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• Hardware specs for web cache

  - by Raj

  I am looking for recommendations for hardware specs for a server that needs to be a web cache for a user population of about 2,000 concurrent connections. The clients are viewing segmented HTTP video in bitrates ranging from 150kbps to 2mbps. Most video is "live" meaning segments of 2-10 secs each, of which 100 or so are maintained at a time. There are also some pre-recorded fixed length videos. How would I go about doing the provisioning calculation for such a server: What kind of HDD (SSD?), how many NICs how much RAM etc? I am thinking of using Varnish on Linux, all the RAM I can get my hands on, 2 CPUs with 6-8 cores each.

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• help('modules') crashing? Not sure how to fix..

  - by Chris

  I was trying to install a module for opencv and added an opencv.pth file to the folder beyond my sites.py file. I have since deleted it and no change. When I try to run help('modules'), I get the following error: Please wait a moment while I gather a list of all available modules... /System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/words/im/init.py:8: UserWarning: twisted.im will be undergoing a rewrite at some point in the future. warnings.warn("twisted.im will be undergoing a rewrite at some point in the future.") /System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/pkgutil.py:110: DeprecationWarning: The wxPython compatibility package is no longer automatically generated or actively maintained. Please switch to the wx package as soon as possible. import(name) Traceback (most recent call last): File "", line 1, in File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site.py", line 348, in call return pydoc.help(*args, **kwds) File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/pydoc.py", line 1644, in call self.help(request) File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/pydoc.py", line 1681, in help elif request == 'modules': self.listmodules() File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/pydoc.py", line 1802, in listmodules ModuleScanner().run(callback) File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/pydoc.py", line 1853, in run for importer, modname, ispkg in pkgutil.walk_packages(): File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/pkgutil.py", line 110, in walk_packages import(name) File "/BinaryCache/wxWidgets/wxWidgets-11~262/Root/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/wxaddons/init.py", line 180, in import_hook File "/Library/Python/2.5/site-packages/ctypes_opencv/init.py", line 19, in from ctypes_opencv.cv import * File "/BinaryCache/wxWidgets/wxWidgets-11~262/Root/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/wxaddons/init.py", line 180, in import_hook File "/Library/Python/2.5/site-packages/ctypes_opencv/cv.py", line 2567, in ('desc', CvMat_r, 1), # CvMat* desc File "/Library/Python/2.5/site-packages/ctypes_opencv/cxcore.py", line 114, in cfunc return CFUNCTYPE(result, *atypes)((name, dll), tuple(aflags)) AttributeError: dlsym(0x2674d10, cvCreateFeatureTree): symbol not found What gives?!

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• Making a visual bar timer for iPhone

  - by Ohmnastrum

  I've looked up all results for progress bars and changing the width of an image but it only refers to scaling, and the progress bars aren't customizable so that they fit other functions or design schemes... unless I missed that part. I'm trying to make a bar timer that crops off of the right over a period of time. I tried using an NStimer so that it would subtract from a value each time its function is called. the Timerbar function gets called as a result of another timer invalidating and it works. What doesn't work is that the width isn't changing just the position. further more I keep getting values like Inf and 0 for power and pwrBarWidth I was sure that the changes would occur when Mult was plugged into the equation. it seems like casting mult as an int is causing problems but i'm not sure exactly how. int pwrBarMaxWidth = 137; int pwrBarWidth 0; int limit = 1; float mult; float power = 0; -(void) Timerbar:(NSTimer *)barTimer { if(!waitForPlayer) { [barTimer invalidate]; } if(mult > 0.0) { mult -= 0.001 * [colorChoices count]; if(mult < 0.0) { mult = 0.0; } } power = (mult * 10) / pwrBarMaxWidth; pwrBarWidth = (int)power % limit; // causes the bar to repeat after it reaches a certain point //At this point however the variable Power is always "inf" and PwrBarWidth is always 0. [powerBar setBounds:CGRectMake(powerBar.frame.origin.x, powerBar.frame.origin.y,pwrBarWidth,20)]; //supposed to change the crop of the bar } Any reason why I'm getting inf as a value for power, 0 as a value for pwrBarWidth, and the bar itself isn't cropping? if this question is a bit vague i'll provide more information as needed.

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• Calculating collission for a moving circle, without overlapping the boundaries

  - by Robert Vella

  Let's say I have circle bouncing around inside a rectangular area. At some point this circle will collide with one of the surfaces of the rectangle and reflect back. The usual way I'd do this would be to let the circle overlap that boundary and then reflect the velocity vector. The fact that the circle actually overlaps the boundary isn't usually a problem, nor really noticeable at low velocity. At high velocity it becomes quite clear that the circle is doing something it shouldn't. What I'd like to do is to programmitically take reflection into account and place the circle at it's proper position before displaying it on the screen. This means that I have to calculate the point where it hits the boundary between it's current position and it's future position -- rather than calculating it's new position and then checking if it has hit the boundary. This is a little bit more complicated than the usual circle/rectangle collission problem. I have a vague idea of how I should do it -- basically create a bounding rectangle between the current position and the new position, which brings up a slew of problems of it's own (Since the rectangle is rotated according to the direction of the circle's velocity). However, I'm thinking that this is a common problem, and that a common solution already exists. Is there a common solution to this kind of problem? Perhaps some basic theories which I should look into?

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• netgear GS108TV2 RSTP configuration

  - by jhowland

  I have a large set of GS108TV2 units--my goal is to set up a network which is comprised of several loops for redundancy/fault tolerance. I have a minimal 3 switch loop configured, with RSTP enabled on two ports on each switch. I have my bridge max age set to 6, and my bridge forward delay set to 4, which are the minimum values allowed. Hello time is fixed at 2 seconds. The switches respond to a cable being removed from a socket, but it takes too long. I cannot get the switch to respond to a loss of connection on one of the redundant ports in less than 20 seconds. Is there any way to configure these switches to respond faster than 20 seconds? That is unacceptable for my application. thanks in advance for any help

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• Selecting row in SSMS causes Entity Framework 4 to Fail

  - by Eric J.

  I have a simple Entity Framework 4 unit test that creates a new record, saves it, attempts to find it, then deletes it. All works great, unless... ... I open up SQL Server Management Studio while stopped at a breakpoint in the unit test and execute a SELECT statement that returns the row I just created (not SELECT FOR UPDATE, not WITH (updlock), no transaction, just a plain SELECT). If I do that before attempting to find the row I just created, I don't find the row. If I instead do that after finding the row but before deleting the row, I do find the row but get an OptimisticConcurrencyException. This is consistently repeatable. Unit Test: [TestMethod()] public void CreateFindDeleteActiveParticipantsTest() { // Setup this test Participant utPart = CreateUTParticipant(); ctx.Participants.AddObject(utPart); ctx.SaveChanges(); // External SELECT Point #1: // part is null // Find participant Participant part = ParticipantRepository.Find(UT_SURVEY_ID, UT_TOKEN); Assert.IsNotNull(part, "Expected to find a participant"); // External SELECT Point #2: // SaveChanges throws OptimisticConcurrencyException // Cleanup this test ctx.Participants.DeleteObject(utPart); ctx.SaveChanges(); }

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• R Tree 50,000 foot overview?

  - by roufamatic

  I'm working on a school project that involves taking a lat/long point and finding the top five closest points in a known list of places. The list is to be stored in memory, with the caveat that we must choose an "appropriate data structure" -- that is, we cannot simply store all the places in an array and compare distances one-by-one in a linear fashion. The teacher suggested grouping the place data by US State to prevent calculating the distance for places that are obviously too far away. I think I can do better. From my research online it seems like an R-Tree or one of its variants might be a neat solution. Unfortunately, that sentence is as far as I've gotten with understanding the actual technique, as the literature is simply too dense for my non-academic head. Can somebody give me a really high overview of what the process is for populating an R-Tree with lat/long data, and then traversing the tree to find those 5 nearest neighbors of a given point? Additionally the project is in C, and I don't have to reinvent the wheel on this, so if you've used an existing open source C implementation of an R Tree I'd be interested in your experiences.

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• Unreadable sectors reported by smartd, is it serious?

  - by stribika

  I have a RAID 5 array of 4 disks. In the last 2 days I began to see these messages in the log: Jun 13 23:01:05 localhost smartd[4537]: Device: /dev/sda [SAT], 1 Currently unreadable (pending) sectors Jun 13 23:01:05 localhost smartd[4537]: Device: /dev/sdb [SAT], 2 Currently unreadable (pending) sectors If I have 2 faulty disks then the array should not show all disks OK: md0 : active raid1 sdd1[3] sdb1[1] sdc1[2] sda1[0] 64128 blocks [4/4] [UUUU] Strangely there are no other problems just the log messages. I am worried because sda is new and I previously had problems with sdb. (Completely died but the guy who sold it to me fixed it somehow.) Am I in danger of losing data? What should I do now?

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• Removing specific tags in a KML file

  - by Legion

  I have a KML file which is a list of places around the world with coordinates and some other attributes. It looks like this for one place: <Placemark> <name>Albania - Durrës</name> <open>0</open> <visibility>1</visibility> <description>(Spot ID: 275801) show <![CDATA[<a href="http://www.windguru.cz/int/index.php?go=1&vs=1&sc=275801">forecast</a>]]></description> <styleUrl>#wgStyle001</styleUrl><Point> <coordinates>19.489747,41.277806,0</coordinates> </Point> <LookAt><range>200000</range><longitude>19.489747</longitude><latitude>41.277806</latitude></LookAt> </Placemark> I would like to remove everything except the name of the place. So in this case that would mean I would like to remove everything except <name>Albania - Durrës</name> The problem is, this KML file includes more than 1000 of these places. Doing this manually obviously isn't an option, so then how can I remove all tags except for the name tags for all of the items in the list? Can I use some kind of program for that?

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• How Do I Parse a String?

  - by Russ

  I am new to bash, and I am creating a script that loops through the files in a directory and based on part of the filename, does something with the file, so far I have this: #!/bin/bash DIR="/Users/me/Documents/import/*" for f in "$DIR" do $t=?????? echo "Loading $f int $t..." done so $f will output something like this: /Users/me/Documents/import/time_dim-1272037430173 out of this, I want time_dim, the directory can be variable length and -1272037430173 is a fixed length (it's the unix timestamp btw). What is the best way to go about this?

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• Will 5 Terabyte NAS drive be compatible with Windows XP SP3 32 bit?

  - by TrevorBoydSmith

  (NOTE: The operating system (in this case Windows XP SP3 32 bit) we are using is not a choice.) I am trying to setup a short term storage device. First, I found a large 5 Terabyte NAS drive that would IMO fulfill my storage requirements. Second, I also found that Windows XP seems to have a hard drive size limit (see 'Is there a limit to the size of a hard drive for Windows XP pre-SP1?'): XP should handle up to 2 TB per volume after the service packs are applied. You are correct. There was a 137gb limit on the orginal pre service pack windows xp. This was addressed/fixed in SP1. My question is, will my Windows XP SP3 32 bit machine see the 5 Terabyte NAS and be able to read/write properly to the NAS drive?

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• ctypes DLL with optional dependencies

  - by pisswillis

  Disclaimer: I'm new to windows programming so some of my assumptions may be wrong. Please correct me if so. I am developing a python wrapper for a C API using ctypes. The API ships with both 64 and 32 DLLs/LIBs. I can succesfully load the DLL using ctypes.WinDLL('TheLibName') and call functions etc etc. However some functions were not doing what they should. Upon further investigation it appears that the 32bit DLL is being used, which is what is causing the unexpected behaviour. I have tried using ctypes.WinDLL('TheLibName64') but the module is not found. I have tried registering the DLL with regsrv32, but it reports there is no entry point (it also reports no entry point when I try and register TheLibName, which is found by WinDLL(). The DLL came with a sample project in Visual Studio (I have 0 experience with VS so again please correct me here) which builds both 32 and 64 bit versions of the sample project. In the .vcsproj file the configurations for the 64 bit version include: AdditionalDependencies="TheLibName64.lib" in the VCLinkerTool section. In windows/system32 there are both TheLibName.dll/.lib, and TheLibName64.dll/.lib. So it seems to me that my problem is now to make the python ctypes DLL loader load these optional dependencies when the DLL is loaded. However I can't find any information on this (perhaps because, as a doze noob, I do not know the correct terminology) in the ctypes documentation. Is there a way to do this in ctypes? Am I going about this in completely the wrong way? Any help or general information about optional DLL dependencies and how they are loaded in windows would be much appreciated. Thanks

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• E: The package adobe-flashplugin needs to be reinstalled, but I can't find an archive for it. Ubuntu 9.10

  - by Paikkos

  I had some problems with amarok player, I couldn't get any sound from it. Anyway, I fixed it somehow, from terminal, with some packages, after a couple of reboots, now I have problem with the adobe-flashplugin. I'm trying this in terminal but: sudo apt-get install adobe-flashplugin Reading package lists... Done Building dependency tree Reading state information... Done E: The package adobe-flashplugin needs to be reinstalled, but I can't find an archive for it. I also tried the update manager, but I get something about partial upgrade but that thing also isnt working, and I get a message that I have to install it manually or I remove it completely. So, how can I remove it completely and then I will install it clean again from the beggining?

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• How to differentiate between method and function in a decorator?

  - by defnull

  I want to write a decorator that acts differently depending on whether it is applied to a function or to a method. def some_decorator(func): if the_magic_happens_here(func): # <---- Point of interest print 'Yay, found a method ^_^ (unbound jet)' else: print 'Meh, just an ordinary function :/' return func class MyClass(object): @some_decorator def method(self): pass @some_decorator def function(): pass I tried inspect.ismethod(), inspect.ismethoddescriptor() and inspect.isfunction() but no luck. The problem is that a method actually is neither a bound nor an unbound method but an ordinary function as long as it is accessed from within the class body. What I really want to do is to delay the actions of the decorator to the point the class is actually instantiated because I need the methods to be callable in their instance scope. For this, I want to mark methods with an attribute and later search for these attributes when the .__new__() method of MyClass is called. The classes for which this decorator should work are required to inherit from a class that is under my control. You can use that fact for your solution. In the case of a normal function the delay is not necessary and the decorator should take action immediately. That is why I wand to differentiate these two cases.

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• Disk controller speed responsible for slow write speeds?

  - by vizvayu

  I have question. I'm using ESXi 4.0U1 in an IBM x3200M2 with an integrated LSI 1064e RAID controller, without any kind of cache. I have 3 250GB HOT-SWAP SATA HDs configured in RAID1E (IME). ESXi works fine, read speed are quite OK, but write speeds are incredible slow, never more than 8MB/s, and this is the best case scenario, benchmarking with iozone streaming writes, using a VMWare Paravirtual controller and with only this VM active, no swapping of any kind (total vm memory reserved). Already wrote to IBM but I don't have any kind of pay support so they didn't even answered, so I'm just wondering... anybody has any experience with a similar setup? I just want to be sure this is hardware related and can't be fixed with some kind of config option, because I'm thinking on buying a new RAID controller (Adaptec 2405 looks nice). Thanks again!

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• Is programming overrated?

  - by aengine

  [Subjective and intended to be a community wiki] I am sorry for such an offensive question: But here are my arguments Most of the progress in "computing" has came from non-programming sources. i.e. People invented faster microprocessors and better routers and novel memory devices. I dont think on average people are writting more efficient programs than those written 10 years ago. And the newer and popular languages are infact slower than C. though speed is one of the lesser criterias. Most of the progress came from novel paradigms. Web, Internet, Cloud computing and Social networking are novel paradigms and did not involve progress in programming as such. Heck even facebook was written in PHP and not some extreme language. Though it did face scalability issues (same with twitter) but i believe money and better programmers (who came in much later) took care of that. Thus ideating capability trumped programming capability/ Even things like Map-Reduce, Column oriented database and Probablistic algorithms (E.g. bloom filters) came from hardcore Algorithms research, rather than some programming convention. Thus my final point is why programming skill is so overstressed? To point a recent example about how only 10% of programmers can "write code" (binary search) without debugging. Isnt it a bit hypocritical, considering your real successs lies in coming up with better algorithm or a novel feature rather than getting right first time???

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• $this->url() to another subdomain

  - by Supertino7

  Hello, I created subdomain for my application. host_www.type = "Zend_Controller_Router_Route_Hostname" host_www.route = "www.mywebsite.com" host_www.defaults.module = "produits" host_www.defaults.controller = "produits" host_www.defaults.action = "index" fiche_boutique.route = "ficheboutique/:boutique" fiche_boutique.defaults.controller = "boutique" fiche_boutique.defaults.action = "fiche-boutique" fiche_boutique.defaults.module = "default" fiche_boutique.chain = "host_www" host_produits.type = "Zend_Controller_Router_Route_Hostname" host_produits.route = "produits.mywebsite.com" host_produits.defaults.module = "produits" host_produits.defaults.controller = "produits" host_produits.defaults.action = "index" fiche_produit.type = "Zend_Controller_Router_Route_Regex" fiche_produit.route = "([-\w]+).htm" fiche_produit.reverse = "%s.htm" fiche_produit.map.1 = "q" fiche_produit.defaults.module = "produits" fiche_produit.defaults.controller = "produits" fiche_produit.defaults.action = "voir-produit" fiche_produit.chain = "host" I don't know if the syntax in this zend config ini file is correct, in particular for routes chaining. Once I'm on this subdomain, urls constructed with $this-url() like this : <a href="<?= $this->url(array('boutique' => 1234), 'fiche_boutique', true) ?>"> Visit this store </a> still point to the subdomain produits.mywebsite.com, where I want it to point to www.mywebsite.com For the moment, I do this : <a href="http://www.mywebsite.com<?= $this->url(array('boutique' => 1234), 'fiche_boutique', true) ?>"> Visit this store </a> But it's not flexible at all. Is there a solution, a parameter to add, or my config file is wrong ? thanks in advance for your help.

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• Context path routing in Tomcat ( service swapping )

  - by jojovilco

  Here is what I would like to achieve: I have a web service A which I want to be able to deploy side by side with other web services of type A - different version(s). For now I assume 2 instances side by side. I need it because the service has a warm up stage, which takes some time to build up stuff from DB and only after it is ready it can start serving requests ... I was thinking to deploy to Tomcat context paths like: "/ServiceA-1.0", "/ServiceA-2.0" and then have a "virtual" context like "/ServiceA" which will point to the desired physical service e.g. "/ServiceA-1.0". So external world will know about ServiceA, but internally, my ServiceA related stack would know about versioned ServiceA url ( there are more components involved but only ServiceA is serving outer world ). When new service is ready, I would just reconfigure the "virtual" context to point to a new service. So far, I was not able to find out how to do this with Tomcat and starting to tkink it is not possible. I found suggestions to place Apache Server in front of Tomcat and do the routing there, but I do not want to enroll another piece of software unless necessary. My questions are: - is this kind of a "virtual" context and routing possible to do with Tomcat? - any other options, wisdom and lessons learned how to achieve this kind of service swapping scenario? Best, Jozef

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• Handling nulls in Datawarehouse

  - by rrydman

  I'd like to ask your input on what the best practice is for handling null or empty data values when it pertains to data warehousing and SSIS/SSAS. I have several fact and dimension tables that contain null values in different rows. Specifics: 1) What is the best way to handle null date/times values? Should I make a 'default' row in my time or date dimensions and point SSIS to the default row when there is a null found? 2) What is the best way to handle nulls/empty values inside of dimension data. Ex: I have some rows in an 'Accounts' dimensions that have empty (not NULL) values in the Account Name column. Should I convert these empty or null values inside the column to a specific default value? 3) Similar to point 1 above - What should I do if I end up with a Facttable row that has no record in one of the dimension columns? Do I need default dimension records for each dimension in case this happens? 4) Any suggestion or tips in regards to how to handle these operation in Sql server integration services (SSIS)? Best data flow configurations or best transformation objects to use would be helpful. Thanks :-)

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• Speedup of fixing an openssl bug with 8192 bit key [on hold]

  - by rubo77

  This is related to this Bug-Report https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=747453 OpenSSL contains a set of arbitrary limitations on the size of accepted key parameters that make unrelated software fail to establish secure connections. The problem was found while debugging a XMPP s2s connection issue where two servers with long certificate keys (8192 Bit RSA) failed to establish a secure connection because OpenSSL rejected the handshake. This seems to be a small problem to be fixed but although there is an easy patch available to fix the issue in that bug report, no reactions are noticed so far.. The last patch that broke the 2048 barrier took 2 years to be implemented and only resulted in an increase to 4096bit, which seems to be a bad joke. Where would we have to report this to speed up the implementation for such an issue?

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• Is it possible in SQLAlchemy to filter by a database function or stored procedure?

  - by Rico Suave

  We're using SQLalchemy in a project with a legacy database. The database has functions/stored procedures. In the past we used raw SQL and we could use these functions as filters in our queries. I would like to do the same for SQLAlchemy queries if possible. I have read about the @hybrid_property, but some of these functions need one or more parameters, for example; I have a User model that has a JOIN to a bunch of historical records. These historical records for this user, have a date and a debit and credit field, so we can look up the balance of a user at a specific point in time, by doing a SUM(credit) - SUM(debit) up until the given date. We have a database function for that called dbo.Balance(user_id, date_time). I can use this to check the balance of a user at a given point in time. I would like to use this as a criterium in a query, to select only users that have a negative balance at a specific date/time. selection = users.filter(coalesce(Users.status, 0) == 1, coalesce(Users.no_reminders, 0) == 0, dbo.pplBalance(Users.user_id, datetime.datetime.now()) < -0.01).all() This is of course a non-working example, just for you to get the gist of what I'd like to do. The solution looks to be to use hybrd properties, but as I mentioned above, these only work without parameters (as they are properties, not methods). Any suggestions on how to implement something like this (if it's even possible) are welcome. Thanks,

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• Opening notebooks

  - by Plastkort

  I have a Compaq CQ40 which has a defective CPU fan, it seems unable to cool the notebook enough at this time, it is constantly running, and if you move the pc up/down to look under it, it makes some sort of chainsaw sound. I have tried to take out all the screws underneath, but I still have a problem with the plastic cover on the above; I am afraid I might break it since it seem to be connected with plastic clips underneath. I have fixed notebooks before, but this one seem new, how can I open the plastic cover above without breaking it? Any advice, tips and tricks would be so nice to have, not only for this notebook, but any future notebook also I might need to repair. It would be nice if anyone here knows a place with video tutorials on this subject as well.

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• Can a conforming C# compiler optimize away a local (but unused) variable if it is the only strong re

  - by stakx

  The title says it all, but let me explain: void Case_1() { var weakRef = new WeakReference(new object()); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. if (weakRef.IsAlive) ... } In this code example, I obviously have to plan for the possibility that the new'ed object is reclaimed by the garbage collector; therefore the if statement. (Note that I'm using weakRef for the sole purpose of checking if the new'ed object is still around.) void Case_2() { var unusedLocalVar = new object(); var weakRef = new WeakReference(unusedLocalVar); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. Debug.Assert(weakReferenceToUseless.IsAlive); } The main change in this code example from the previous one is that the new'ed object is strongly referenced by a local variable (unusedLocalVar). However, this variable is never used again after the weak reference (weakRef) has been created. Question: Is a conforming C# compiler allowed to optimize the first two lines of Case_2 into those of Case_1 if it sees that unusedLocalVar is only used in one place, namely as an argument to the WeakReference constructor? i.e. is there any possibility that the assertion in Case_2 could ever fail?

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• Tracking down origin of I/O in multi-process server

  - by Craig Ringer

  I'm currently trying to track down some phantom I/O in a PostgreSQL build I'm testing. It's a multi-process server and it isn't simple to associate disk I/O back to a particular back-end and query. I thought Linux's perf tool would be ideal for this, but I'm struggling to capture block I/O performance counter metrics and associate them with user-space activity. It's easy to record block I/O requests and completions with, eg: sudo perf record -g -T -u postgres -e 'block:block_rq_*' and the user-space pid is recorded, but there's no kernel or user-space stack captured, or ability to snapshot bits of the user-space process's heap (say, query text) etc. So while you have the pid, you don't know what the process was doing at that point. Just perf script output like: postgres 7462 [002] 301125.113632: block:block_rq_issue: 8,0 W 0 () 208078848 + 1024 [postgres] If I add the -g flag to perf record it'll take snapshots of the kernel stack, but doesn't capture user-space state for perf events captured in the kernel. The user-space stack only goes up to the entry-point from userspace, like LWLockRelease, LWLockAcquire, memcpy (mmap'd IO), __GI___libc_write, etc. So. Any tips? Being able to capture a snapshot of the user-space stack in response to kernel events would be ideal.

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• Ubuntu 10.4 No internet

  - by Keeper780

  I have Ubuntu 10.4 dual booted with Windows Vista on a work Lenovo R61 laptop. The home and work wireless connection were working fine. I lost all internet connection at work. The IT guy clearly knew nothing about Linux. Since he 'fixed' it get nothing, no wlan signal the Network manager icon was gone, no internet. I still have the live disc and if I run from the live disc the connections are there and everything works perfectly. How do I restore the internet easily on my laptop. I have been using Linux for 3 Years but I am still a bit of a newbie, this is the first major problem I've had in three years. It's driving me nuts. Thanks

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