Search Results

Search found 2108 results on 85 pages for 'differences'.

Page 78/85 | < Previous Page | 74 75 76 77 78 79 80 81 82 83 84 85  | Next Page >

• When can Java produce a NaN (with specific code question)

  - by Brent

  I'm a bit perplexed by some code I'm currently writing. I am trying to preform a specific gradient descent (main loop included below) and depending on the initial conditions I will alternatively get good looking results (perhaps 20% of the time) or everything becomes NaN (the other 80% of the time). However it seems to me that none of the operations in my code could produce NaN's when given honest numbers! My main loop is: // calculate errors delta = m1 + m2 - M; eta = f1 + f2 - F; for (int i = 0; i < numChildren; i++) { epsilon[i] = p[i]*m1+(1-p[i])*m2+q[i]*f1+(1-q[i])*f2-C[i]; } // use errors in gradient descent // set aside differences for the p's and q's float mDiff = m1 - m2; float fDiff = f1 - f2; // first update m's and f's m1 -= rate*delta; m2 -= rate*delta; f1 -= rate*eta; f2 -= rate*eta; for (int i = 0; i < numChildren; i++) { m1 -= rate*epsilon[i]*p[i]; m2 -= rate*epsilon[i]*(1-p[i]); f1 -= rate*epsilon[i]*q[i]; f2 -= rate*epsilon[i]*(1-q[i]); } // now update the p's and q's for (int i = 0; i < numChildren; i++) { p[i] -= rate*epsilon[i]*mDiff; q[i] -= rate*epsilon[i]*fDiff; } This behavior can be seen when we have rate = 0.01; M = 30; F = 30; C = {15, 25, 35, 45}; with the p[i] and q[i] chosen randomly uniformly between 0 and 1, m1 and m2 chosen randomly uniformly to add to M, and f1 and f2 chosen randomly uniformly to add up to F. Does anyone see anything that could create these NaN's?

  Read the article

• Is there a Silverlight equivalent to "Application.OpenForms"?

  - by lightmeetsdark

  Basically, I'm trying to take information entered by the user on one page and print it out to another page via a "printer friendly" version, or report, of something. I have a MainPage.xaml that is, as the name suggests, my main page, but in a window there is the subpage AdCalculator.xaml where the user enters the information and PrintEstimate.xaml that is navigated to via a button on AdCalculator. I would like to be able to transfer the information entered in the textboxes from AdCalculator and print it out via text blocks in PrintEstimate. So in order to do that I have the following code: Views.AdCalculator AdCalc = new Views.AdCalculator(); string PrintCompanyName = AdCalc.CompanyName; string PrintContactName = AdCalc.txt_CustomerName.Text; string PrintBillingAddress1 = AdCalc.txt_BillingAddress.Text; string PrintBillingAddress2 = AdCalc.txt_BillingAddressLine2.Text; string PrintPhoneNumber = AdCalc.txt_PhoneNumber.Text; string PrintNumOfAds = AdCalc.txt_NumofAds.Text; string PrintRateOfPlay = AdCalc.Cmb_Rate.SelectedValue.ToString(); string PrintNumOfMonths = AdCalc.txt_NumofMonths.Text; string PrintTotalDue = AdCalc.txt_InvoiceSummary_TotalDue.Text; PrintEstimate PrintEstimatePage = new PrintEstimate(); PrintEstimatePage.txt_CompanyName.Text = PrintCompanyName; PrintEstimatePage.txt_CustomerName.Text = PrintContactName; PrintEstimatePage.txt_BillingAddress.Text = PrintBillingAddress1; PrintEstimatePage.txt_BillingAddressLine2.Text = PrintBillingAddress2; PrintEstimatePage.txt_PhoneNumber.Text = PrintPhoneNumber; PrintEstimatePage.txt_InvoiceSummary_NumofAds.Text = PrintNumOfAds; PrintEstimatePage.txt_InvoiceSummary_RateofPlay.Text = PrintRateOfPlay; PrintEstimatePage.txt_InvoiceSummary_NumOfMonths.Text = PrintNumOfMonths; PrintEstimatePage.txt_EstimateTotal.Text = PrintTotalDue; Only problem is, when I instantiate the new AdCalculator page, it clears the values, so nothing is actually retained as far as user-input goes. Following a lead from a colleague, I believe all I need to do is change the line Views.AdCalculator AdCalc = new Views.AdCalculator(); to Views.AdCalculator AdCalc = (AdCalculator)Application.OpenForms["AdCalculator"]; except the "Apllication.OpenForms" doesn't register. I know there are a lot of differences in the way C# code-behind is laid out for silverlight applications, so I didn't know if there was an equivalent that anyone knew about to "Application.OpenForms" that would help solve my issue or if there was any other way to go about getting my task done. Thank you very much!

  Read the article

• Passing custom info to mongrel_rails start

  - by whaka

  One thing I really don't understand is how I can pass custom start-up options to a mongrel instance. I see that a common approach is the use environment variables, but in my environment this is not going to work because my rails application serves many different clients. Much code is shared between clients, but there are also many differences which I implement by subclassing controllers and views to overload or extend existing features or introduce new ones. To make this all work, I simply add the paths to client specific modules the module load path ($:). In order to start the application for a particular client, I could now use an environment variable like say, TARGET=AMAZONE. Unfortunately, on some systems I'm running multiple mongrel clusters, each cluster serving a different client. Some of these systems run under Windows and to start mongrel I installed mongrel_services. Clearly, this makes my environment variable unsuitable. Passing this extra bit of data to the application is proving to be a real challenge. For a start, mongrel_rails service_install will reject any [custom] command line parameters that aren't documented. I'm not too concerned as installing the services using the install program is trivial. However, even if I manage to install mongrel_services such that when run it passes the custom command line option --target to mongrel_rails start, I get an error because mongrel_rails doesn't recognize the switch. So here were the things I looked at: Pass an extra parameter: mongrel_rails start --target XYZ ... use a config file and add target:XYZ, then do: mongrel_rails start -C x:\myapp\myconfig.yml modify the file: Ruby\lib\ruby\gems\1.8\gems\mongrel-1.1.5-x86-mswin32-60\lib\mongrel\command.rb Perhaps I can use the --script option, but all docs that I found on it were for Unix 1 and 2 simply don't work. I played with 4 but never managed it to do anything. So I had no choice but to go with 3. While it is relatively simple, I hate changing ruby library code. Particularly disappointing is that 2 doesn't work. I mean what is so unreasonable about adding other [custom] options in the config file? Actually I think this is a fundamental piece that is missing in rails. Somehow, the application should be able to register and access command line arguments it expects. If anybody has a good idea how to do this more elegantly using the current infrastructure, I have a chocolate fish to give away!!!

  Read the article

• Defined variables and arrays vs functions in php

  - by Frank Presencia Fandos

  Introduction I have some sort of values that I might want to access several times each page is loaded. I can take two different approaches for accessing them but I'm not sure which one is 'better'. Three already implemented examples are several options for the Language, URI and displaying text that I describe here: Language Right now it is configured in this way: lang() is a function that returns different values depending on the argument. Example: lang("full") returns the current language, "English", while lang() returns the abbreviation of the current language, "en". There are many more options, like lang("select"), lang("selectact"), etc that return different things. The code is too long and irrelevant for the case so if anyone wants it just ask for it. Url The $Url array also returns different values depending on the request. The whole array is fully defined in the beginning of the page and used to get shorter but accurate links of the current page. Example: $Url['full'] would return "http://mypage.org/path/to/file.php?page=1" and $Url['file'] would return "file.php". It's useful for action="" within the forms and many other things. There are more values for $Url['folder'], $Url['file'], etc. Same thing about the code, if wanted, just request it. Text [You can skip this section] There's another array called $Text that is defined in the same way than $Url. The whole array is defined at the beginning, making a mysql call and defining all $Text[$i] for current page with a while loop. I'm not sure if this is more efficient than multiple calls for a single mysql cell. Example: $Text['54'] returns "This is just a test array!" which this could perfectly be implemented with a function like text(54). Question With the 3 examples you can see that I use different methods to do almost the same function (no pun intended), but I'm not sure which one should become the standard one for my code. I could create a function called url() and other called text() to output what I want. I think that working with functions in those cases is better, but I'm not sure why. So I'd really appreciate your opinions and advice. Should I mix arrays and functions in the way I described or should I just use funcions? Please, base your answer in this: The source needs to be readable and reusable by other developers Resource consumption (processing, time and memory). The shorter the code the better. The more you explain the reasons the better. Thank you PS, now I know the differences between $Url and $Uri.

  Read the article

• PHP problems when transfering code from Windows to OS X

  - by Makka95

  I have recently bought a new MacBook Pro. Before I had my MacBook Pro I was working on a website on my desktop computer. And now I want to transfer this code to my new MacBook Pro. The problem is that when I transfered the code (I put it on Dropbox and simply downloaded it on my MacBook Pro) I started to see lots of error messages in my PHP code. The error message I”m receiving is: Warning: Cannot modify header information - headers already sent by (output started at /some/file.php:1) in /some/file.php on line 23 I have done some research on this and it seems that this error is most frequently caused by a new line, simple whitespace or any output before the <?php sign. I have looked through all the places where I have cookies that are being sent in the HTTP request and also where I'm using the header() function. I haven’t detected any output or whitespace that possibly could interfere and cause this problem. Noteworthy is that the error always says that the output is started at line 1. Which got me thinking if there is some kind of coding differences in the way that the Mac OS X and Windows operating systems handle new lines or white spaces? Or could the Dropbox transfer messed something up? The code on one of the sites(login.php) which produces the error: <?php include "mysql_database.php"; login(); $id = $_SESSION['Loggedin']; setcookie("login", $id, (time()+60*60*24*30)); header('Location: ' . $_SERVER['HTTP_REFERER']); ?> login function: function login() { $connection = connecttodatabase(); $pass = ""; $user = ""; $query = ""; if (isset($_POST['user']) && $_POST['user'] != null) { $user = $_POST['user']; if (isset($_POST['pass']) && $_POST['pass'] != null) { $pass = md5($_POST['pass']); $query = "SELECT ID FROM Anvandare WHERE Nickname='$user' AND Password ='$pass'"; } } if ($query != "") { $id = $connection->query($query); $id = mysqli_fetch_assoc($id); $id = $id['ID']; $_SESSION['Loggedin'] = $id; } closeconnection($connection); } Complete error: Warning: Cannot modify header information - headers already sent by (output started at /Users/name/GitHub/website/login.php:1) in /Users/namn/GitHub/website/login.php on line 9

  Read the article

• How does the CLR (.NET) internally allocate and pass around custom value types (structs)?

  - by stakx

  Question: Do all CLR value types, including user-defined structs, live on the evaluation stack exclusively, meaning that they will never need to be reclaimed by the garbage-collector, or are there cases where they are garbage-collected? Background: I have previously asked a question on SO about the impact that a fluent interface has on the runtime performance of a .NET application. I was particuarly worried that creating a large number of very short-lived temporary objects would negatively affect runtime performance through more frequent garbage-collection. Now it has occured to me that if I declared those temporary objects' types as struct (ie. as user-defined value types) instead of class, the garbage collector might not be involved at all if it turns out that all value types live exclusively on the evaluation stack. What I've found out so far: I did a brief experiment to see what the differences are in the CIL generated for user-defined value types and reference types. This is my C# code: struct SomeValueType { public int X; } class SomeReferenceType { public int X; } . . static void TryValueType(SomeValueType vt) { ... } static void TryReferenceType(SomeReferenceType rt) { ... } . . var vt = new SomeValueType { X = 1 }; var rt = new SomeReferenceType { X = 2 }; TryValueType(vt); TryReferenceType(rt); And this is the CIL generated for the last four lines of code: .locals init ( [0] valuetype SomeValueType vt, [1] class SomeReferenceType rt, [2] valuetype SomeValueType <>g__initLocal0, // [3] class SomeReferenceType <>g__initLocal1, // why are these generated? [4] valuetype SomeValueType CS$0$0000 // ) L_0000: ldloca.s CS$0$0000 L_0002: initobj SomeValueType // no newobj required, instance already allocated L_0008: ldloc.s CS$0$0000 L_000a: stloc.2 L_000b: ldloca.s <>g__initLocal0 L_000d: ldc.i4.1 L_000e: stfld int32 SomeValueType::X L_0013: ldloc.2 L_0014: stloc.0 L_0015: newobj instance void SomeReferenceType::.ctor() L_001a: stloc.3 L_001b: ldloc.3 L_001c: ldc.i4.2 L_001d: stfld int32 SomeReferenceType::X L_0022: ldloc.3 L_0023: stloc.1 L_0024: ldloc.0 L_0025: call void Program::TryValueType(valuetype SomeValueType) L_002a: ldloc.1 L_002b: call void Program::TryReferenceType(class SomeReferenceType) What I cannot figure out from this code is this: Where are all those local variables mentioned in the .locals block allocated? How are they allocated? How are they freed? Why are so many anonymous local variables needed and copied to-and-fro only to initialize my two local variables rt and vt?

  Read the article

• Connecting debian and windows via IPsec VPN with Racoon and ipsec-tools

  - by Michi Qne

  I've some trouble with the IPsec configuration on my debian server (6 squeeze). This server should connect via IPsec VPN to an windows server, which is protected by an firewall. I've used racoon and ipsec-tools and this tutorial http://wiki.debian.org/IPsec. However, I am not quite sure, if this tutorial fits to my purpose, because of some differences: my Host and my gateway are the same server. So I don't have two different ip addresses. I guess, that's not a problem the other server is an windows system behind a firewall. Hopefully, not a problem the subnet of the windows system is /32 not /24. So I change it to /32. I worked through the tutorial step by step, but I wasn't able to route the ip. The following command didn't work for me: ip route add to 172.16.128.100/32 via XXX.XXX.XXX.XXX src XXX.XXX.XXX.XXX So I tried the following instead: ip route add to 172.16.128.100 .., which obviously not solved the problem. The next problem is the compression. The windows doesn't use a compression, but 'compression_algorithm none;' doesn't work with my racoon. So the current value is 'compression_algorithm deflate;' So my current result looks like this: When I am trying to ping the windows host (ping 172.16.128.100), I receive the following error message from ping: ping: sendmsg: Operation not permitted And racoon logs: racoon: ERROR: failed to get sainfo. After googling for a while I came to no conclusion, what's the solution. Does this error message mean that the first phase of IPsec works? I am thankful for any advice. I guess my configs might be helpful. My racoon.conf looks like this: path pre_shared_key "/etc/racoon/psk.txt"; remote YYY.YYY.YYY.YYY { exchange_mode main; proposal { lifetime time 8 hour; encryption_algorithm 3des; hash_algorithm sha1; authentication_method pre_shared_key; dh_group 2; } } sainfo address XXX.XXX.XXX.XXX/32 any address 172.16.128.100/32 any { pfs_group 2; lifetime time 8 hour; encryption_algorithm aes 256; authentication_algorithm hmac_sha1; compression_algorithm deflate; } And my ipsec-tools.conf looks like this: flush; spdflush; spdadd XXX.XXX.XXX.XXX/32 172.16.128.100/32 any -P out ipsec esp/tunnel/XXX.XXX.XXX.XXX-YYY.YYY.YYY.YYY/require; spdadd 172.16.128.100/32 XXX.XXX.XXX.XXX/32 any -P in ipsec esp/tunnel/YYY.YYY.YYY.YYY-XXX.XXX.XXX.XXX/require; If anyone has an advice, that would be awesome. Thanks in Advance. Greets, Michael It was a simple copy-and-paste error in an ip address.

  Read the article

• Google Apps e-mail being rejected from some domains

  - by Paul J. Lucas

  I'm migrating e-mail for my domains to Google Apps' e-mail. Most everything seems to work except e-mail sent to any user at (at least) sonic.net is rejected with a message of the form (where any-address has been substituted for my friend's address): From: Mail Delivery Subsystem <[email protected]> Date: March 11, 2010 10:04:48 AM PST To: [email protected] Subject: Delivery Status Notification (Failure) Delivered-To: [email protected] Received: by 10.229.194.26 with SMTP id dw26cs8717qcb; Thu, 11 Mar 2010 10:04:48 -0800 (PST) Received: by 10.223.68.143 with SMTP id v15mr3841599fai.62.1268330688325; Thu, 11 Mar 2010 10:04:48 -0800 (PST) Received: by 10.223.68.143 with SMTP id v15mr5119424fai.62; Thu, 11 Mar 2010 10:04:48 -0800 (PST) Mime-Version: 1.0 Return-Path: <> X-Failed-Recipients: [email protected] Message-Id: <[email protected]> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Delivery to the following recipient failed permanently: [email protected] Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 5.1.1 <[email protected]>... No such user here (state 13). And here are the headers from the message it bounces back: Received: by 10.101.90.7 with SMTP id s7mr2515885anl.176.1267979929490; Sun, 07 Mar 2010 08:38:49 -0800 (PST) Return-Path: <[email protected]> Received: from [10.0.1.203] (adsl-76-201-171-194.dsl.pltn13.sbcglobal.net [76.201.171.194]) by mx.google.com with ESMTPS id 4sm1046550yxd.70.2010.03.07.08.38.48 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 07 Mar 2010 08:38:49 -0800 (PST) From: "Paul J. Lucas" <[email protected]> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: Some fascinating subject Date: Sun, 7 Mar 2010 08:38:46 -0800 References: <[email protected]> To: [email protected] Message-Id: <[email protected]> Mime-Version: 1.0 (Apple Message framework v1077) X-Mailer: Apple Mail (2.1077) However, I am able to send mail to a user at sonic.net using my old e-mail account. Also, my company uses Google Apps for e-mail and I can send e-mail to a user at sonic.net from my company. The differences between my personal e-mail and my company's are: My company's domain has no SPF record whereas mine does. My company's domain has an A record whereas mine does not. My SPF record initially was as prescribed by Google here. However, this guy claims Google is wrong and gives a fix. I've tried it both ways with no difference. My SPF record is currently: v=spf1 mx include:aspmx.googlemail.com include:_spf.google.com ~all As for the lack of an A record, you wouldn't think that a mail host would care about that so long as mx records are defined. However, the funny thing is that if you look at the error message, why does Google state that the recipient's domain stated that there is "No such user here" for my address? That makes no sense. Of course there is no user having my address at sonic.net. Also, I assume that I just discovered that I can't send mail to users at sonic.net by accident and that there are probably other domains I can't send e-mail to. So... anybody have any idea what's going on? And how I can get mail to users at sonic.net?

  Read the article

• AMD 24 core server memory bandwidth

  - by ntherning

  I need some help to determine whether the memory bandwidth I'm seeing under Linux on my server is normal or not. Here's the server spec: HP ProLiant DL165 G7 2x AMD Opteron 6164 HE 12-Core 40 GB RAM (10 x 4GB DDR1333) Debian 6.0 Using mbw on this server I get the following numbers: foo1:~# mbw -n 3 1024 Long uses 8 bytes. Allocating 2*134217728 elements = 2147483648 bytes of memory. Using 262144 bytes as blocks for memcpy block copy test. Getting down to business... Doing 3 runs per test. 0 Method: MEMCPY Elapsed: 0.58047 MiB: 1024.00000 Copy: 1764.082 MiB/s 1 Method: MEMCPY Elapsed: 0.58012 MiB: 1024.00000 Copy: 1765.152 MiB/s 2 Method: MEMCPY Elapsed: 0.58010 MiB: 1024.00000 Copy: 1765.201 MiB/s AVG Method: MEMCPY Elapsed: 0.58023 MiB: 1024.00000 Copy: 1764.811 MiB/s 0 Method: DUMB Elapsed: 0.36174 MiB: 1024.00000 Copy: 2830.778 MiB/s 1 Method: DUMB Elapsed: 0.35869 MiB: 1024.00000 Copy: 2854.817 MiB/s 2 Method: DUMB Elapsed: 0.35848 MiB: 1024.00000 Copy: 2856.481 MiB/s AVG Method: DUMB Elapsed: 0.35964 MiB: 1024.00000 Copy: 2847.310 MiB/s 0 Method: MCBLOCK Elapsed: 0.23546 MiB: 1024.00000 Copy: 4348.860 MiB/s 1 Method: MCBLOCK Elapsed: 0.23544 MiB: 1024.00000 Copy: 4349.230 MiB/s 2 Method: MCBLOCK Elapsed: 0.23544 MiB: 1024.00000 Copy: 4349.359 MiB/s AVG Method: MCBLOCK Elapsed: 0.23545 MiB: 1024.00000 Copy: 4349.149 MiB/s On one of my other servers (based on Intel Xeon E3-1270): foo2:~# mbw -n 3 1024 Long uses 8 bytes. Allocating 2*134217728 elements = 2147483648 bytes of memory. Using 262144 bytes as blocks for memcpy block copy test. Getting down to business... Doing 3 runs per test. 0 Method: MEMCPY Elapsed: 0.18960 MiB: 1024.00000 Copy: 5400.901 MiB/s 1 Method: MEMCPY Elapsed: 0.18922 MiB: 1024.00000 Copy: 5411.690 MiB/s 2 Method: MEMCPY Elapsed: 0.18944 MiB: 1024.00000 Copy: 5405.491 MiB/s AVG Method: MEMCPY Elapsed: 0.18942 MiB: 1024.00000 Copy: 5406.024 MiB/s 0 Method: DUMB Elapsed: 0.14838 MiB: 1024.00000 Copy: 6901.200 MiB/s 1 Method: DUMB Elapsed: 0.14818 MiB: 1024.00000 Copy: 6910.561 MiB/s 2 Method: DUMB Elapsed: 0.14820 MiB: 1024.00000 Copy: 6909.628 MiB/s AVG Method: DUMB Elapsed: 0.14825 MiB: 1024.00000 Copy: 6907.127 MiB/s 0 Method: MCBLOCK Elapsed: 0.04362 MiB: 1024.00000 Copy: 23477.623 MiB/s 1 Method: MCBLOCK Elapsed: 0.04262 MiB: 1024.00000 Copy: 24025.151 MiB/s 2 Method: MCBLOCK Elapsed: 0.04258 MiB: 1024.00000 Copy: 24048.849 MiB/s AVG Method: MCBLOCK Elapsed: 0.04294 MiB: 1024.00000 Copy: 23847.599 MiB/s For reference here's what I get on my Intel based laptop: laptop:~$ mbw -n 3 1024 Long uses 8 bytes. Allocating 2*134217728 elements = 2147483648 bytes of memory. Using 262144 bytes as blocks for memcpy block copy test. Getting down to business... Doing 3 runs per test. 0 Method: MEMCPY Elapsed: 0.40566 MiB: 1024.00000 Copy: 2524.269 MiB/s 1 Method: MEMCPY Elapsed: 0.38458 MiB: 1024.00000 Copy: 2662.638 MiB/s 2 Method: MEMCPY Elapsed: 0.38876 MiB: 1024.00000 Copy: 2634.043 MiB/s AVG Method: MEMCPY Elapsed: 0.39300 MiB: 1024.00000 Copy: 2605.600 MiB/s 0 Method: DUMB Elapsed: 0.30707 MiB: 1024.00000 Copy: 3334.745 MiB/s 1 Method: DUMB Elapsed: 0.30425 MiB: 1024.00000 Copy: 3365.653 MiB/s 2 Method: DUMB Elapsed: 0.30342 MiB: 1024.00000 Copy: 3374.849 MiB/s AVG Method: DUMB Elapsed: 0.30491 MiB: 1024.00000 Copy: 3358.328 MiB/s 0 Method: MCBLOCK Elapsed: 0.07875 MiB: 1024.00000 Copy: 13003.670 MiB/s 1 Method: MCBLOCK Elapsed: 0.08374 MiB: 1024.00000 Copy: 12228.034 MiB/s 2 Method: MCBLOCK Elapsed: 0.07635 MiB: 1024.00000 Copy: 13411.216 MiB/s AVG Method: MCBLOCK Elapsed: 0.07961 MiB: 1024.00000 Copy: 12862.006 MiB/s So according to mbw my laptop is 3 times faster than the server!!! Please help me explain this. I've also tried to mount a ram disk and use dd to benchmark it and I get similar differences so I don't think mbw is to blame. I've checked the BIOS settings and the memory seem to be running at full speed. According to the hosting company the modules are all OK. Could this have something to do with NUMA? It seems like Node Interleaving is disabled on this server. Will enabling it (thus turning off NUMA) make a difference? foo1:~# numactl --hardware available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 4 5 node 0 size: 8190 MB node 0 free: 7898 MB node 1 cpus: 6 7 8 9 10 11 node 1 size: 12288 MB node 1 free: 12073 MB node 2 cpus: 18 19 20 21 22 23 node 2 size: 12288 MB node 2 free: 12034 MB node 3 cpus: 12 13 14 15 16 17 node 3 size: 8192 MB node 3 free: 8032 MB node distances: node 0 1 2 3 0: 10 20 20 20 1: 20 10 20 20 2: 20 20 10 20 3: 20 20 20 10

  Read the article

• synchronization of file locations between two machines

  - by intuited

  Although similar threads have been asked on this site and its siblings before, I've not managed to glean the answer to this persistent question. Any help is much appreciated. The situation: I've got two laptops; both contain a ton of music. Sometimes I move these music files to different locations, or change the metadata in them, or convert them to a different format. I might do any of these things on either machine. I rarely do all of them at once — ie it's unlikely that I'll convert a file's format and move it to a different location all in one go. I'd like to be able to synchronize these changes without having to sift through everything that was renamed or moved. I'm familiar with rsync but I find it inadequate, because although it can compute checksums, it doesn't have any way to store them. So if a file differs, it can't figure out which side it changed on. This also means that it can't attempt to match a missing file to a new one with the same checksum (ie a move) if the filesize and date are the same, it , so it takes an epoch to do a sync on a large repository. I would like to only check the checksum if the files even if you turn on checksumming, it still doesn't use it intelligently: ie it checksums files even if the sizes differ. IIRC. it's not able to use file metadata as a means of file comparison. this is sort of a wishlist item but it seems doable. I've also looked into rsnapshot, but its requirement to create a full backup is impractical in this situation. I don't need a backup, I just need a record of what file with each hash was where when. Unison seems like it might be able to do something vaguely along these lines, but I'm loathe to spend hours wading through its details only to discover that it's sadly lacking. Plus, it's fun asking questions on here. What I'd like is a tool that does something along these lines: keeps track of file checksums or of actual renames, possibly using inotify to greatly reduce resource consumption/latency stores a database containing this info, along with other pertinencies like the file format and metadata, the actual inode, the filename history, etc. uses this info to provide more-intelligent synchronization with a counterpart on the other side. So for example: if a file has been converted from flac to ogg, but kept the same base filename, or the same metadata, it should be able to send the new version over, and the other side should delete the original. Probably it should actually sequester it somewhere in case they or you screwed up, but that's a detail. And then when the transaction is done, the state is logged so that the next time the two interact they can work out their differences. Maybe all this metadata stuff is a fancy pipe dream. I would actually be pretty happy if there was something out there that could just use checksums in an intelligent way. This would be sort of like having the intelligence of something like git, minus the need to duplicate data in an index/backup/etc (and branching, and checkouts, and all the other great stuff that RCSs do. basically just fast forward commit pushes are all I want, with maybe the option to roll back.) So is there something out there that can do this? If not, can someone suggest a good way to start making it?

  Read the article

• Email sent from Centos end up in user spam folder

  - by oObe

  I am facing this issue, I use the default postfix MTA in centos but the mail end up in user spam folder, but this does not seem to be a problem in Debian using exim4, both host have hostname and domain name configured, and relay mail through external smtp host. Both configuration and recieving email header are attached. The different seems that Debian has this additional (envelope tag) and (from) tag other than some minor syntax differences. Any help to resolve is appreciated. The IP address and DNS is masked as follow: 1.2.3.4 = My IP address smtp.host.com = external smtp host for my company [email protected] = account at smtp host centos.abc.com = Local centos server debian.abc.com = Local debian server Thanks. Centos main.cf config with the following params configured myhostname = centos.abc.com mydomain = abc.com myorigin = centos.abc.com relayhost = smtp.host.com Centos - User receiving mail header Return-Path: <[email protected]> Received: from 1.2.3.4 [1.2.3.4] by smtp.host.com with SMTP; Thu, 27 Sep 2012 13:36:49 +0800 Received: by centos.abc.com (Postfix, from userid 0) id 1E0637B89; Fri, 28 Sep 2012 13:36:39 +0800 (SGT) Return-Path: <[email protected]> Received: from 1.2.3.4 [1.2.3.4] by smtp.host.com with SMTP; Thu, 27 Sep 2012 13:36:49 +0800 Received: by centos.abc.com (Postfix, from userid 0) id 1E0637B89; Fri, 28 Sep 2012 13:36:39 +0800 (SGT) Date: Fri, 28 Sep 2012 13:36:39 +0800 To: [email protected] Subject: Test mail from centos User-Agent: Heirloom mailx 12.4 7/29/08 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <[email protected]> From: [email protected] (root) X-SmarterMail-TotalSpamWeight: 0 X-Antivirus: avast! (VPS 120926-1, 27/09/2012), Inbound message X-Antivirus-Status: Clean http://i.imgur.com/7WAYX.jpg Debain exim4 config .... # This is a Debian specific file dc_eximconfig_configtype='smarthost' dc_other_hostnames='debian.abc.com' dc_local_interfaces='127.0.0.1 ; ::1' dc_readhost='debian.abc.com' dc_relay_domains='smtp.host.com' dc_minimaldns='false' dc_relay_nets='127.0.0.1' dc_smarthost='smtp.host.com' CFILEMODE='644' dc_use_split_config='false' dc_hide_mailname='true' dc_mailname_in_oh='true' dc_localdelivery='mail_spool' debian - User receiving mail header Return-Path: <[email protected]> Received: from 1.2.3.4 [1.2.3.4] by smtp.host.com with SMTP; Thu, 27 Sep 2012 15:02:53 +0800 Received: from root by debian.abc.com with local (Exim 4.72) (envelope-from <[email protected]>) id 1TH86d-00010v-G9 for [email protected]; Thu, 27 Sep 2012 15:01:55 +0800 Return-Path: <[email protected]> Received: from 1.2.3.4 [1.2.3.4] by smtp.host.com with SMTP; Thu, 27 Sep 2012 15:02:53 +0800 Received: from root by debian.abc.com with local (Exim 4.72) (envelope-from <[email protected]>) id 1TH86d-00010v-G9 for [email protected]; Thu, 27 Sep 2012 15:01:55 +0800 Date: Thu, 27 Sep 2012 15:01:55 +0800 Message-Id: <[email protected]> To: [email protected] Subject: Test from debian From: root <[email protected]> X-SmarterMail-TotalSpamWeight: 0 X-Antivirus: avast! (VPS 120926-1, 27/09/2012), Inbound message X-Antivirus-Status: Clean http://imgur.com/nMsMA.jpg

  Read the article

• Reinstall Postfix

  - by Kevin

  I tried to reinstall Postfix, but I get this bunch of errors: root@***:/etc/init.d# sudo apt-get install -f postfix Reading package lists... Done Building dependency tree Reading state information... Done Suggested packages: procmail postfix-mysql postfix-pgsql postfix-ldap postfix-pcre resolvconf postfix-cdb mail-reader The following NEW packages will be installed: postfix 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 0B/1,389kB of archives. After this operation, 3,531kB of additional disk space will be used. Preconfiguring packages ... Selecting previously deselected package postfix. (Reading database ... 56122 files and directories currently installed.) Unpacking postfix (from .../postfix_2.7.1-1ubuntu0.1_amd64.deb) ... Processing triggers for ureadahead ... Processing triggers for ufw ... Processing triggers for man-db ... Setting up postfix (2.7.1-1ubuntu0.1) ... Configuration file `/etc/init.d/postfix' ==> File on system created by you or by a script. ==> File also in package provided by package maintainer. What would you like to do about it ? Your options are: Y or I : install the package maintainer's version N or O : keep your currently-installed version D : show the differences between the versions Z : start a shell to examine the situation The default action is to keep your current version. *** postfix (Y/I/N/O/D/Z) [default=N] ? Y Installing new version of config file /etc/init.d/postfix ... Adding group `postfix' (GID 109) ... Done. Adding system user `postfix' (UID 106) ... Adding new user `postfix' (UID 106) with group `postfix' ... Not creating home directory `/var/spool/postfix'. Creating /etc/postfix/dynamicmaps.cf Adding tcp map entry to /etc/postfix/dynamicmaps.cf Adding group `postdrop' (GID 115) ... Done. setting myhostname: ***.net setting alias maps setting alias database setting myorigin setting destinations: ***.net, localhost.***.net, , localhost setting relayhost: setting mynetworks: 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 setting mailbox_size_limit: 0 setting recipient_delimiter: + setting inet_interfaces: all Postfix is now set up with a default configuration. If you need to make changes, edit /etc/postfix/main.cf (and others) as needed. To view Postfix configuration values, see postconf(1). After modifying main.cf, be sure to run '/etc/init.d/postfix reload'. Running newaliases postalias: fatal: /etc/mailname: cannot open file: Permission denied dpkg: error processing postfix (--configure): subprocess installed post-installation script returned error exit status 1 Processing triggers for libc-bin ... ldconfig deferred processing now taking place Errors were encountered while processing: postfix E: Sub-process /usr/bin/dpkg returned an error code (1) I tried aptitude purge, remove, autoclean and all of dpkg options (configure, remove, purge) but nothing did the trick. /etc/mailname exists (0644 root:root) with as content *.net (fetched from hostname). What am I doing wrong?

  Read the article

• What's the difference between find and findstr commands in Windows?

  - by Prashant Bhate

  In Windows, what are the differences between find and findstr commands? Both seems to search text in files: find c:\>find /? Searches for a text string in a file or files. FIND [/V] [/C] [/N] [/I] [/OFF[LINE]] "string" [[drive:][path]filename[ ...]] /V Displays all lines NOT containing the specified string. /C Displays only the count of lines containing the string. /N Displays line numbers with the displayed lines. /I Ignores the case of characters when searching for the string. /OFF[LINE] Do not skip files with offline attribute set. "string" Specifies the text string to find. [drive:][path]filename Specifies a file or files to search. If a path is not specified, FIND searches the text typed at the prompt or piped from another command. findstr c:\>findstr /? Searches for strings in files. FINDSTR [/B] [/E] [/L] [/R] [/S] [/I] [/X] [/V] [/N] [/M] [/O] [/P] [/F:file] [/C:string] [/G:file] [/D:dir list] [/A:color attributes] [/OFF[LINE]] strings [[drive:][path]filename[ ...]] /B Matches pattern if at the beginning of a line. /E Matches pattern if at the end of a line. /L Uses search strings literally. /R Uses search strings as regular expressions. /S Searches for matching files in the current directory and all subdirectories. /I Specifies that the search is not to be case-sensitive. /X Prints lines that match exactly. /V Prints only lines that do not contain a match. /N Prints the line number before each line that matches. /M Prints only the filename if a file contains a match. /O Prints character offset before each matching line. /P Skip files with non-printable characters. /OFF[LINE] Do not skip files with offline attribute set. /A:attr Specifies color attribute with two hex digits. See "color /?" /F:file Reads file list from the specified file(/ stands for console). /C:string Uses specified string as a literal search string. /G:file Gets search strings from the specified file(/ stands for console). /D:dir Search a semicolon delimited list of directories strings Text to be searched for. [drive:][path]filename Specifies a file or files to search. Use spaces to separate multiple search strings unless the argument is prefixed with /C. For example, 'FINDSTR "hello there" x.y' searches for "hello" or "there" in file x.y. 'FINDSTR /C:"hello there" x.y' searches for "hello there" in file x.y. Regular expression quick reference: . Wildcard: any character * Repeat: zero or more occurances of previous character or class ^ Line position: beginning of line $ Line position: end of line [class] Character class: any one character in set [^class] Inverse class: any one character not in set [x-y] Range: any characters within the specified range \x Escape: literal use of metacharacter x \<xyz Word position: beginning of word xyz\> Word position: end of word For full information on FINDSTR regular expressions refer to the online Command Reference.

  Read the article

• Interesting articles and blogs on SPARC T4

  - by mv

  Interesting articles and blogs on SPARC T4 processor   I have consolidated all the interesting information I could get on SPARC T4 processor and its hardware cryptographic capabilities.  Hope its useful. 1. Advantages of SPARC T4 processor  Most important points in this T4 announcement are : "The SPARC T4 processor was designed from the ground up for high speed security and has a cryptographic stream processing unit (SPU) integrated directly into each processor core. These accelerators support 16 industry standard security ciphers and enable high speed encryption at rates 3 to 5 times that of competing processors. By integrating encryption capabilities directly inside the instruction pipeline, the SPARC T4 processor eliminates the performance and cost barriers typically associated with secure computing and makes it possible to deliver high security levels without impacting the user experience." Data Sheet has more details on these  : "New on-chip Encryption Instruction Accelerators with direct non-privileged support for 16 industry-standard cryptographic algorithms plus random number generation in each of the eight cores: AES, Camellia, CRC32c, DES, 3DES, DH, DSA, ECC, Kasumi, MD5, RSA, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512" I ran "isainfo -v" command on Solaris 11 Sparc T4-1 system. It shows the new instructions as expected  : $ isainfo -v 64-bit sparcv9 applications crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5 camellia kasumi des aes ima hpc vis3 fmaf asi_blk_init vis2 vis popc 32-bit sparc applications crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5 camellia kasumi des aes ima hpc vis3 fmaf asi_blk_init vis2 vis popc v8plus div32 mul32  2.  Dan Anderson's Blog have some interesting points about how these can be used : "New T4 crypto instructions include: aes_kexpand0, aes_kexpand1, aes_kexpand2,         aes_eround01, aes_eround23, aes_eround01_l, aes_eround_23_l, aes_dround01, aes_dround23, aes_dround01_l, aes_dround_23_l.       Having SPARC T4 hardware crypto instructions is all well and good, but how do we access it ?      The software is available with Solaris 11 and is used automatically if you are running Solaris a SPARC T4.  It is used internally in the kernel through kernel crypto modules.  It is available in user space through the PKCS#11 library." 3.   Dans' Blog on Where's the Crypto Libraries? Although this was written in 2009 but still is very useful  "Here's a brief tour of the major crypto libraries shown in the digraph:   The libpkcs11 library contains the PKCS#11 API (C_\*() functions, such as C_Initialize()). That in turn calls library pkcs11_softtoken or pkcs11_kernel, for userland or kernel crypto providers. The latter is used mostly for hardware-assisted cryptography (such as n2cp for Niagara2 SPARC processors), as that is performed more efficiently in kernel space with the "kCF" module (Kernel Crypto Framework). Additionally, for Solaris 10, strong crypto algorithms were split off in separate libraries, pkcs11_softtoken_extra libcryptoutil contains low-level utility functions to help implement cryptography. libsoftcrypto (OpenSolaris and Solaris Nevada only) implements several symmetric-key crypto algorithms in software, such as AES, RC4, and DES3, and the bignum library (used for RSA). libmd implements MD5, SHA, and SHA2 message digest algorithms" 4. Difference in T3 and T4 Diagram in this blog is good and self explanatory. Jeff's blog also highlights the differences  "The T4 servers have improved crypto acceleration, described at https://blogs.oracle.com/DanX/entry/sparc_t4_openssl_engine. It is "just built in" so administrators no longer have to assign crypto accelerator units to domains - it "just happens". Every physical or virtual CPU on a SPARC-T4 has full access to hardware based crypto acceleration at all times. .... For completeness sake, it's worth noting that the T4 adds more crypto algorithms, and accelerates Camelia, CRC32c, and more SHA-x." 5. About performance counters In this blog, performance counters are explained : "Note that unlike T3 and before, T4 crypto doesn't require kernel modules like ncp or n2cp, there is no visibility of crypto hardware with kstats or cryptoadm. T4 does provide hardware counters for crypto operations.  You can see these using cpustat: cpustat -c pic0=Instr_FGU_crypto 5 You can check the general crypto support of the hardware and OS with the command "isainfo -v". Since T4 crypto's implementation now allows direct userland access, there are no "crypto units" visible to cryptoadm.  " For more details refer Martin's blog as well. 6. How to turn off  SPARC T4 or Intel AES-NI crypto acceleration  I found this interesting blog from Darren about how to turn off  SPARC T4 or Intel AES-NI crypto acceleration. "One of the new Solaris 11 features of the linker/loader is the ability to have a single ELF object that has multiple different implementations of the same functions that are selected at runtime based on the capabilities of the machine.   The alternate to this is having the application coded to call getisax(2) system call and make the choice itself.  We use this functionality of the linker/loader when we build the userland libraries for the Solaris Cryptographic Framework (specifically libmd.so and libsoftcrypto.so) The Solaris linker/loader allows control of a lot of its functionality via environment variables, we can use that to control the version of the cryptographic functions we run.  To do this we simply export the LD_HWCAP environment variable with values that tell ld.so.1 to not select the HWCAP section matching certain features even if isainfo says they are present.  This will work for consumers of the Solaris Cryptographic Framework that use the Solaris PKCS#11 libraries or use libmd.so interfaces directly.  For SPARC T4 : export LD_HWCAP="-aes -des -md5 -sha256 -sha512 -mont -mpul" .. For Intel systems with AES-NI support: export LD_HWCAP="-aes"" Note that LD_HWCAP is explained in  http://docs.oracle.com/cd/E23823_01/html/816-5165/ld.so.1-1.html "LD_HWCAP, LD_HWCAP_32, and LD_HWCAP_64 -  Identifies an alternative hardware capabilities value... A “-” prefix results in the capabilities that follow being removed from the alternative capabilities." 7. Whitepaper on SPARC T4 Servers—Optimized for End-to-End Data Center Computing This Whitepaper on SPARC T4 Servers—Optimized for End-to-End Data Center Computing explains more details.  It has DTrace scripts which may come in handy : "To ensure the hardware-assisted cryptographic acceleration is configured to use and working with the security scenarios, it is recommended to use the following Solaris DTrace script. #!/usr/sbin/dtrace -s pid$1:libsoftcrypto:yf*:entry, pid$target:libsoftcrypto:rsa*:entry, pid$1:libmd:yf*:entry { @[probefunc] = count(); } tick-1sec { printa(@ops); trunc(@ops); }" Note that I have slightly modified the D Script to have RSA "libsoftcrypto:rsa*:entry" as well as per recommendations from Chi-Chang Lin. 8. References http://www.oracle.com/us/corporate/features/sparc-t4-announcement-494846.html http://www.oracle.com/us/products/servers-storage/servers/sparc-enterprise/t-series/sparc-t4-1-ds-487858.pdf https://blogs.oracle.com/DanX/entry/sparc_t4_openssl_engine https://blogs.oracle.com/DanX/entry/where_s_the_crypto_libraries https://blogs.oracle.com/darren/entry/howto_turn_off_sparc_t4 http://docs.oracle.com/cd/E23823_01/html/816-5165/ld.so.1-1.html   https://blogs.oracle.com/hardware/entry/unleash_the_power_of_cryptography https://blogs.oracle.com/cmt/entry/t4_crypto_cheat_sheet https://blogs.oracle.com/martinm/entry/t4_performance_counters_explained  https://blogs.oracle.com/jsavit/entry/no_mau_required_on_a http://www.oracle.com/us/products/servers-storage/servers/sparc-enterprise/t-series/sparc-t4-business-wp-524472.pdf

  Read the article

• A Guided Tour of Complexity

  - by JoshReuben

  I just re-read Complexity – A Guided Tour by Melanie Mitchell , protégé of Douglas Hofstadter ( author of “Gödel, Escher, Bach”) http://www.amazon.com/Complexity-Guided-Tour-Melanie-Mitchell/dp/0199798109/ref=sr_1_1?ie=UTF8&qid=1339744329&sr=8-1 here are some notes and links:   Evolved from Cybernetics, General Systems Theory, Synergetics some interesting transdisciplinary fields to investigate: Chaos Theory - http://en.wikipedia.org/wiki/Chaos_theory – small differences in initial conditions (such as those due to rounding errors in numerical computation) yield widely diverging outcomes for chaotic systems, rendering long-term prediction impossible. System Dynamics / Cybernetics - http://en.wikipedia.org/wiki/System_Dynamics – study of how feedback changes system behavior Network Theory - http://en.wikipedia.org/wiki/Network_theory – leverage Graph Theory to analyze symmetric  / asymmetric relations between discrete objects Algebraic Topology - http://en.wikipedia.org/wiki/Algebraic_topology – leverage abstract algebra to analyze topological spaces There are limits to deterministic systems & to computation. Chaos Theory definitely applies to training an ANN (artificial neural network) – different weights will emerge depending upon the random selection of the training set. In recursive Non-Linear systems http://en.wikipedia.org/wiki/Nonlinear_system – output is not directly inferable from input. E.g. a Logistic map: Xt+1 = R Xt(1-Xt) Different types of bifurcations, attractor states and oscillations may occur – e.g. a Lorenz Attractor http://en.wikipedia.org/wiki/Lorenz_system Feigenbaum Constants http://en.wikipedia.org/wiki/Feigenbaum_constants express ratios in a bifurcation diagram for a non-linear map – the convergent limit of R (the rate of period-doubling bifurcations) is 4.6692016 Maxwell’s Demon - http://en.wikipedia.org/wiki/Maxwell%27s_demon - the Second Law of Thermodynamics has only a statistical certainty – the universe (and thus information) tends towards entropy. While any computation can theoretically be done without expending energy, with finite memory, the act of erasing memory is permanent and increases entropy. Life & thought is a counter-example to the universe’s tendency towards entropy. Leo Szilard and later Claude Shannon came up with the Information Theory of Entropy - http://en.wikipedia.org/wiki/Entropy_(information_theory) whereby Shannon entropy quantifies the expected value of a message’s information in bits in order to determine channel capacity and leverage Coding Theory (compression analysis). Ludwig Boltzmann came up with Statistical Mechanics - http://en.wikipedia.org/wiki/Statistical_mechanics – whereby our Newtonian perception of continuous reality is a probabilistic and statistical aggregate of many discrete quantum microstates. This is relevant for Quantum Information Theory http://en.wikipedia.org/wiki/Quantum_information and the Physics of Information - http://en.wikipedia.org/wiki/Physical_information. Hilbert’s Problems http://en.wikipedia.org/wiki/Hilbert's_problems pondered whether mathematics is complete, consistent, and decidable (the Decision Problem – http://en.wikipedia.org/wiki/Entscheidungsproblem – is there always an algorithm that can determine whether a statement is true).  Godel’s Incompleteness Theorems http://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_theorems  proved that mathematics cannot be both complete and consistent (e.g. “This statement is not provable”). Turing through the use of Turing Machines (http://en.wikipedia.org/wiki/Turing_machine symbol processors that can prove mathematical statements) and Universal Turing Machines (http://en.wikipedia.org/wiki/Universal_Turing_machine Turing Machines that can emulate other any Turing Machine via accepting programs as well as data as input symbols) that computation is limited by demonstrating the Halting Problem http://en.wikipedia.org/wiki/Halting_problem (is is not possible to know when a program will complete – you cannot build an infinite loop detector). You may be used to thinking of 1 / 2 / 3 dimensional systems, but Fractal http://en.wikipedia.org/wiki/Fractal systems are defined by self-similarity & have non-integer Hausdorff Dimensions !!!  http://en.wikipedia.org/wiki/List_of_fractals_by_Hausdorff_dimension – the fractal dimension quantifies the number of copies of a self similar object at each level of detail – eg Koch Snowflake - http://en.wikipedia.org/wiki/Koch_snowflake Definitions of complexity: size, Shannon entropy, Algorithmic Information Content (http://en.wikipedia.org/wiki/Algorithmic_information_theory - size of shortest program that can generate a description of an object) Logical depth (amount of info processed), thermodynamic depth (resources required). Complexity is statistical and fractal. John Von Neumann’s other machine was the Self-Reproducing Automaton http://en.wikipedia.org/wiki/Self-replicating_machine  . Cellular Automata http://en.wikipedia.org/wiki/Cellular_automaton are alternative form of Universal Turing machine to traditional Von Neumann machines where grid cells are locally synchronized with their neighbors according to a rule. Conway’s Game of Life http://en.wikipedia.org/wiki/Conway's_Game_of_Life demonstrates various emergent constructs such as “Glider Guns” and “Spaceships”. Cellular Automatons are not practical because logical ops require a large number of cells – wasteful & inefficient. There are no compilers or general program languages available for Cellular Automatons (as far as I am aware). Random Boolean Networks http://en.wikipedia.org/wiki/Boolean_network are extensions of cellular automata where nodes are connected at random (not to spatial neighbors) and each node has its own rule –> they demonstrate the emergence of complex  & self organized behavior. Stephen Wolfram’s (creator of Mathematica, so give him the benefit of the doubt) New Kind of Science http://en.wikipedia.org/wiki/A_New_Kind_of_Science proposes the universe may be a discrete Finite State Automata http://en.wikipedia.org/wiki/Finite-state_machine whereby reality emerges from simple rules. I am 2/3 through this book. It is feasible that the universe is quantum discrete at the plank scale and that it computes itself – Digital Physics: http://en.wikipedia.org/wiki/Digital_physics – a simulated reality? Anyway, all behavior is supposedly derived from simple algorithmic rules & falls into 4 patterns: uniform , nested / cyclical, random (Rule 30 http://en.wikipedia.org/wiki/Rule_30) & mixed (Rule 110 - http://en.wikipedia.org/wiki/Rule_110 localized structures – it is this that is interesting). interaction between colliding propagating signal inputs is then information processing. Wolfram proposes the Principle of Computational Equivalence - http://mathworld.wolfram.com/PrincipleofComputationalEquivalence.html - all processes that are not obviously simple can be viewed as computations of equivalent sophistication. Meaning in information may emerge from analogy & conceptual slippages – see the CopyCat program: http://cognitrn.psych.indiana.edu/rgoldsto/courses/concepts/copycat.pdf Scale Free Networks http://en.wikipedia.org/wiki/Scale-free_network have a distribution governed by a Power Law (http://en.wikipedia.org/wiki/Power_law - much more common than Normal Distribution). They are characterized by hubs (resilience to random deletion of nodes), heterogeneity of degree values, self similarity, & small world structure. They grow via preferential attachment http://en.wikipedia.org/wiki/Preferential_attachment – tipping points triggered by positive feedback loops. 2 theories of cascading system failures in complex systems are Self-Organized Criticality http://en.wikipedia.org/wiki/Self-organized_criticality and Highly Optimized Tolerance http://en.wikipedia.org/wiki/Highly_optimized_tolerance. Computational Mechanics http://en.wikipedia.org/wiki/Computational_mechanics – use of computational methods to study phenomena governed by the principles of mechanics. This book is a great intuition pump, but does not cover the more mathematical subject of Computational Complexity Theory – http://en.wikipedia.org/wiki/Computational_complexity_theory I am currently reading this book on this subject: http://www.amazon.com/Computational-Complexity-Christos-H-Papadimitriou/dp/0201530821/ref=pd_sim_b_1   stay tuned for that review!

  Read the article

• [GEEK SCHOOL] Network Security 4: Windows Firewall: Your System’s Best Defense

  - by Ciprian Rusen

  If you have your computer connected to a network, or directly to your Internet connection, then having a firewall is an absolute necessity. In this lesson we will discuss the Windows Firewall – one of the best security features available in Windows! The Windows Firewall made its debut in Windows XP. Prior to that, Windows system needed to rely on third-party solutions or dedicated hardware to protect them from network-based attacks. Over the years, Microsoft has done a great job with it and it is one of the best firewalls you will ever find for Windows operating systems. Seriously, it is so good that some commercial vendors have decided to piggyback on it! Let’s talk about what you will learn in this lesson. First, you will learn about what the Windows Firewall is, what it does, and how it works. Afterward, you will start to get your hands dirty and edit the list of apps, programs, and features that are allowed to communicate through the Windows Firewall depending on the type of network you are connected to. Moving on from there, you will learn how to add new apps or programs to the list of allowed items and how to remove the apps and programs that you want to block. Last but not least, you will learn how to enable or disable the Windows Firewall, for only one type of networks or for all network connections. By the end of this lesson, you should know enough about the Windows Firewall to use and manage it effectively. What is the Windows Firewall? Windows Firewall is an important security application that’s built into Windows. One of its roles is to block unauthorized access to your computer. The second role is to permit authorized data communications to and from your computer. Windows Firewall does these things with the help of rules and exceptions that are applied both to inbound and outbound traffic. They are applied depending on the type of network you are connected to and the location you have set for it in Windows, when connecting to the network. Based on your choice, the Windows Firewall automatically adjusts the rules and exceptions applied to that network. This makes the Windows Firewall a product that’s silent and easy to use. It bothers you only when it doesn’t have any rules and exceptions for what you are trying to do or what the programs running on your computer are trying to do. If you need a refresher on the concept of network locations, we recommend you to read our How-To Geek School class on Windows Networking. Another benefit of the Windows Firewall is that it is so tightly and nicely integrated into Windows and all its networking features, that some commercial vendors decided to piggyback onto it and use it in their security products. For example, products from companies like Trend Micro or F-Secure no longer provide their proprietary firewall modules but use the Windows Firewall instead. Except for a few wording differences, the Windows Firewall works the same in Windows 7 and Windows 8.x. The only notable difference is that in Windows 8.x you will see the word “app” being used instead of “program”. Where to Find the Windows Firewall By default, the Windows Firewall is turned on and you don’t need to do anything special in order for it work. You will see it displaying some prompts once in a while but they show up so rarely that you might forget that is even working. If you want to access it and configure the way it works, go to the Control Panel, then go to “System and Security” and select “Windows Firewall”. Now you will see the Windows Firewall window where you can get a quick glimpse on whether it is turned on and the type of network you are connected to: private networks or public network. For the network type that you are connected to, you will see additional information like: The state of the Windows Firewall How the Windows Firewall deals with incoming connections The active network When the Windows Firewall will notify you You can easily expand the other section and view the default settings that apply when connecting to networks of that type. If you have installed a third-party security application that also includes a firewall module, chances are that the Windows Firewall has been disabled, in order to avoid performance issues and conflicts between the two security products. If that is the case for your computer or device, you won’t be able to view any information in the Windows Firewall window and you won’t be able to configure the way it works. Instead, you will see a warning that says: “These settings are being managed by vendor application – Application Name”. In the screenshot below you can see an example of how this looks. How to Allow Desktop Applications Through the Windows Firewall Windows Firewall has a very comprehensive set of rules and most Windows programs that you install add their own exceptions to the Windows Firewall so that they receive network and Internet access. This means that you will see prompts from the Windows Firewall on occasion, generally when you install programs that do not add their own exceptions to the Windows Firewall’s list. In a Windows Firewall prompt, you are asked to select the network locations to which you allow access for that program: private networks or public networks. By default, Windows Firewall selects the checkbox that’s appropriate for the network you are currently using. You can decide to allow access for both types of network locations or just to one of them. To apply your setting press “Allow access”. If you want to block network access for that program, press “Cancel” and the program will be set as blocked for both network locations. At this step you should note that only administrators can set exceptions in the Windows Firewall. If you are using a standard account without administrator permissions, the programs that do not comply with the Windows Firewall rules and exceptions are automatically blocked, without any prompts being shown. You should note that in Windows 8.x you will never see any Windows Firewall prompts related to apps from the Windows Store. They are automatically given access to the network and the Internet based on the assumption that you are aware of the permissions they require based on the information displayed by the Windows Store. Windows Firewall rules and exceptions are automatically created for each app that you install from the Windows Store. However, you can easily block access to the network and the Internet for any app, using the instructions in the next section. How to Customize the Rules for Allowed Apps Windows Firewall allows any user with an administrator account to change the list of rules and exceptions applied for apps and desktop programs. In order to do this, first start the Windows Firewall. On the column on the left, click or tap “Allow an app or feature through Windows Firewall” (in Windows 8.x) or “Allow a program or feature through Windows Firewall” (in Windows 7). Now you see the list of apps and programs that are allowed to communicate through the Windows Firewall. At this point, the list is grayed out and you can only view which apps, features, and programs have rules that are enabled in the Windows Firewall.

  Read the article

• .NET 4.5 is an in-place replacement for .NET 4.0

  - by Rick Strahl

  With the betas for .NET 4.5 and Visual Studio 11 and Windows 8 shipping many people will be installing .NET 4.5 and hacking away on it. There are a number of great enhancements that are fairly transparent, but it's important to understand what .NET 4.5 actually is in terms of the CLR running on your machine. When .NET 4.5 is installed it effectively replaces .NET 4.0 on the machine. .NET 4.0 gets overwritten by a new version of .NET 4.5 which - according to Microsoft - is supposed to be 100% backwards compatible. While 100% backwards compatible sounds great, we all know that 100% is a hard number to hit, and even the aforementioned blog post at the Microsoft site acknowledges this. But there's so much more than backwards compatibility that makes this awkward at best and confusing at worst. What does ‘Replacement’ mean? When you install .NET 4.5 your .NET 4.0 assemblies in the \Windows\.NET Framework\V4.0.30319 are overwritten with a new set of assemblies. You end up with overwritten assemblies as well as a bunch of new ones (like the new System.Net.Http assemblies for example). The following screen shot demonstrates system.dll on my test machine (left) running .NET 4.5 on the right and my production laptop running stock .NET 4.0 (right):   Clearly they are different files with a difference in file sizes (interesting that the 4.5 version is actually smaller). That’s not all. If you actually query the runtime version when .NET 4.5 is installed with with Environment.Version you still get: 4.0.30319 If you open the properties of System.dll assembly in .NET 4.5 you'll also see: Notice that the file version is also left at 4.0.xxx. There are differences in build numbers: .NET 4.0 shows 261 and the current .NET 4.5 beta build is 17379. I suppose you can use assume a build number greater than 17000 is .NET 4.5, but that's pretty hokey to say the least. There’s no easy or obvious way to tell whether you are running on 4.0 or 4.5 – to the application they appear to be the same runtime version. And that is what Microsoft intends here. .NET 4.5 is intended as an in-place upgrade. Compile to 4.5 run on 4.0 – not quite! You can compile an application for .NET 4.5 and run it on the 4.0 runtime – that is until you hit a new feature that doesn’t exist on 4.0. At which point the app bombs at runtime. Say you write some code that is mostly .NET 4.0, but only has a few of the new features of .NET 4.5 like aync/await buried deep in the bowels of the application where it only fires occasionally. .NET will happily start your application and run everything 4.0 fine, until it hits that 4.5 code – and then crash unceremoniously at runtime. Oh joy! You can .NET 4.0 applications on .NET 4.5 of course and that should work without much fanfare. Different than .NET 3.0/3.5 Note that this in-place replacement is very different from the side by side installs of .NET 2.0 and 3.0/3.5 which all ran on the 2.0 version of the CLR. The two 3.x versions were basically library enhancements on top of the core .NET 2.0 runtime. Both versions ran under the .NET 2.0 runtime which wasn’t changed (other than for security patches and bug fixes) for the whole 3.x cycle. The 4.5 update instead completely replaces the .NET 4.0 runtime and leaves the actual version number set at v4.0.30319. When you build a new project with Visual Studio 2011, you can still target .NET 4.0 or you can target .NET 4.5. But you are in effect referencing the same set of assemblies for both regardless which version you use. What's different is the compiler used to compile and link your code so compiling with .NET 4.0 gives you just the subset of the functionality that is available in .NET 4.0, but when you use the 4.5 compiler you get the full functionality of what’s actually available in the assemblies and extra libraries. It doesn’t look like you will be able to use Visual Studio 2010 to develop .NET 4.5 applications. Good news – Bad news Microsoft is trying hard to experiment with every possible permutation of releasing new versions of the .NET framework apparently. No two updates have been the same. Clearly updating to a full new version of .NET (ie. .NET 2.0, 4.0 and at some point 5.0 runtimes) has its own set of challenges, but doing an in-place update of the runtime and then not even providing a good way to tell which version is installed is pretty whacky even by Microsoft’s standards. Especially given that .NET 4.5 includes a fairly significant update with all the aysnc functionality baked into the runtime. Most of the IO APIs have been updated to support task based async operation which significantly affects many existing APIs. To make things worse .NET 4.5 will be the initial version of .NET that ships with Windows 8 so it will be with us for a long time to come unless Microsoft finally decides to push .NET versions onto Windows machines as part of system upgrades (which currently doesn’t happen). This is the same story we had when Vista launched with .NET 3.0 which was a minor version that quickly was replaced by 3.5 which was more long lived and practical. People had enough problems dealing with the confusing versioning of the 3.x versions which ran on .NET 2.0. I can’t count the amount support calls and questions I’ve fielded because people couldn’t find a .NET 3.5 entry in the IIS version dialog. The same is likely to happen with .NET 4.5. It’s all well and good when we know that .NET 4.5 is an in-place replacement, but administrators and IT folks not intimately familiar with .NET are unlikely to understand this nuance and end up thoroughly confused which version is installed. It’s hard for me to see any upside to an in-place update and I haven’t really seen a good explanation of why this approach was decided on. Sure if the version stays the same existing assembly bindings don’t break so applications can stay running through an update. I suppose this is useful for some component vendors and strongly signed assemblies in corporate environments. But seriously, if you are going to throw .NET 4.5 into the mix, who won’t be recompiling all code and thoroughly test that code to work on .NET 4.5? A recompile requirement doesn’t seem that serious in light of a major version upgrade.  Resources http://blogs.msdn.com/b/dotnet/archive/2011/09/26/compatibility-of-net-framework-4-5.aspx http://www.devproconnections.com/article/net-framework/net-framework-45-versioning-faces-problems-141160© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

  Read the article

• WebSocket and Java EE 7 - Getting Ready for JSR 356 (TOTD #181)

  - by arungupta

  WebSocket is developed as part of HTML 5 specification and provides a bi-directional, full-duplex communication channel over a single TCP socket. It provides dramatic improvement over the traditional approaches of Polling, Long-Polling, and Streaming for two-way communication. There is no latency from establishing new TCP connections for each HTTP message. There is a WebSocket API and the WebSocket Protocol. The Protocol defines "handshake" and "framing". The handshake defines how a normal HTTP connection can be upgraded to a WebSocket connection. The framing defines wire format of the message. The design philosophy is to keep the framing minimum to avoid the overhead. Both text and binary data can be sent using the API. WebSocket may look like a competing technology to Server-Sent Events (SSE), but they are not. Here are the key differences: WebSocket can send and receive data from a client. A typical example of WebSocket is a two-player game or a chat application. Server-Sent Events can only push data data to the client. A typical example of SSE is stock ticker or news feed. With SSE, XMLHttpRequest can be used to send data to the server. For server-only updates, WebSockets has an extra overhead and programming can be unecessarily complex. SSE provides a simple and easy-to-use model that is much better suited. SSEs are sent over traditional HTTP and so no modification is required on the server-side. WebSocket require servers that understand the protocol. SSE have several features that are missing from WebSocket such as automatic reconnection, event IDs, and the ability to send arbitrary events. The client automatically tries to reconnect if the connection is closed. The default wait before trying to reconnect is 3 seconds and can be configured by including "retry: XXXX\n" header where XXXX is the milliseconds to wait before trying to reconnect. Event stream can include a unique event identifier. This allows the server to determine which events need to be fired to each client in case the connection is dropped in between. The data can span multiple lines and can be of any text format as long as EventSource message handler can process it. WebSockets provide true real-time updates, SSE can be configured to provide close to real-time by setting appropriate timeouts. OK, so all excited about WebSocket ? Want to convert your POJOs into WebSockets endpoint ? websocket-sdk and GlassFish 4.0 is here to help! The complete source code shown in this project can be downloaded here. On the server-side, the WebSocket SDK converts a POJO into a WebSocket endpoint using simple annotations. Here is how a WebSocket endpoint will look like: @WebSocket(path="/echo")public class EchoBean { @WebSocketMessage public String echo(String message) { return message + " (from your server)"; }} In this code "@WebSocket" is a class-level annotation that declares a POJO to accept WebSocket messages. The path at which the messages are accepted is specified in this annotation. "@WebSocketMessage" indicates the Java method that is invoked when the endpoint receives a message. This method implementation echoes the received message concatenated with an additional string. The client-side HTML page looks like <div style="text-align: center;"> <form action=""> <input onclick="send_echo()" value="Press me" type="button"> <input id="textID" name="message" value="Hello WebSocket!" type="text"><br> </form></div><div id="output"></div> WebSocket allows a full-duplex communication. So the client, a browser in this case, can send a message to a server, a WebSocket endpoint in this case. And the server can send a message to the client at the same time. This is unlike HTTP which follows a "request" followed by a "response". In this code, the "send_echo" method in the JavaScript is invoked on the button click. There is also a <div> placeholder to display the response from the WebSocket endpoint. The JavaScript looks like: <script language="javascript" type="text/javascript"> var wsUri = "ws://localhost:8080/websockets/echo"; var websocket = new WebSocket(wsUri); websocket.onopen = function(evt) { onOpen(evt) }; websocket.onmessage = function(evt) { onMessage(evt) }; websocket.onerror = function(evt) { onError(evt) }; function init() { output = document.getElementById("output"); } function send_echo() { websocket.send(textID.value); writeToScreen("SENT: " + textID.value); } function onOpen(evt) { writeToScreen("CONNECTED"); } function onMessage(evt) { writeToScreen("RECEIVED: " + evt.data); } function onError(evt) { writeToScreen('<span style="color: red;">ERROR:</span> ' + evt.data); } function writeToScreen(message) { var pre = document.createElement("p"); pre.style.wordWrap = "break-word"; pre.innerHTML = message; output.appendChild(pre); } window.addEventListener("load", init, false);</script> In this code The URI to connect to on the server side is of the format ws://<HOST>:<PORT>/websockets/<PATH> "ws" is a new URI scheme introduced by the WebSocket protocol. <PATH> is the path on the endpoint where the WebSocket messages are accepted. In our case, it is ws://localhost:8080/websockets/echo WEBSOCKET_SDK-1 will ensure that context root is included in the URI as well. WebSocket is created as a global object so that the connection is created only once. This object establishes a connection with the given host, port and the path at which the endpoint is listening. The WebSocket API defines several callbacks that can be registered on specific events. The "onopen", "onmessage", and "onerror" callbacks are registered in this case. The callbacks print a message on the browser indicating which one is called and additionally also prints the data sent/received. On the button click, the WebSocket object is used to transmit text data to the endpoint. Binary data can be sent as one blob or using buffering. The HTTP request headers sent for the WebSocket call are: GET ws://localhost:8080/websockets/echo HTTP/1.1Origin: http://localhost:8080Connection: UpgradeSec-WebSocket-Extensions: x-webkit-deflate-frameHost: localhost:8080Sec-WebSocket-Key: mDbnYkAUi0b5Rnal9/cMvQ==Upgrade: websocketSec-WebSocket-Version: 13 And the response headers received are Connection:UpgradeSec-WebSocket-Accept:q4nmgFl/lEtU2ocyKZ64dtQvx10=Upgrade:websocket(Challenge Response):00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00 The headers are shown in Chrome as shown below: The complete source code shown in this project can be downloaded here. The builds from websocket-sdk are integrated in GlassFish 4.0 builds. Would you like to live on the bleeding edge ? Then follow the instructions below to check out the workspace and install the latest SDK: Check out the source code svn checkout https://svn.java.net/svn/websocket-sdk~source-code-repository Build and install the trunk in your local repository as: mvn install Copy "./bundles/websocket-osgi/target/websocket-osgi-0.3-SNAPSHOT.jar" to "glassfish3/glassfish/modules/websocket-osgi.jar" in your GlassFish 4 latest promoted build. Notice, you need to overwrite the JAR file. Anybody interested in building a cool application using WebSocket and get it running on GlassFish ? :-) This work will also feed into JSR 356 - Java API for WebSocket. On a lighter side, there seems to be less agreement on the name. Here are some of the options that are prevalent: WebSocket (W3C API, the URL is www.w3.org/TR/websockets though) Web Socket (HTML5 Demos - html5demos.com/web-socket) Websocket (Jenkins Plugin - wiki.jenkins-ci.org/display/JENKINS/Websocket%2BPlugin) WebSockets (Used by Mozilla - developer.mozilla.org/en/WebSockets, but use WebSocket as well) Web sockets (HTML5 Working Group - www.whatwg.org/specs/web-apps/current-work/multipage/network.html) Web Sockets (Chrome Blog - blog.chromium.org/2009/12/web-sockets-now-available-in-google.html) I prefer "WebSocket" as that seems to be most common usage and used by the W3C API as well. What do you use ?

  Read the article

• Win a place at a SQL Server Masterclass with Kimberly Tripp and Paul Randal

  - by Testas

  The top things YOU need to know about managing SQL Server - in one place, on one day - presented by two of the best SQL Server industry trainers!And you could be there courtesy of UK SQL Server User Group and SQL Server Magazine! This week the UK SQL Server User Group will provide you with details of how to win a place at this must see seminar   You can also register for the seminar yourself at:www.regonline.co.uk/kimtrippsql More information about the seminar   Where: Radisson Edwardian Heathrow Hotel, London When: Thursday 17th June 2010 This one-day MasterClass will focus on many of the top issues companies face when implementing and maintaining a SQL Server-based solution. In the case where a company has no dedicated DBA, IT managers sometimes struggle to keep the data tier performing well and the data available. This can be especially troublesome when the development team is unfamiliar with the affect application design choices have on database performance. The Microsoft SQL Server MasterClass 2010 is presented by Paul S. Randal and Kimberly L. Tripp, two of the most experienced and respected people in the SQL Server world. Together they have over 30 years combined experience working with SQL Server in the field, and on the SQL Server product team itself. This is a unique opportunity to hear them present at a UK event which will:·         Debunk many of the ingrained misconceptions around SQL Server's behaviour   ·         Show you disaster recovery techniques critical to preserving your company's life-blood - the data   ·         Explain how a common application design pattern can wreak havoc in the database ·         Walk through the top-10 points to follow around operations and maintenance for a well-performing and available data tier! Please Note: Agenda may be subject to changeSessions AbstractsKEYNOTE: Bridging the Gap Between Development and Production  Applications are commonly developed with little regard for how design choices will affect performance in production. This is often because developers don't realize the implications of their design on how SQL Server will be able to handle a high workload (e.g. blocking, fragmentation) and/or because there's no full-time trained DBA that can recognize production problems and help educate developers. The keynote sets the stage for the rest of the day. Discussing some of the issues that can arise, explaining how some can be avoided and highlighting some of the features in SQL 2008 that can help developers and DBAs make better use of SQL Server, and troubleshoot when things go wrong.  SESSION ONE: SQL Server MythbustersIt's amazing how many myths and misconceptions have sprung up and persisted over the years about SQL Server - after many years helping people out on forums, newsgroups, and customer engagements, Paul and Kimberly have heard it all. Are there really non-logged operations? Can interrupting shrinks or rebuilds cause corruption? Can you override the server's MAXDOP setting? Will the server always do a table-scan to get a row count? Many myths lead to poor design choices and inappropriate maintenance practices so these are just a few of many, many myths that Paul and Kimberly will debunk in this fast-paced session on how SQL Server operates and should be managed and maintained. SESSION TWO: Database Recovery Techniques Demo-Fest Even if a company has a disaster recovery strategy in place, they need to practice to make sure that the plan will work when a disaster does strike. In this fast-paced demo session Paul and Kimberly will repeatedly do nasty things to databases and then show how they are recovered - demonstrating many techniques that can be used in production for disaster recovery. Not for the faint-hearted! SESSION THREE: GUIDs: Use, Abuse, and How To Move Forward Since the addition of the GUID (Microsoft’s implementation of the UUID), my life as a consultant and "tuner" has been busy. I’ve seen databases designed with GUID keys run fairly well with small workloads but completely fall over and fail because they just cannot scale. And, I know why GUIDs are chosen - it simplifies the handling of parent/child rows in your batches so you can reduce round-trips or avoid dealing with identity values. And, yes, sometimes it's even for distributed databases and/or security that GUIDs are chosen. I'm not entirely against ever using a GUID but overusing and abusing GUIDs just has to be stopped! Please, please, please let me give you better solutions and explanations on how to deal with your parent/child rows, round-trips and clustering keys! SESSION 4: Essential Database MaintenanceIn this session, Paul and Kimberly will run you through their top-ten database maintenance recommendations, with a lot of tips and tricks along the way. These are distilled from almost 30 years combined experience working with SQL Server customers and are geared towards making your databases more performant, more available, and more easily managed (to save you time!). Everything in this session will be practical and applicable to a wide variety of databases. Topics covered include: backups, shrinks, fragmentation, statistics, and much more! Focus will be on 2005 but we'll explain some of the key differences for 2000 and 2008 as well.    Speaker Biographies     Paul S.Randal  Kimberley L. Tripp Paul and Kimberly are a husband-and-wife team who own and run SQLskills.com, a world-renowned SQL Server consulting and training company. They are both SQL Server MVPs and Microsoft Regional Directors, with over 30 years of combined experience on SQL Server. Paul worked on the SQL Server team for nine years in development and management roles, writing many of the DBCC commands, and ultimately with responsibility for core Storage Engine for SQL Server 2008. Paul writes extensively on his blog (SQLskills.com/blogs/Paul) and for TechNet Magazine, for which he is also a Contributing Editor. Kimberly worked on the SQL Server team in the early 1990s as a tester and writer before leaving to found SQLskills and embrace her passion for teaching and consulting. Kimberly has been a staple at worldwide conferences since she first presented at TechEd in 1996, and she blogs at SQLskills.com/blogs/Kimberly. They have written Microsoft whitepapers and books for SQL Server 2000, 2005 and 2008, and are regular, top-rated presenters worldwide on database maintenance, high availability, disaster recovery, performance tuning, and SQL Server internals. Together they teach the SQL MCM certification and throughout Microsoft.In their spare time, they like to find frogfish in remote corners of the world.  

  Read the article

• Creating A SharePoint Parent/Child List Relationship&ndash; SharePoint 2010 Edition

  - by Mark Rackley

  Hey blog readers… It has been almost 2 years since I posted my most read blog on creating a Parent/Child list relationship in SharePoint 2007: Creating a SharePoint List Parent / Child Relationship - Out of the Box And then a year ago I improved on my method and redid the blog post… still for SharePoint 2007: Creating a SharePoint List Parent/Child Relationship – VIDEO REMIX Since then many of you have been asking me how to get this to work in SharePoint 2010, and frankly I have just not had time to look into it. I wish I could have jumped into this sooner, but have just recently began to look at it. Well.. after all this time I have actually come up with two solutions that work, neither of them are as clean as I’d like them to be, but I wanted to get something in your hands that you can start using today. Hopefully in the coming weeks and months I’ll be able to improve upon this further and give you guys some better options. For the most part, the process is identical to the 2007 process, but you have probably found out that the list view web parts in 2010 behave differently, and getting the Parent ID to your new child form can be a pain in the rear (at least that’s what I’ve discovered). Anyway, like I said, I have found a couple of solutions that work. If you know of a better one, please let us know as it bugs me that this not as eloquent as my 2007 implementation. Getting on the same page First thing I’d recommend is recreating this blog: Creating a SharePoint List Parent/Child Relationship – VIDEO REMIX in SharePoint 2010… There are some vague differences, but it’s basically the same…  Here’s a quick video of me doing this in SP 2010: Creating Lists necessary for this blog post Now that you have the lists created, lets set up the New Time form to use a QueryString variable to populate the Parent ID field: Creating parameters in Child’s new item form to set parent ID Did I talk fast enough through both of those videos? Hopefully by now that stuff is old hat to you, but I wanted to make sure everyone could get on the same page.  Okay… let’s get started. Solution 1 – XSLTListView with Javascript This solution is the more elegant of the two, however it does require the use of a little javascript.  The other solution does not use javascript, but it also doesn’t use the pretty new SP 2010 pop-ups.  I’ll let you decide which you like better. The basic steps of this solution are: Inserted a Related Item View Insert a ContentEditorWebPart Insert script in ContentEditorWebPart that pulls the ID from the Query string and calls the method to insert a new item on the child entry form Hide the toolbar from data view to remove “add new item” link. Again, you don’t HAVE to use a CEWP, you could just put the javascript directly in the page using SPD.  Anyway, here is how I did it: Using Related Item View / JavaScript Here’s the JavaScript I used in my Content Editor Web Part: <script type="text/javascript"> function NewTime() { // Get the Query String values and split them out into the vals array var vals = new Object(); var qs = location.search.substring(1, location.search.length); var args = qs.split("&"); for (var i=0; i < args.length; i++) { var nameVal = args[i].split("="); var temp = unescape(nameVal[1]).split('+'); nameVal[1] = temp.join(' '); vals[nameVal[0]] = nameVal[1]; } var issueID = vals["ID"]; //use this to bring up the pretty pop up NewItem2(event,"http://sp2010dev:1234/Lists/Time/NewForm.aspx?IssueID=" + issueID); //use this to open a new window //window.location="http://sp2010dev:1234/Lists/Time/NewForm.aspx?IssueID=" + issueID; } </script> Solution 2 – DataFormWebPart and exact same 2007 Process This solution is a little more of a hack, but it also MUCH more close to the process we did in SP 2007. So, if you don’t mind not having the pretty pop-up and prefer the comforts of what you are used to, you can give this one a try.  The basics steps are: Insert a DataFormWebPart instead of the List Data View Create a Parameter on DataFormWebPart to store “ID” Query String Variable Filter DataFormWebPart using Parameter Insert a link at bottom of DataForm Web part that points to the Child’s new item form and passes in the Parent Id using the Parameter. See.. like I told you, exact same process as in 2007 (except using the DataFormWeb Part). The DataFormWebPart also requires a lot more work to make it look “pretty” but it’s just table rows and cells, and can be configured pretty painlessly.  Here is that video: Using DataForm Web Part One quick update… if you change the link in this solution from: <tr> <td><a href="http://sp2010dev:1234/Lists/Time/NewForm.aspx?IssueID={$IssueIDParam}">Click here to create new item...</a> </td> </tr> to: <tr> <td> <a href="javascript:NewItem2(event,'http://sp2010dev:1234/Lists/Time/NewForm.aspx?IssueID={$IssueIDParam}');">Click here to create new item...</a> </td> </tr> It will open up in the pretty pop up and act the same as solution one… So… both Solutions will now behave the same to the end user. Just depends on which you want to implement. That’s all for now… Remember in both solutions when you have them working, you can make the “IssueID” invisible to users by using the “ms-hidden” class (it’s my previous blog post on the subject up there). That’s basically all there is to it! No pithy or witty closing this time… I am sorry it took me so long to dive into this and I hope your questions are answered. As I become more polished myself I will try to come up with a cleaner solution that will make everyone happy… As always, thanks for taking the time to stop by.

  Read the article

• WCF – interchangeable data-contract types

  - by nmarun

  In a WSDL based environment, unlike a CLR-world, we pass around the ‘state’ of an object and not the reference of an object. Well firstly, what does ‘state’ mean and does this also mean that we can send a struct where a class is expected (or vice-versa) as long as their ‘state’ is one and the same? Let’s see. So I have an operation contract defined as below: 1: [ServiceContract] 2: public interface ILearnWcfServiceExtend : ILearnWcfService 3: { 4: [OperationContract] 5: Employee SaveEmployee(Employee employee); 6: } 7:  8: [ServiceBehavior] 9: public class LearnWcfService : ILearnWcfServiceExtend 10: { 11: public Employee SaveEmployee(Employee employee) 12: { 13: employee.EmployeeId = 123; 14: return employee; 15: } 16: } Quite simplistic operation there (which translates to ‘absolutely no business value’). Now, the data contract Employee mentioned above is a struct. 1: public struct Employee 2: { 3: public int EmployeeId { get; set; } 4:  5: public string FName { get; set; } 6: } After compilation and consumption of this service, my proxy (in the Reference.cs file) looks like below (I’ve ignored the rest of the details just to avoid unwanted confusion): 1: public partial struct Employee : System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged I call the service with the code below: 1: private static void CallWcfService() 2: { 3: Employee employee = new Employee { FName = "A" }; 4: Console.WriteLine("IsValueType: {0}", employee.GetType().IsValueType); 5: Console.WriteLine("IsClass: {0}", employee.GetType().IsClass); 6: Console.WriteLine("Before calling the service: {0} - {1}", employee.EmployeeId, employee.FName); 7: employee = LearnWcfServiceClient.SaveEmployee(employee); 8: Console.WriteLine("Return from the service: {0} - {1}", employee.EmployeeId, employee.FName); 9: } The output is: I now change my Employee type from a struct to a class in the proxy class and run the application: 1: public partial class Employee : System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged { The output this time is: The state of an object implies towards its composition, the properties and the values of these properties and not based on whether it is a reference type (class) or a value type (struct). And as shown above, we’re actually passing an object by its state and not by reference. Continuing on the same topic of ‘type-interchangeability’, WCF treats two data contracts as equivalent if they have the same ‘wire-representation’. We can do so using the DataContract and DataMember attributes’ Name property. 1: [DataContract] 2: public struct Person 3: { 4: [DataMember] 5: public int Id { get; set; } 6:  7: [DataMember] 8: public string FirstName { get; set; } 9: } 10:  11: [DataContract(Name="Person")] 12: public class Employee 13: { 14: [DataMember(Name = "Id")] 15: public int EmployeeId { get; set; } 16:  17: [DataMember(Name="FirstName")] 18: public string FName { get; set; } 19: } I’ve created two data contracts with the exact same wire-representation. Just remember that the names and the types of data members need to match to be considered equivalent. The question then arises as to what gets generated in the proxy class. Despite us declaring two data contracts (Person and Employee), only one gets emitted – Person. This is because we’re saying that the Employee type has the same wire-representation as the Person type. Also that the signature of the SaveEmployee operation gets changed on the proxy side: 1: [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")] 2: [System.ServiceModel.ServiceContractAttribute(ConfigurationName="ServiceProxy.ILearnWcfServiceExtend")] 3: public interface ILearnWcfServiceExtend 4: { 5: [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/ILearnWcfServiceExtend/SaveEmployee", ReplyAction="http://tempuri.org/ILearnWcfServiceExtend/SaveEmployeeResponse")] 6: ClientApplication.ServiceProxy.Person SaveEmployee(ClientApplication.ServiceProxy.Person employee); 7: } But, on the service side, the SaveEmployee still accepts and returns an Employee data contract. 1: [ServiceBehavior] 2: public class LearnWcfService : ILearnWcfServiceExtend 3: { 4: public Employee SaveEmployee(Employee employee) 5: { 6: employee.EmployeeId = 123; 7: return employee; 8: } 9: } Despite all these changes, our output remains the same as the last one: This is type-interchangeability at work! Here’s one more thing to ponder about. Our Person type is a struct and Employee type is a class. Then how is it that the Person type got emitted as a ‘class’ in the proxy? It’s worth mentioning that WSDL describes a type called Employee and does not say whether it is a class or a struct (see the SOAP message below): 1: <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 2: xmlns:tem="http://tempuri.org/" 3: xmlns:ser="http://schemas.datacontract.org/2004/07/ServiceApplication"> 4: <soapenv:Header/> 5: <soapenv:Body> 6: <tem:SaveEmployee> 7: <!--Optional:--> 8: <tem:employee> 9: <!--Optional:--> 10: <ser:EmployeeId>?</ser:EmployeeId> 11: <!--Optional:--> 12: <ser:FName>?</ser:FName> 13: </tem:employee> 14: </tem:SaveEmployee> 15: </soapenv:Body> 16: </soapenv:Envelope> There are some differences between how ‘Add Service Reference’ and the svcutil.exe generate the proxy class, but turns out both do some kind of reflection and determine the type of the data contract and emit the code accordingly. So since the Employee type is a class, the proxy ‘Person’ type gets generated as a class. In fact, reflecting on svcutil.exe application, you’ll see that there are a couple of places wherein a flag actually determines a type as a class or a struct. One example is in the ExportISerializableDataContract method in the System.Runtime.Serialization.CodeExporter class. Seems like these flags have a say in deciding whether the type gets emitted as a struct or a class. This behavior is different if you use the WSDL tool though. WSDL tool does not do any kind of reflection of the data contract / serialized type, it emits the type as a class by default. You can check this using the two command lines below:   Note to self: Remember ‘state’ and type-interchangeability when traversing through the WSDL planet!

  Read the article

• SQL Server Master class winner

  - by Testas

   The winner of the SQL Server MasterClass competition courtesy of the UK SQL Server User Group and SQL Server Magazine!    Steve Hindmarsh     There is still time to register for the seminar yourself at:  www.regonline.co.uk/kimtrippsql     More information about the seminar     Where: Radisson Edwardian Heathrow Hotel, London  When: Thursday 17th June 2010  This one-day MasterClass will focus on many of the top issues companies face when implementing and maintaining a SQL Server-based solution. In the case where a company has no dedicated DBA, IT managers sometimes struggle to keep the data tier performing well and the data available. This can be especially troublesome when the development team is unfamiliar with the affect application design choices have on database performance. The Microsoft SQL Server MasterClass 2010 is presented by Paul S. Randal and Kimberly L. Tripp, two of the most experienced and respected people in the SQL Server world. Together they have over 30 years combined experience working with SQL Server in the field, and on the SQL Server product team itself. This is a unique opportunity to hear them present at a UK event which will: Debunk many of the ingrained misconceptions around SQL Server's behaviour    Show you disaster recovery techniques critical to preserving your company's life-blood - the data    Explain how a common application design pattern can wreak havoc in the database Walk through the top-10 points to follow around operations and maintenance for a well-performing and available data tier! Please Note: Agenda may be subject to change  Sessions Abstracts  KEYNOTE: Bridging the Gap Between Development and Production    Applications are commonly developed with little regard for how design choices will affect performance in production. This is often because developers don't realize the implications of their design on how SQL Server will be able to handle a high workload (e.g. blocking, fragmentation) and/or because there's no full-time trained DBA that can recognize production problems and help educate developers. The keynote sets the stage for the rest of the day. Discussing some of the issues that can arise, explaining how some can be avoided and highlighting some of the features in SQL 2008 that can help developers and DBAs make better use of SQL Server, and troubleshoot when things go wrong.   SESSION ONE: SQL Server Mythbusters  It's amazing how many myths and misconceptions have sprung up and persisted over the years about SQL Server - after many years helping people out on forums, newsgroups, and customer engagements, Paul and Kimberly have heard it all. Are there really non-logged operations? Can interrupting shrinks or rebuilds cause corruption? Can you override the server's MAXDOP setting? Will the server always do a table-scan to get a row count? Many myths lead to poor design choices and inappropriate maintenance practices so these are just a few of many, many myths that Paul and Kimberly will debunk in this fast-paced session on how SQL Server operates and should be managed and maintained.   SESSION TWO: Database Recovery Techniques Demo-Fest  Even if a company has a disaster recovery strategy in place, they need to practice to make sure that the plan will work when a disaster does strike. In this fast-paced demo session Paul and Kimberly will repeatedly do nasty things to databases and then show how they are recovered - demonstrating many techniques that can be used in production for disaster recovery. Not for the faint-hearted!   SESSION THREE: GUIDs: Use, Abuse, and How To Move Forward   Since the addition of the GUID (Microsoft’s implementation of the UUID), my life as a consultant and "tuner" has been busy. I’ve seen databases designed with GUID keys run fairly well with small workloads but completely fall over and fail because they just cannot scale. And, I know why GUIDs are chosen - it simplifies the handling of parent/child rows in your batches so you can reduce round-trips or avoid dealing with identity values. And, yes, sometimes it's even for distributed databases and/or security that GUIDs are chosen. I'm not entirely against ever using a GUID but overusing and abusing GUIDs just has to be stopped! Please, please, please let me give you better solutions and explanations on how to deal with your parent/child rows, round-trips and clustering keys!   SESSION 4: Essential Database Maintenance  In this session, Paul and Kimberly will run you through their top-ten database maintenance recommendations, with a lot of tips and tricks along the way. These are distilled from almost 30 years combined experience working with SQL Server customers and are geared towards making your databases more performant, more available, and more easily managed (to save you time!). Everything in this session will be practical and applicable to a wide variety of databases. Topics covered include: backups, shrinks, fragmentation, statistics, and much more! Focus will be on 2005 but we'll explain some of the key differences for 2000 and 2008 as well. Speaker Biographies     Kimberley L. Tripp Paul and Kimberly are a husband-and-wife team who own and run SQLskills.com, a world-renowned SQL Server consulting and training company. They are both SQL Server MVPs and Microsoft Regional Directors, with over 30 years of combined experience on SQL Server. Paul worked on the SQL Server team for nine years in development and management roles, writing many of the DBCC commands, and ultimately with responsibility for core Storage Engine for SQL Server 2008. Paul writes extensively on his blog (SQLskills.com/blogs/Paul) and for TechNet Magazine, for which he is also a Contributing Editor. Kimberly worked on the SQL Server team in the early 1990s as a tester and writer before leaving to found SQLskills and embrace her passion for teaching and consulting. Kimberly has been a staple at worldwide conferences since she first presented at TechEd in 1996, and she blogs at SQLskills.com/blogs/Kimberly. They have written Microsoft whitepapers and books for SQL Server 2000, 2005 and 2008, and are regular, top-rated presenters worldwide on database maintenance, high availability, disaster recovery, performance tuning, and SQL Server internals. Together they teach the SQL MCM certification and throughout Microsoft.In their spare time, they like to find frogfish in remote corners of the world.   Speaker Testimonials  "To call them good trainers is an epic understatement. They know how to deliver technical material in ways that illustrate it well. I had to stop Paul at one point and ask him how long it took to build a particular slide because the animations were so good at conveying a hard-to-describe process." "These are not beginner presenters, and they put an extreme amount of preparation and attention to detail into everything that they do. Completely, utterly professional." "When it comes to the instructors themselves, Kimberly and Paul simply have no equal. Not only are they both ultimate authorities, but they have endless enthusiasm about the material, and spot on delivery. If either ever got tired they never showed it, even after going all day and all week. We witnessed countless demos over the course of the week, some extremely involved, multi-step processes, and I can’t recall one that didn’t go the way it was supposed to." "You might think that with this extreme level of skill comes extreme levels of egotism and lack of patience. Nothing could be further from the truth. ... They simply know how to teach, and are approachable, humble, and patient." "The experience Paul and Kimberly have had with real live customers yields a lot more information and things to watch out for than you'd ever get from documentation alone." “Kimberly, I just wanted to send you an email to let you know how awesome you are! I have applied some of your indexing strategies to our website’s homegrown CMS and we are experiencing a significant performance increase. WOW....amazing tips delivered in an exciting way!  Thanks again” 

  Read the article

• Observations in Migrating from JavaFX Script to JavaFX 2.0

  - by user12608080

  Observations in Migrating from JavaFX Script to JavaFX 2.0 Introduction Having been available for a few years now, there is a decent body of work written for JavaFX using the JavaFX Script language. With the general availability announcement of JavaFX 2.0 Beta, the natural question arises about converting the legacy code over to the new JavaFX 2.0 platform. This article reflects on some of the observations encountered while porting source code over from JavaFX Script to the new JavaFX API paradigm. The Application The program chosen for migration is an implementation of the Sudoku game and serves as a reference application for the book JavaFX – Developing Rich Internet Applications. The design of the program can be divided into two major components: (1) A user interface (ideally suited for JavaFX design) and (2) the puzzle generator. For the context of this article, our primary interest lies in the user interface. The puzzle generator code was lifted from a sourceforge.net project and is written entirely in Java. Regardless which version of the UI we choose (JavaFX Script vs. JavaFX 2.0), no code changes were required for the puzzle generator code. The original user interface for the JavaFX Sudoku application was written exclusively in JavaFX Script, and as such is a suitable candidate to convert over to the new JavaFX 2.0 model. However, a few notable points are worth mentioning about this program. First off, it was written in the JavaFX 1.1 timeframe, where certain capabilities of the JavaFX framework were as of yet unavailable. Citing two examples, this program creates many of its own UI controls from scratch because the built-in controls were yet to be introduced. In addition, layout of graphical nodes is done in a very manual manner, again because much of the automatic layout capabilities were in flux at the time. It is worth considering that this program was written at a time when most of us were just coming up to speed on this technology. One would think that having the opportunity to recreate this application anew, it would look a lot different from the current version. Comparing the Size of the Source Code An attempt was made to convert each of the original UI JavaFX Script source files (suffixed with .fx) over to a Java counterpart. Due to language feature differences, there are a small number of source files which only exist in one version or the other. The table below summarizes the size of each of the source files. JavaFX Script source file Number of Lines Number of Character JavaFX 2.0 Java source file Number of Lines Number of Characters ArrowKey.java 6 72 Board.fx 221 6831 Board.java 205 6508 BoardNode.fx 446 16054 BoardNode.java 723 29356 ChooseNumberNode.fx 168 5267 ChooseNumberNode.java 302 10235 CloseButtonNode.fx 115 3408 CloseButton.java 99 2883 ParentWithKeyTraversal.java 111 3276 FunctionPtr.java 6 80 Globals.java 20 554 Grouping.fx 8 140 HowToPlayNode.fx 121 3632 HowToPlayNode.java 136 4849 IconButtonNode.fx 196 5748 IconButtonNode.java 183 5865 Main.fx 98 3466 Main.java 64 2118 SliderNode.fx 288 10349 SliderNode.java 350 13048 Space.fx 78 1696 Space.java 106 2095 SpaceNode.fx 227 6703 SpaceNode.java 220 6861 TraversalHelper.fx 111 3095 Total 2,077 79,127 2531 87,800 A few notes about this table are in order: The number of lines in each file was determined by running the Unix ‘wc –l’ command over each file. The number of characters in each file was determined by running the Unix ‘ls –l’ command over each file. The examination of the code could certainly be much more rigorous. No standard formatting was performed on these files.  All comments however were deleted. There was a certain expectation that the new Java version would require more lines of code than the original JavaFX script version. As evidenced by a count of the total number of lines, the Java version has about 22% more lines than its FX Script counterpart. Furthermore, there was an additional expectation that the Java version would be more verbose in terms of the total number of characters.  In fact the preceding data shows that on average the Java source files contain fewer characters per line than the FX files.  But that's not the whole story.  Upon further examination, the FX Script source files had a disproportionate number of blank characters.  Why?  Because of the nature of how one develops JavaFX Script code.  The object literal dominates FX Script code.  Its not uncommon to see object literals indented halfway across the page, consuming lots of meaningless space characters. RAM consumption Not the most scientific analysis, memory usage for the application was examined on a Windows Vista system by running the Windows Task Manager and viewing how much memory was being consumed by the Sudoku version in question. Roughly speaking, the FX script version, after startup, had a RAM footprint of about 90MB and remained pretty much the same size. The Java version started out at about 55MB and maintained that size throughout its execution. What About Binding? Arguably, the most striking observation about the conversion from JavaFX Script to JavaFX 2.0 concerned the need for data synchronization, or lack thereof. In JavaFX Script, the primary means to synchronize data is via the bind expression (using the “bind” keyword), and perhaps to a lesser extent it’s “on replace” cousin. The bind keyword does not exist in Java, so for JavaFX 2.0 a Data Binding API has been introduced as a replacement. To give a feel for the difference between the two versions of the Sudoku program, the table that follows indicates how many binds were required for each source file. For JavaFX Script files, this was ascertained by simply counting the number of occurrences of the bind keyword. As can be seen, binding had been used frequently in the JavaFX Script version (and does not take into consideration an additional half dozen or so “on replace” triggers). The JavaFX 2.0 program achieves the same functionality as the original JavaFX Script version, yet the equivalent of binding was only needed twice throughout the Java version of the source code. JavaFX Script source file Number of Binds JavaFX Next Java source file Number of “Binds” ArrowKey.java 0 Board.fx 1 Board.java 0 BoardNode.fx 7 BoardNode.java 0 ChooseNumberNode.fx 11 ChooseNumberNode.java 0 CloseButtonNode.fx 6 CloseButton.java 0 CustomNodeWithKeyTraversal.java 0 FunctionPtr.java 0 Globals.java 0 Grouping.fx 0 HowToPlayNode.fx 7 HowToPlayNode.java 0 IconButtonNode.fx 9 IconButtonNode.java 0 Main.fx 1 Main.java 0 Main_Mobile.fx 1 SliderNode.fx 6 SliderNode.java 1 Space.fx 0 Space.java 0 SpaceNode.fx 9 SpaceNode.java 1 TraversalHelper.fx 0 Total 58 2 Conclusions As the JavaFX 2.0 technology is so new, and experience with the platform is the same, it is possible and indeed probable that some of the observations noted in the preceding article may not apply across other attempts at migrating applications. That being said, this first experience indicates that the migrated Java code will likely be larger, though not extensively so, than the original Java FX Script source. Furthermore, although very important, it appears that the requirements for data synchronization via binding, may be significantly less with the new platform.

  Read the article

• How can a code editor effectively hint at code nesting level - without using indentation?

  - by pgfearo

  I've written an XML text editor that provides 2 view options for the same XML text, one indented (virtually), the other left-justified. The motivation for the left-justified view is to help users 'see' the whitespace characters they're using for indentation of plain-text or XPath code without interference from indentation that is an automated side-effect of the XML context. I want to provide visual clues (in the non-editable part of the editor) for the left-justified mode that will help the user, but without getting too elaborate. I tried just using connecting lines, but that seemed too busy. The best I've come up with so far is shown in a mocked up screenshot of the editor below, but I'm seeking better/simpler alternatives (that don't require too much code). [Edit] Taking the heatmap idea (from: @jimp) I get this and 3 alternatives - labelled a, b and c: The following section describes the accepted answer as a proposal, bringing together ideas from a number of other answers and comments. As this question is now community wiki, please feel free to update this. NestView The name for this idea which provides a visual method to improve the readability of nested code without using indentation. Contour Lines The name for the differently shaded lines within the NestView The image above shows the NestView used to help visualise an XML snippet. Though XML is used for this illustration, any other code syntax that uses nesting could have been used for this illustration. An Overview: The contour lines are shaded (as in a heatmap) to convey nesting level The contour lines are angled to show when a nesting level is being either opened or closed. A contour line links the start of a nesting level to the corresponding end. The combined width of contour lines give a visual impression of nesting level, in addition to the heatmap. The width of the NestView may be manually resizable, but should not change as the code changes. Contour lines can either be compressed or truncated to keep acheive this. Blank lines are sometimes used code to break up text into more digestable chunks. Such lines could trigger special behaviour in the NestView. For example the heatmap could be reset or a background color contour line used, or both. One or more contour lines associated with the currently selected code can be highlighted. The contour line associated with the selected code level would be emphasized the most, but other contour lines could also 'light up' in addition to help highlight the containing nested group Different behaviors (such as code folding or code selection) can be associated with clicking/double-clicking on a Contour Line. Different parts of a contour line (leading, middle or trailing edge) may have different dynamic behaviors associated. Tooltips can be shown on a mouse hover event over a contour line The NestView is updated continously as the code is edited. Where nesting is not well-balanced assumptions can be made where the nesting level should end, but the associated temporary contour lines must be highlighted in some way as a warning. Drag and drop behaviors of Contour Lines can be supported. Behaviour may vary according to the part of the contour line being dragged. Features commonly found in the left margin such as line numbering and colour highlighting for errors and change state could overlay the NestView. Additional Functionality The proposal addresses a range of additional issues - many are outside the scope of the original question, but a useful side-effect. Visually linking the start and end of a nested region The contour lines connect the start and end of each nested level Highlighting the context of the currently selected line As code is selected, the associated nest-level in the NestView can be highlighted Differentiating between code regions at the same nesting level In the case of XML different hues could be used for different namespaces. Programming languages (such as c#) support named regions that could be used in a similar way. Dividing areas within a nesting area into different visual blocks Extra lines are often inserted into code to aid readability. Such empty lines could be used to reset the saturation level of the NestView's contour lines. Multi-Column Code View Code without indentation makes the use of a multi-column view more effective because word-wrap or horizontal scrolling is less likely to be required. In this view, once code has reach the bottom of one column, it flows into the next one: Usage beyond merely providing a visual aid As proposed in the overview, the NestView could provide a range of editing and selection features which would be broadly in line with what is expected from a TreeView control. The key difference is that a typical TreeView node has 2 parts: an expander and the node icon. A NestView contour line can have as many as 3 parts: an opener (sloping), a connector (vertical) and a close (sloping). On Indentation The NestView presented alongside non-indented code complements, but is unlikely to replace, the conventional indented code view. It's likely that any solutions adopting a NestView, will provide a method to switch seamlessly between indented and non-indented code views without affecting any of the code text itself - including whitespace characters. One technique for the indented view would be 'Virtual Formatting' - where a dynamic left-margin is used in lieu of tab or space characters. The same nesting-level data used to dynamically render the NestView could also used for the more conventional-looking indented view. Printing Indentation will be important for the readability of printed code. Here, the absence of tab/space characters and a dynamic left-margin means that the text can wrap at the right-margin and still maintain the integrity of the indented view. Line numbers can be used as visual markers that indicate where code is word-wrapped and also the exact position of indentation: Screen Real-Estate: Flat Vs Indented Addressing the question of whether the NestView uses up valuable screen real-estate: Contour lines work well with a width the same as the code editor's character width. A NestView width of 12 character widths can therefore accommodate 12 levels of nesting before contour lines are truncated/compressed. If an indented view uses 3 character-widths for each nesting level then space is saved until nesting reaches 4 levels of nesting, after this nesting level the flat view has a space-saving advantage that increases with each nesting level. Note: A minimum indentation of 4 character widths is often recommended for code, however XML often manages with less. Also, Virtual Formatting permits less indentation to be used because there's no risk of alignment issues A comparison of the 2 views is shown below: Based on the above, its probably fair to conclude that view style choice will be based on factors other than screen real-estate. The one exception is where screen space is at a premium, for example on a Netbook/Tablet or when multiple code windows are open. In these cases, the resizable NestView would seem to be a clear winner. Use Cases Examples of real-world examples where NestView may be a useful option: Where screen real-estate is at a premium a. On devices such as tablets, notepads and smartphones b. When showing code on websites c. When multiple code windows need to be visible on the desktop simultaneously Where consistent whitespace indentation of text within code is a priority For reviewing deeply nested code. For example where sub-languages (e.g. Linq in C# or XPath in XSLT) might cause high levels of nesting. Accessibility Resizing and color options must be provided to aid those with visual impairments, and also to suit environmental conditions and personal preferences: Compatability of edited code with other systems A solution incorporating a NestView option should ideally be capable of stripping leading tab and space characters (identified as only having a formatting role) from imported code. Then, once stripped, the code could be rendered neatly in both the left-justified and indented views without change. For many users relying on systems such as merging and diff tools that are not whitespace-aware this will be a major concern (if not a complete show-stopper). Other Works: Visualisation of Overlapping Markup Published research by Wendell Piez, dated from 2004, addresses the issue of the visualisation of overlapping markup, specifically LMNL. This includes SVG graphics with significant similarities to the NestView proposal, as such, they are acknowledged here. The visual differences are clear in the images (below), the key functional distinction is that NestView is intended only for well-nested XML or code, whereas Wendell Piez's graphics are designed to represent overlapped nesting. The graphics above were reproduced - with kind permission - from http://www.piez.org Sources: Towards Hermenutic Markup Half-steps toward LMNL

  Read the article

• Fixing a SkyDrive Sync Disaster

  - by Rick Strahl

  For a few months I've been using SkyDrive to handle some basic synching tasks for a number of folders of mine. Specifically I've been dumping a few of my development folders into sky drive so I have a live running backup. It had been working just fine until about a week ago when something went awry. Badly! The idea is that the SkyDrive should sync files, but somewhere in its sync relationship it appears that SkyDrive got confused and assumed it needed to sync back older files to my local machine from the SkyDrive server. So rather than syncing my newer files to the server SkyDrive was pushing older files back to me. Because SkyDrive is so slow actually updating data it's not unusual for SkyDrive to be far behind in syncing and apparently some files were out of date by several months. Of course this is insidious because I didn't notice it for quite some time. I'd been happily working away on my files when a few days ago I noted a bunch of files with -RasXps (my machine name) popping up in various folders. At first I thought my Git repository was giving me a fit, but eventually realized that SkyDrive was actually pushing old files into my monitored folders. To be fair SkyDrive did make backups of the existing files, but by the time I caught it there were literally a few thousand files scattered on my machine that were now updated with old files from online. Here's what some of this looks like: If you look at the directory list you see a bunch of files with a -RasXps postfix appended to them. Those are the files that SkyDrive replaced and backed up on my machine. As you can see the backed up files are actually newer than the ones it pulled from the online SkyDrive. Unless I modified the files after they were updated they all were older than the existing local files. Not exactly how I imagined my synching would work. At first I started cleaning up this mess manually. In most cases the obvious solution was to simply delete the original file and replace with the -RasXps file, but not in all files. Some scrutiny was required and besides being a pain in the ass to rename files, quite frequently I had to dig out Beyond Compare to compare a few files where it wasn't quite clear what's wrong. I quickly realized that doing this by hand would be too hard for the large number of files that got hosed. Hacking together a small .NET Utility So, I figured the easiest way to tackle this is to write a small utility app that shows me all the mangled files that have backups, allows me to compare them and then quickly select and update them, removing the -RasXps file after choosing one of the two files. What I ended up with was a quick and dirty WinForms app that allows me to pick a root folder, and then shows all the -MachineName files: I start by picking a base folder and a template to search for - typically the -MachineName. Clicking Go brings up a list of all files in that folder and its subdirectories.  The list also displays the dates for the saved (-MachineName) file and the current file on disk, along with highlighting for the newer of the two. I can right click on any file and get a context menu pop up to open the folder in Explorer, or open Beyond Compare and view the two files to compare differences which I found very helpful for a number of files where I had modified the files after SkyDrive had updated to an old one. Typically these would be the green files (of which there were thankfully few). To 'fix' files I can select any number of files in the list, then use one of the three buttons on the right to apply an operation. I can use the Saved files - that is the backup file that SkyDrive created with the -MachineName extension (-RasXps above). Or I can use the current file, which is the file with the right name on disk right now and delete the -MachineName file. Or on some occasions I can just opt to delete both of them. For some files like binaries it's often easier to just delete and them be rebuild than choosing. For the most part the process involves accepting the pink files, and checking the few green files and see if any modifications were made since the file was updated incorrectly by SkyDrive. For me luckily those are few in number. Anyways, I thought I share this utility in case anybody else runs into this issue. I've included the VS2012 solution and all the source code so you can see how it works and you can tweak it as needed. The .NET 4.5 binaries are also included if you can't compile. Be warned though!  This rough code is provided as is and makes no guarantees or claims about file safety. All three of the action buttons on the form will delete data. It's a very rough utility and there are no safeguards that ask nicely before deleting files. I highly recommend you make a backup before you have at it. This tools is very narrow in focus, but it might also work with other sync issues from other vendors. I seem to remember that I had similar issues with SugarSync at some point and it too created the -MachineName style files on sync conflicts. Hope this helps somebody out so you can avoid wasting the better part of a full work day on this… Resources Download the Source Code and Binaries for SkyDrive Rescue© Rick Strahl, West Wind Technologies, 2005-2013Posted in Windows  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

  Read the article

< Previous Page | 74 75 76 77 78 79 80 81 82 83 84 85  | Next Page >