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• ESXi 5 VM Putty session hangs, vSphere client timing out

  - by user192702

  First of all I believe this is a ESXi issue but let me know if you have seen this. It started about a year ago when I noticed occasionally when I putty via SSH to my VM guests, if I do anything that makes it to display a lot of things at once, the session will hang and I have to start a new one quite often only to find the same behaviour. What I meant by display a lot of things can be any of the following: 1) tail -f filename 2) Paste a long command 3) less filename If I type in one character at a time this won't happen. I tried searching online and it always point me to flow control settings and the various suggestions I've tried have never been able to resolve the issue. Since last week, I've noticed I'm not able to connect to my POP3 server from Outlook (it's timing out from Outlook's perspective). Today I tried to connect to the ESXi via vSphere client and it gives me a time out also. Exact behavior and error I saw is similar to the one posted at the following URL but the suggested technique also failed to resolve the issue. http://davidcocke.blogspot.hk/2012/02/unable-to-login-with-vsphere-client.html Has anyone experienced this before? Any suggestions on how to troubleshoot this?

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• Thunderbird 11.0.1 and Lightning 1.3: How do I propose a different time for a meeting?

  - by seaao

  This all happens on my x64 Linux workstation btw. tl;dr: My colleague invited some people and me for a meeting. The meeting was scheduled a week to late. I -wrongfully- accepted. How do I propose a new time? To explain a bit more in detail: I received a meeting request in my mailbox. Thunderbird is so nice to let me accept or reject it, and after I click the button to accept, it is directly added to my calendar. But when I double click on the meeting to edit it, I get a function-wise scaled-down version of the meeting: The only settings I can alter are whether I want reminders, and if I go at all. Trying to drag it to another day doesn't work either: My calendar behaves like read-only (which it isn't btw). There are several questions (without answer...) to be found on Stack Overflow and on the Thunderbird knowledge base about using lightning. But I get the idea that I'm one of the few who won't comply with the team even before the meeting is started. My googling revealed no bugs or feature requests in the direction I'm thinking. A link to an explanation how to achieve this, or another perspective about how to reach the desired goal (meeting with my colleagues and me) would be mostly welcome!

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• Understanding Microsoft Word Formatting Behavior. Does anyone?

  - by deemer

  This isn't a question about how to do something (well, not directly), but rather an inquiry to see if anyone understands why MS Word behaves the way it does with respect to formatting from a design perspective. This is also admittedly a rant about Word. This is a question that has plagued me, well, every time I open a document in Word, and covers a lot of individual topics, so I'll restrict the discussion here to two concrete behaviors that baffle me. 1) Backspacing over whitespace changes the format of preceding text. This seems to most often occur when the preceding text is a header or list number. The strangest thing about this is the new format of the changed text usually doesn't appear anywhere else in the document. 2) Numbered lists count almost at random. I am working on a document today where the list numbers count as follows: 1, 2, 2, 3, 3. The lettering in the sublists go like this 1: a, 2: a, 2: b c d, 3: e f g, 3: a. Clicking on each number or letter highlights the other numbers or letters that Word thinks it is related to, which are scattered around the document pretty heavily. Attempts to renumber the list have so far proven fruitless, as Word seems to maintain these associations through clipboard copies, etc. Why could this even happen?

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• Nginx + WordPress + HHVM: Why isn't Batcache working? Would Varnish help even more?

  - by javipas

  I've heard great things about HHVM, so I've setup a copy of WordPress blog (on another domain) with Nginx (with the Pagespeed module) and HHVM. Right now the benefits are obvious: on the same config, load times are between two and three times faster. I'm trying to speed up things a little bit, and I've also installed Memcached and Batcache. I've installed the memcached package, copied object-cache.php (Pastebin) onto the root folder of the WordPress blog, and after that I've installed the Batcache plugin and copied the advanced-cache.php (Pastebin) file onto the wp-content folder. Also, I've included the line define('WP_CACHE', true); in the wp-config.php file. It seems it doesn't work, though. If I quickly reload the page several times Batcache should show the cached page, but it doesn't. It's easy to check that by reloading (Cmd+R on Chrome on OS X) the page several times and then viewing the page's code. Under the <head> section I should see some batcache stats, but they aren't there. I wonder if someone could give me some hint on this. On a side note, I don't know if I could add some other component in order to help the performance be even better. I'm thing about Varnish, but I'm not sure if it's just useless and it's just another way to the same I'm currently doing. Any other component there? (I'll test CDN for images, minifying js, etc and some other tricks as well, but I'm talking from the server perspective).

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• Migrating WebLogic 10.3.0 to new host. Slow managed server startup times

  - by wadevondoom

  We are migrating our Blue Martini Commerce application (only supported on WebLogic 10.3.0) to a new host (Redhat 6.3 on a VMWare ESX vm). We are seeing extremely slow start up times for our managed server(s) that is basically 20x slower than our current production. As a for instance the Publish managed server takes ~30 - 45 seconds in current production and in the new environment it takes ~10 minutes. The setup uses the same domain structure and JVM as the current production environment. The same setup files are used. We use jdk1.6.0_33 on 64 bit architecture. We used the generic 64bit weblogic installer and used pack / unpack utilities to migrate the domain. The JAVA_OPTS to start this server are: "-d64 -Xms256m -Xmx512m -XX:PermSize=48m -XX:MaxPermSize=256m" The sysadmins have checked /etc/sysctl.conf and /etc/limits.conf to ensure we were not hitting some kind of process limit. As I am not sure what this managed server does from a Blue Martini perspective during the phase of startup I also had the DBA check to ensure that Oracle RAC (11.2.0.3) wasn't also hitting some kind of process limit or if there was a tns listener issue. The new host is quite a bit stricter with their server lock downs so there are a few differences.... Redhat 6.3 in new env, RH 5.7 in current SElinux is targeted in new env and disabled in current VM in new env and dedicated hardware in current iptables disabled in current. It was enabled in new prod but I had them disable it just in case I apologize for not being more specific. I am mostly hoping got some tips. I do not have the typical root access I would normally have in this environment. I am just hoping got a path forward. I did a few 'kill -3' to see if there are blocked threads and I got nadda. The service works for all intents and purposes it is just painfully slow. Thanks you all in advance for reading and best regards. Wade

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• Viewing Postscript (or PDF) on OS X: Aliasing issues

  - by mankoff

  I am generating postscript graphics and am trying to find a balance between non-aliasing and over-aliasing. If I use the raw ghostscript viewer gs on the Postscript, it looks good. The text appears anti-aliased, but the image remains nice and blocky. Unfortunately, gs has no real user interface and loses all of the nice things that Preview.app has. I could install gv, but the dependency bloat is huge! It requires all of gnome. And even that isn't a great viewer compared to Preview.app or Skim.app. Here is an image viewed with gs: From a user-interaction and Mac-ish perspective, Preview.app (or Skim.app is a much nicer program to use. They have the option to turn on or off aliasing, but neither option looks very good. Which aliasing on, the image is blurry. When it is off, the graphic matches what is seen from gs, but there are two issues. Minor issue: the font is ugly. Uglier than with gs. Major issue: Every PDF is un-aliased, making it hard to read regular PDFs full of text. So, in summary: Is there a way to manually generate the PDF from the PS that overcomes these issues? Is there a way to find a middle ground of alias/unalias with Preview.app? Is there another app that displays with quality like gs, but has a decent UI like Skim.app or Preview.app Is there a way to have Preview.app turn off aliasing for only one file (containing graphics) but leave it enabled in general so that text PDFs are still readable?

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• What could be wrong with my VLAN?

  - by Matt

  I've got a VLAN 10 setup as a management VLAN. The management VLAN comes off port 48 and links to another set of switches that do not support VLAN's so it was I believe set up as an untagged access port. In the past this was a different brand of switch and this worked fine. However, since changing to the HP V1910-48G series I can't seem to get this working. I must point out that as far as I'm aware it is wired up properly (I can't check this physically as I'm working remote and have asked the tech who's got access to double check for me). Now I don't have a huge amount of experience with VLAN environments but AFAIK this is right. I've set the port 48 (linked to the management switches) as an untagged port with PVID 10 and access link type. Is this all I'd need to do from a configuration perspective to ensure all devices connected to port 48 would end up being on VLAN 10 and not needing to tag their frames. i.e. the tag would be added by the switch before being forwarded.

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• Multi- authentication scenario for a public internet service using Kerberos

  - by StrangeLoop

  I have a public web server which has users coming from internet (via HTTPS) and from a corporate intranet. I wish to use Kerberos authentication for the intranet users so that they would be automatically logged in the web application without the need to provide any login/password (assuming they are already logged to the Windows domain). For the users coming from internet I want to provide traditional basic/form- based authentication. User/password data for these users would be stored internally in a database used by the application. Web application will be configured to use Kerberos authentication for users coming from specific intranet ip networks and basic/form- based authentication will be used for the rest of the users. From a security perspective, are there some risks involved in this kind of setup or is this a generally accepted solution? My understanding is that server doesn't need access to KDC (see Kerberos authentication, service host and access to KDC) and it can be completely isolated from AD and corporate intranet. The server has a keytab file stored locally that is used to decrypt tickets sent by the users coming from intranet. The tickets only contain username and domain of the incoming user. Server never sees the passwords of authenticated users. If the server would be hacked and the keytab file compromised, it would mean that attacker could forge tickets for any domain user and get access to the web application as any user. But typically this is the case anyway if hacker gains access to the keytab file on the local filesystem. The encryption key contained in the keytab file is based on the service account password in AD and is in hashed form, I guess it is very difficult to brute force this password if strong Kerberos encryption like AES-256-SHA1 is used. As the server has no network access to intranet, even the compromised service account couldn't be directly used for anything.

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• iptables, blocking large numbers of IP Addresses

  - by Twirrim

  I'm looking to block IP addresses in a relatively automated fashion if they look to be 'screen scraping' content from websites that we host. In the past this was achieved by some ingenious perl scripts and OpenBSD's pf. pf is great in that you can provide it nice tables of IP addresses and it will efficiently handle blocking based on them. However for various reasons (before my time) they made the decision to switch to CentOS. iptables doesn't natively provide the ability to block large numbers of addresses (I'm told it wasn't unusual to be blocking 5000+), and I'm a bit cautious over adding that many rules into an iptable. ipt_recent would be awesome for doing this, plus it provides a lot of flexibility for just severely slowing down access, but there is a bug in the CentOS kernel that is stopping me from using it (reported, but awaiting fix). Using ipset would entail compiling a more up-to-date version of iptables than comes with CentOS which whilst I'm perfectly capable of doing it, I'd rather not do from a patching, security and consistency perspective. Other than those two it looks like nfblock is a reasonable alternative. Is anyone aware of other ways of achieving this? Are my concerns about several thousand IP addresses in iptables as individual rules unfounded?

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• Anyone have real world experience with Rackspace Cloud Sites at high scale?

  - by Allara

  I have a pure web service application layer using .NET. I was originally planning to use Amazon EC2, but rolling my own autoscaling procedures is a bit intimidating, and the scaling isn't very granular from a cost perspective. If the app is successful, we could be looking at relatively high scale (millions of requests per month). The app uses Amazon SimpleDB as the database layer. As a test, I have the app running successfully in Rackspace Cloud Sites. Performance seems to be equal to (if not better than) a standard EC2 instance, even with the added latency of the SimpleDB requests travelling to the Rackspace network. However, testing at this stage is at a very low scale. My question is this: has anyone had real-world experience running a high scale application on Rackspace Cloud Sites? Moreover, once you pass the "included" 10,000 compute cycles per month, does the overall cost seem to be lower than rolling lots of EC2 instances? My assumption would be that with completely smooth scaling (i.e. only adding compute resources as needed), the cost could be lower on average. However, their stated goal of calibrating 10,000 CCs as a single 1.2 Ghz CPU seems on average to be much more expensive than EC2. I like the idea of no-touch scaling, but is it too good to be true?

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• How to secure a group of Amazon EC2 instances

  - by ks78

  I have several Amazon EC2 instances running Ubuntu 10.04 and I've recently started using Amazon's Route 53 as my DNS. The purpose of doing that was to allow the instances to refer to each other by name rather than private IP (which can change). I've pointed my domain name (via GoDaddy) to Amazon's name servers, allowing me to access my EC2 webservers. However, I noticed I can now access the EC2 instances which I don't want to be public, such as the dedicated MySQL Server. I was thinking Amazon's Security Groups would still be in effect when using Route 53, but that doesn't seem to be the case. Before I started using Route 53, I was thinking of having one instance run a reverse proxy, which would help protect the web servers behind it. Then IP-restrict all the other instances. I know IP restricting can be done using the firewall within each instance, but should I ever need to access them from another IP address, I'd need a way in. Amazon's control panel made it a breeze to open a port when necessary. Does anyone have any suggestions for keeping EC2 instances secure, but also accessible to their administrator? Also, what's the best topology for a group of EC2 instances, consisting of web servers and a dedicated database server, from a security perspective? Does having a reverse proxy server even make sense?

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• Allowing directory view/traversal for a specific VirtualHost in Apache 2.2

  - by warren

  I have the following vhost configured: <VirtualHost *:80> DocumentRoot /var/www/myvhost ServerName myv.host.com ServerAlias myv.host.com ErrorLog logs/myvhost-error_log CustomLog logs/myvhost-access_log combined ServerAdmin [email protected] <Directory /var/www/myvhost> AllowOverride All Options +Indexes </Directory> </VirtualHost> The configuration appears to be correct from the apachectl tool's perspective. However, I cannot get a directory listing on that vhost: Forbidden You don't have permission to access / on this server. Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request. The error log shows the following: [Wed Mar 07 19:23:33 2012] [error] [client 66.6.145.214] Directory index forbidden by Options directive: /var/www/****** update2 More recently, the following is now kicking-into the error.log: [Wed Mar 07 20:16:10 2012] [error] [client 192.152.243.233] Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden: /var/www/error/noindex.html update3 Today, the following is getting kicked-out: [Thu Mar 08 14:05:56 2012] [error] [client 66.6.145.214] Directory index forbidden by Options directive: /var/www/<mydir> [Thu Mar 08 14:05:56 2012] [error] [client 66.6.145.214] Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden: /var/www/error/noindex.html [Thu Mar 08 14:05:57 2012] [error] [client 66.6.145.214] Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace. This is after modifying the vhosts.conf file thusly: <VirtualHost *:80> DocumentRoot /var/www/<mydir> ServerName myhost ServerAlias myhost ErrorLog logs/myhost-error_log CustomLog logs/myhost-access_log combined ServerAdmin admin@myhost <Directory "/var/www/<mydir>"> Options All +Indexes +FollowSymLinks AllowOverride All Order allow,deny Allow from all </Directory> </VirtualHost> What is missing? update 4 All subdirectories of the root directory do directory listings properly - it is only the root which cannot.

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• I need to build a mini computer lab with 6 PCs

  - by chiurox

  Hello everyone, This weekend I need to build a mini computer lab with 5-6 PCs. The purpose is for a small computer class that will be taking place. They're mostly going to be doing office and daily kind of stuff, so nothing high performance. However, I hope it will last at least for 2 more years. I already have some parts for 2 PCs, one is a P4 3.0 and another is Celeron 2.4GHz, both socket 478. For the other 4 PCs, I'm wondering if I should buy individual parts and put it all together or get workstations like those Dell Optiplex with P4s. To put things into perspective, I am not currently in the US. I'm in South America and prices here are ridiculously. Another really important thing is that I need to share an internet connection between a total of 8 PCs at this place. Right now I only have a crappy wireless router, should I get another one? Or go with switch hub? I'm not experienced in this matter. Thanks guys!

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• Remote Desktop Services Licensing - Does server have to have a RDS role?

  - by transistor1

  I recently set up a "micro" size Windows 2008 Datacenter server on Amazon AWS. My small group needs several concurrent RDS users to be able to access the machine. Without installing the "Remote Desktop Server" role, it allows 2 concurrent connections. I read on MS' website that in order to set up multiple users, we needed to install the RDS role. I did so, but now the application we are trying to share is running much slower than it was before. Prior to the role installation, it was taking about 5 seconds to open; now it is taking a few minutes to open -- without any other users logged on except me. My assumption is that the RDS role may be too much for this micro instance to handle, and currently, changing to another size instance is not an option (it may be possible later if we were to receive enough funding). This leads me to the following questions: 1) Is it a sensible assessment to assume that it is the RDS role is slowing things down, or are there other things that I could look at to speed it up? We are talking about a machine with ~600MB of memory. 2) If I revert back to the pre-RDS role, is there any legitimate way (in terms of purchasing RDS licenses) to get more than 2 concurrent desktops? I did read this, and am not questioning that the answerer is knowlegeable; but someone else may have some other experience. I am also making it clear that we want to do this in a legitimate way. Thanks in advance for any assistance that can be provided! EDIT: if it is helpful in answering the question, the application in question is a Lotus Approach database. Also, I am asking this from a technical perspective: not a legal one. I want to know if it is possible to install valid licenses without the RDS role.

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• How can I optimize my ajax calls to deliver at 60ms.

  - by Quintin Par

  I am building an autocomplete functionality for my site and the Google instant results are my benchmark. When I look at Google, the 50-60 ms response time baffle me. They look insane. In comparison here’s how mine looks like. To give you an idea my results are cached on the load balancer and served from a machine that has httpd slowstart and initcwnd fixed. My site is also behind cloudflare From a server side perspective I don’t think I can do anything more. Can someone help me take this 500 ms response time to 60ms? What more should I be doing to achieve Google level performance? Edit: People, you seemed to be angry that I did a comparison to Google and the question is very generic. Sorry about that. To rephrase: How can I bring down response time from 500 ms to 60 ms provided my server response time is just a fraction of ms. Assume the results are served from Nginx - Varnish with a cache hit. Here are some answers I would like to answer myself assume the response sizes remained more or less the same. Ensure results are http compressed Ensure SPDY if you are on https Ensure you have initcwnd set to 10 and disable slow start on linux machines. Etc. I don’t think I’ll end up with 60 ms at Google level but your collective expertise can help easily shave off a 100 ms and that’s a big win.

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• Powershell Script to help archive company email

  - by sec_goat

  I am attempting to use powershell to gather emails that pertain to a certain subject, so that these correspondences might be turned over to a legal department. I am having a couple of issues here that I would like some assistance getting past. I run the following command: get-mailbox -Database "Mailbox Database" | Export-Mailbox -ContentKeywords "Keywords To Search" -TargetMailbox "sec_goat" -TargetFolder EmailSearch -StartDate "01/13/2011 12:01:00 This has pretty much done what I want, and returned a boat load of emails, however it has also flooded my inbox with hundreds of blank calendars and contact lists. I realize now I should have used the exclusion on these folders, as well as a test environment (which we don't have). 1.How can I clean up this script to not include all the blank folders, contacts and calendars that DO NOT match the keywords search? 2.How do I clean up hundreds of blank contact lists and calendars in my mailbox without right clicking and deleting each one? EDIT: I edited the post to change the scope of the question. I think my focus is less on the legal perspective and more on the "How can I clean up my mess and make future archives less messy and painful?"

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• Potential impact of large broadcast domains

  - by john

  I recently switched jobs. By the time I left my last job our network was three years old and had been planned very well (in my opinion). Our address range was split down into a bunch of VLANs with the largest subnet a /22 range. It was textbook. The company I now work for has built up their network over about 20 years. It's quite large, reaches multiple sites, and has an eclectic mix of devices. This organisation only uses VLANs for very specific things. I only know of one usage of VLANs so far and that is the SAN which also crosses a site boundary. I'm not a network engineer, I'm a support technician. But occasionally I have to do some network traces for debugging problems and I'm astounded by the quantity of broadcast traffic I see. The largest network is a straight Class B network, so it uses a /16 mask. Of course if that were filled with devices the network would likely grind to a halt. I think there are probably 2000+ physical and virtual devices currently using that subnet, but it (mostly) seems to work. This practise seems to go against everything I've been taught. My question is: In your opinion and  From my perspective - What measurement of which metric would tell me that there is too much broadcast traffic bouncing about the network? And what are the tell-tale signs that you are perhaps treading on thin ice? The way I see it, there are more and more devices being added and that can only mean more broadcast traffic, so there must be a threshold. Would things just get slower and slower, or would the effects be more subtle than that?

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• Nepotism In The SQL Family

  - by Rob Farley

  There’s a bunch of sayings about nepotism. It’s unpopular, unless you’re the family member who is getting the opportunity. But of course, so much in life (and career) is about who you know. From the perspective of the person who doesn’t get promoted (when the family member is), nepotism is simply unfair; even more so when the promoted one seems less than qualified, or incompetent in some way. We definitely get a bit miffed about that. But let’s also look at it from the other side of the fence – the person who did the promoting. To them, their son/daughter/nephew/whoever is just another candidate, but one in whom they have more faith. They’ve spent longer getting to know that person. They know their weaknesses and their strengths, and have seen them in all kinds of situations. They expect them to stay around in the company longer. And yes, they may have plans for that person to inherit one day. Sure, they have a vested interest, because they’d like their family members to have strong careers, but it’s not just about that – it’s often best for the company as well. I’m not announcing that the next LobsterPot employee is one of my sons (although I wouldn’t be opposed to the idea of getting them involved), but actually, admitting that almost all the LobsterPot employees are SQLFamily members… …which makes this post good for T-SQL Tuesday, this month hosted by Jeffrey Verheul (@DevJef). You see, SQLFamily is the concept that the people in the SQL Server community are close. We have something in common that goes beyond ordinary friendship. We might only see each other a few times a year, at events like the PASS Summit and SQLSaturdays, but the bonds that are formed are strong, going far beyond typical professional relationships. And these are the people that I am prepared to hire. People that I have got to know. I get to know their skill level, how well they explain things, how confident people are in their expertise, and what their values are. Of course there people that I wouldn’t hire, but I’m a lot more comfortable hiring someone that I’ve already developed a feel for. I need to trust the LobsterPot brand to people, and that means they need to have a similar value system to me. They need to have a passion for helping people and doing what they can to make a difference. Above all, they need to have integrity. Therefore, I believe in nepotism. All the people I’ve hired so far are people from the SQL community. I don’t know whether I’ll always be able to hire that way, but I have no qualms admitting that the things I look for in an employee are things that I can recognise best in those that are referred to as SQLFamily. …like Ted Krueger (@onpnt), LobsterPot’s newest employee and the guy who is representing our brand in America. I’m completely proud of this guy. He’s everything I want in an employee. He’s an experienced consultant (even wrote a book on it!), loving husband and father, genuine expert, and incredibly respected by his peers. It’s not favouritism, it’s just choosing someone I’ve been interviewing for years. @rob_farley

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• GPGPU

  WhatGPU obviously stands for Graphics Processing Unit (the silicon powering the display you are using to read this blog post). The extra GP in front of that stands for General Purpose computing.So, altogether GPGPU refers to computing we can perform on GPU for purposes beyond just drawing on the screen. In effect, we can use a GPGPU a bit like we already use a CPU: to perform some calculation (that doesn’t have to have any visual element to it). The attraction is that a GPGPU can be orders of magnitude faster than a CPU.WhyWhen I was at the SuperComputing conference in Portland last November, GPGPUs were all the rage. A quick online search reveals many articles introducing the GPGPU topic. I'll just share 3 here: pcper (ignoring all pages except the first, it is a good consumer perspective), gizmodo (nice take using mostly layman terms) and vizworld (answering the question on "what's the big deal").The GPGPU programming paradigm (from a high level) is simple: in your CPU program you define functions (aka kernels) that take some input, can perform the costly operation and return the output. The kernels are the things that execute on the GPGPU leveraging its power (and hence execute faster than what they could on the CPU) while the host CPU program waits for the results or asynchronously performs other tasks.However, GPGPUs have different characteristics to CPUs which means they are suitable only for certain classes of problem (i.e. data parallel algorithms) and not for others (e.g. algorithms with branching or recursion or other complex flow control). You also pay a high cost for transferring the input data from the CPU to the GPU (and vice versa the results back to the CPU), so the computation itself has to be long enough to justify the overhead transfer costs. If your problem space fits the criteria then you probably want to check out this technology.HowSo where can you get a graphics card to start playing with all this? At the time of writing, the two main vendors ATI (owned by AMD) and NVIDIA are the obvious players in this industry. You can read about GPGPU on this AMD page and also on this NVIDIA page. NVIDIA's website also has a free chapter on the topic from the "GPU Gems" book: A Toolkit for Computation on GPUs.If you followed the links above, then you've already come across some of the choices of programming models that are available today. Essentially, AMD is offering their ATI Stream technology accessible via a language they call Brook+; NVIDIA offers their CUDA platform which is accessible from CUDA C. Choosing either of those locks you into the GPU vendor and hence your code cannot run on systems with cards from the other vendor (e.g. imagine if your CPU code would run on Intel chips but not AMD chips). Having said that, both vendors plan to support a new emerging standard called OpenCL, which theoretically means your kernels can execute on any GPU that supports it. To learn more about all of these there is a website: gpgpu.org. The caveat about that site is that (currently) it completely ignores the Microsoft approach, which I touch on next.On Windows, there is already a cross-GPU-vendor way of programming GPUs and that is the DirectX API. Specifically, on Windows Vista and Windows 7, the DirectX 11 API offers a dedicated subset of the API for GPGPU programming: DirectCompute. You use this API on the CPU side, to set up and execute the kernels that run on the GPU. The kernels are written in a language called HLSL (High Level Shader Language). You can use DirectCompute with HLSL to write a "compute shader", which is the term DirectX uses for what I've been referring to in this post as a "kernel". For a comprehensive collection of links about this (including tutorials, videos and samples) please see my blog post: DirectCompute.Note that there are many efforts to build even higher level languages on top of DirectX that aim to expose GPGPU programming to a wider audience by making it as easy as today's mainstream programming models. I'll mention here just two of those efforts: Accelerator from MSR and Brahma by Ananth. Comments about this post welcome at the original blog.

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• What I don&rsquo;t like about WIF&rsquo;s Claims-based Authorization

  - by Your DisplayName here!

  In my last post I wrote about what I like about WIF’s proposed approach to authorization – I also said that I definitely would build upon that infrastructure for my own systems. But implementing such a system is a little harder as it could be. Here’s why (and that’s purely my perspective): First of all WIF’s authorization comes in two “modes” Per-request authorization. When an ASP.NET/WCF request comes in, the registered authorization manager gets called. For SOAP the SOAP action gets passed in. For HTTP requests (ASP.NET, WCF REST) the URL and verb. Imperative authorization This happens when you explicitly call the claims authorization API from within your code. There you have full control over the values for action and resource. In ASP.NET per-request authorization is optional (depends on if you have added the ClaimsAuthorizationHttpModule). In WCF you always get the per-request checks as soon as you register the authorization manager in configuration. I personally prefer the imperative authorization because first of all I don’t believe in URL based authorization. Especially in the times of MVC and routing tables, URLs can be easily changed – but then you also have to adjust your authorization logic every time. Also – you typically need more knowledge than a simple “if user x is allowed to invoke operation x”. One problem I have is, both the per-request calls as well as the standard WIF imperative authorization APIs wrap actions and resources in the same claim type. This makes it hard to distinguish between the two authorization modes in your authorization manager. But you typically need that feature to structure your authorization policy evaluation in a clean way. The second problem (which is somehow related to the first one) is the standard API for interacting with the claims authorization manager. The API comes as an attribute (ClaimsPrincipalPermissionAttribute) as well as a class to use programmatically (ClaimsPrincipalPermission). Both only allow to pass in simple strings (which results in the wrapping with standard claim types mentioned earlier). Both throw a SecurityException when the check fails. The attribute is a code access permission attribute (like PrincipalPermission). That means it will always be invoked regardless how you call the code. This may be exactly what you want, or not. In a unit testing situation (like an MVC controller) you typically want to test the logic in the function – not the security check. The good news is, the WIF API is flexible enough that you can build your own infrastructure around their core. For my own projects I implemented the following extensions: A way to invoke the registered claims authorization manager with more overloads, e.g. with different claim types or a complete AuthorizationContext. A new CAS attribute (with the same calling semantics as the built-in one) with custom claim types. A MVC authorization attribute with custom claim types. A way to use branching – as opposed to catching a SecurityException. I will post the code for these various extensions here – so stay tuned.

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• SQL SERVER – Transcript of Learning SQL Server Performance: Indexing Basics – Interview of Vinod Kumar by Pinal Dave

  - by pinaldave

  Recently I just wrote a blog post on about Learning SQL Server Performance: Indexing Basics and I received lots of request that if we can share some insight into the course. Here is 200 seconds interview of Vinod Kumar I took right after completing the course. We have few free codes to watch the course, please your comment at http://facebook.com/SQLAuth and we will few of first ones, we will send the code. There are many people who said they would like to read the transcript of the video. Here I have generated the same. Pinal: Vinod, we recently released this course, SQL Server Indexing. It is about performance tuning. So tell me – how do indexes help performance? Vinod: I think what happens in the industry when it comes to performance is that developers and DBAs look at indexes first.  So that’s the first step for any performance tuning exercise, indexing is one of the most critical aspects and it is important to learn it the right way. Pinal: Correct. So what you mean to say is that if you know indexing you can pretty much tune any server and query. Vinod: So I might contradict my false statement now. Indexing is usually a stepping stone but it does not lead you to the end. But it’s good to start with indexing and there are lots of nuances to indexing that you need to understand, like how SQL uses indexing and how performance can improve because of the strategies that you have made. Pinal: But now I’m confused. First you said indexes are good, and then you said that indexes can degrade your performance.  So what is this course about?  I mean how does this course really make an impact? Vinod: Ok -so from the course perspective, what we are trying to do is give you a capsule which gives you a good start. Every journey needs a beginning, you need that first step.  This course is that first step in understanding. This is the most basic, fundamental course that we have tried to attack. This is the fundamentals of indexing, some of the key things that you must know about indexing.   Some of the basics of indexing are lesser known and so I think this course is geared towards each and every one of you out there who wants to understand little bit more about indexing. Pinal: So what I understand is that if I enrolled in this course I will have a minimum understanding about indexing when dealing with performance tuning.  Right? Vinod: Exactly. In this course is we have tried to give you a nice summary. We are talking about clustered indexing, non clustered indexing, too many indexes, too few indexes, over indexing, under indexing, duplicate indexing, columns tune indexing, with SQL Server 2012. There’s lot’s to learn. Pinal: You can see the URL [http://bit.ly/sql-index] of the course on the screen. Go ahead, attend, and let us know what you think about it. Thank you. Vinod: Thank you. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology, Video

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• Using NServiceBus behind a custom web service

  - by Michael Stephenson

  In this post I'd like to talk about an architecture scenario we had recently and how we were able to utilise NServiceBus to help us address this problem. Scenario Cognos is a reporting system used by one of my clients. A while back we developed a web service façade to allow line of business applications to be able to access reports from Cognos to support their various functions. The service was intended to provide access to reports which were quick running reports or pre-generated reports which could be accessed real-time on demand. One of the key aims of the web service was to provide a simple generic interface to allow applications to get any report without needing to worry about the complex .net SDK for Cognos. The web service also supported multi-hop kerberos delegation so that report data could be accesses under the context of the end user. This service was working well for a period of time. The Problem The problem we encountered was that reports were now also required to be available to batch processes. The original design was optimised for low latency so users would enjoy a positive experience, however when the batch processes started to request 250+ concurrent reports over an extended period of time you can begin to imagine the sorts of problems that come into play. The key problems this new scenario caused are: Users may be affected and the latency of on demand reports was significantly slower The Cognos infrastructure was not scaled sufficiently to be able to cope with these long peaks of load From a cost perspective it just isn't feasible to scale the Cognos infrastructure to be able to handle the load when it is only for a couple of hour window each night. We really needed to introduce a second pattern for accessing this service which would support high through-put scenarios. We also had little control over the batch process in terms of being able to throttle its load. We could however make some changes to the way it accessed the reports. The Approach My idea was to introduce a throttling mechanism between the Web Service Façade and Cognos. This would allow the batch processes to push reports requests hard at the web service which we were confident the web service can handle. The web service would then queue these requests and process them behind the scenes and make a call back to the batch application to provide the report once it had been accessed. In terms of technology we had some limitations because we were not able to use WCF or IIS7 where the MSMQ-Activated WCF services could have helped, but we did have MSMQ as an option and I thought NServiceBus could do just the job to help us here. The flow of how this would work was as follows: The batch applications would send a request for a report to the web service The web service uses NServiceBus to send the message to a Queue The NServiceBus Generic Host is running as a windows service with a message handler which subscribes to these messages The message handler gets the message, accesses the report from Cognos The message handler calls back to the original batch application, this is decoupled because the calling application provides a call back url The report gets into the batch application and is processed as normal This approach looks something like the below diagram: The key points are an application wanting to take advantage of the batch driven reports needs to do the following: Implement our call back contract Make a call to the service providing a call back url Provide a correlation ID so it knows how to tie each response back to its request What does NServiceBus offer in this solution So this scenario is not the typical messaging service bus type of solution people implement with NServiceBus, but it did offer the following: Simplified interaction with MSMQ Offered the ability to configure the number of processes working through the queue so we could find a balance between load on Cognos versus the applications end to end processing time NServiceBus offers retries and a way to manage failed messages NServiceBus offers a high availability setup The simple thing is that NServiceBus gave us the platform to build the solution on. We just implemented a message handler which functionally processed a message and we could rely on NServiceBus to do all of the hard work around managing the queues and all of the lower level things that would have took ages to write to any kind of robust level. Conclusion With this approach we were able to deal with a fairly significant performance issue with out too much rework. Hopefully this write up gives people some insight into ideas on how to leverage the excellent NServiceBus framework to help solve integration and high through-put scenarios.

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• SEO: Nested List vs List, Split Over Divs vs Definition List

  - by Jon P

  From an SEO perspective which, if any, is better: Option 1: Nested lists with h2 tags <ul id="mainpoints"> <li><h2>Powerful Analysis</h2> <ul> <li>Charting and indicators</li> <li>Daily trading signals</li> <li>Company health checks</li> </ul> </li> <li><h2>World Market Data</h2> <ul> [List Items removed for brevity] </ul> </li> <li><h2>Daily Market Data</h2> <ul> [List Items removed for brevity] </ul> </li> </ul> Option 2: Divs with h2 and lists <div id="mainpoints"> <div> <h2>Powerful Analysis</h2> <ul> <li>Charting and indicators</li> <li>Daily trading signals</li> <li>Company health checks</li> </ul> </div> <div> <h2>World Market Data</h2> <ul> [List Items removed for brevity] </ul> </div> <div> <h2>Daily Market Data</h2> <ul> [List Items removed for brevity] </ul> </div> </div> Option 3: Definition List <dl id="mainpoints"> <dt>Powerful Analysis</dt> <dd>- Charting and indicators</dd> <dd>- Daily trading signals</dd> <dd>- Company health checks</dd> <dt>World Market Data</dt> [List Items removed for brevity] <dt>Daily Market Data</dt> [List Items removed for brevity] </dl> My instincts tell me that semanticaly the pure list options (1 & 3) are the best and that h2 may be more SEO friendly (1 & 2) which would point to option 1 as being the best option. I do love the lean makeup of the definition list but will I take an SEO hit by losing the h2 tags? Before anyone asks, h2 is not valid markup in a dt tag. Are my instincts right with a nested list being the way to go?

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• Oracle Enterprise Manager 11g is Here!

  - by chung.wu

  We hope that you enjoyed the launch event. If you missed it, you may still watch it via our on demand webcast, which is being produced and will be posted very shortly. 11gR1 is a major release of Oracle Enterprise Manager, and as one would expect from a big release, there are many new capabilities that appeal to a broad set of audience. Before going into the laundry list of new features, let's talk about the key themes for this release to put things in perspective. First, this release is about Business Driven Application Management. The traditional paradigm of component centric systems management simply cannot satisfy the management needs of modern distributed applications, as they do not provide adequate visibility of whether these applications are truly meeting the service level expectations of the business users. Business Driven Application Management helps IT manage applications according to the needs of the business users so that valuable IT resources can be better focused to help deliver better business results. To support Business Driven Application Management, 11gR1 builds on the work that we started in 10g to provide better support for user experience management. This capability helps IT better understand how users use applications and the experience that the applications provide so that IT can take actions to help end users get their work done more effectively. In addition, this release also delivers improved business transaction management capabilities to make it faster and easier to understand and troubleshoot transaction problems that impact end user experience. Second, this release includes strengthened Integrated Application-to-Disk Management. Every component of an application environment, from the application logic to the application server, to database, host machines and storage devices, etc... can affect end user experience. After user experience improvement needs are identified, IT needs tools that can be used do deep dive diagnostics for each of the application environment component, analyze configurations and deploy changes. Enterprise Manager 11gR1 extends coverage of key application environment components to include full support for Oracle Database 11gR2, Exadata V2, and Fusion Middleware 11g. For composite and Java application management, two key pieces of technologies, JVM Diagnostic and Composite Application Monitoring and Modeler, are now fully integrated into Enterprise Manager so there is no need to install and maintain separate tools. In addition, we have delivered the first set of integration between Enterprise Manager Grid Control and Enterprise Manager Ops Center so that hardware level events can be centrally monitored via Grid Control. Finally, this release delivers Integrated Systems Management and Support for customers of Oracle technologies. Traditionally, systems management tools and tech support were separate silos. When problems occur, administrators used internally deployed tools to try to solve the problems themselves. If they couldn't fix the problems, then they would use some sort of support website to get help from the vendor's support staff. Oracle Enterprise Manager 11g integrates problem diagnostic and remediation workflow. Administrators can use Oracle Enterprise Manager's various diagnostic tools to begin the troubleshooting process. They can also use the integrated access to My Oracle Support to look up solutions and download software patches. If further help is needed, administrators can open service requests from right within Oracle Enterprise Manager and track status update. Oracle's support staff, using Enterprise Manager's configuration management capabilities, can collect important configuration information about customer environments in order to expedite problem resolution. This tight integration between Oracle Enterprise Manager and My Oracle Support helps Oracle customers achieve a Superior Ownership Experience for their Oracle products. So there you have it. This is a brief 50,000 feet overview of Oracle Enterprise Manager 11g. We know you are hungry for the details. We are going to write about it in the coming days and weeks. For those of you that absolutely can't wait to find out more, you may download our software to try it out today. In fact, for the first time ever, the initial release of Oracle Enterprise Manager is available for both 32 and 64 bit Linux. Additional O/S ports will arrive in the coming weeks. Please stay tuned on the Oracle Enterprise Manager blog for additional updates.

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• Talking JavaOne with Rock Star Simon Ritter

  - by Janice J. Heiss

  Oracle’s Java Technology Evangelist Simon Ritter is well known at JavaOne for his quirky and fun-loving sessions, which, this year include: CON4644 -- “JavaFX Extreme GUI Makeover” (with Angela Caicedo on how to improve UIs in JavaFX) CON5352 -- “Building JavaFX Interfaces for the Real World” (Kinect gesture tracking and mind reading) CON5348 -- “Do You Like Coffee with Your Dessert?” (Some cool demos of Java of the Raspberry Pi) CON6375 -- “Custom JavaFX Charts: (How to extend JavaFX Chart controls with some interesting things) I recently asked Ritter about the significance of the Raspberry Pi, the topic of one of his sessions that consists of a credit card-sized single-board computer developed in the UK with the intention of stimulating the teaching of basic computer science in schools. “I don't think there's one definitive thing that makes the RP significant,” observed Ritter, “but a combination of things that really makes it stand out. First, it's the cost: $35 for what is effectively a completely usable computer. OK, so you have to add a power supply, SD card for storage and maybe a screen, keyboard and mouse, but this is still way cheaper than a typical PC. The choice of an ARM processor is also significant, as it avoids problems like cooling (no heat sink or fan) and can use a USB power brick.  Combine these two things with the immense groundswell of community support and it provides a fantastic platform for teaching young and old alike about computing, which is the real goal of the project.”He informed me that he’ll be at the Raspberry Pi meetup on Saturday (not part of JavaOne). Check out the details here.JavaFX InterfacesWhen I asked about how JavaFX can interface with the real world, he said that there are many ways. “JavaFX provides you with a simple set of programming interfaces that can create complex, cool and compelling user interfaces,” explained Ritter. “Because it's just Java code you can combine JavaFX with any other Java library to provide data to display and control the interface. What I've done for my session is look at some of the possible ways of doing this using some of the amazing hardware that's available today at very low cost. The Kinect sensor has added a new dimension to gaming in terms of interaction; there's a Java API to access this so you can easily collect skeleton tracking data from it. Some clever people have also written libraries that can track gestures like swipes, circles, pushes, and so on. We use these to control parts of the UI. I've also experimented with a Neurosky EEG sensor that can in some ways ‘read your mind’ (well, at least measure some of the brain functions like attention and meditation).  I've written a Java library for this that I include as a way of controlling the UI. We're not quite at the stage of just thinking a command though!” Here Comes Java EmbeddedAnd what, from Ritter’s perspective, is the most exciting thing happening in the world of Java today? “I think it's seeing just how Java continues to become more and more pervasive,” he said. “One of the areas that is growing rapidly is embedded systems.  We've talked about the ‘Internet of things’ for many years; now it's finally becoming a reality. With the ability of more and more devices to include processing, storage and networking we need an easy way to write code for them that's reliable, has high performance, and is secure. Java fits all these requirements. With Java Embedded being a conference within a conference, I'm very excited about the possibilities of Java in this space.”Check out Ritter’s sessions or say hi if you run into him. Originally published on blogs.oracle.com/javaone.

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