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  • Building Enterprise Smartphone App &ndash; Part 2: Platforms and Features

    - by Tim Murphy
    This is part 2 in a series of posts based on a talk I gave recently at the Chicago Information Technology Architects Group.  Feel free to leave feedback. In the previous post I discussed what reasons a company might have for creating a smartphone application.  In this installment I will cover some of history and state of the different platforms as well as features that can be leveraged for building enterprise smartphone applications. Platforms Before you start choosing a platform to develop your solutions on it is good to understand how we got here and what features you can leverage. History To my memory we owe all of this to a product called the Apple Newton that came out in 1987. It was the first PDA and back then I was much more of an Apple fan.  I was very impressed with this device even though it never really went anywhere.  The Palm Pilot by US Robotics was the next major advancement in PDA. It had a simple short hand window that allowed for quick stylus entry.. Later, Windows CE came out and started the broadening of the PDA market. After that it was the Palm and CE operating systems that started showing up on cell phones and for some time these were the two dominant operating systems that were distributed with devices from multiple hardware vendors. Current The iPhone was the first smartphone to take away the stylus and give us a multi-touch interface.  It was a revolution in usability and really changed the attractiveness of smartphones for the general public.  This brought us to the beginning of the current state of the market with the concept of an online store that makes it easy for customers to get new features and functionality on demand. With Android, Google made this more than a one horse race.  Not only did they come to compete, their low cost actually made them the leading OS.  Of course what made Android so attractive also is its major fault.  It is so open that it has been a target for malware which leaves consumers exposed.  Fortunately for Google though, most consumers aren’t aware of the threat that they are under. Although Microsoft had put out one of the first smart phone operating systems with CE it had to play catch up and finally came out with the Windows Phone.  They have gone for a market approach between those of iOS and Android.  They support multiple hardware vendors like Google, but they kept a certification process for applications that is similar to Apple.  They also created a user interface that was different enough to give it a clear separation from the other two platforms. The result of all this is hundreds of millions of smartphones being sold monthly across all three platforms giving us a wide range of choices and challenges when it comes to developing solutions. Features So what are the features that make these devices flexible enough be considered for use in the enterprise? The biggest advantage of today's devices is network connectivity.  The ability to access information from multiple sources at a moment’s notice is critical for businesses.  Add to that the ability to communicate over a variety of text, voice and video modes and we have a powerful starting point. Every smartphone has a cameras and they are not just useful for posting to Instagram. We are seeing more applications such as Bing vision that allow us to scan just about any printed code or text to find information.  These capabilities have been made available to developers in the form of standard libraries for reading barcodes of just about an flavor and optical character recognition (OCR) interpretation. Bluetooth give us the ability to communicate with multiple devices. Whether these are headsets, keyboard or printers the wireless communication capabilities are just starting to evolve.  The more these wireless communication protocols grow, the more opportunities we will see to transfer data between users and a variety of devices. Local storage of information that can be called up even when the device cannot reach the network is the other big capability.  This give users the ability to work offline as well and transmit information when connections are restored. These are the tools that we have to work with to build applications that can be leveraged to gain a competitive advantage for companies that implement them. Coming Up In the third installment I will cover key concerns that you face when building enterprise smartphone apps. del.icio.us Tags: smartphones,enterprise smartphone Apps,architecture,iOS,Android,Windows Phone

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  • Key Windows Phone Development Concepts

    - by Tim Murphy
    As I am doing more development in and out of the enterprise arena for Windows Phone I decide I would study for the 70-599 test.  I generally take certification tests as a way to force me to dig deeper into a technology.  Between the development and studying I decided it would be good to put a post together of key development features in Windows Phone 7 environment.  Contrary to popular belief the launch of Windows Phone 8 will not obsolete Windows Phone 7 development.  With the launch of 7.8 coming shortly and people who will remain on 7.X for the foreseeable future there are still consumers needing these apps so don’t throw out the baby with the bath water. PhoneApplicationService This is a class that every Windows Phone developer needs to become familiar with.  When it comes to application state this is your go to repository.  It also contains events that help with management of your application’s lifecycle.  You can access it like the following code sample. 1: PhoneApplicationService.Current.State["ValidUser"] = userResult; DeviceNetworkInformation This class allows you to determine the connectivity of the device and be notified when something changes with that connectivity.  If you are making web service calls you will want to check here before firing off. I have found that this class doesn’t actually work very well for determining if you have internet access.  You are better of using the following code where IsConnectedToInternet is an App level property. private void Application_Launching(object sender, LaunchingEventArgs e){ // Validate user access if (Microsoft.Phone.Net.NetworkInformation.NetworkInterface.NetworkInterfaceType != Microsoft.Phone.Net.NetworkInformation.NetworkInterfaceType.None) { IsConnectedToInternet = true; } else { IsConnectedToInternet = false; } NetworkChange.NetworkAddressChanged += new NetworkAddressChangedEventHandler(NetworkChange_NetworkAddressChanged);}void NetworkChange_NetworkAddressChanged(object sender, EventArgs e){ IsConnectedToInternet = (Microsoft.Phone.Net.NetworkInformation.NetworkInterface.NetworkInterfaceType != Microsoft.Phone.Net.NetworkInformation.NetworkInterfaceType.None);} Push Notification Push notification allows your application to receive notifications in a way that reduces the application’s power needs. This MSDN article is a good place to get the basics of push notification, but you can see the essential concept in the diagram below.  There are three types of push notification: toast, Tile and raw.  The first two work regardless of the state of the application where as raw messages are discarded if your application is not running.   Live Tiles Live tiles are one of the main differentiators of the Windows Phone platform.  They allow users to find information at a glance from their start screen without navigating into individual apps.  Knowing how to implement them can be a great boost to the attractiveness of your application. The simplest step-by-step explanation for creating live tiles is here. Local Database While your application really only has Isolated Storage as a data store there are some ways of giving you database functionality to develop against.  There are a number of open source ORM style solutions.  Probably the best and most native way I have found is to use LINQ to SQL.  It does take a significant amount of setup, but the ease of use once it is configured is worth the cost.  Rather than repeat the full concepts here I will point you to a post that I wrote previously. Tasks (Bing, Email) Leveraging built in features of the Windows Phone platform is an easy way to add functionality that would be expensive to develop on your own.  The classes that you need to make yourself familiar with are BingMapsDirectionsTask and EmailComposeTask.  This will allow your application to supply directions and give the user an email path to relay information to friends and associates. Event model Because of the ability for users to switch quickly to switch to other apps or the home screen is just one reason why knowing the Windows Phone event model is important.  You need to be able to save data so that if a user gets a phone call they can come back to exactly where they were in your application.  This means that you will need to handle such events as Launching, Activated, Deactivated and Closing at an application level.  You will probably also want to get familiar with the OnNavigatedTo and OnNavigatedFrom events at the page level.  These will give you an opportunity to save data as a user navigates through your app. Summary This is just a small portion of the concepts that you will use while building Windows Phone apps, but these are some of the most critical.  With the launch of Windows Phone 8 this list will probably expand.  Take the time to investigate these topics further and try them out in your apps. del.icio.us Tags: Windows Phone 7,Windows Phone,WP7,Software Development,70-599

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  • Application crashing when talking to oracle unless executable path contains spaces

    - by Lasse V. Karlsen
    We have an x-files problem with our .NET application. Or, rather, hybrid Win32 and .NET application. When it attempts to communicate with Oracle, it just dies. Vanishes. Goes to the big black void in the sky. No event log message, no exception, no nothing. If we simply ask the application to talk to a MS SQL Server instead, which has the effect of replacing the usage of OracleConnection and related classes with SqlConnection and related classes, it works as expected. Today we had a breakthrough. For some reason, a customer had figured out that by placing all the application files in a directory on his desktop, it worked as expected with Oracle as well. Moving the directory down to the root of the drive, or in C:\Temp or, well, around a bit, made the crash reappear. Basically it was 100% reproducable that the application worked if run from directory on desktop, and failed if run from directory in root. Today we figured out that the difference that counted was wether there was a space in the directory name or not. So, these directories would work: C:\Program Files\AppDir\Executable.exe C:\Temp Lemp\AppDir\Executable.exe C:\Documents and Settings\someuser\Desktop\AppDir\Executable.exe whereas these would not: C:\CompanyName\AppDir\Executable.exe C:\Programfiler\AppDir\Executable.exe <-- Program Files in norwegian C:\Temp\AppDir\Executable.exe I'm hoping someone reading this has seen similar behavior and have a "aha, you need to twiddle the frob on the oracle glitz driver configuration" or similar. Anyone? Followup #1: Ok, I've processed the procmon output now, both files from when I hit the button that attempts to open the window that triggers the cascade failure, and I've noticed that they keep track mostly, there's some smallish differences near the top of both files, and they they keep track a long way down. However, when one run fails, the other keeps going and the next few lines of the log output are these: ReadFile C:\oracle\product\10.2.0\db_1\BIN\orageneric10.dll SUCCESS Offset: 274 432, Length: 32 768, I/O Flags: Non-cached, Paging I/O, Synchronous Paging I/O ReadFile C:\oracle\product\10.2.0\db_1\BIN\orageneric10.dll SUCCESS Offset: 233 472, Length: 32 768, I/O Flags: Non-cached, Paging I/O, Synchronous Paging I/O After this, the working run continues to execute, and the other touches the mscorwks.dll files a few times before threads close down and the app closes. Thus, the failed run does not touch the above files. Followup #2: Figured I'd try to upgrade the oracle client drivers, but 10.2.0.1 is apparently the highest version available for Windows 2003 server and XP clients. Followup #3: Well, we've ended up with a black-box solution. Basically we found that the problem is somewhere related to XPO and Oracle. XPO has a system-table it manages, called XPObjectType, with three columns: Oid, TypeName and AssemblyName. Due to how Oracle is configured in the databases we talk to, the column names were OID, TYPENAME and ASSEMBLYNAME. This would ordinarily not be a problem, except that XPO talks to the schema information directly and checks if the table is there with the right column names, and XPO doesn't handle case differences so it sees a XPObjectType table with three unknown columns and none of those it expects. Exactly what XPO does now I don't really know, but if I dropped this table, and recreated it with the right case, using double quotes around all the column names to get the case right, the problem doesn't crop up. Exactly where the space in the folder name comes into this, I still have no idea, but this problem had two tiers: Stop the application from crashing at our customers, short-term solution Fix the bug, long-term solution Right now tier 1 is solved, tier 2 will be put back into the queue for now and prioritized. We're facing some bigger changes to our data tier anyway so this might not be a problem we need to solve, at least if all our Oracle-customers verify that the table-fix actually gets rid of the problem. I'll accept the answer by Dave Markle since though Process Monitor (the big brother of File Monitor) didn't actually pinpoint the problem, I was able to use it to determine that after my breakpoint in user-code where XPO had built up the query for this table, no I/O happened until all the entries for the application closing down was logged, which led me to believe it was this table that was the culprit, or at least influenced the problem somehow. If I manage to get to the real cause of this, I'll update the post.

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  • Windows Phone 8 Launch Event Summary

    - by Tim Murphy
    Today was the official coming out party for Windows Phone 8.  Below is a summary of the launch event.  There is a lot here to stay with me. They started with a commercial staring Joe Belfiore show how his Windows Phone 8 was personal too him which highlights something I think Microsoft has done well over the last couple of event: spotlight how Windows Phone is a different experience from other smartphones.  Joe actually called iPhone and Android “tired old metaphors" and explained that the idea around Windows Phone was to “reinvent the smartphone around you” as “the most personal smartphone operating system”.  The is the message that they need to drive home in their adds. The only real technical aspect we found out was that they have optimized the operating system around the dual core Qualcomm Snapdragon chip set.  It seems like all of the other hardware goodies had already been announced.  The remainder of the event was centered around new features of the OS and app announcements. So what are we getting?  The integrated features included lock screen live tile, Data Sense, Rooms and Kids corner.  There wasn’t a lot of information about it, but Joe also talked about apps not just having live tiles, but being live apps that could integrate with wallet and the hub. The lock screen will now be able to be personalized with live tile data or even a photo slide show.  This gives the lock screen an even better ability to give you the information you want to know before you even unlock the phone. The Kids Corner allows you as a parent to setup an area on your phone that you kids can go into an use it without disturbing your apps.  They can play games or use apps that you have designated and will only see those apps.  It even has a special lock screen gesture just for the kids corner. Rooms allow you to organize your phone around the groups of people in your life.  You get a shared calendar, a room wall as well as shared notes beyond just being able to send messages to a group.  You can also invite people not on the Windows Phone platform to access an online version of the room. Data Sense is a new feature that gives you better control and understanding of your data plan usage.  You can see which applications are using data and it can automatically adjust they way your phone behaves as you get close to your data limit. Add to these features the fact that the entire Windows ecosystem is integrated with SkyDrive and you have an available anywhere experience that is unequaled by any other platform.  Your document, photos and music are available on your Windows Phone, Window 8 device and Xbox.  SkyDrive also doesn’t limit how long you can keep files like the competing cloud platforms and give more free storage. It was interesting the way they made the launch event more personal.  First Joe brought out his own kids to demo the Kids Corner.  They followed this up by bringing out Jessica Alba to discuss her experience on the Windows Phone 8.  They need to keep putting a face on the product instead of just showing features as a cold list. Then we get to apps.  We knew that the new Skype was coming, but we found out that it was created in such a way that it can receive calls without running consistently in the background which would eat up battery.  This announcement was follow by the coming Facebook app that is optimized for Windows Phone 8.  As a matter of fact they indicated that just after launch the marketplace would have 46 out of the top 50 apps used by all smartphone platforms.  In a rational world this tide with over 120,000 apps currently in the marketplace there should be no more argument about the Windows Phone ecosystem. For those of us who develop for Windows Phone and weren’t on the early adoption program will finally get access to the SDK tomorrow after an announcement at Build (more waiting).  Perhaps we will get a few new features then. In the end I wouldn’t say there were any huge surprises, but I am really excited about getting my hands on the devices next month and starting to develop.  Stay tuned. del.icio.us Tags: Windows Phone,Windows Phone 8,Winodws Phone 8 Launch,Joe Belfiore,Jessica Alba

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  • Tweaking Hudson memory usage

    - by rovarghe
    Hudson 3.1 has some performance optimizations that greatly reduces its memory footprint. Prior to this Hudson used to always hold the entire data model (all jobs and all builds) in memory which affected scalability. Some installations configured heap sizes in excess of 1GB to counteract this. Hudson 3.1.x maintains an MRU cache and only loads jobs and builds as they are required. Because of the inability to change existing APIs and be backward compatible with plugins, there were limits to how far we could go with this approach. Memory optimizations almost always come with a related cost, in this case its additional I/O that has to be performed to load data on request. On a small site that has frequent traffic, this is usually not noticeable since the MRU cache will usually hold on to all the data. A large site with infrequent traffic might experience some delays when the first request hits the server after a long gap. If you have a large heap and are able to allocate more memory, the cache settings can be adjusted to take advantage of this and even go back to pre-3.1 behavior. All the cache settings can be passed as options to the JVM container (Tomcat or the default Jetty container) using the -D option. There are two caches, independant of each other, one for Jobs and the other for Builds. For the jobs cache: hudson.jobs.cache.evict_in_seconds ( default=60 ) Seconds from last access (could be because of a servlet request or a background cron thread) a job should be purged from the cache. Set this to 0 to never purge based on time. hudson.jobs.cache.initial_capacity ( default=1024 ) Initial number of jobs the cache can accomodate. Setting this to the number of jobs you typically display on your Hudson landing page or home page will speed up consecutive access to that page. If the default is too large you may consider downsizing and using that memory for the Builds cache instead. hudson.jobs.cache.max_entries ( default=1024) Maximum number of jobs in the cache. The default is large enough for most installations, but if you find I/O activity when always accessing the hudson home page you might consider increasing this, but first verify if the I/O is caused by frequent eviction (see above), rather than by the cache not being large enough. For the builds cache: The builds cache is used to store Build objects as they are read from storage. Typically this happens when a user drills down into the details of a particular Job from the hudson hom epage. The cache is shared among builds for different jobs since in most installations all jobs are not accessed with the same frequency, so a per-job builds cache would be a waste of memory. hudson.job.builds.cache.evict_in_seconds ( default=60 ) Same as the equivalent Job cache, applied to Build. hudson.job.builds.cache.initial_capacity" ( default=512 ) Same as equivalent Job cache setting. Note the smaller initial size. If your site stores a large number of builds and has frequent access to more builds you might consider bumping this up. hudson.job.builds.cache.max_entries ( default=10240 ) The default max is large enough for most installations, the builds cache has bigger sized objects, so be careful about increasing the upper limit on this. See section on monitoring below. Sample usage: java -jar hudson-war-3.1.2-SNAPSHOT.war -Dhudson.jobs.cache.evict_in_seconds=300 \ -Dhudson.job.builds.cache.evict_in_seconds=300 Monitoring cache usage The 'jmap' tool that comes with the JDK can be used to monitor cache performance in an indirect way by looking at the number of Job and Build objects in each cache. Find the PID of the hudson instance and run $ jmap -histo:live <pid | grep 'hudson.model.*Lazy.*Key$' Here's a sample output: num #instances #bytes class name 523: 28 896 hudson.model.RunMap$LazyRunValue$Key 1200: 3 96 hudson.model.LazyTopLevelItem$Key These are the keys to the Jobs (LazyTopLevelItem$Key) and Builds (RunMap$LazyRunValue$Key) in the caches, so counting the number of keys is a good indicator of the number of items in the cache at any given moment. The size in bytes can be ignored, they are just the size of the keys, not the actual sizes of the objects they hold. Those sizes can only be obtained with a profiler. With the output above we can conclude that there are 3 jobs and 28 builds in memory. The 28 builds can all be from 1 job or all 3 jobs. Over time on an idle system, these should get evicted and memory cache should be empty. In practice, because of background cron threads and triggers, jobs rarely fall down to zero. Access of a job or a build by a cron thread resets the eviction timer.

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  • ?????????????!4?21?Oracle Enterprise Cloud Summit??

    - by yusuke.nakamura
    Oracle Newsletter img{border:0;} p{margin:0; padding:0;} td{color:#333333; line-height:1.5; font-family:"MS P????", Osaka, Hiragino Kaku Gothic Pro; font-size:12px;} table.t10 td, .small{font-size:10px;} a:link, a:visited{color:#ff0000;} a:hover, a:active{color:#ff0000; text-decoration:none;} a.l01:link, a.l01:visited, a.l01:hover, a.l01:active{color:#333333;} span.r, td.r{color:#ff0000;} ??????????????????·???????????????????????????????????????????????? ??????????·????????????????????????????????????????????????????????????????????????????????????????????????·???????????????????????????????????????? ???????????????! >> ????????????SOA???????????????????????????????????? ?????????? Oracle SOA?????ECM(Engineering Chain Management)??????????????????????????????? ???IT?????????????????????ECM???????? ??????????? ?????????????(?????????)????????????????????????????3??1????????????????????????????????????? ????????? >> «????»?????BPM?????????????????Oracle BPM 11g ????? eBook????? ????????? >> IFRS?????????&????????????????????????????????Oracle E-Business Suite Release R12?????????????????IFRS????????????????????????????????IFRS ???????????(???????)???????????????????Oracle E-Business Suite??????12???????????????12???????????! ???????:2011?3?31? ????????? >> ??????????·????????????????????????????????????????????????????????????????????????? ??????/IFRS(??????)??????????????????????????????????? ???????Oracle Hyperion Financial Management / Oracle Hyperion Planning????????????????????????????????????? ??????????????????? Oracle Hyperion Financial Management???????????????????????????????? ?????????? ???????????????Oracle Hyperion Financial Management?????? ??????????????EPM????????????????? >> ?????SPARC Supercluster??Oracle???????RAC???????????????????????·??????????SPARC Supercluster??????????????????????????TPC-C???????????????????????????????SPARC????FlashFire?InfiniBand QDR?Oracle Solaris????ZFS Storage Appliance????????? ?SPARC Supercluster???????????? >> ???????????????????? >> ?SPARC Supercluster???????????????! ??????? ?SPARC Supercluster????????Webcast???? >> ???????Caption???????????????????????????? ?????????????!??????????????? ? ?????SOA/BPM??????? [NEW]SOA??????IT????????"??????·???????"??? ? CFO for Tomorrow [NEW]IFRS??????????????·????????? ? Sun???&?????·???? [NEW]?????????????????IT????????? ? Facebook??????????????????????(Facebook????????????) more solutions ? ?????????[PDF] Oracle Exadata??????????????????????????????????????????????????????????????? ? ?????????[PDF] ???????????????????????ERP??????????????????????????????????????????? ? ?????????[PDF]Oracle SOA Suite????????????????????ECM????????????????????????????????????????????????????? more success stories IT?????????????????????????????????????·???·?????? >> ? @Oracle_Japan????????????????????????"?"???????! ? @OracleApps_jp?????????????????????????! ? @OracleDB_jp???????????????????????????????????????·?????! ? @OracleMiddle_jpOracle Fusion Middleware????????????????! ? @oracletechnetjpOracle Technology Network Japan??????????????????????????????????????! ? @Candy_Candy???????????4????????????? more accounts-- ???????? 3/4(?)14:00~17:00 ?????????????????????~???????????????~ ?????????????????????????????(??) 3/8(?)9:30~18:00 ?6? BPM????? 2011 ?????(??) 3/8(?)~11(?)10:00~17:00 ???????JAPAN 2011 ??????????????????1·2???(??) 3/9(?)18:00~19:30 ???????????????? ??????~?????? ??????????(??) 3/9(?)18:30~20:30 ?56? ????! ????????-WebLogic Server ??? Mark IX- ????????????(??) 3/10(?)14:00~17:10 ???????????????????????????? ??????????(??) 3/23(?)18:00~19:30 ???????????????? ??????~?????? ??????????(??) 3/30(?)13:30~17:00 ??????????????????????? ????????????(??) Copyright © 2011, Oracle.All Rights Reserved. ???????????? | ???????????? | ??????????/????????

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  • Toorcon14

    - by danx
    Toorcon 2012 Information Security Conference San Diego, CA, http://www.toorcon.org/ Dan Anderson, October 2012 It's almost Halloween, and we all know what that means—yes, of course, it's time for another Toorcon Conference! Toorcon is an annual conference for people interested in computer security. This includes the whole range of hackers, computer hobbyists, professionals, security consultants, press, law enforcement, prosecutors, FBI, etc. We're at Toorcon 14—see earlier blogs for some of the previous Toorcon's I've attended (back to 2003). This year's "con" was held at the Westin on Broadway in downtown San Diego, California. The following are not necessarily my views—I'm just the messenger—although I could have misquoted or misparaphrased the speakers. Also, I only reviewed some of the talks, below, which I attended and interested me. MalAndroid—the Crux of Android Infections, Aditya K. Sood Programming Weird Machines with ELF Metadata, Rebecca "bx" Shapiro Privacy at the Handset: New FCC Rules?, Valkyrie Hacking Measured Boot and UEFI, Dan Griffin You Can't Buy Security: Building the Open Source InfoSec Program, Boris Sverdlik What Journalists Want: The Investigative Reporters' Perspective on Hacking, Dave Maas & Jason Leopold Accessibility and Security, Anna Shubina Stop Patching, for Stronger PCI Compliance, Adam Brand McAfee Secure & Trustmarks — a Hacker's Best Friend, Jay James & Shane MacDougall MalAndroid—the Crux of Android Infections Aditya K. Sood, IOActive, Michigan State PhD candidate Aditya talked about Android smartphone malware. There's a lot of old Android software out there—over 50% Gingerbread (2.3.x)—and most have unpatched vulnerabilities. Of 9 Android vulnerabilities, 8 have known exploits (such as the old Gingerbread Global Object Table exploit). Android protection includes sandboxing, security scanner, app permissions, and screened Android app market. The Android permission checker has fine-grain resource control, policy enforcement. Android static analysis also includes a static analysis app checker (bouncer), and a vulnerablity checker. What security problems does Android have? User-centric security, which depends on the user to grant permission and make smart decisions. But users don't care or think about malware (the're not aware, not paranoid). All they want is functionality, extensibility, mobility Android had no "proper" encryption before Android 3.0 No built-in protection against social engineering and web tricks Alternative Android app markets are unsafe. Simply visiting some markets can infect Android Aditya classified Android Malware types as: Type A—Apps. These interact with the Android app framework. For example, a fake Netflix app. Or Android Gold Dream (game), which uploads user files stealthy manner to a remote location. Type K—Kernel. Exploits underlying Linux libraries or kernel Type H—Hybrid. These use multiple layers (app framework, libraries, kernel). These are most commonly used by Android botnets, which are popular with Chinese botnet authors What are the threats from Android malware? These incude leak info (contacts), banking fraud, corporate network attacks, malware advertising, malware "Hackivism" (the promotion of social causes. For example, promiting specific leaders of the Tunisian or Iranian revolutions. Android malware is frequently "masquerated". That is, repackaged inside a legit app with malware. To avoid detection, the hidden malware is not unwrapped until runtime. The malware payload can be hidden in, for example, PNG files. Less common are Android bootkits—there's not many around. What they do is hijack the Android init framework—alteering system programs and daemons, then deletes itself. For example, the DKF Bootkit (China). Android App Problems: no code signing! all self-signed native code execution permission sandbox — all or none alternate market places no robust Android malware detection at network level delayed patch process Programming Weird Machines with ELF Metadata Rebecca "bx" Shapiro, Dartmouth College, NH https://github.com/bx/elf-bf-tools @bxsays on twitter Definitions. "ELF" is an executable file format used in linking and loading executables (on UNIX/Linux-class machines). "Weird machine" uses undocumented computation sources (I think of them as unintended virtual machines). Some examples of "weird machines" are those that: return to weird location, does SQL injection, corrupts the heap. Bx then talked about using ELF metadata as (an uintended) "weird machine". Some ELF background: A compiler takes source code and generates a ELF object file (hello.o). A static linker makes an ELF executable from the object file. A runtime linker and loader takes ELF executable and loads and relocates it in memory. The ELF file has symbols to relocate functions and variables. ELF has two relocation tables—one at link time and another one at loading time: .rela.dyn (link time) and .dynsym (dynamic table). GOT: Global Offset Table of addresses for dynamically-linked functions. PLT: Procedure Linkage Tables—works with GOT. The memory layout of a process (not the ELF file) is, in order: program (+ heap), dynamic libraries, libc, ld.so, stack (which includes the dynamic table loaded into memory) For ELF, the "weird machine" is found and exploited in the loader. ELF can be crafted for executing viruses, by tricking runtime into executing interpreted "code" in the ELF symbol table. One can inject parasitic "code" without modifying the actual ELF code portions. Think of the ELF symbol table as an "assembly language" interpreter. It has these elements: instructions: Add, move, jump if not 0 (jnz) Think of symbol table entries as "registers" symbol table value is "contents" immediate values are constants direct values are addresses (e.g., 0xdeadbeef) move instruction: is a relocation table entry add instruction: relocation table "addend" entry jnz instruction: takes multiple relocation table entries The ELF weird machine exploits the loader by relocating relocation table entries. The loader will go on forever until told to stop. It stores state on stack at "end" and uses IFUNC table entries (containing function pointer address). The ELF weird machine, called "Brainfu*k" (BF) has: 8 instructions: pointer inc, dec, inc indirect, dec indirect, jump forward, jump backward, print. Three registers - 3 registers Bx showed example BF source code that implemented a Turing machine printing "hello, world". More interesting was the next demo, where bx modified ping. Ping runs suid as root, but quickly drops privilege. BF modified the loader to disable the library function call dropping privilege, so it remained as root. Then BF modified the ping -t argument to execute the -t filename as root. It's best to show what this modified ping does with an example: $ whoami bx $ ping localhost -t backdoor.sh # executes backdoor $ whoami root $ The modified code increased from 285948 bytes to 290209 bytes. A BF tool compiles "executable" by modifying the symbol table in an existing ELF executable. The tool modifies .dynsym and .rela.dyn table, but not code or data. Privacy at the Handset: New FCC Rules? "Valkyrie" (Christie Dudley, Santa Clara Law JD candidate) Valkyrie talked about mobile handset privacy. Some background: Senator Franken (also a comedian) became alarmed about CarrierIQ, where the carriers track their customers. Franken asked the FCC to find out what obligations carriers think they have to protect privacy. The carriers' response was that they are doing just fine with self-regulation—no worries! Carriers need to collect data, such as missed calls, to maintain network quality. But carriers also sell data for marketing. Verizon sells customer data and enables this with a narrow privacy policy (only 1 month to opt out, with difficulties). The data sold is not individually identifiable and is aggregated. But Verizon recommends, as an aggregation workaround to "recollate" data to other databases to identify customers indirectly. The FCC has regulated telephone privacy since 1934 and mobile network privacy since 2007. Also, the carriers say mobile phone privacy is a FTC responsibility (not FCC). FTC is trying to improve mobile app privacy, but FTC has no authority over carrier / customer relationships. As a side note, Apple iPhones are unique as carriers have extra control over iPhones they don't have with other smartphones. As a result iPhones may be more regulated. Who are the consumer advocates? Everyone knows EFF, but EPIC (Electrnic Privacy Info Center), although more obsecure, is more relevant. What to do? Carriers must be accountable. Opt-in and opt-out at any time. Carriers need incentive to grant users control for those who want it, by holding them liable and responsible for breeches on their clock. Location information should be added current CPNI privacy protection, and require "Pen/trap" judicial order to obtain (and would still be a lower standard than 4th Amendment). Politics are on a pro-privacy swing now, with many senators and the Whitehouse. There will probably be new regulation soon, and enforcement will be a problem, but consumers will still have some benefit. Hacking Measured Boot and UEFI Dan Griffin, JWSecure, Inc., Seattle, @JWSdan Dan talked about hacking measured UEFI boot. First some terms: UEFI is a boot technology that is replacing BIOS (has whitelisting and blacklisting). UEFI protects devices against rootkits. TPM - hardware security device to store hashs and hardware-protected keys "secure boot" can control at firmware level what boot images can boot "measured boot" OS feature that tracks hashes (from BIOS, boot loader, krnel, early drivers). "remote attestation" allows remote validation and control based on policy on a remote attestation server. Microsoft pushing TPM (Windows 8 required), but Google is not. Intel TianoCore is the only open source for UEFI. Dan has Measured Boot Tool at http://mbt.codeplex.com/ with a demo where you can also view TPM data. TPM support already on enterprise-class machines. UEFI Weaknesses. UEFI toolkits are evolving rapidly, but UEFI has weaknesses: assume user is an ally trust TPM implicitly, and attached to computer hibernate file is unprotected (disk encryption protects against this) protection migrating from hardware to firmware delays in patching and whitelist updates will UEFI really be adopted by the mainstream (smartphone hardware support, bank support, apathetic consumer support) You Can't Buy Security: Building the Open Source InfoSec Program Boris Sverdlik, ISDPodcast.com co-host Boris talked about problems typical with current security audits. "IT Security" is an oxymoron—IT exists to enable buiness, uptime, utilization, reporting, but don't care about security—IT has conflict of interest. There's no Magic Bullet ("blinky box"), no one-size-fits-all solution (e.g., Intrusion Detection Systems (IDSs)). Regulations don't make you secure. The cloud is not secure (because of shared data and admin access). Defense and pen testing is not sexy. Auditors are not solution (security not a checklist)—what's needed is experience and adaptability—need soft skills. Step 1: First thing is to Google and learn the company end-to-end before you start. Get to know the management team (not IT team), meet as many people as you can. Don't use arbitrary values such as CISSP scores. Quantitive risk assessment is a myth (e.g. AV*EF-SLE). Learn different Business Units, legal/regulatory obligations, learn the business and where the money is made, verify company is protected from script kiddies (easy), learn sensitive information (IP, internal use only), and start with low-hanging fruit (customer service reps and social engineering). Step 2: Policies. Keep policies short and relevant. Generic SANS "security" boilerplate policies don't make sense and are not followed. Focus on acceptable use, data usage, communications, physical security. Step 3: Implementation: keep it simple stupid. Open source, although useful, is not free (implementation cost). Access controls with authentication & authorization for local and remote access. MS Windows has it, otherwise use OpenLDAP, OpenIAM, etc. Application security Everyone tries to reinvent the wheel—use existing static analysis tools. Review high-risk apps and major revisions. Don't run different risk level apps on same system. Assume host/client compromised and use app-level security control. Network security VLAN != segregated because there's too many workarounds. Use explicit firwall rules, active and passive network monitoring (snort is free), disallow end user access to production environment, have a proxy instead of direct Internet access. Also, SSL certificates are not good two-factor auth and SSL does not mean "safe." Operational Controls Have change, patch, asset, & vulnerability management (OSSI is free). For change management, always review code before pushing to production For logging, have centralized security logging for business-critical systems, separate security logging from administrative/IT logging, and lock down log (as it has everything). Monitor with OSSIM (open source). Use intrusion detection, but not just to fulfill a checkbox: build rules from a whitelist perspective (snort). OSSEC has 95% of what you need. Vulnerability management is a QA function when done right: OpenVas and Seccubus are free. Security awareness The reality is users will always click everything. Build real awareness, not compliance driven checkbox, and have it integrated into the culture. Pen test by crowd sourcing—test with logging COSSP http://www.cossp.org/ - Comprehensive Open Source Security Project What Journalists Want: The Investigative Reporters' Perspective on Hacking Dave Maas, San Diego CityBeat Jason Leopold, Truthout.org The difference between hackers and investigative journalists: For hackers, the motivation varies, but method is same, technological specialties. For investigative journalists, it's about one thing—The Story, and they need broad info-gathering skills. J-School in 60 Seconds: Generic formula: Person or issue of pubic interest, new info, or angle. Generic criteria: proximity, prominence, timeliness, human interest, oddity, or consequence. Media awareness of hackers and trends: journalists becoming extremely aware of hackers with congressional debates (privacy, data breaches), demand for data-mining Journalists, use of coding and web development for Journalists, and Journalists busted for hacking (Murdock). Info gathering by investigative journalists include Public records laws. Federal Freedom of Information Act (FOIA) is good, but slow. California Public Records Act is a lot stronger. FOIA takes forever because of foot-dragging—it helps to be specific. Often need to sue (especially FBI). CPRA is faster, and requests can be vague. Dumps and leaks (a la Wikileaks) Journalists want: leads, protecting ourselves, our sources, and adapting tools for news gathering (Google hacking). Anonomity is important to whistleblowers. They want no digital footprint left behind (e.g., email, web log). They don't trust encryption, want to feel safe and secure. Whistleblower laws are very weak—there's no upside for whistleblowers—they have to be very passionate to do it. Accessibility and Security or: How I Learned to Stop Worrying and Love the Halting Problem Anna Shubina, Dartmouth College Anna talked about how accessibility and security are related. Accessibility of digital content (not real world accessibility). mostly refers to blind users and screenreaders, for our purpose. Accessibility is about parsing documents, as are many security issues. "Rich" executable content causes accessibility to fail, and often causes security to fail. For example MS Word has executable format—it's not a document exchange format—more dangerous than PDF or HTML. Accessibility is often the first and maybe only sanity check with parsing. They have no choice because someone may want to read what you write. Google, for example, is very particular about web browser you use and are bad at supporting other browsers. Uses JavaScript instead of links, often requiring mouseover to display content. PDF is a security nightmare. Executible format, embedded flash, JavaScript, etc. 15 million lines of code. Google Chrome doesn't handle PDF correctly, causing several security bugs. PDF has an accessibility checker and PDF tagging, to help with accessibility. But no PDF checker checks for incorrect tags, untagged content, or validates lists or tables. None check executable content at all. The "Halting Problem" is: can one decide whether a program will ever stop? The answer, in general, is no (Rice's theorem). The same holds true for accessibility checkers. Language-theoretic Security says complicated data formats are hard to parse and cannot be solved due to the Halting Problem. W3C Web Accessibility Guidelines: "Perceivable, Operable, Understandable, Robust" Not much help though, except for "Robust", but here's some gems: * all information should be parsable (paraphrasing) * if not parsable, cannot be converted to alternate formats * maximize compatibility in new document formats Executible webpages are bad for security and accessibility. They say it's for a better web experience. But is it necessary to stuff web pages with JavaScript for a better experience? A good example is The Drudge Report—it has hand-written HTML with no JavaScript, yet drives a lot of web traffic due to good content. A bad example is Google News—hidden scrollbars, guessing user input. Solutions: Accessibility and security problems come from same source Expose "better user experience" myth Keep your corner of Internet parsable Remember "Halting Problem"—recognize false solutions (checking and verifying tools) Stop Patching, for Stronger PCI Compliance Adam Brand, protiviti @adamrbrand, http://www.picfun.com/ Adam talked about PCI compliance for retail sales. Take an example: for PCI compliance, 50% of Brian's time (a IT guy), 960 hours/year was spent patching POSs in 850 restaurants. Often applying some patches make no sense (like fixing a browser vulnerability on a server). "Scanner worship" is overuse of vulnerability scanners—it gives a warm and fuzzy and it's simple (red or green results—fix reds). Scanners give a false sense of security. In reality, breeches from missing patches are uncommon—more common problems are: default passwords, cleartext authentication, misconfiguration (firewall ports open). Patching Myths: Myth 1: install within 30 days of patch release (but PCI §6.1 allows a "risk-based approach" instead). Myth 2: vendor decides what's critical (also PCI §6.1). But §6.2 requires user ranking of vulnerabilities instead. Myth 3: scan and rescan until it passes. But PCI §11.2.1b says this applies only to high-risk vulnerabilities. Adam says good recommendations come from NIST 800-40. Instead use sane patching and focus on what's really important. From NIST 800-40: Proactive: Use a proactive vulnerability management process: use change control, configuration management, monitor file integrity. Monitor: start with NVD and other vulnerability alerts, not scanner results. Evaluate: public-facing system? workstation? internal server? (risk rank) Decide:on action and timeline Test: pre-test patches (stability, functionality, rollback) for change control Install: notify, change control, tickets McAfee Secure & Trustmarks — a Hacker's Best Friend Jay James, Shane MacDougall, Tactical Intelligence Inc., Canada "McAfee Secure Trustmark" is a website seal marketed by McAfee. A website gets this badge if they pass their remote scanning. The problem is a removal of trustmarks act as flags that you're vulnerable. Easy to view status change by viewing McAfee list on website or on Google. "Secure TrustGuard" is similar to McAfee. Jay and Shane wrote Perl scripts to gather sites from McAfee and search engines. If their certification image changes to a 1x1 pixel image, then they are longer certified. Their scripts take deltas of scans to see what changed daily. The bottom line is change in TrustGuard status is a flag for hackers to attack your site. Entire idea of seals is silly—you're raising a flag saying if you're vulnerable.

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  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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  • Issue 15: Oracle Exadata Marketing Campaigns

    - by rituchhibber
         PARTNER FOCUS Oracle ExadataMarketing Campaign Steve McNickleVP Europe, cVidya Steve McNickle is VP Europe for cVidya, an innovative provider of revenue intelligence solutions for telecom, media and entertainment service providers including AT&T, BT, Deutsche Telecom and Vodafone. The company's product portfolio helps operators and service providers maximise margins, improve customer experience and optimise ecosystem relationships through revenue assurance, fraud and security management, sales performance management, pricing analytics, and inter-carrier services. cVidya has partnered with Oracle for more than a decade. RESOURCES -- Oracle PartnerNetwork (OPN) Oracle Exastack Program Oracle Exastack Optimized Oracle Exastack Labs and Enablement Resources Oracle Engineered Systems Oracle Communications cVidya SUBSCRIBE FEEDBACK PREVIOUS ISSUES Are you ready for Oracle OpenWorld this October? -- -- Please could you tell us a little about cVidya's partnering history with Oracle, and expand on your Oracle Exastack accreditations? "cVidya was established just over ten years ago and we've had a strong relationship with Oracle almost since the very beginning. Through our Revenue Intelligence work with some of the world's largest service providers we collect tremendous amounts of information, amounting to billions of records per day. We help our clients to collect, store and analyse that data to ensure that their end customers are getting the best levels of service, are billed correctly, and are happy that they are on the correct price plan. We have been an Oracle Gold level partner for seven years, and crucially just two months ago we were also accredited as Oracle Exastack Optimized for MoneyMap, our core Revenue Assurance solution. Very soon we also expect to be Oracle Exastack Optimized DRMap, our Data Retention solution." What unique capabilities and customer benefits does Oracle Exastack add to your applications? "Oracle Exastack enables us to deliver radical benefits to our customers. A typical mobile operator in the UK might handle between 500 million and two billion call data record details daily. Each transaction needs to be validated, billed correctly and fraud checked. Because of the enormous volumes involved, our clients demand scalable infrastructure that allows them to efficiently acquire, store and process all that data within controlled cost, space and environmental constraints. We have proved that the Oracle Exadata system can process data up to seven times faster and load it as much as 20 times faster than other standard best-of-breed server approaches. With the Oracle Exadata Database Machine they can reduce their datacentre equipment from say, the six or seven cabinets that they needed in the past, down to just one. This dramatic simplification delivers incredible value to the customer by cutting down enormously on all of their significant cost, space, energy, cooling and maintenance overheads." "The Oracle Exastack Program has given our clients the ability to switch their focus from reactive to proactive. Traditionally they may have spent 80 percent of their day processing, and just 20 percent enabling end customers to see advanced analytics, and avoiding issues before they occur. With our solutions and Oracle Exadata they can now switch that balance around entirely, resulting not only in reduced revenue leakage, but a far higher focus on proactive leakage prevention. How has the Oracle Exastack Program transformed your customer business? "We can already see the impact. Oracle solutions allow our delivery teams to achieve successful deployments, happy customers and self-satisfaction, and the power of Oracle's Exa solutions is easy to measure in terms of their transformational ability. We gained our first sale into a major European telco by demonstrating the major performance gains that would transform their business. Clients can measure the ease of organisational change, the early prevention of business issues, the reduction in manpower required to provide protection and coverage across all their products and services, plus of course end customer satisfaction. If customers know that that service is provided accurately and that their bills are calculated correctly, then over time this satisfaction can be attributed to revenue intelligence and the underlying systems which provide it. Combine this with the further integration we have with the other layers of the Oracle stack, including the telecommunications offerings such as NCC, OCDM and BRM, and the result is even greater customer value—not to mention the increased speed to market and the reduced project risk." What does the Oracle Exastack community bring to cVidya, both in terms of general benefits, and also tangible new opportunities and partnerships? "A great deal. We have participated in the Oracle Exastack community heavily over the past year, and have had lots of meetings with Oracle and our peers around the globe. It brings us into contact with like-minded, innovative partners, who like us are not happy to just stand still and want to take fresh technology to their customer base in order to gain enhanced value. We identified three new partnerships in each of two recent meetings, and hope these will open up new opportunities, not only in areas that exactly match where we operate today, but also in some new associative areas that will expand our reach into new business sectors. Notably, thanks to the Exastack community we were invited on stage at last year's Oracle OpenWorld conference. Appearing so publically with Oracle senior VP Judson Althoff elevated awareness and visibility of cVidya and has enabled us to participate in a number of other events with Oracle over the past eight months. We've been involved in speaking opportunities, forums and exhibitions, providing us with invaluable opportunities that we wouldn't otherwise have got close to." How has Exastack differentiated cVidya as an ISV, and helped you to evolve your business to the next level? "When we are selling to our core customer base of Tier 1 telecommunications providers, we know that they want more than just software. They want an enduring partnership that will last many years, they want innovation, and a forward thinking partner who knows how to guide them on where they need to be to meet market demand three, five or seven years down the line. Membership of respected global bodies, such as the Telemanagement Forum enables us to lead standard adherence in our area of business, giving us a lot of credibility, but Oracle is also involved in this forum with its own telecommunications portfolio, strengthening our position still further. When we approach CEOs, CTOs and CIOs at the very largest Tier 1 operators, not only can we easily show them that our technology is fantastic, we can also talk about our strong partnership with Oracle, and our joint embracing of today's standards and tomorrow's innovation." Where would you like cVidya to be in one year's time? "We want to get all of our relevant products Oracle Exastack Optimized. Our MoneyMap Revenue Assurance solution is already Exastack Optimised, our DRMAP Data Retention Solution should be Exastack Optimised within the next month, and our FraudView Fraud Management solution within the next two to three months. We'd then like to extend our Oracle accreditation out to include other members of the Oracle Engineered Systems family. We are moving into the 'Big Data' space, and so we're obviously very keen to work closely with Oracle to conduct pilots, map new technologies onto Oracle Big Data platforms, and embrace and measure the benefits of other Oracle systems, namely Oracle Exalogic Elastic Cloud, the Oracle Exalytics In-Memory Machine and the Oracle SPARC SuperCluster. We would also like to examine how the Oracle Database Appliance might benefit our Tier 2 service provider customers. Finally, we'd also like to continue working with the Oracle Communications Global Business Unit (CGBU), furthering our integration with Oracle billing products so that we are able to quickly deploy fraud solutions into Oracle's Engineered System stack, give operational benefits to our clients that are pre-integrated, more cost-effective, and can be rapidly deployed rapidly and producing benefits in three months, not nine months." Chris Baker ,Senior Vice President, Oracle Worldwide ISV-OEM-Java Sales Chris Baker is the Global Head of ISV/OEM Sales responsible for working with ISV/OEM partners to maximise Oracle's business through those partners, whilst maximising those partners' business to their end users. Chris works with partners, customers, innovators, investors and employees to develop innovative business solutions using Oracle products, services and skills. Firstly, could you please explain Oracle's current strategy for ISV partners, globally and in EMEA? "Oracle customers use independent software vendor (ISV) applications to run their businesses. They use them to generate revenue and to fulfil obligations to their own customers. Our strategy is very straight-forward. We want all of our ISV partners and OEMs to concentrate on the things that they do the best – building applications to meet the unique industry and functional requirements of their customer. We want to ensure that we deliver a best in class application platform so the ISV is free to concentrate their effort on their application functionality and user experience We invest over four billion dollars in research and development every year, and we want our ISVs to benefit from all of that investment in operating systems, virtualisation, databases, middleware, engineered systems, and other hardware. By doing this, we help them to reduce their costs, gain more consistency and agility for quicker implementations, and also rapidly differentiate themselves from other application vendors. It's all about simplification because we believe that around 25 to 30 percent of the development costs incurred by many ISVs are caused by customising infrastructure and have nothing to do with their applications. Our strategy is to enable our ISV partners to standardise their application platform using engineered architecture, so they can write once to the Oracle stack and deploy seamlessly in the cloud, on-premise, or in hybrid deployments. It's really important that architecture is the same in order to keep cost and time overheads at a minimum, so we provide standardisation and an environment that enables our ISVs to concentrate on the core business that makes them the most money and brings them success." How do you believe this strategy is helping the ISVs to work hand-in-hand with Oracle to ensure that end customers get the industry-leading solutions that they need? "We work with our ISVs not just to help them be successful, but also to help them market themselves. We have something called the 'Oracle Exastack Ready Program', which enables ISVs to publicise themselves as 'Ready' to run the core software platforms that run on Oracle's engineered systems including Exadata and Exalogic. So, for example, they can become 'Database Ready' which means that they use the latest version of Oracle Database and therefore can run their application without modification on Exadata or the Oracle Database Appliance. Alternatively, they can become WebLogic Ready, Oracle Linux Ready and Oracle Solaris Ready which means they run on the latest release and therefore can run their application, with no new porting work, on Oracle Exalogic. Those 'Ready' logos are important in helping ISVs advertise to their customers that they are using the latest technologies which have been fully tested. We now also have Exadata Ready and Exalogic Ready programmes which allow ISVs to promote the certification of their applications on these platforms. This highlights these partners to Oracle customers as having solutions that run fluently on the Oracle Exadata Database Machine, the Oracle Exalogic Elastic Cloud or one of our other engineered systems. This makes it easy for customers to identify solutions and provides ISVs with an avenue to connect with Oracle customers who are rapidly adopting engineered systems. We have also taken this programme to the next level in the shape of 'Oracle Exastack Optimized' for partners whose applications run best on the Oracle stack and have invested the time to fully optimise application performance. We ensure that Exastack Optimized partner status is promoted and supported by press releases, and we help our ISVs go to market and differentiate themselves through the use our technology and the standardisation it delivers. To date we have had several hundred organisations successfully work through our Exastack Optimized programme." How does Oracle's strategy of offering pre-integrated open platform software and hardware allow ISVs to bring their products to market more quickly? "One of the problems for many ISVs is that they have to think very carefully about the technology on which their solutions will be deployed, particularly in the cloud or hosted environments. They have to think hard about how they secure these environments, whether the concern is, for example, middleware, identity management, or securing personal data. If they don't use the technology that we build-in to our products to help them to fulfil these roles, they then have to build it themselves. This takes time, requires testing, and must be maintained. By taking advantage of our technology, partners will now know that they have a standard platform. They will know that they can confidently talk about implementation being the same every time they do it. Very large ISV applications could once take a year or two to be implemented at an on-premise environment. But it wasn't just the configuration of the application that took the time, it was actually the infrastructure - the different hardware configurations, operating systems and configurations of databases and middleware. Now we strongly believe that it's all about standardisation and repeatability. It's about making sure that our partners can do it once and are then able to roll it out many different times using standard componentry." What actions would you recommend for existing ISV partners that are looking to do more business with Oracle and its customer base, not only to maximise benefits, but also to maximise partner relationships? "My team, around the world and in the EMEA region, is available and ready to talk to any of our ISVs and to explore the possibilities together. We run programmes like 'Excite' and 'Insight' to help us to understand how we can help ISVs with architecture and widen their environments. But we also want to work with, and look at, new opportunities - for example, the Machine-to-Machine (M2M) market or 'The Internet of Things'. Over the next few years, many millions, indeed billions of devices will be collecting massive amounts of data and communicating it back to the central systems where ISVs will be running their applications. The only way that our partners will be able to provide a single vendor 'end-to-end' solution is to use Oracle integrated systems at the back end and Java on the 'smart' devices collecting the data – a complete solution from device to data centre. So there are huge opportunities to work closely with our ISVs, using Oracle's complete M2M platform, to provide the infrastructure that enables them to extract maximum value from the data collected. If any partners don't know where to start or who to contact, then they can contact me directly at [email protected] or indeed any of our teams across the EMEA region. We want to work with ISVs to help them to be as successful as they possibly can through simplification and speed to market, and we also want all of the top ISVs in the world based on Oracle." What opportunities are immediately opened to new ISV partners joining the OPN? "As you know OPN is very, very important. New members will discover a huge amount of content that instantly becomes accessible to them. They can access a wealth of no-cost training and enablement materials to build their expertise in Oracle technology. They can download Oracle software and use it for development projects. They can help themselves become more competent by becoming part of a true community and uncovering new opportunities by working with Oracle and their peers in the Oracle Partner Network. As well as publishing massive amounts of information on OPN, we also hold our global Oracle OpenWorld event, at which partners play a huge role. This takes place at the end of September and the beginning of October in San Francisco. Attending ISV partners have an unrivalled opportunity to contribute to elements such as the OpenWorld / OPN Exchange, at which they can talk to other partners and really begin thinking about how they can move their businesses on and play key roles in a very large ecosystem which revolves around technology and standardisation." Finally, are there any other messages that you would like to share with the Oracle ISV community? "The crucial message that I always like to reinforce is architecture, architecture and architecture! The key opportunities that ISVs have today revolve around standardising their architectures so that they can confidently think: “I will I be able to do exactly the same thing whenever a customer is looking to deploy on-premise, hosted or in the cloud”. The right architecture is critical to being competitive and to really start changing the game. We want to help our ISV partners to do just that; to establish standard architecture and to seize the opportunities it opens up for them. New market opportunities like M2M are enormous - just look at how many devices are all around you right now. We can help our partners to interface with these devices more effectively while thinking about their entire ecosystem, rather than just the piece that they have traditionally focused upon. With standardised architecture, we can help people dramatically improve their speed, reach, agility and delivery of enhanced customer satisfaction and value all the way from the Java side to their centralised systems. All Oracle ISV partners must take advantage of these opportunities, which is why Oracle will continue to invest in and support them." -- Gergely Strbik is Oracle Hardware and Software Product Manager for Avnet in Hungary. Avnet Technology Solutions is an OracleValue Added Distributor focused on the development of the existing Oracle channel. This includes the recruitment and enablement of Oracle partners as well as driving deeper adoption of Oracle's technology and application products within the IT channel. "The main business benefits of ODA for our customers and partners are scalability, flexibility, a great price point for the high performance delivered, and the easily configurable embedded Linux operating system. People welcome a lower point of entry and the ability to grow capacity on demand as their business expands." "Marketing and selling the ODA requires another way of thinking because it is an appliance. We have to transform the ways in which our partners and customers think from buying hardware and software independently to buying complete solutions. Successful early adopters and satisfied customer reactions will certainly help us to sell the ODA. We will have more experience with the product after the first deliveries and installations—end users need to see the power and benefits for themselves." "Our typical ODA customers will be those looking for complete solutions from a single reseller partner who is also able to manage the appliance. They will have enjoyed using Oracle Database but now want a new product that is able to unlock new levels of performance. A higher proportion of potential customers will come from our existing Oracle base, with around 30% from new business, but we intend to evangelise the ODA on the market to see how we can change this balance as all our customers adjust to the concept of 'Hardware and Software, Engineered to Work Together'. -- Back to the welcome page

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  • GeoIP and Nginx

    - by JavierMartinez
    I have a nginx with geoip, but it is not working rightly. The issue is the next: Nginx are getting geodata from $_SERVER['REMOTE_ADDR'] instead of $_SERVER['HTTP_X_HAPROXY_IP'], which have the real client ip. So, the reported geodata belongs to my server ip instead of client ip. Does anybody where could be the error to fix it? Nginx version and compiled modules: nginx -V nginx version: nginx/1.2.3 TLS SNI support enabled configure arguments: --prefix=/etc/nginx --conf-path=/etc/nginx/nginx.conf --error-log- path=/var/log/nginx/error.log --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-log-path=/var/log/nginx/access.log --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --lock-path=/var/lock/nginx.lock --pid-path=/var/run/nginx.pid --with-pcre-jit --with-debug --with-file-aio --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_realip_module --with-http_secure_link_module --with-http_stub_status_module --with-http_ssl_module --with-http_sub_module --with-http_xslt_module --with-ipv6 --with-sha1=/usr/include/openssl --with-md5=/usr/include/openssl --with-mail --with-mail_ssl_module --add-module=/usr/src/nginx/source/nginx-1.2.3/debian/modules/nginx-auth-pam --add-module=/usr/src/nginx/source/nginx-1.2.3/debian/modules/nginx-echo --add-module=/usr/src/nginx/source/nginx-1.2.3/debian/modules/nginx-upstream-fair --add-module=/usr/src/nginx/source/nginx-1.2.3/debian/modules/nginx-dav-ext-module --add-module=/usr/src/nginx/source/nginx-1.2.3/debian/modules/nginx-syslog --add-module=/usr/src/nginx/source/nginx-1.2.3/debian/modules/nginx-cache-purge nginx site conf (frontend machine) server { root /var/www/storage; server_name ~^.*(\.)?mydomain.com$; if ($host ~ ^(.*)\.mydomain\.com$) { set $new_host $1.mydomain.com; } if ($host !~ ^(.*)\.mydomain\.com$) { set $new_host www.mydomain.com; } add_header Staging true; real_ip_header X-HAProxy-IP; set_real_ip_from 10.5.0.10/32; location /files { expires 30d; if ($uri !~ ^/files/([a-fA-F0-9]+)_(220|45)\.jpg$) { return 403; } rewrite ^/files/([a-fA-F0-9][a-fA-F0-9])([a-fA-F0-9][a-fA-F0-9])([a-fA-F0-9][a-fA-F0-9])([a-fA-F0-9][a-fA-F0-9])([a-fA-F0-9]+)_(220|45)\.jpg$ /files/$1/$2/$3/$4/$1$2$3$4$5_$6.jpg break; try_files $uri @to_backend; } location /assets { if ($uri ~ ^/assets/r([a-zA-Z0-9]+[^/])(/(css|js|fonts)/.*)) { rewrite ^/assets/r([a-zA-Z0-9]+[^/])/(css|js|fonts)/(.*)$ /assets/$2/$3 break; } try_files $uri @to_backend; } location / { proxy_set_header Host $new_host; proxy_set_header X-HAProxy-IP $remote_addr; proxy_pass http://10.5.0.10:8080; } location @to_backend { proxy_set_header Host $new_host; proxy_pass http://10.5.0.10:8080; } } nginx.conf (backend machine) http{ ... ## # GeoIP Config ## geoip_country /etc/nginx/geoip/GeoIP.dat; # the country IP database geoip_city /etc/nginx/geoip/GeoLiteCity.dat; # the city IP database ... } fastcgi_params (backend machine) ### SET GEOIP Variables ### fastcgi_param GEOIP_COUNTRY_CODE $geoip_country_code; fastcgi_param GEOIP_COUNTRY_CODE3 $geoip_country_code3; fastcgi_param GEOIP_COUNTRY_NAME $geoip_country_name; fastcgi_param GEOIP_CITY_COUNTRY_CODE $geoip_city_country_code; fastcgi_param GEOIP_CITY_COUNTRY_CODE3 $geoip_city_country_code3; fastcgi_param GEOIP_CITY_COUNTRY_NAME $geoip_city_country_name; fastcgi_param GEOIP_REGION $geoip_region; fastcgi_param GEOIP_CITY $geoip_city; fastcgi_param GEOIP_POSTAL_CODE $geoip_postal_code; fastcgi_param GEOIP_CITY_CONTINENT_CODE $geoip_city_continent_code; fastcgi_param GEOIP_LATITUDE $geoip_latitude; fastcgi_param GEOIP_LONGITUDE $geoip_longitude; haproxy.conf (frontend machine) defaults log global option forwardfor option httpclose mode http retries 3 option redispatch maxconn 4096 contimeout 100000 clitimeout 100000 srvtimeout 100000 listen cluster_webs *:8080 mode http option tcpka option httpchk option httpclose option forwardfor balance roundrobin server backend-stage 10.5.0.11:80 weight 1 $_SERVER dump: http://paste.laravel.com/7dy Where 10.5.0.10 is frontend private ip and 10.5.0.11 backend private ip

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  • postfix with mailman

    - by Thufir
    What should happen is that [email protected] should be delivered to that users inbox on localhost, user@localhost. Thunderbird works fine at reading user@localhost. I'm just using a small portion of postfix-dovecot with Ubuntu mailman. How can I get postfix to recognize the FQDN and deliver them to a localhost inbox? root@dur:~# root@dur:~# tail /var/log/mail.err;tail /var/log/mailman/subscribe;postconf -n Aug 27 18:59:16 dur dovecot: lda(root): Error: chdir(/root) failed: Permission denied Aug 27 18:59:16 dur dovecot: lda(root): Error: user root: Initialization failed: Initializing mail storage from mail_location setting failed: stat(/root/Maildir) failed: Permission denied (euid=65534(nobody) egid=65534(nogroup) missing +x perm: /root, dir owned by 0:0 mode=0700) Aug 27 18:59:16 dur dovecot: lda(root): Fatal: Invalid user settings. Refer to server log for more information. Aug 27 20:09:16 dur postfix/trivial-rewrite[15896]: error: open database /etc/postfix/transport.db: No such file or directory Aug 27 21:19:17 dur postfix/trivial-rewrite[16569]: error: open database /etc/postfix/transport.db: No such file or directory Aug 27 22:27:00 dur postfix[17042]: fatal: usage: postfix [-c config_dir] [-Dv] command Aug 27 22:29:19 dur postfix/trivial-rewrite[17062]: error: open database /etc/postfix/transport.db: No such file or directory Aug 27 22:59:07 dur postfix/postfix-script[17459]: error: unknown command: 'restart' Aug 27 22:59:07 dur postfix/postfix-script[17460]: fatal: usage: postfix start (or stop, reload, abort, flush, check, status, set-permissions, upgrade-configuration) Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: error: open database /etc/postfix/transport.db: No such file or directory Aug 27 21:39:03 2012 (16734) cola: pending "[email protected]" <[email protected]> 127.0.0.1 Aug 27 21:40:37 2012 (16749) cola: pending "[email protected]" <[email protected]> 127.0.0.1 Aug 27 22:45:31 2012 (17288) gmane.mail.mailman.user.1: pending [email protected] 127.0.0.1 Aug 27 22:45:46 2012 (17293) gmane.mail.mailman.user.1: pending [email protected] 127.0.0.1 Aug 27 23:02:01 2012 (17588) test3: pending [email protected] 127.0.0.1 Aug 27 23:05:41 2012 (17652) test4: pending [email protected] 127.0.0.1 Aug 27 23:56:20 2012 (17985) test5: pending [email protected] 127.0.0.1 alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases append_dot_mydomain = no biff = no broken_sasl_auth_clients = yes config_directory = /etc/postfix default_transport = smtp home_mailbox = Maildir/ inet_interfaces = loopback-only mailbox_command = /usr/lib/dovecot/deliver -c /etc/dovecot/conf.d/01-mail-stack-delivery.conf -m "${EXTENSION}" mailbox_size_limit = 0 mailman_destination_recipient_limit = 1 mydestination = dur, dur.bounceme.net, localhost.bounceme.net, localhost myhostname = dur.bounceme.net mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 readme_directory = no recipient_delimiter = + relay_domains = lists.dur.bounceme.net relay_transport = relay relayhost = smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtp_use_tls = yes smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) smtpd_recipient_restrictions = reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination smtpd_sasl_auth_enable = yes smtpd_sasl_authenticated_header = yes smtpd_sasl_local_domain = $myhostname smtpd_sasl_path = private/dovecot-auth smtpd_sasl_security_options = noanonymous smtpd_sasl_type = dovecot smtpd_tls_auth_only = yes smtpd_tls_cert_file = /etc/ssl/certs/ssl-mail.pem smtpd_tls_key_file = /etc/ssl/private/ssl-mail.key smtpd_tls_mandatory_ciphers = medium smtpd_tls_mandatory_protocols = SSLv3, TLSv1 smtpd_tls_received_header = yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtpd_use_tls = yes tls_random_source = dev:/dev/urandom transport_maps = hash:/etc/postfix/transport root@dur:~# there's definitely a transport problem: root@dur:~# root@dur:~# root@dur:~# grep transport /var/log/mail.log | tail Aug 27 22:29:19 dur postfix/trivial-rewrite[17062]: warning: hash:/etc/postfix/transport lookup error for "[email protected]" Aug 27 22:29:19 dur postfix/trivial-rewrite[17062]: warning: transport_maps lookup failure Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: error: open database /etc/postfix/transport.db: No such file or directory Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: hash:/etc/postfix/transport is unavailable. open database /etc/postfix/transport.db: No such file or directory Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: hash:/etc/postfix/transport lookup error for "*" Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: hash:/etc/postfix/transport is unavailable. open database /etc/postfix/transport.db: No such file or directory Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: hash:/etc/postfix/transport lookup error for "*" Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: hash:/etc/postfix/transport is unavailable. open database /etc/postfix/transport.db: No such file or directory Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: hash:/etc/postfix/transport lookup error for "[email protected]" Aug 27 23:39:17 dur postfix/trivial-rewrite[17794]: warning: transport_maps lookup failure root@dur:~# trying to add the transport file: EDIT root@dur:~# root@dur:~# touch /etc/postfix/transport root@dur:~# ll /etc/postfix/transport -rw-r--r-- 1 root root 0 Aug 28 00:16 /etc/postfix/transport root@dur:~# root@dur:~# cd /etc/postfix/ root@dur:/etc/postfix# root@dur:/etc/postfix# postmap transport root@dur:/etc/postfix# root@dur:/etc/postfix# cat transport

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  • Mac OS X 10.6 assign mapped IP to Windows 7 VM in Parallels

    - by Alex
    I'm trying to assign a mapped IP address to a Windows 7 VM. I have setup running in Parallels 5 in wireless bridged networking mode. The problem I am having is that it looks like the VM is actually broadcasting the MAC address of the host machine and thus causing a clash of IP addresses on the network. This is my current setup: Macbook Pro :~ ifconfig -a lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 inet 127.0.0.1 netmask 0xff000000 gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 stf0: flags=0<> mtu 1280 en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 00:26:b0:df:31:b4 media: autoselect status: inactive supported media: none autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,flow-control> 10baseT/UTP <full-duplex,hw-loopback> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,flow-control> 100baseTX <full-duplex,hw-loopback> 1000baseT <full-duplex> 1000baseT <full-duplex,flow-control> 1000baseT <full-duplex,hw-loopback> fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 4078 lladdr 00:26:b0:ff:fe:df:31:b4 media: autoselect <full-duplex> status: inactive supported media: autoselect <full-duplex> en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet6 fe80::226:bbff:fe0a:59a1%en1 prefixlen 64 scopeid 0x6 inet 192.168.1.97 netmask 0xffffff00 broadcast 192.168.1.255 ether 00:26:bb:0a:59:a1 media: autoselect status: active supported media: autoselect vnic0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 192.168.1.81 netmask 0xffffff00 broadcast 192.168.1.255 ether 00:1c:42:00:00:08 media: autoselect status: active supported media: autoselect vnic1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 10.37.129.2 netmask 0xffffff00 broadcast 10.37.129.255 ether 00:1c:42:00:00:09 media: autoselect status: active supported media: autoselect Windows 7: :~ ipconfig -all Windows IP Configuration Host Name . . . . . . . . . . . . : Alex-PC Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Ethernet adapter Local Area Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Parallels Ethernet Adapter Physical Address. . . . . . . . . : 00-1C-42-B8-E7-B4 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Tunnel adapter Teredo Tunneling Pseudo-Interface: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft Teredo Tunneling Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{ACAC7EBB-5E5F-4F53-AFD9-E6EAEEA0FEE2}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Billion Bipac 7200 modem router: In DHCP server settings have the following two mapping entries. alex-macbook-win7 00:1c:42:00:00:08 192.168.1.98 alex-macbook 00:26:bb:0a:59:a1 192.168.1.97 The problem I have is that when the VM starts up it gets assigned the 192.168.1.97 address instead of the .98 address and thus networking on the host stops working as it says there is a clash. I have tried removing the mapping for "alex-macbook" which results in the guest machine being assigned a normal DHCP address and NOT the one that is in the mapping of the router.

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  • NetBackup with VSS and Instant Recovery - Failing to delete old snapshots

    - by Jonathan Bourke
    We are attempting to implement Microsoft VSS for snap-shotting in our NetBackup 6.5.3.1 environment. The clients are both 32 & 64 bit Windows 2003 Server. Snapshot parameters are: Instant recovery is enabled Maximum snapshots = 1 Provider type = 1 (System) Snapshot attribute = 1 (Differential) All backups successfully complete, and VSS shadows are successfully created both for the snapshot backup and for the open files (shadow copy components). The Issue: NetBackup is not clearing or overwriting old snapshots with each successive backup. When we list shadows, and shadow storage, it is increasing and increasing. IT is not honouring the Maximum Snapshot setting. The Logs: The bpfis log doesn’t really appear to show any errors other than for methods which we are not employing (VxVM, Flashsnap, etc.). A section is as follows: 11:54:10.744 [348.4724] <2> logparams: D:\Program Files\Veritas\NetBackup\bin\bpfis.exe delete -nbu -id htpststr001.san.mgmt.det_1248918143 -bpstart_to 300 -bpend_to 300 -clnt htpststr001.san.mgmt.det 11:54:10.744 [348.4724] <4> bpfis: INF - BACKUP START 348 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: VfMS error 10; see following messages: 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: Non-fatal method error was reported 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: vfm_configure_fi_one: method: FlashSnap, type: FIM, function: FlashSnap_init 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: VfMS method error 3; see following message: 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: FlashSnap_init: Veritas Volume Manager not installed. 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: VfMS error 10; see following messages: 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: Non-fatal method error was reported 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: vfm_configure_fi_one: method: vxvm, type: FIM, function: vxvm_init 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: VfMS method error 3; see following message: 11:54:11.713 [348.4724] <8> onlfi_initialize_vfms: vxvm_init: Veritas Volume Manager not installed. 11:54:11.713 [348.4724] <4> onlfi_thaw: Thawing C:\ using snapshot method VSS. 11:54:11.713 [348.4724] <2> onlfi_vfms_logf: vfm_thaw: delete snapshot ... 11:54:11.744 [348.4724] <2> onlfi_vfms_logf: snapshot services: emcclariionfi:Thu Jul 30 2009 11:54:11.744000 <Thread id - 4724> Unable to import any login credentials for any appliances. 11:54:11.760 [348.4724] <2> onlfi_vfms_logf: snapshot services: hpevafi:Thu Jul 30 2009 11:54:11.760000 <Thread id - 4724> CHpEvaPlugin::init: CLI tool is not installed. 11:54:11.760 [348.4724] <2> onlfi_vfms_logf: snapshot services: hpmsafi:Thu Jul 30 2009 11:54:11.760000 <Thread id - 4724> No array mangement credentials are available in configuration file. 11:54:13.806 [348.4724] <4> onlfi_thaw: do_thaw return value: 0 11:54:13.806 [348.4724] <4> onlfi_thaw: Thawing D:\ using snapshot method VSS. 11:54:15.806 [348.4724] <4> onlfi_thaw: do_thaw return value: 0 11:54:19.806 [348.4724] <2> fis_delete_id: removing D:\Program Files\Veritas\NetBackup\online_util\fi_cntl\bpfis.fim.htpststr001.san.mgmt.det_1248918143.0 11:54:19.806 [348.4724] <2> fis_delete_id: removing D:\Program Files\Veritas\NetBackup\online_util\fi_cntl\bpfis.fim.htpststr001.san.mgmt.det_1248918143.0.fiid 11:54:19.853 [348.4724] <4> bpfis: INF - EXIT STATUS 0: the requested operation was successfully completed The Question: Has anyone any experience of NetBackup / VSS not clearing snapshots after backups? We will ultimately be using a HP EVA for the snapshots, but we want to ensure correct functioning at a VSS level before we go further. Regards, Jonathan (PS: Question previously posted by my colleague on entsupport.symantec.com)

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  • What free space thresholds/limits are advisable for 640 GB and 2 TB hard disk drives with ZEVO ZFS on OS X?

    - by Graham Perrin
    Assuming that free space advice for ZEVO will not differ from advice for other modern implementations of ZFS … Question Please, what percentages or amounts of free space are advisable for hard disk drives of the following sizes? 640 GB 2 TB Thoughts A standard answer for modern implementations of ZFS might be "no more than 96 percent full". However if apply that to (say) a single-disk 640 GB dataset where some of the files most commonly used (by VirtualBox) are larger than 15 GB each, then I guess that blocks for those files will become sub optimally spread across the platters with around 26 GB free. I read that in most cases, fragmentation and defragmentation should not be a concern with ZFS. Sill, I like the mental picture of most fragments of a large .vdi in reasonably close proximity to each other. (Do features of ZFS make that wish for proximity too old-fashioned?) Side note: there might arise the question of how to optimise performance after a threshold is 'broken'. If it arises, I'll keep it separate. Background On a 640 GB StoreJet Transcend (product ID 0x2329) in the past I probably went beyond an advisable threshold. Currently the largest file is around 17 GB –  – and I doubt that any .vdi or other file on this disk will grow beyond 40 GB. (Ignore the purple masses, those are bundles of 8 MB band files.) Without HFS Plus: the thresholds of twenty, ten and five percent that I associate with Mobile Time Machine file system need not apply. I currently use ZEVO Community Edition 1.1.1 with Mountain Lion, OS X 10.8.2, but I'd like answers to be not too version-specific. References, chronological order ZFS Block Allocation (Jeff Bonwick's Blog) (2006-11-04) Space Maps (Jeff Bonwick's Blog) (2007-09-13) Doubling Exchange Performance (Bizarre ! Vous avez dit Bizarre ?) (2010-03-11) … So to solve this problem, what went in 2010/Q1 software release is multifold. The most important thing is: we increased the threshold at which we switched from 'first fit' (go fast) to 'best fit' (pack tight) from 70% full to 96% full. With TB drives, each slab is at least 5GB and 4% is still 200MB plenty of space and no need to do anything radical before that. This gave us the biggest bang. Second, instead of trying to reuse the same primary slabs until it failed an allocation we decided to stop giving the primary slab this preferential threatment as soon as the biggest allocation that could be satisfied by a slab was down to 128K (metaslab_df_alloc_threshold). At that point we were ready to switch to another slab that had more free space. We also decided to reduce the SMO bonus. Before, a slab that was 50% empty was preferred over slabs that had never been used. In order to foster more write aggregation, we reduced the threshold to 33% empty. This means that a random write workload now spread to more slabs where each one will have larger amount of free space leading to more write aggregation. Finally we also saw that slab loading was contributing to lower performance and implemented a slab prefetch mechanism to reduce down time associated with that operation. The conjunction of all these changes lead to 50% improved OLTP and 70% reduced variability from run to run … OLTP Improvements in Sun Storage 7000 2010.Q1 (Performance Profiles) (2010-03-11) Alasdair on Everything » ZFS runs really slowly when free disk usage goes above 80% (2010-07-18) where commentary includes: … OpenSolaris has changed this in onnv revision 11146 … [CFT] Improved ZFS metaslab code (faster write speed) (2010-08-22)

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  • Cisco ASA (Client VPN) to LAN - through second VPN to second LAN

    - by user50855
    We have 2 site that is linked by an IPSEC VPN to remote Cisco ASAs: Site 1 1.5Mb T1 Connection Cisco(1) 2841 Site 2 1.5Mb T1 Connection Cisco 2841 In addition: Site 1 has a 2nd WAN 3Mb bonded T1 Connection Cisco 5510 that connects to same LAN as Cisco(1) 2841. Basically, Remote Access (VPN) users connecting through Cisco ASA 5510 needs access to a service at the end of Site 2. This is due to the way the service is sold - Cisco 2841 routers are not under our management and it is setup to allow connection from local LAN VLAN 1 IP address 10.20.0.0/24. My idea is to have all traffic from Remote Users through Cisco ASA destined for Site 2 to go via the VPN between Site 1 and Site 2. The end result being all traffic that hits Site 2 has come via Site 1. I'm struggling to find a great deal of information on how this is setup. So, firstly, can anyone confirm that what I'm trying to achieve is possible? Secondly, can anyone help me to correct the configuration bellow or point me in the direction of an example of such a configuration? Many Thanks. interface Ethernet0/0 nameif outside security-level 0 ip address 7.7.7.19 255.255.255.240 interface Ethernet0/1 nameif inside security-level 100 ip address 10.20.0.249 255.255.255.0 object-group network group-inside-vpnclient description All inside networks accessible to vpn clients network-object 10.20.0.0 255.255.255.0 network-object 10.20.1.0 255.255.255.0 object-group network group-adp-network description ADP IP Address or network accessible to vpn clients network-object 207.207.207.173 255.255.255.255 access-list outside_access_in extended permit icmp any any echo-reply access-list outside_access_in extended permit icmp any any source-quench access-list outside_access_in extended permit icmp any any unreachable access-list outside_access_in extended permit icmp any any time-exceeded access-list outside_access_in extended permit tcp any host 7.7.7.20 eq smtp access-list outside_access_in extended permit tcp any host 7.7.7.20 eq https access-list outside_access_in extended permit tcp any host 7.7.7.20 eq pop3 access-list outside_access_in extended permit tcp any host 7.7.7.20 eq www access-list outside_access_in extended permit tcp any host 7.7.7.21 eq www access-list outside_access_in extended permit tcp any host 7.7.7.21 eq https access-list outside_access_in extended permit tcp any host 7.7.7.21 eq 5721 access-list acl-vpnclient extended permit ip object-group group-inside-vpnclient any access-list acl-vpnclient extended permit ip object-group group-inside-vpnclient object-group group-adp-network access-list acl-vpnclient extended permit ip object-group group-adp-network object-group group-inside-vpnclient access-list PinesFLVPNTunnel_splitTunnelAcl standard permit 10.20.0.0 255.255.255.0 access-list inside_nat0_outbound_1 extended permit ip 10.20.0.0 255.255.255.0 10.20.1.0 255.255.255.0 access-list inside_nat0_outbound_1 extended permit ip 10.20.0.0 255.255.255.0 host 207.207.207.173 access-list inside_nat0_outbound_1 extended permit ip 10.20.1.0 255.255.255.0 host 207.207.207.173 ip local pool VPNPool 10.20.1.100-10.20.1.200 mask 255.255.255.0 route outside 0.0.0.0 0.0.0.0 7.7.7.17 1 route inside 207.207.207.173 255.255.255.255 10.20.0.3 1 crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac crypto ipsec security-association lifetime seconds 28800 crypto ipsec security-association lifetime kilobytes 4608000 crypto dynamic-map outside_dyn_map 20 set transform-set ESP-3DES-SHA crypto dynamic-map outside_dyn_map 20 set security-association lifetime seconds 288000 crypto dynamic-map outside_dyn_map 20 set security-association lifetime kilobytes 4608000 crypto dynamic-map outside_dyn_map 20 set reverse-route crypto map outside_map 20 ipsec-isakmp dynamic outside_dyn_map crypto map outside_map interface outside crypto map outside_dyn_map 20 match address acl-vpnclient crypto map outside_dyn_map 20 set security-association lifetime seconds 28800 crypto map outside_dyn_map 20 set security-association lifetime kilobytes 4608000 crypto isakmp identity address crypto isakmp enable outside crypto isakmp policy 20 authentication pre-share encryption 3des hash sha group 2 lifetime 86400 group-policy YeahRightflVPNTunnel internal group-policy YeahRightflVPNTunnel attributes wins-server value 10.20.0.9 dns-server value 10.20.0.9 vpn-tunnel-protocol IPSec password-storage disable pfs disable split-tunnel-policy tunnelspecified split-tunnel-network-list value acl-vpnclient default-domain value YeahRight.com group-policy YeahRightFLVPNTunnel internal group-policy YeahRightFLVPNTunnel attributes wins-server value 10.20.0.9 dns-server value 10.20.0.9 10.20.0.7 vpn-tunnel-protocol IPSec split-tunnel-policy tunnelspecified split-tunnel-network-list value YeahRightFLVPNTunnel_splitTunnelAcl default-domain value yeahright.com tunnel-group YeahRightFLVPN type remote-access tunnel-group YeahRightFLVPN general-attributes address-pool VPNPool tunnel-group YeahRightFLVPNTunnel type remote-access tunnel-group YeahRightFLVPNTunnel general-attributes address-pool VPNPool authentication-server-group WinRadius default-group-policy YeahRightFLVPNTunnel tunnel-group YeahRightFLVPNTunnel ipsec-attributes pre-shared-key *

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  • Oracle performance problem

    - by jreid42
    We are using an Oracle 11G machine that is very powerful; has redundant storage etc. It's a beast from what I have been told. We just got this DB for a tool that when I first came on as a coop had like 20 people using, now its upwards of 150 people. I am the only one working on it :( We currently have a system in place that distributes PERL scripts across our entire data center essentially giving us a sort of "grid" computing power. The Perl scripts run a sort of simulation and report back the results to the database. They do selects / inserts. The load is not very high for each script but it could be happening across 20-50 systems at the same time. We then have multiple data centers and users all hitting the same database with this same approach. Our main problem with this is that our database is getting overloaded with connections and having to drop some. We sometimes have upwards of 500 connections. These are old perl scripts and they do not handle this well. Essentially they fail and the results are lost. I would rather avoid having to rewrite a lot of these as they are poorly written, and are a headache to even look at. The database itself is not overloaded, just the connection overhead is too high. We open a connection, make a quick query and then drop the connection. Very short connections but many of them. The database team has basically said we need to lower the number of connections or they are going to ignore us. Because this is distributed across our farm we cant implement persistent connections. I do this with our webserver; but its on a fixed system. The other ones are perl scripts that get opened and closed by the distribution tool and thus arent always running. What would be my best approach to resolving this issue? The scripts themselves can wait for a connection to be open. They do not need to act immediately. Some sort of queing system? I've been suggested to set up a few instances of a tool called "SQL Relay". Maybe one in each data center. How reliable is this tool? How good is this approach? Would it work for what we need? We could have one for each data center and relay requests through it to our main database, keeping a pipeline of open persistent connections? Does this make sense? Is there any other suggestions you can make? Any ideas? Any help would be greatly appreciated. Sadly I am just a coop student working for a very big company and somehow all of this has landed all on my shoulders (there is literally nobody to ask for help; its a hardware company, everybody is hardware engineers, and the database team is useless and in India) and I am quite lost as what the best approach would be? I am extremely overworked and this problem is interfering with on going progress and basically needs to be resolved as quickly as possible; preferably without rewriting the whole system, purchasing hardware (not gonna happen), or shooting myself in the foot. HELP LOL!

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  • Building nginx 1.0.4 on Amazon EC2 micro - perl and python problems

    - by digitaltoast
    I'd like to run nginx as a reverse proxy with apache2 on my EC2 micro instance. yum install nginx gives me nginx-0.8.53-1.2.amzn1.x86_64.rpm The current nginx is 1.0.4 I found and followed this guide: http://kdn2.info/2011/05/install-nginx-on-amazon-ec2/ It works fine up to and including "make". When I get to checkinstall --fstrans=no I get ERROR: ld.so: object '/usr/lib/installwatch.so' from LD_PRELOAD cannot be preloaded: ignored. test -d '/var/log/nginx' || mkdir -p '/var/log/nginx' ERROR: ld.so: object '/usr/lib/installwatch.so' from LD_PRELOAD cannot be preloaded: ignored. make[1]: Leaving directory `/root/src/nginx-1.0.4' ======================== Installation successful ========================== Copying documentation directory... ./ ./CHANGES ./LICENSE ./README cp: cannot stat `//var/tmp/gRWoVgIcdbmjfTjoVGBM/newfiles.tmp': No such file or directory Copying files to the temporary directory...OK Striping ELF binaries and libraries...OK Compressing man pages...OK Building file list...OK Building RPM package... FAILED! *** Failed to build the package ...and the logfile is full of: Building target platforms: x86_64 Building for target x86_64 Processing files: nginx-1.0.4-1.x86_64 error: File not found: /usr/src/rpm/BUILDROOT/nginx-1.0.4-1.x86_64/usr error: File not found: /usr/src/rpm/BUILDROOT/nginx-1.0.4-1.x86_64/usr/doc There IS /usr/src/rpm/BUILDROOT/nginx-1.0.4-1.x86_64/ but no /usr Following further down the page, it says: "If we want to use, for example, PHP 5.2 we can download PHP and Nginx compatible with Amazon Kernel(Xen Kernel) from the CentosALT Repository." So I install the two repositories, but when I yum install http://centos.alt.ru/pub/nginx/1.0/RPMS/x86_64/nginx-stable-1.0.4-1.el5.x86_64.rpm I get Error: Package: nginx-stable-1.0.4-1.el5.x86_64 (/nginx-stable-1.0.4-1.el5.x86_64) Requires: perl(:MODULE_COMPAT_5.8.8) You could try using --skip-broken to work around the problem but that doesn't fix it. When I do yum update, I get --> Finished Dependency Resolution Error: Package: python-distribute-0.6.19-10.1.x86_64 (devel_languages_python) Requires: python < 2.5 Installed: 1:python-2.6-1.19.amzn1.noarch (@amzn-main) python = 1:2.6-1.19.amzn1 Error: Package: python-distribute-0.6.19-10.1.i586 (devel_languages_python) Requires: python < 2.5 Installed: 1:python-2.6-1.19.amzn1.noarch (@amzn-main) python = 1:2.6-1.19.amzn1 I've tried everything - yum clean all and various other suggestions found on other sites. If anyone has any suggestions or a known package of the current 1.04 nginx working on EC2 Micro (Linux ip-10-56-63-85 2.6.35.11-83.9.amzn1.x86_64 #1 SMP Sat Feb 19 23:42:04 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux - which I think is RHEL 5?) then I'd be grateful. Incidentally, does this repolist look right? repo id repo name status CentALT CentALT Packages for Enterprise Linux 5 - x86_64 enabled: 112+157 amzn-main amzn-main-Base enabled: 2,706 amzn-main-debuginfo amzn-main-debuginfo disabled amzn-main-nosrc amzn-main-nosrc disabled amzn-updates amzn-updates-Base enabled: 328 amzn-updates-debuginfo amzn-updates-debuginfo disabled amzn-updates-nosrc amzn-updates-nosrc disabled devel_languages_python Python and Python Modules (SLE_10) enabled: 1,452+768 epel Extra Packages for Enterprise Linux 5 - x86_64 enabled: 5,892+604 epel-debuginfo Extra Packages for Enterprise Linux 5 - x86_64 - Debug disabled epel-source Extra Packages for Enterprise Linux 5 - x86_64 - Source disabled epel-testing Extra Packages for Enterprise Linux 5 - Testing - x86_64 disabled epel-testing-debuginfo Extra Packages for Enterprise Linux 5 - Testing - x86_64 - Debug disabled epel-testing-source Extra Packages for Enterprise Linux 5 - Testing - x86_64 - Source disabled s3tools Tools for managing Amazon S3 - Simple Storage Service (RHEL_6) enabled: 2+1 repolist: 10,492

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  • Network authentication + roaming home directory - which technology should I look into using?

    - by Brian
    I'm looking into software which provides a user with a single identity across multiple computers. That is, a user should have the same permissions on each computer, and the user should have access to all of his or her files (roaming home directory) on each computer. There seem to be many solutions for this general idea, but I'm trying to determine the best one for me. Here are some details along with requirements: The network of machines are Amazon EC2 instances running Ubuntu. We access the machines with SSH. Some machines on this LAN may have different uses, but I am only discussing machines for a certain use (running a multi-tenancy platform). The system will not necessarily have a constant amount of machines. We may have to permanently or temporarily alter the amount of machines running. This is the the reason why I'm looking into centralized authentication/storage. The implementation of this effect should be a secure one. We're unsure if users will have direct shell access, but their software will potentially be running (under restricted Linux user names, of course) on our systems, which is as good as direct shell access. Let's assume that their software could potentially be malicious for the sake of security. I have heard of several technologies/combinations to achieve my goal, but I'm unsure of the ramifications of each. An older ServerFault post recommended NFS & NIS, though the combination has security problems according to this old article by Symantec. The article suggests moving to NIS+, but, as it is old, this Wikipedia article has cited statements suggesting a trending away from NIS+ by Sun. The recommended replacement is another thing I have heard of... LDAP. It looks like LDAP can be used to save user information in a centralized location on a network. NFS would still need to be used to cover the 'roaming home folder' requirement, but I see references of them being used together. Since the Symantec article pointed out security problems in both NIS and NFS, is there software to replace NFS, or should I heed that article's suggestions for locking it down? I'm tending toward LDAP because another fundamental piece of our architecture, RabbitMQ, has a authentication/authorization plugin for LDAP. RabbitMQ will be accessible in a restricted manner to users on the system, so I would like to tie the security systems together if possible. Kerberos is another secure authentication protocol that I have heard of. I learned a bit about it some years ago in a cryptography class but don't remember much about it. I have seen suggestions online that it can be combined with LDAP in several ways. Is this necessary? What are the security risks of LDAP without Kerberos? I also remember Kerberos being used in another piece of software developed by Carnegie Mellon University... Andrew File System, or AFS. OpenAFS is available for use, though its setup seems a bit complicated. At my university, AFS provides both requirements... I can log in to any machine, and my "AFS folder" is always available (at least when I acquire an AFS token). Along with suggestions for which path I should look into, does anybody have any guides which were particularly helpful? As the bold text pointed out, LDAP looks to be the best choice, but I'm particularly interested in the implementation details (Keberos? NFS?) with respect to security.

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  • SATA drive problems with two SIL RAID cards

    - by Jon Topper
    I've just put a second SiI 3114 SATARaid card in my home server so that I could add another pair of SATA drives and increase my storage space. Annoyingly, it doesn't seem to work: [ 32.816030] ata5: lost interrupt (Status 0x0) [ 32.816072] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [ 32.816091] ata5.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in [ 32.816094] res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) [ 32.816101] ata5.00: status: { DRDY } [ 32.816117] ata5: hard resetting link [ 33.136082] ata5: SATA link down (SStatus 0 SControl 0) [ 36.060940] irq 18: nobody cared (try booting with the "irqpoll" option) [ 36.060949] Pid: 0, comm: swapper Not tainted 2.6.31-20-generic #58-Ubuntu [ 36.060954] Call Trace: [ 36.060977] [] ? printk+0x18/0x1c [ 36.060997] [] __report_bad_irq+0x27/0x90 [ 36.061005] [] note_interrupt+0x150/0x190 [ 36.061011] [] handle_fasteoi_irq+0xac/0xd0 [ 36.061023] [] handle_irq+0x18/0x30 [ 36.061029] [] do_IRQ+0x47/0xc0 [ 36.061042] [] ? irq_exit+0x50/0x70 [ 36.061058] [] ? smp_apic_timer_interrupt+0x57/0x90 [ 36.061065] [] common_interrupt+0x30/0x40 [ 36.061075] [] ? native_safe_halt+0x5/0x10 [ 36.061082] [] default_idle+0x46/0xd0 [ 36.061088] [] cpu_idle+0x8c/0xd0 [ 36.061103] [] rest_init+0x55/0x60 [ 36.061111] [] start_kernel+0x2e6/0x2ec [ 36.061117] [] ? unknown_bootoption+0x0/0x19e [ 36.061133] [] i386_start_kernel+0x7c/0x83 [ 36.061137] handlers: [ 36.061139] [] (sil_interrupt+0x0/0xb0) [ 36.061151] Disabling IRQ #18 [ 38.136014] ata5: hard resetting link [ 38.456022] ata5: SATA link down (SStatus 0 SControl 0) [ 43.456013] ata5: hard resetting link [ 43.776022] ata5: SATA link down (SStatus 0 SControl 0) [ 43.776035] ata5.00: disabled [ 43.776055] ata5.00: device reported invalid CHS sector 0 [ 43.776074] sd 4:0:0:0: [sde] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 43.776082] sd 4:0:0:0: [sde] Sense Key : Aborted Command [current] [descriptor] [ 43.776092] Descriptor sense data with sense descriptors (in hex): [ 43.776097] 72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00 [ 43.776112] 00 00 00 00 [ 43.776118] sd 4:0:0:0: [sde] Add. Sense: No additional sense information [ 43.776127] end_request: I/O error, dev sde, sector 0 [ 43.776136] Buffer I/O error on device sde, logical block 0 [ 43.776170] ata5: EH complete [ 43.776187] ata5.00: detaching (SCSI 4:0:0:0) root@core:~# cat /proc/interrupts CPU0 0: 47 IO-APIC-edge timer 1: 8 IO-APIC-edge i8042 6: 3 IO-APIC-edge floppy 7: 0 IO-APIC-edge parport0 8: 0 IO-APIC-edge rtc0 9: 0 IO-APIC-fasteoi acpi 14: 53069 IO-APIC-edge pata_sis 15: 53004 IO-APIC-edge pata_sis 17: 112265 IO-APIC-fasteoi sata_sil 18: 200002 IO-APIC-fasteoi sata_sil, SiS SI7012 19: 111140 IO-APIC-fasteoi eth0 20: 0 IO-APIC-fasteoi ohci_hcd:usb2 21: 0 IO-APIC-fasteoi ohci_hcd:usb3 23: 0 IO-APIC-fasteoi ehci_hcd:usb1 NMI: 0 Non-maskable interrupts LOC: 6650492 Local timer interrupts SPU: 0 Spurious interrupts CNT: 0 Performance counter interrupts PND: 0 Performance pending work RES: 0 Rescheduling interrupts CAL: 0 Function call interrupts TLB: 0 TLB shootdowns TRM: 0 Thermal event interrupts THR: 0 Threshold APIC interrupts MCE: 0 Machine check exceptions MCP: 160 Machine check polls ERR: 0 MIS: 0 root@core:~# lspci | grep Raid 00:09.0 RAID bus controller: Silicon Image, Inc. SiI 3114 [SATALink/SATARaid] Serial ATA Controller (rev 02) 00:0a.0 RAID bus controller: Silicon Image, Inc. SiI 3114 [SATALink/SATARaid] Serial ATA Controller (rev 02) root@core:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 9.10 Release: 9.10 Codename: karmic root@core:~# uname -a Linux core.topper.me.uk 2.6.31-20-generic #58-Ubuntu SMP Fri Mar 12 05:23:09 UTC 2010 i686 GNU/Linux I've tried a combination of different kernel options (irqpoll, noapic, noacpi, pci=noapic) all to no avail. Does anyone have any bright ideas about how I can go about making this work? Swapping PCI cards around isn't an option as there are only two slots in this motherboard (an ASRock K7S41GX). The BIOS doesn't look to have too much in the way of configuration options regarding IRQ usage. Plan B is to ditch this server completely and buy a new QNAP for these drives to go in, but I was hoping to avoid doing this right now.

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  • Prevent auto mounting Android sdcard under Linux Mint

    - by BullShark
    I recently obtained an older Android phone, so that I could test Android Apps on it. I've needed it because I have a Nexus 7 but not older Android versions, hardware, etc. to test on. I'm having a problem with it under Linux Mint with Cinnamon. When I plug the phone in, or remove and plug the sdcard from the phone back to it while the phone is plugged in, Linux automatically mounts the sdcard. This is a problem because once it is mounted under Linux, it dismounts from the phone running Android 2.3.5, and I can no longer test Android Apps I write that require the sdcard to be present, writable. I went to Menu System Tools System Settings System Details Removable Media, and it brings up this window. I have changed the settings to always "Ask what to do" on "Select how media should be handled". However, the sdcard still gets mounted and then I am asked how I want to open these files (media players, photo importers, file browser, etc.). If I click the checkbox for "Never prompt or start programs on media insertion", then the sdcard is mounted, and I am not asked how to open these files. Eject is just a noob word for Ubuntu users that means umount (unmount) like "Adminstrator" is another ubuntu noob word for the root user. And if I unmount the sdcard, the phone doesn't recognize it again until I take the sdcard out and plug it back in. The phone sees it for a brief moment until Linux Mint takes it over. There are 2 possible solutions and maybe more: 1) Prevent Linux from automounting sdcards some how 2) Tell Android not to allow the computer it is plugged into to take over the sdcard, HOW? Edit: I found out how to prevent the sdcard from being automatically mounted: Now it gets recognized by Linux: bullshark@beastlinux ~ $ dmesg | tail -n 25 [597212.218323] sd 21:0:0:0: [sde] Attached SCSI removable disk [597212.218639] sr 21:0:0:1: Attached scsi CD-ROM sr2 [597212.218910] sr 21:0:0:1: Attached scsi generic sg7 type 5 [597217.139373] sd 21:0:0:0: [sde] 3862528 512-byte logical blocks: (1.97 GB/1.84 GiB) [597217.140726] sd 21:0:0:0: [sde] No Caching mode page present [597217.140735] sd 21:0:0:0: [sde] Assuming drive cache: write through [597217.143595] sd 21:0:0:0: [sde] No Caching mode page present [597217.143602] sd 21:0:0:0: [sde] Assuming drive cache: write through [597217.152240] sde: sde1 [597389.751008] 4:2:1: cannot get freq at ep 0x84 [597390.238742] 4:2:1: cannot get freq at ep 0x84 [597624.903132] sde: detected capacity change from 1977614336 to 0 [597637.677763] sd 21:0:0:0: [sde] 3862528 512-byte logical blocks: (1.97 GB/1.84 GiB) [597637.679616] sd 21:0:0:0: [sde] No Caching mode page present [597637.679626] sd 21:0:0:0: [sde] Assuming drive cache: write through [597637.682508] sd 21:0:0:0: [sde] No Caching mode page present [597637.682515] sd 21:0:0:0: [sde] Assuming drive cache: write through [597637.692758] sde: sde1 [597661.857979] sde: detected capacity change from 1977614336 to 0 [597688.775455] sd 21:0:0:0: [sde] 3862528 512-byte logical blocks: (1.97 GB/1.84 GiB) [597688.776814] sd 21:0:0:0: [sde] No Caching mode page present [597688.776823] sd 21:0:0:0: [sde] Assuming drive cache: write through [597688.780055] sd 21:0:0:0: [sde] No Caching mode page present [597688.780062] sd 21:0:0:0: [sde] Assuming drive cache: write through [597688.788639] sde: sde1 bullshark@beastlinux ~ $ However, the phone still unmounts the sdcard upon being detected by Linux. Linux detects but does not mount, and a few seconds later: Edit #2 (Solution): I solved this one by changing the usb connection type (was usb mass storage) :

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  • BSOD & System Failure after trying to install a new RAM

    - by Praveen Kumar
    I have updated the question with sections, so that people won't find it difficult to read. Basic System Information Let me give a basic introduction on my system. I have a system of following configuration: Processor: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz 3.40GHz RAM: Corsair Vengeance - 4GB Single Module DDR3 Memory Kit (CMZ4GX3M1A1600C9) x 2 OS: Windows 7 Ultimate, SP1 Build 7601 HDD: 1 TB Seagate 7200 RPM The Problem It was working fine for about an year. Yesterday I planned to increase my RAM to 16 GB by putting another set of two Corsair Vengeance - 4GB Single Module DDR3 Memory Kit (CMZ4GX3M1A1600C9). I got it from an authorized reseller and also, the RAM was fitted by a service engineer only. After the RAM was fit (all the four), the system failed to start, with an error code of 0x000000f4. The complete information of it is: Problem signature: Problem Event Name: BlueScreen OS Version: 6.1.7601.2.1.0.256.1 Locale ID: 16393 Additional information about the problem: BCCode: f4 BCP1: 0000000000000003 BCP2: FFFFFA8008A39060 BCP3: FFFFFA8008A39340 BCP4: FFFFF800037C8510 OS Version: 6_1_7601 Service Pack: 1_0 Product: 256_1 Files that help describe the problem: C:\Windows\Minidump\093012-13041-01.dmp C:\Users\Praveen Kumar\AppData\Local\Temp\WER-30716-0.sysdata.xml Read our privacy statement online: http://go.microsoft.com/fwlink/?linkid=104288&clcid=0x0409 If the online privacy statement is not available, please read our privacy statement offline: C:\Windows\system32\en-US\erofflps.txt Another Problem We first thought that it was the RAM, which caused the issue. So I returned the RAMs and now my computer configuration is exactly how it was the previous day. But, following the removal of the RAM, I also had several crashes after that. One suspicious thing was with an error code c0000134: STOP: c0000135 The program can’t start because %hs is missing from your computer . Try resintalling the program to fix this problem. After reading contents from this, this and this, which were never my case, they didn't help me. But I didn't receive any more STOP c0000134 messages. But this 0x000000f4 keeps on coming. I am writing from the same system and it allows me to work for say, half an hour max. Then I hear a device disconnect sound, the one you hear in Windows 7, when a USB Mass Storage Device is plugged out. Immediately following that, my screen goes blank and I get 0x000000f4 blue screen. Okay, now I am really concerned about my Hard Disk data, but I have no clue if there is a problem with the HDD. My Question What all files do I need to submit for your reference? Can this issue be fixed? I am getting more time if I remove my RAM, clean it and then put it back. Weird! Hope I have given the necessary information to help you guys. Thanks in advance. Minidumps I have uploaded all the Minidump DMP files from C:\Windows\Minidump folder here: http://www.praveen-kumar.com/Minidumps.zip Let me know if you face any issues in accessing it. Will be able to share elsewhere. Updates 30-Sep-2012 10:15 AM IST: When I keep the system cover opened, pressed the HDD Cable well, it is allowing me to be on for about half an hour, I guess? Also, I feel that the CPU fan speed is kind of slow. It rotates at around 900 RPM, but the CPU Temperature is not more than 70° C. 30-Sep-2012 10:30 AM IST: My Modem (Beetel 220BX ADSL2+ Router) failed. I have no idea how it is related to this issue, but I thought that I need to document this too. I really have a bad day here. 30-Sep-2012 11:00 AM IST: System still running fine, with the cabinet cover open, now for about an hour. 30-Sep-2012 12:00 PM IST: I shut down the system and closed the cabinet. Started the system, and it hung after giving the password. After a few minutes, got the same 0x000000f4 error. So, while it is in the upright position, fixed the Hard Disk cable and now it is booting fine. Waiting for more observations and answers.

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  • How to transfer data between two networks efficiently

    - by Tono Nam
    I would like to transfer files between two places over the internet. Right now I have a VPN and I am able to browse, download and transfer files. So my question is not really how to transfer the files; Instead, I would like to use the most efficient approach because the two places constantly share a lot of data. The reason why I want to get rid of the VPN is because it is two slow. Having high upload speed is very expensive/impossible in residential places so I would like to use a different approach. I was thinking about using programs such as http://www.dropbox.com . The problem with Dropbox is that the free version comes with only 2 GB of storage. I think the deals they offer are OK and I might be willing to pay to get that increase in speed. But I am concerned with the speed of transferring data. Dropbox will upload the file to their server then send it from the server to the other location. I would like it to be even faster. Anyway I was thinking why not create a program myself. This is the algorithm that I was thinking of. Let me know if it sounds too crazy. (Remember my goal is to transfer files as fast as possible) Things that I will use in this algorithm: Server on the internet called S (Has fast download and upload speed. I pay to host a website and some services in there. I want to take advantage of it.) Client A at location 1 Client B at location 2 So lets say at location 1, 20 large files are created and need to be transferred to location 2. Client A compresses the files with the highest compression ratio possible. Client A starts sending data via UDP to client B. Because I am using UDP I will include the sequence number on each packet. Have server S help speed up things. For example every time a packet is lost we can use Server S to inform client A that it needs to resend a packet. Anyways I think this approach will increase the transfer rate. I do not know if it is possible to start sending data while it is being compressed. Or if it is possible to start decompressing data even if we are not done receiving the whole file. Maybe it will be faster to start sending the files right away without compressing. If I knew that I will always be sending large text files then I will obviously use the compression. I need this as a general algorithm. So I guess my question is could I increase performance by using UDP instead of TCP and by using an extra server to keep track of lost packets? And how should I compress files before sending? Compressing a 1 GB file with the highest compression ratio takes about 1 hour! I would like to take advantage of that time by sending it as it is being compressed.

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  • How to transfer data between two netowks efficiently

    - by Tono Nam
    I will like to transfer files between two places over the internet. Right now I have a VPN and I am able to browse, download and transfer files. So my question is not really how to transfer the files; Instead, I will like to use the most efficient approach because the two places constantly share a lot of data. The reason why I want to get rid of the vpn is because it is two slow. Having high upload speed is very expensive/impossible on residential places so I will like to use a different approach. I was thinking about using programs such as http://www.dropbox.com . The problem with dropbox is it only enables 2 GB of storage in order for it to be free. I think the deals they offer are ok and I might be willing to pay to get that increase in speed. But I am concerned with the speed of transferring data. Dropbox will upload the file to their server then send it from the server to the other location. I will like it even faster lol. Anyways I was thinking why not create a program my self. This is the algorithm that I was thinking let me know if it sounds to crazy. (remember my goal is to transfer files as fastest as possible) Things that I will use in this algorithm: Server on the internet called S ( has fast download and upload speed. I pay to host a website and some services in there. I want to take advantage of it) Client A on location 1 Client B on location 2 So lets say on location 1 20 large files are created and need to be transferred to location 2. Client A compresses the files with the highest compression ratio possible. Client A starts sending data via UDP to client B. Because I am using UDP I will include the sequence number on each package. Have server S help speed up things. For example every time a package is lost we can use Server S to inform client A that it needs to resend a package. Anyways I think this approach will increase the transfer rate. I do not know if it is possible to start sending data meanwhile it is being compressed. Also if it is possible to start decompressing data even if we are not done receiving all the info. Maybe it will be faster to start sending the files right away without compressing. If I knew that I will always be sending large text files then I will obviously use the compression. I need this as a general algorithm. So i guess my question is should using UDP over TCP could increase performance by using an extra server to keep track of lost packages? and How should I compress files before sending? compressing a 1 GB file with the highest compression ration takes about 1 hour! I will like to take advantage of that time by sending it meanwhile it is compressed.

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  • Something very strange with network

    - by Rodnower
    Hello, I have Windows 7 and I have very strange thing with my network. Some time I was connected through wireless router and my IP was 192.168.2.103, router's IP was 192.168.2.1 and some other IP was 192.168.2.100. The last I get from page "active DHCP clients" of web interface of the router and from "wireless clients" I may to see that 192.168.2.100 not (!) belong to my MAC address. Router build by EDimax. So after that I disabled wireless function of the router and restarted it. In this time I had not ping to 192.168.2.1. Also I had not any other connection, not wireless nor cable, but (!) I still had ping to 192.168.2.100 and I not understand what this voodoo is... C:\Users\Andrey>ping 192.168.2.100 Pinging 192.168.2.100 with 32 bytes of data: Reply from 192.168.2.100: bytes=32 time<1ms TTL=128 Reply from 192.168.2.100: bytes=32 time<1ms TTL=128 Reply from 192.168.2.100: bytes=32 time<1ms TTL=128 Reply from 192.168.2.100: bytes=32 time<1ms TTL=128 Ping statistics for 192.168.2.100: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms This is what I had: C:\Users\Andrey>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : Andrey-PC Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Wireless LAN adapter Wireless Network Connection 3: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter #2 Physical Address. . . . . . . . . : 06-1D-7D-40-61-EB DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Wireless LAN adapter Wireless Network Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Gigabyte GN-WS50G (mini) PCI-E WLAN Card Physical Address. . . . . . . . . : 00-1D-7D-40-61-EB DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Ethernet adapter Local Area Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Marvell Yukon 88E8055 PCI-E Gigabit Ethernet Controller Physical Address. . . . . . . . . : 00-1B-24-B6-09-91 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes C:\Users\Andrey>arp -a -v Interface: 127.0.0.1 --- 0x1 Internet Address Physical Address Type 224.0.0.22 static 239.255.255.250 static Interface: 0.0.0.0 --- 0xffffffff Internet Address Physical Address Type 192.168.2.1 00-0e-2e-d2-8c-af invalid 192.168.2.255 ff-ff-ff-ff-ff-ff static 224.0.0.22 01-00-5e-00-00-16 static 224.0.0.252 01-00-5e-00-00-fc static 239.255.255.250 01-00-5e-7f-ff-fa static 255.255.255.255 ff-ff-ff-ff-ff-ff static Interface: 0.0.0.0 --- 0xffffffff Internet Address Physical Address Type 192.168.2.1 00-0e-2e-ff-f1-f6 dynamic 192.168.2.101 00-27-19-bc-8b-9c dynamic 192.168.2.102 00-16-e6-6c-ae-d4 dynamic 192.168.2.255 ff-ff-ff-ff-ff-ff static 224.0.0.22 01-00-5e-00-00-16 static 224.0.0.252 01-00-5e-00-00-fc static 239.255.255.250 01-00-5e-7f-ff-fa static 255.255.255.255 ff-ff-ff-ff-ff-ff static Interface: 0.0.0.0 --- 0xffffffff Internet Address Physical Address Type 224.0.0.22 01-00-5e-00-00-16 static 255.255.255.255 ff-ff-ff-ff-ff-ff static C:\Users\Andrey>route print =========================================================================== Interface List 14...06 1d 7d 40 61 eb ......Microsoft Virtual WiFi Miniport Adapter #2 13...00 1d 7d 40 61 eb ......Gigabyte GN-WS50G (mini) PCI-E WLAN Card 11...00 1b 24 b6 09 91 ......Marvell Yukon 88E8055 PCI-E Gigabit Ethernet Controller 1...........................Software Loopback Interface 1 =========================================================================== IPv4 Route Table =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 127.0.0.0 255.0.0.0 On-link 127.0.0.1 306 127.0.0.1 255.255.255.255 On-link 127.0.0.1 306 127.255.255.255 255.255.255.255 On-link 127.0.0.1 306 224.0.0.0 240.0.0.0 On-link 127.0.0.1 306 255.255.255.255 255.255.255.255 On-link 127.0.0.1 306 =========================================================================== Persistent Routes: None IPv6 Route Table =========================================================================== Active Routes: If Metric Network Destination Gateway 1 306 ::1/128 On-link 1 306 ff00::/8 On-link =========================================================================== Persistent Routes: None Only after reboot I lost ping to there: C:\Users\Andrey>ping 192.168.2.100 Pinging 192.168.2.100 with 32 bytes of data: PING: transmit failed. General failure. PING: transmit failed. General failure. PING: transmit failed. General failure. PING: transmit failed. General failure. Ping statistics for 192.168.2.100: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), So what this mysterious cache is? Thank you for ahead.

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  • Using "route add" to tell my computer to use a direct ethernet connexion instead of wifi ?

    - by TheSamFrom1984
    2 PCs are involved. Both are connected to the internet via Wifi on the same router. I can ping to/from each other and share folders flawlessly, but I'd like to be able to set a direct Ethernet link between them to speed up file transfers AND keep the Wifi connections (no gateway). So I plugged my RJ45 cable, and set up the connection. It works, but the PCs are only using this connection if one of them if disconnected from the Wifi. PC1 local address is 192.168.0.7 on its ethernet interface, and 192.168.1.21 on the wifi one. PC2 local address is 192.168.0.6 on its ethernet interface, and 192.168.1.22 on the wifi one. My question is : I'd like to using the route add command to tell PC1 to use the Ethernet interface when it needs to connect with PC2, by specifying "IF 2" at the end of the route add command. How can I do this ? I don't know what to put in the "gateway" parameter of the command, and everything I tried returns "the parameter is incorrect" (i don't know which one). ipconfig /all on PC1 : Windows IP Configuration Host Name . . . . . . . . . . . . : Sam-PC Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Wireless LAN adapter Wireless Network Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : NETGEAR WG111v3 54Mbps Wireless USB 2.0 Adapter Physical Address. . . . . . . . . : 00-22-3F-DA-51-56 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::1d33:60b:476c:d396%12(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.1.21(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : vendredi 27 novembre 2009 15:38:48 Lease Expires . . . . . . . . . . : dimanche 29 novembre 2009 07:33:04 Default Gateway . . . . . . . . . : 192.168.1.1 DHCP Server . . . . . . . . . . . : 192.168.1.1 DHCPv6 IAID . . . . . . . . . . . : 301998655 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-7E-58-EA-00-1A-4D-59-B2-71 DNS Servers . . . . . . . . . . . : 192.168.1.1 NetBIOS over Tcpip. . . . . . . . : Enabled Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller Physical Address. . . . . . . . . : 00-1A-4D-59-B2-71 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::f598:c3a0:df8d:706e%11(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.0.7(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : DHCPv6 IAID . . . . . . . . . . . : 234887757 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-7E-58-EA-00-1A-4D-59-B2-71 DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1 fec0:0:0:ffff::2%1 fec0:0:0:ffff::3%1 NetBIOS over Tcpip. . . . . . . . : Enabled

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