changes with hdparm since I get the following: $ sudo htparm -I /dev/xvdf /dev/xvdf: HDIO_DRIVE_CMD(identify) failed: Invalid argument Looks like that option is not available in the kind of setup you get in EC2. Am I missing anything here? Are there any other obvious caches I have to disable to ensure the WAL's safety?

  Read the article

• Does immutability entirely eliminate the need for locks in multi-processor programming?

  - by GlenPeterson

  Part 1 Clearly Immutability minimizes the need for locks in multi-processor programming, but does it eliminate that need, or are there instances where immutability alone is not enough? It seems to me that you can only defer processing and encapsulate state so long before most programs have to actually DO something. If a program performs actions on multiple processors, something needs to collect and aggregate the results. All this involves multi-process communication before, after, and possibly during some transformations. The start and end state of the machines are different. Can this always be done with no locks just by throwing out each object and creating a new one instead of changing the original (a crude view of immutability)? What cases still require locking? I'm interested in both the theoretical/academic answer and the practical/real-world answer. I know a lot of functional programmers like to talk about "no side effect" but in the "real world" everything has a side effect. Every processor click takes time and electricity and machine resources away from other processes. So I understand that there may be more than one perspective to answer this question from. If immutability is safe, given certain bounds or assumptions, I want to know what the borders of the "safety zone" are exactly. Some examples of possible boundaries: I/O Exceptions/errors Interfaces with programs written in other languages Interfaces with other machines (physical, virtual, or theoretical) Special thanks to @JimmaHoffa for his comment which started this question! Part 2 Multi-processor programming is often used as an optimization technique - to make some code run faster. When is it faster to use locks vs. immutable objects? Given the limits set out in Amdahl's Law, when can you achieve better over-all performance (with or without the garbage collector taken into account) with immutable objects vs. locking mutable ones? Summary I'm combining these two questions into one to try to get at where the bounding box is for Immutability as a solution to threading problems.

  Read the article

• How is software used in critical life-or-death systems tested?

  - by waiwai933

  An airplane, as opposed to, for example, a website, is a system where any failure in certain systems is completely unacceptable, since errors in e.g. flight monitoring can cause the autopilot to malfunction and do a dive. Obviously, this doesn't happen since the brilliant engineers at Boeing and Airbus have checks in the autopilot to make sure it doesn't suddenly decide a dive is a perfectly acceptable and safe maneuver. Or perhaps the computer crashes, and the pilots in the newer fly-by-wire aircraft can no longer actually fly the plane. Of course, there are various safety procedures and redundancies built into these systems to prevent a crash (of both the software and the aircraft). However, on the other hand, it's quite obvious that software isn't perfect—both open source and closed source software do crash regularly, and only the simplest "Hello World" program doesn't fail. How can the engineers who design the software systems in the aeronautic, medical, and other life-or-death industries manage to test their software so that it doesn't fail (and if it does fail, at least fail gracefully)? I'm desperately hoping that you're not all going to go: "Oh, I work for Boeing/Airbus/(some other company) and it's not! Have fun on your next flight/hospital visit."

  Read the article

< Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >