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• Red Gate Coder interviews: Robin Hellen

  - by Michael Williamson

  Robin Hellen is a test engineer here at Red Gate, and is also the latest coder I’ve interviewed. We chatted about debugging code, the roles of software engineers and testers, and why Vala is currently his favourite programming language. How did you get started with programming?It started when I was about six. My dad’s a professional programmer, and he gave me and my sister one of his old computers and taught us a bit about programming. It was an old Amiga 500 with a variant of BASIC. I don’t think I ever successfully completed anything! It was just faffing around. I didn’t really get anywhere with it.But then presumably you did get somewhere with it at some point.At some point. The PC emerged as the dominant platform, and I learnt a bit of Visual Basic. I didn’t really do much, just a couple of quick hacky things. A bit of demo animation. Took me a long time to get anywhere with programming, really.When did you feel like you did start to get somewhere?I think it was when I started doing things for someone else, which was my sister’s final year of university project. She called up my dad two days before she was due to submit, saying “We need something to display a graph!”. Dad says, “I’m too busy, go talk to your brother”. So I hacked up this ugly piece of code, sent it off and they won a prize for that project. Apparently, the graph, the bit that I wrote, was the reason they won a prize! That was when I first felt that I’d actually done something that was worthwhile. That was my first real bit of code, and the ugliest code I’ve ever written. It’s basically an array of pre-drawn line elements that I shifted round the screen to draw a very spikey graph.When did you decide that programming might actually be something that you wanted to do as a career?It’s not really a decision I took, I always wanted to do something with computers. And I had to take a gap year for uni, so I was looking for twelve month internships. I applied to Red Gate, and they gave me a job as a tester. And that’s where I really started having to write code well. To a better standard that I had been up to that point.How did you find coming to Red Gate and working with other coders?I thought it was really nice. I learnt so much just from other people around. I think one of the things that’s really great is that people are just willing to help you learn. Instead of “Don’t you know that, you’re so stupid”, it’s “You can just do it this way”.If you could go back to the very start of that internship, is there something that you would tell yourself?Write shorter code. I have a tendency to write massive, many-thousand line files that I break out of right at the end. And then half-way through a project I’m doing something, I think “Where did I write that bit that does that thing?”, and it’s almost impossible to find. I wrote some horrendous code when I started. Just that principle, just keep things short. Even if looks a bit crazy to be jumping around all over the place all of the time, it’s actually a lot more understandable.And how do you hold yourself to that?Generally, if a function’s going off my screen, it’s probably too long. That’s what I tell myself, and within the team here we have code reviews, so the guys I’m with at the moment are pretty good at pulling me up on, “Doesn’t that look like it’s getting a bit long?”. It’s more just the subjective standard of readability than anything.So you’re an advocate of code review?Yes, definitely. Both to spot errors that you might have made, and to improve your knowledge. The person you’re reviewing will say “Oh, you could have done it that way”. That’s how we learn, by talking to others, and also just sharing knowledge of how your project works around the team, or even outside the team. Definitely a very firm advocate of code reviews.Do you think there’s more we could do with them?I don’t know. We’re struggling with how to add them as part of the process without it becoming too cumbersome. We’ve experimented with a few different ways, and we’ve not found anything that just works.To get more into the nitty gritty: how do you like to debug code?The first thing is to do it in my head. I’ll actually think what piece of code is likely to have caused that error, and take a quick look at it, just to see if there’s anything glaringly obvious there. The next thing I’ll probably do is throw in print statements, or throw some exceptions from various points, just to check: is it going through the code path I expect it to? A last resort is to actually debug code using a debugger.Why is the debugger the last resort?Probably because of the environments I learnt programming in. VB and early BASIC didn’t have much of a debugger, the only way to find out what your program was doing was to add print statements. Also, because a lot of the stuff I tend to work with is non-interactive, if it’s something that takes a long time to run, I can throw in the print statements, set a run off, go and do something else, and look at it again later, rather than trying to remember what happened at that point when I was debugging through it. So it also gives me the record of what happens. I hate just sitting there pressing F5, F5, continually. If you’re having to find out what your code is doing at each line, you’ve probably got a very wrong mental model of what your code’s doing, and you can find that out just as easily by inspecting a couple of values through the print statements.If I were on some codebase that you were also working on, what should I do to make it as easy as possible to understand?I’d say short and well-named methods. The one thing I like to do when I’m looking at code is to find out where a value comes from, and the more layers of indirection there are, particularly DI [dependency injection] frameworks, the harder it is to find out where something’s come from. I really hate that. I want to know if the value come from the user here or is a constant here, and if I can’t find that out, that makes code very hard to understand for me.As a tester, where do you think the split should lie between software engineers and testers?I think the split is less on areas of the code you write and more what you’re designing and creating. The developers put a structure on the code, while my major role is to say which tests we should have, whether we should test that, or it’s not worth testing that because it’s a tiny function in code that nobody’s ever actually going to see. So it’s not a split in the code, it’s a split in what you’re thinking about. Saying what code we should write, but alternatively what code we should take out.In your experience, do the software engineers tend to do much testing themselves?They tend to control the lowest layer of tests. And, depending on how the balance of people is in the team, they might write some of the higher levels of test. Or that might go to the testers. I’m the only tester on my team with three other developers, so they’ll be writing quite a lot of the actual test code, with input from me as to whether we should test that functionality, whereas on other teams, where it’s been more equal numbers, the testers have written pretty much all of the high level tests, just because that’s the best use of resource.If you could shuffle resources around however you liked, do you think that the developers should be writing those high-level tests?I think they should be writing them occasionally. It helps when they have an understanding of how testing code works and possibly what assumptions we’ve made in tests, and they can say “actually, it doesn’t work like that under the hood so you’ve missed this whole area”. It’s one of those agile things that everyone on the team should be at least comfortable doing the various jobs. So if the developers can write test code then I think that’s a very good thing.So you think testers should be able to write production code?Yes, although given most testers skills at coding, I wouldn’t advise it too much! I have written a few things, and I did make a few changes that have actually gone into our production code base. They’re not necessarily running every time but they are there. I think having that mix of skill sets is really useful. In some ways we’re using our own product to test itself, so being able to make those changes where it’s not working saves me a round-trip through the developers. It can be really annoying if the developers have no time to make a change, and I can’t touch the code.If the software engineers are consistently writing tests at all levels, what role do you think the role of a tester is?I think on a team like that, those distinctions aren’t quite so useful. There’ll be two cases. There’s either the case where the developers think they’ve written good tests, but you still need someone with a test engineer mind-set to go through the tests and validate that it’s a useful set, or the correct set for that code. Or they won’t actually be pure developers, they’ll have that mix of test ability in there.I think having slightly more distinct roles is useful. When it starts to blur, then you lose that view of the tests as a whole. The tester job is not to create tests, it’s to validate the quality of the product, and you don’t do that just by writing tests. There’s more things you’ve got to keep in your mind. And I think when you blur the roles, you start to lose that end of the tester.So because you’re working on those features, you lose that holistic view of the whole system?Yeah, and anyone who’s worked on the feature shouldn’t be testing it. You always need to have it tested it by someone who didn’t write it. Otherwise you’re a bit too close and you assume “yes, people will only use it that way”, but the tester will come along and go “how do people use this? How would our most idiotic user use this?”. I might not test that because it might be completely irrelevant. But it’s coming in and trying to have a different set of assumptions.Are you a believer that it should all be automated if possible?Not entirely. So an automated test is always better than a manual test for the long-term, but there’s still nothing that beats a human sitting in front of the application and thinking “What could I do at this point?”. The automated test is very good but they follow that strict path, and they never check anything off the path. The human tester will look at things that they weren’t expecting, whereas the automated test can only ever go “Is that value correct?” in many respects, and it won’t notice that on the other side of the screen you’re showing something completely wrong. And that value might have been checked independently, but you always find a few odd interactions when you’re going through something manually, and you always need to go through something manually to start with anyway, otherwise you won’t know where the important bits to write your automation are.When you’re doing that manual testing, do you think it’s important to do that across the entire product, or just the bits that you’ve touched recently?I think it’s important to do it mostly on the bits you’ve touched, but you can’t ignore the rest of the product. Unless you’re dealing with a very, very self-contained bit, you’re almost always encounter other bits of the product along the way. Most testers I know, even if they are looking at just one path, they’ll keep open and move around a bit anyway, just because they want to find something that’s broken. If we find that your path is right, we’ll go out and hunt something else.How do you think this fits into the idea of continuously deploying, so long as the tests pass?With deploying a website it’s a bit different because you can always pull it back. If you’re deploying an application to customers, when you’ve released it, it’s out there, you can’t pull it back. Someone’s going to keep it, no matter how hard you try there will be a few installations that stay around. So I’d always have at least a human element on that path. With websites, you could probably automate straight out, or at least straight out to an internal environment or a single server in a cloud of fifty that will serve some people. But I don’t think you should release to everyone just on automated tests passing.You’ve already mentioned using BASIC and C# — are there any other languages that you’ve used?I’ve used a few. That’s something that has changed more recently, I’ve become familiar with more languages. Before I started at Red Gate I learnt a bit of C. Then last year, I taught myself Python which I actually really enjoyed using. I’ve also come across another language called Vala, which is sort of a C#-like language. It’s basically a pre-processor for C, but it has very nice syntax. I think that’s currently my favourite language.Any particular reason for trying Vala?I have a completely Linux environment at home, and I’ve been looking for a nice language, and C# just doesn’t cut it because I won’t touch Mono. So, I was looking for something like C# but that was useable in an open source environment, and Vala’s what I found. C#’s got a few features that Vala doesn’t, and Vala’s got a few features where I think “It would be awesome if C# had that”.What are some of the features that it’s missing?Extension methods. And I think that’s the only one that really bugs me. I like to use them when I’m writing C# because it makes some things really easy, especially with libraries that you can’t touch the internals of. It doesn’t have method overloading, which is sometimes annoying.Where it does win over C#?Everything is non-nullable by default, you never have to check that something’s unexpectedly null.Also, Vala has code contracts. This is starting to come in C# 4, but the way it works in Vala is that you specify requirements in short phrases as part of your function signature and they stick to the signature, so that when you inherit it, it has exactly the same code contract as the base one, or when you inherit from an interface, you have to match the signature exactly. Just using those makes you think a bit more about how you’re writing your method, it’s not an afterthought when you’ve got contracts from base classes given to you, you can’t change it. Which I think is a lot nicer than the way C# handles it. When are those actually checked?They’re checked both at compile and run-time. The compile-time checking isn’t very strong yet, it’s quite a new feature in the compiler, and because it compiles down to C, you can write C code and interface with your methods, so you can bypass that compile-time check anyway. So there’s an extra runtime check, and if you violate one of the contracts at runtime, it’s game over for your program, there’s no exception to catch, it’s just goodbye!One thing I dislike about C# is the exceptions. You write a bit of code and fifty exceptions could come from any point in your ten lines, and you can’t mentally model how those exceptions are going to come out, and you can’t even predict them based on the functions you’re calling, because if you’ve accidentally got a derived class there instead of a base class, that can throw a completely different set of exceptions. So I’ve got no way of mentally modelling those, whereas in Vala they’re checked like Java, so you know only these exceptions can come out. You know in advance the error conditions.I think Raymond Chen on Old New Thing says “the only thing you know when you throw an exception is that you’re in an invalid state somewhere in your program, so just kill it and be done with it!”You said you’ve also learnt bits of Python. How did you find that compared to Vala and C#?Very different because of the dynamic typing. I’ve been writing a website for my own use. I’m quite into photography, so I take photos off my camera, post-process them, dump them in a file, and I get a webpage with all my thumbnails. So sort of like Picassa, but written by myself because I wanted something to learn Python with. There are some things that are really nice, I just found it really difficult to cope with the fact that I’m not quite sure what this object type that I’m passed is, I might not ever be sure, so it can randomly blow up on me. But once I train myself to ignore that and just say “well, I’m fairly sure it’s going to be something that looks like this, so I’ll use it like this”, then it’s quite nice.Any particular features that you’ve appreciated?I don’t like any particular feature, it’s just very straightforward to work with. It’s very quick to write something in, particularly as you don’t have to worry that you’ve changed something that affects a different part of the program. If you have, then that part blows up, but I can get this part working right now.If you were doing a big project, would you be willing to do it in Python rather than C# or Vala?I think I might be willing to try something bigger or long term with Python. We’re currently doing an ASP.NET MVC project on C#, and I don’t like the amount of reflection. There’s a lot of magic that pulls values out, and it’s all done under the scenes. It’s almost managed to put a dynamic type system on top of C#, which in many ways destroys the language to me, whereas if you’re already in a dynamic language, having things done dynamically is much more natural. In many ways, you get the worst of both worlds. I think for web projects, I would go with Python again, whereas for anything desktop, command-line or GUI-based, I’d probably go for C# or Vala, depending on what environment I’m in.It’s the fact that you can gain from the strong typing in ways that you can’t so much on the web app. Or, in a web app, you have to use dynamic typing at some point, or you have to write a hell of a lot of boilerplate, and I’d rather use the dynamic typing than write the boilerplate.What do you think separates great programmers from everyone else?Probably design choices. Choosing to write it a piece of code one way or another. For any given program you ask me to write, I could probably do it five thousand ways. A programmer who is capable will see four or five of them, and choose one of the better ones. The excellent programmer will see the largest proportion and manage to pick the best one very quickly without having to think too much about it. I think that’s probably what separates, is the speed at which they can see what’s the best path to write the program in. More Red Gater Coder interviews

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• JMS Step 5 - How to Create an 11g BPEL Process Which Reads a Message Based on an XML Schema from a JMS Queue

  - by John-Brown.Evans

  JMS Step 5 - How to Create an 11g BPEL Process Which Reads a Message Based on an XML Schema from a JMS Queue .jblist{list-style-type:disc;margin:0;padding:0;padding-left:0pt;margin-left:36pt} ol{margin:0;padding:0} .c12_5{vertical-align:top;width:468pt;border-style:solid;background-color:#f3f3f3;border-color:#000000;border-width:1pt;padding:5pt 5pt 5pt 5pt} .c8_5{vertical-align:top;border-style:solid;border-color:#000000;border-width:1pt;padding:5pt 5pt 0pt 5pt} .c10_5{vertical-align:top;width:207pt;border-style:solid;border-color:#000000;border-width:1pt;padding:5pt 5pt 5pt 5pt} .c14_5{vertical-align:top;border-style:solid;border-color:#000000;border-width:1pt;padding:0pt 5pt 0pt 5pt} .c21_5{background-color:#ffffff} .c18_5{color:#1155cc;text-decoration:underline} .c16_5{color:#666666;font-size:12pt} .c5_5{background-color:#f3f3f3;font-weight:bold} .c19_5{color:inherit;text-decoration:inherit} .c3_5{height:11pt;text-align:center} .c11_5{font-weight:bold} .c20_5{background-color:#00ff00} .c6_5{font-style:italic} .c4_5{height:11pt} .c17_5{background-color:#ffff00} .c0_5{direction:ltr} .c7_5{font-family:"Courier New"} .c2_5{border-collapse:collapse} .c1_5{line-height:1.0} .c13_5{background-color:#f3f3f3} .c15_5{height:0pt} .c9_5{text-align:center} .title{padding-top:24pt;line-height:1.15;text-align:left;color:#000000;font-size:36pt;font-family:"Arial";font-weight:bold;padding-bottom:6pt} .subtitle{padding-top:18pt;line-height:1.15;text-align:left;color:#666666;font-style:italic;font-size:24pt;font-family:"Georgia";padding-bottom:4pt} li{color:#000000;font-size:10pt;font-family:"Arial"} p{color:#000000;font-size:10pt;margin:0;font-family:"Arial"} h1{padding-top:0pt;line-height:1.15;text-align:left;color:#888;font-size:24pt;font-family:"Arial";font-weight:normal} h2{padding-top:0pt;line-height:1.15;text-align:left;color:#888;font-size:18pt;font-family:"Arial";font-weight:normal} h3{padding-top:0pt;line-height:1.15;text-align:left;color:#888;font-size:14pt;font-family:"Arial";font-weight:normal} h4{padding-top:0pt;line-height:1.15;text-align:left;color:#888;font-size:12pt;font-family:"Arial";font-weight:normal} h5{padding-top:0pt;line-height:1.15;text-align:left;color:#888;font-size:11pt;font-family:"Arial";font-weight:normal} h6{padding-top:0pt;line-height:1.15;text-align:left;color:#888;font-size:10pt;font-family:"Arial";font-weight:normal} Welcome to another post in the series of blogs which demonstrates how to use JMS queues in a SOA context. The previous posts were: JMS Step 1 - How to Create a Simple JMS Queue in Weblogic Server 11g JMS Step 2 - Using the QueueSend.java Sample Program to Send a Message to a JMS Queue JMS Step 3 - Using the QueueReceive.java Sample Program to Read a Message from a JMS Queue JMS Step 4 - How to Create an 11g BPEL Process Which Writes a Message Based on an XML Schema to a JMS Queue Today we will create a BPEL process which will read (dequeue) the message from the JMS queue, which we enqueued in the last example. The JMS adapter will dequeue the full XML payload from the queue. 1. Recap and Prerequisites In the previous examples, we created a JMS Queue, a Connection Factory and a Connection Pool in the WebLogic Server Console. Then we designed and deployed a BPEL composite, which took a simple XML payload and enqueued it to the JMS queue. In this example, we will read that same message from the queue, using a JMS adapter and a BPEL process. As many of the configuration steps required to read from that queue were done in the previous samples, this one will concentrate on the new steps. A summary of the required objects is listed below. To find out how to create them please see the previous samples. They also include instructions on how to verify the objects are set up correctly. WebLogic Server Objects Object Name Type JNDI Name TestConnectionFactory Connection Factory jms/TestConnectionFactory TestJMSQueue JMS Queue jms/TestJMSQueue eis/wls/TestQueue Connection Pool eis/wls/TestQueue Schema XSD File The following XSD file is used for the message format. It was created in the previous example and will be copied to the new process. stringPayload.xsd <?xml version="1.0" encoding="windows-1252" ?> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"                 xmlns="http://www.example.org"                 targetNamespace="http://www.example.org"                 elementFormDefault="qualified">   <xsd:element name="exampleElement" type="xsd:string">   </xsd:element> </xsd:schema> JMS Message After executing the previous samples, the following XML message should be in the JMS queue located at jms/TestJMSQueue: <?xml version="1.0" encoding="UTF-8" ?><exampleElement xmlns="http://www.example.org">Test Message</exampleElement> JDeveloper Connection You will need a valid Application Server Connection in JDeveloper pointing to the SOA server which the process will be deployed to. 2. Create a BPEL Composite with a JMS Adapter Partner Link In the previous example, we created a composite in JDeveloper called JmsAdapterWriteSchema. In this one, we will create a new composite called JmsAdapterReadSchema. There are probably many ways of incorporating a JMS adapter into a SOA composite for incoming messages. One way is design the process in such a way that the adapter polls for new messages and when it dequeues one, initiates a SOA or BPEL instance. This is possibly the most common use case. Other use cases include mid-flow adapters, which are activated from within the BPEL process. In this example we will use a polling adapter, because it is the most simple to set up and demonstrate. But it has one disadvantage as a demonstrative model. When a polling adapter is active, it will dequeue all messages as soon as they reach the queue. This makes it difficult to monitor messages we are writing to the queue, because they will disappear from the queue as soon as they have been enqueued. To work around this, we will shut down the composite after deploying it and restart it as required. (Another solution for this would be to pause the consumption for the queue and resume consumption again if needed. This can be done in the WLS console JMS-Modules -> queue -> Control -> Consumption -> Pause/Resume.) We will model the composite as a one-way incoming process. Usually, a BPEL process will do something useful with the message after receiving it, such as passing it to a database or file adapter, a human workflow or external web service. But we only want to demonstrate how to dequeue a JMS message using BPEL and a JMS adapter, so we won’t complicate the design with further activities. However, we do want to be able to verify that we have read the message correctly, so the BPEL process will include a small piece of embedded java code, which will print the message to standard output, so we can view it in the SOA server’s log file. Alternatively, you can view the instance in the Enterprise Manager and verify the message. The following steps are all executed in JDeveloper. Create the project in the same JDeveloper application used for the previous examples or create a new one. Create a SOA Project Create a new project and choose SOA Tier > SOA Project as its type. Name it JmsAdapterReadSchema. When prompted for the composite type, choose Empty Composite. Create a JMS Adapter Partner Link In the composite editor, drag a JMS adapter over from the Component Palette to the left-hand swim lane, under Exposed Services. This will start the JMS Adapter Configuration Wizard. Use the following entries: Service Name: JmsAdapterRead Oracle Enterprise Messaging Service (OEMS): Oracle WebLogic JMS AppServer Connection: Use an application server connection pointing to the WebLogic server on which the JMS queue and connection factory mentioned under Prerequisites above are located. Adapter Interface > Interface: Define from operation and schema (specified later) Operation Type: Consume Message Operation Name: Consume_message Consume Operation Parameters Destination Name: Press the Browse button, select Destination Type: Queues, then press Search. Wait for the list to populate, then select the entry for TestJMSQueue , which is the queue created in a previous example. JNDI Name: The JNDI name to use for the JMS connection. As in the previous example, this is probably the most common source of error. This is the JNDI name of the JMS adapter’s connection pool created in the WebLogic Server and which points to the connection factory. JDeveloper does not verify the value entered here. If you enter a wrong value, the JMS adapter won’t find the queue and you will get an error message at runtime, which is very difficult to trace. In our example, this is the value eis/wls/TestQueue . (See the earlier step on how to create a JMS Adapter Connection Pool in WebLogic Server for details.) Messages/Message SchemaURL: We will use the XSD file created during the previous example, in the JmsAdapterWriteSchema project to define the format for the incoming message payload and, at the same time, demonstrate how to import an existing XSD file into a JDeveloper project. Press the magnifying glass icon to search for schema files. In the Type Chooser, press the Import Schema File button. Select the magnifying glass next to URL to search for schema files. Navigate to the location of the JmsAdapterWriteSchema project > xsd and select the stringPayload.xsd file. Check the “Copy to Project” checkbox, press OK and confirm the following Localize Files popup. Now that the XSD file has been copied to the local project, it can be selected from the project’s schema files. Expand Project Schema Files > stringPayload.xsd and select exampleElement: string . Press Next and Finish, which will complete the JMS Adapter configuration.Save the project. Create a BPEL Component Drag a BPEL Process from the Component Palette (Service Components) to the Components section of the composite designer. Name it JmsAdapterReadSchema and select Template: Define Service Later and press OK. Wire the JMS Adapter to the BPEL Component Now wire the JMS adapter to the BPEL process, by dragging the arrow from the adapter to the BPEL process. A Transaction Properties popup will be displayed. Set the delivery mode to async.persist. This completes the steps at the composite level. 3 . Complete the BPEL Process Design Invoke the BPEL Flow via the JMS Adapter Open the BPEL component by double-clicking it in the design view of the composite.xml, or open it from the project navigator by selecting the JmsAdapterReadSchema.bpel file. This will display the BPEL process in the design view. You should see the JmsAdapterRead partner link in the left-hand swim lane. Drag a Receive activity onto the BPEL flow diagram, then drag a wire (left-hand yellow arrow) from it to the JMS adapter. This will open the Receive activity editor. Auto-generate the variable by pressing the green “+” button and check the “Create Instance” checkbox. This will result in a BPEL instance being created when a new JMS message is received. At this point it would actually be OK to compile and deploy the composite and it would pick up any messages from the JMS queue. In fact, you can do that to test it, if you like. But it is very rudimentary and would not be doing anything useful with the message. Also, you could only verify the actual message payload by looking at the instance’s flow in the Enterprise Manager. There are various other possibilities; we could pass the message to another web service, write it to a file using a file adapter or to a database via a database adapter etc. But these will all introduce unnecessary complications to our sample. So, to keep it simple, we will add a small piece of Java code to the BPEL process which will write the payload to standard output. This will be written to the server’s log file, which will be easy to monitor. Add a Java Embedding Activity First get the full name of the process’s input variable, as this will be needed for the Java code. Go to the Structure pane and expand Variables > Process > Variables. Then expand the input variable, for example, "Receive1_Consume_Message_InputVariable > body > ns2:exampleElement”, and note variable’s name and path, if they are different from this one. Drag a Java Embedding activity from the Component Palette (Oracle Extensions) to the BPEL flow, after the Receive activity, then open it to edit. Delete the example code and replace it with the following, replacing the variable parts with those in your sample, if necessary.: System.out.println("JmsAdapterReadSchema process picked up a message"); oracle.xml.parser.v2.XMLElement inputPayload =    (oracle.xml.parser.v2.XMLElement)getVariableData(                           "Receive1_Consume_Message_InputVariable",                           "body",                           "/ns2:exampleElement");   String inputString = inputPayload.getFirstChild().getNodeValue(); System.out.println("Input String is " + inputPayload.getFirstChild().getNodeValue()); Tip. If you are not sure of the exact syntax of the input variable, create an Assign activity in the BPEL process and copy the variable to another, temporary one. Then check the syntax created by the BPEL designer. This completes the BPEL process design in JDeveloper. Save, compile and deploy the process to the SOA server. 3. Test the Composite Shut Down the JmsAdapterReadSchema Composite After deploying the JmsAdapterReadSchema composite to the SOA server it is automatically activated. If there are already any messages in the queue, the adapter will begin polling them. To ease the testing process, we will deactivate the process first Log in to the Enterprise Manager (Fusion Middleware Control) and navigate to SOA > soa-infra (soa_server1) > default (or wherever you deployed your composite to) and click on JmsAdapterReadSchema [1.0] . Press the Shut Down button to disable the composite and confirm the following popup. Monitor Messages in the JMS Queue In a separate browser window, log in to the WebLogic Server Console and navigate to Services > Messaging > JMS Modules > TestJMSModule > TestJMSQueue > Monitoring. This is the location of the JMS queue we created in an earlier sample (see the prerequisites section of this sample). Check whether there are any messages already in the queue. If so, you can dequeue them using the QueueReceive Java program created in an earlier sample. This will ensure that the queue is empty and doesn’t contain any messages in the wrong format, which would cause the JmsAdapterReadSchema to fail. Send a Test Message In the Enterprise Manager, navigate to the JmsAdapterWriteSchema created earlier, press Test and send a test message, for example “Message from JmsAdapterWriteSchema”. Confirm that the message was written correctly to the queue by verifying it via the queue monitor in the WLS Console. Monitor the SOA Server’s Output A program deployed on the SOA server will write its standard output to the terminal window in which the server was started, unless this has been redirected to somewhere else, for example to a file. If it has not been redirected, go to the terminal session in which the server was started, otherwise open and monitor the file to which it was redirected. Re-Enable the JmsAdapterReadSchema Composite In the Enterprise Manager, navigate to the JmsAdapterReadSchema composite again and press Start Up to re-enable it. This should cause the JMS adapter to dequeue the test message and the following output should be written to the server’s standard output: JmsAdapterReadSchema process picked up a message. Input String is Message from JmsAdapterWriteSchema Note that you can also monitor the payload received by the process, by navigating to the the JmsAdapterReadSchema’s Instances tab in the Enterprise Manager. Then select the latest instance and view the flow of the BPEL component. The Receive activity will contain and display the dequeued message too. 4 . Troubleshooting This sample demonstrates how to dequeue an XML JMS message using a BPEL process and no additional functionality. For example, it doesn’t contain any error handling. Therefore, any errors in the payload will result in exceptions being written to the log file or standard output. If you get any errors related to the payload, such as Message handle error ... ORABPEL-09500 ... XPath expression failed to execute. An error occurs while processing the XPath expression; the expression is /ns2:exampleElement. ... etc. check that the variable used in the Java embedding part of the process was entered correctly. Possibly follow the tip mentioned in previous section. If this doesn’t help, you can delete the Java embedding part and simply verify the message via the flow diagram in the Enterprise Manager. Or use a different method, such as writing it to a file via a file adapter. This concludes this example. In the next post, we will begin with an AQ JMS example, which uses JMS to write to an Advanced Queue stored in the database. Best regards John-Brown Evans Oracle Technology Proactive Support Delivery

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• Towards Database Continuous Delivery – What Next after Continuous Integration? A Checklist

  - by Ben Rees

  .dbd-banner p{ font-size:0.75em; padding:0 0 10px; margin:0 } .dbd-banner p span{ color:#675C6D; } .dbd-banner p:last-child{ padding:0; } @media ALL and (max-width:640px){ .dbd-banner{ background:#f0f0f0; padding:5px; color:#333; margin-top: 5px; } } -- Database delivery patterns & practices STAGE 4 AUTOMATED DEPLOYMENT If you’ve been fortunate enough to get to the stage where you’ve implemented some sort of continuous integration process for your database updates, then hopefully you’re seeing the benefits of that investment – constant feedback on changes your devs are making, advanced warning of data loss (prior to the production release on Saturday night!), a nice suite of automated tests to check business logic, so you know it’s going to work when it goes live, and so on. But what next? What can you do to improve your delivery process further, moving towards a full continuous delivery process for your database? In this article I describe some of the issues you might need to tackle on the next stage of this journey, and how to plan to overcome those obstacles before they appear. Our Database Delivery Learning Program consists of four stages, really three – source controlling a database, running continuous integration processes, then how to set up automated deployment (the middle stage is split in two – basic and advanced continuous integration, making four stages in total). If you’ve managed to work through the first three of these stages – source control, basic, then advanced CI, then you should have a solid change management process set up where, every time one of your team checks in a change to your database (whether schema or static reference data), this change gets fully tested automatically by your CI server. But this is only part of the story. Great, we know that our updates work, that the upgrade process works, that the upgrade isn’t going to wipe our 4Tb of production data with a single DROP TABLE. But – how do you get this (fully tested) release live? Continuous delivery means being always ready to release your software at any point in time. There’s a significant gap between your latest version being tested, and it being easily releasable. Just a quick note on terminology – there’s a nice piece here from Atlassian on the difference between continuous integration, continuous delivery and continuous deployment. This piece also gives a nice description of the benefits of continuous delivery. These benefits have been summed up by Jez Humble at Thoughtworks as: “Continuous delivery is a set of principles and practices to reduce the cost, time, and risk of delivering incremental changes to users” There’s another really useful piece here on Simple-Talk about the need for continuous delivery and how it applies to the database written by Phil Factor – specifically the extra needs and complexities of implementing a full CD solution for the database (compared to just implementing CD for, say, a web app). So, hopefully you’re convinced of moving on the the next stage! The next step after CI is to get some sort of automated deployment (or “release management”) process set up. But what should I do next? What do I need to plan and think about for getting my automated database deployment process set up? Can’t I just install one of the many release management tools available and hey presto, I’m ready! If only it were that simple. Below I list some of the areas that it’s worth spending a little time on, where a little planning and prep could go a long way. It’s also worth pointing out, that this should really be an evolving process. Depending on your starting point of course, it can be a long journey from your current setup to a full continuous delivery pipeline. If you’ve got a CI mechanism in place, you’re certainly a long way down that path. Nevertheless, we’d recommend evolving your process incrementally. Pages 157 and 129-141 of the book on Continuous Delivery (by Jez Humble and Dave Farley) have some great guidance on building up a pipeline incrementally: http://www.amazon.com/Continuous-Delivery-Deployment-Automation-Addison-Wesley/dp/0321601912 For now, in this post, we’ll look at the following areas for your checklist: You and Your Team Environments The Deployment Process Rollback and Recovery Development Practices You and Your Team It’s a cliché in the DevOps community that “It’s not all about processes and tools, really it’s all about a culture”. As stated in this DevOps report from Puppet Labs: “DevOps processes and tooling contribute to high performance, but these practices alone aren’t enough to achieve organizational success. The most common barriers to DevOps adoption are cultural: lack of manager or team buy-in, or the value of DevOps isn’t understood outside of a specific group”. Like most clichés, there’s truth in there – if you want to set up a database continuous delivery process, you need to get your boss, your department, your company (if relevant) onside. Why? Because it’s an investment with the benefits coming way down the line. But the benefits are huge – for HP, in the book A Practical Approach to Large-Scale Agile Development: How HP Transformed LaserJet FutureSmart Firmware, these are summarized as: -2008 to present: overall development costs reduced by 40% -Number of programs under development increased by 140% -Development costs per program down 78% -Firmware resources now driving innovation increased by a factor of 8 (from 5% working on new features to 40% But what does this mean? It means that, when moving to the next stage, to make that extra investment in automating your deployment process, it helps a lot if everyone is convinced that this is a good thing. That they understand the benefits of automated deployment and are willing to make the effort to transform to a new way of working. Incidentally, if you’re ever struggling to convince someone of the value I’d strongly recommend just buying them a copy of this book – a great read, and a very practical guide to how it can really work at a large org. I’ve spoken to many customers who have implemented database CI who describe their deployment process as “The point where automation breaks down. Up to that point, the CI process runs, untouched by human hand, but as soon as that’s finished we revert to manual.” This deployment process can involve, for example, a DBA manually comparing an environment (say, QA) to production, creating the upgrade scripts, reading through them, checking them against an Excel document emailed to him/her the night before, turning to page 29 in his/her notebook to double-check how replication is switched off and on for deployments, and so on and so on. Painful, error-prone and lengthy. But the point is, if this is something like your deployment process, telling your DBA “We’re changing everything you do and your toolset next week, to automate most of your role – that’s okay isn’t it?” isn’t likely to go down well. There’s some work here to bring him/her onside – to explain what you’re doing, why there will still be control of the deployment process and so on. Or of course, if you’re the DBA looking after this process, you have to do a similar job in reverse. You may have researched and worked out how you’d like to change your methodology to start automating your painful release process, but do the dev team know this? What if they have to start producing different artifacts for you? Will they be happy with this? Worth talking to them, to find out. As well as talking to your DBA/dev team, the other group to get involved before implementation is your manager. And possibly your manager’s manager too. As mentioned, unless there’s buy-in “from the top”, you’re going to hit problems when the implementation starts to get rocky (and what tool/process implementations don’t get rocky?!). You need to have support from someone senior in your organisation – someone you can turn to when you need help with a delayed implementation, lack of resources or lack of progress. Actions: Get your DBA involved (or whoever looks after live deployments) and discuss what you’re planning to do or, if you’re the DBA yourself, get the dev team up-to-speed with your plans, Get your boss involved too and make sure he/she is bought in to the investment. Environments Where are you going to deploy to? And really this question is – what environments do you want set up for your deployment pipeline? Assume everyone has “Production”, but do you have a QA environment? Dedicated development environments for each dev? Proper pre-production? I’ve seen every setup under the sun, and there is often a big difference between “What we want, to do continuous delivery properly” and “What we’re currently stuck with”. Some of these differences are: What we want What we’ve got Each developer with their own dedicated database environment A single shared “development” environment, used by everyone at once An Integration box used to test the integration of all check-ins via the CI process, along with a full suite of unit-tests running on that machine In fact if you have a CI process running, you’re likely to have some sort of integration server running (even if you don’t call it that!). Whether you have a full suite of unit tests running is a different question… Separate QA environment used explicitly for manual testing prior to release “We just test on the dev environments, or maybe pre-production” A proper pre-production (or “staging”) box that matches production as closely as possible Hopefully a pre-production box of some sort. But does it match production closely!? A production environment reproducible from source control A production box which has drifted significantly from anything in source control The big question is – how much time and effort are you going to invest in fixing these issues? In reality this just involves figuring out which new databases you’re going to create and where they’ll be hosted – VMs? Cloud-based? What about size/data issues – what data are you going to include on dev environments? Does it need to be masked to protect access to production data? And often the amount of work here really depends on whether you’re working on a new, greenfield project, or trying to update an existing, brownfield application. There’s a world if difference between starting from scratch with 4 or 5 clean environments (reproducible from source control of course!), and trying to re-purpose and tweak a set of existing databases, with all of their surrounding processes and quirks. But for a proper release management process, ideally you have: Dedicated development databases, An Integration server used for testing continuous integration and running unit tests. [NB: This is the point at which deployments are automatic, without human intervention. Each deployment after this point is a one-click (but human) action], QA – QA engineers use a one-click deployment process to automatically* deploy chosen releases to QA for testing, Pre-production. The environment you use to test the production release process, Production. * A note on the use of the word “automatic” – when carrying out automated deployments this does not mean that the deployment is happening without human intervention (i.e. that something is just deploying over and over again). It means that the process of carrying out the deployment is automatic in that it’s not a person manually running through a checklist or set of actions. The deployment still requires a single-click from a user. Actions: Get your environments set up and ready, Set access permissions appropriately, Make sure everyone understands what the environments will be used for (it’s not a “free-for-all” with all environments to be accessed, played with and changed by development). The Deployment Process As described earlier, most existing database deployment processes are pretty manual. The following is a description of a process we hear very often when we ask customers “How do your database changes get live? How does your manual process work?” Check pre-production matches production (use a schema compare tool, like SQL Compare). Sometimes done by taking a backup from production and restoring in to pre-prod, Again, use a schema compare tool to find the differences between the latest version of the database ready to go live (i.e. what the team have been developing). This generates a script, User (generally, the DBA), reviews the script. This often involves manually checking updates against a spreadsheet or similar, Run the script on pre-production, and check there are no errors (i.e. it upgrades pre-production to what you hoped), If all working, run the script on production.* * this assumes there’s no problem with production drifting away from pre-production in the interim time period (i.e. someone has hacked something in to the production box without going through the proper change management process). This difference could undermine the validity of your pre-production deployment test. Red Gate is currently working on a free tool to detect this problem – sign up here at www.sqllighthouse.com, if you’re interested in testing early versions. There are several variations on this process – some better, some much worse! How do you automate this? In particular, step 3 – surely you can’t automate a DBA checking through a script, that everything is in order!? The key point here is to plan what you want in your new deployment process. There are so many options. At one extreme, pure continuous deployment – whenever a dev checks something in to source control, the CI process runs (including extensive and thorough testing!), before the deployment process keys in and automatically deploys that change to the live box. Not for the faint hearted – and really not something we recommend. At the other extreme, you might be more comfortable with a semi-automated process – the pre-production/production matching process is automated (with an error thrown if these environments don’t match), followed by a manual intervention, allowing for script approval by the DBA. One he/she clicks “Okay, I’m happy for that to go live”, the latter stages automatically take the script through to live. And anything in between of course – and other variations. But we’d strongly recommended sitting down with a whiteboard and your team, and spending a couple of hours mapping out “What do we do now?”, “What do we actually want?”, “What will satisfy our needs for continuous delivery, but still maintaining some sort of continuous control over the process?” NB: Most of what we’re discussing here is about production deployments. It’s important to note that you will also need to map out a deployment process for earlier environments (for example QA). However, these are likely to be less onerous, and many customers opt for a much more automated process for these boxes. Actions: Sit down with your team and a whiteboard, and draw out the answers to the questions above for your production deployments – “What do we do now?”, “What do we actually want?”, “What will satisfy our needs for continuous delivery, but still maintaining some sort of continuous control over the process?” Repeat for earlier environments (QA and so on). Rollback and Recovery If only every deployment went according to plan! Unfortunately they don’t – and when things go wrong, you need a rollback or recovery plan for what you’re going to do in that situation. Once you move in to a more automated database deployment process, you’re far more likely to be deploying more frequently than before. No longer once every 6 months, maybe now once per week, or even daily. Hence the need for a quick rollback or recovery process becomes paramount, and should be planned for. NB: These are mainly scenarios for handling rollbacks after the transaction has been committed. If a failure is detected during the transaction, the whole transaction can just be rolled back, no problem. There are various options, which we’ll explore in subsequent articles, things like: Immediately restore from backup, Have a pre-tested rollback script (remembering that really this is a “roll-forward” script – there’s not really such a thing as a rollback script for a database!) Have fallback environments – for example, using a blue-green deployment pattern. Different options have pros and cons – some are easier to set up, some require more investment in infrastructure; and of course some work better than others (the key issue with using backups, is loss of the interim transaction data that has been added between the failed deployment and the restore). The best mechanism will be primarily dependent on how your application works and how much you need a cast-iron failsafe mechanism. Actions: Work out an appropriate rollback strategy based on how your application and business works, your appetite for investment and requirements for a completely failsafe process. Development Practices This is perhaps the more difficult area for people to tackle. The process by which you can deploy database updates is actually intrinsically linked with the patterns and practices used to develop that database and linked application. So you need to decide whether you want to implement some changes to the way your developers actually develop the database (particularly schema changes) to make the deployment process easier. A good example is the pattern “Branch by abstraction”. Explained nicely here, by Martin Fowler, this is a process that can be used to make significant database changes (e.g. splitting a table) in a step-wise manner so that you can always roll back, without data loss – by making incremental updates to the database backward compatible. Slides 103-108 of the following slidedeck, from Niek Bartholomeus explain the process: https://speakerdeck.com/niekbartho/orchestration-in-meatspace As these slides show, by making a significant schema change in multiple steps – where each step can be rolled back without any loss of new data – this affords the release team the opportunity to have zero-downtime deployments with considerably less stress (because if an increment goes wrong, they can roll back easily). There are plenty more great patterns that can be implemented – the book Refactoring Databases, by Scott Ambler and Pramod Sadalage is a great read, if this is a direction you want to go in: http://www.amazon.com/Refactoring-Databases-Evolutionary-paperback-Addison-Wesley/dp/0321774515 But the question is – how much of this investment are you willing to make? How often are you making significant schema changes that would require these best practices? Again, there’s a difference here between migrating old projects and starting afresh – with the latter it’s much easier to instigate best practice from the start. Actions: For your business, work out how far down the path you want to go, amending your database development patterns to “best practice”. It’s a trade-off between implementing quality processes, and the necessity to do so (depending on how often you make complex changes). Socialise these changes with your development group. No-one likes having “best practice” changes imposed on them, so good to introduce these ideas and the rationale behind them early.   Summary The next stages of implementing a continuous delivery pipeline for your database changes (once you have CI up and running) require a little pre-planning, if you want to get the most out of the work, and for the implementation to go smoothly. We’ve covered some of the checklist of areas to consider – mainly in the areas of “Getting the team ready for the changes that are coming” and “Planning our your pipeline, environments, patterns and practices for development”, though there will be more detail, depending on where you’re coming from – and where you want to get to. This article is part of our database delivery patterns & practices series on Simple Talk. Find more articles for version control, automated testing, continuous integration & deployment.

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• Informed TDD &ndash; Kata &ldquo;To Roman Numerals&rdquo;

  - by Ralf Westphal

  Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/05/28/informed-tdd-ndash-kata-ldquoto-roman-numeralsrdquo.aspxIn a comment on my article on what I call Informed TDD (ITDD) reader gustav asked how this approach would apply to the kata “To Roman Numerals”. And whether ITDD wasn´t a violation of TDD´s principle of leaving out “advanced topics like mocks”. I like to respond with this article to his questions. There´s more to say than fits into a commentary. Mocks and TDD I don´t see in how far TDD is avoiding or opposed to mocks. TDD and mocks are orthogonal. TDD is about pocess, mocks are about structure and costs. Maybe by moving forward in tiny red+green+refactor steps less need arises for mocks. But then… if the functionality you need to implement requires “expensive” resource access you can´t avoid using mocks. Because you don´t want to constantly run all your tests against the real resource. True, in ITDD mocks seem to be in almost inflationary use. That´s not what you usually see in TDD demonstrations. However, there´s a reason for that as I tried to explain. I don´t use mocks as proxies for “expensive” resource. Rather they are stand-ins for functionality not yet implemented. They allow me to get a test green on a high level of abstraction. That way I can move forward in a top-down fashion. But if you think of mocks as “advanced” or if you don´t want to use a tool like JustMock, then you don´t need to use mocks. You just need to stand the sight of red tests for a little longer ;-) Let me show you what I mean by that by doing a kata. ITDD for “To Roman Numerals” gustav asked for the kata “To Roman Numerals”. I won´t explain the requirements again. You can find descriptions and TDD demonstrations all over the internet, like this one from Corey Haines. Now here is, how I would do this kata differently. 1. Analyse A demonstration of TDD should never skip the analysis phase. It should be made explicit. The requirements should be formalized and acceptance test cases should be compiled. “Formalization” in this case to me means describing the API of the required functionality. “[D]esign a program to work with Roman numerals” like written in this “requirement document” is not enough to start software development. Coding should only begin, if the interface between the “system under development” and its context is clear. If this interface is not readily recognizable from the requirements, it has to be developed first. Exploration of interface alternatives might be in order. It might be necessary to show several interface mock-ups to the customer – even if that´s you fellow developer. Designing the interface is a task of it´s own. It should not be mixed with implementing the required functionality behind the interface. Unfortunately, though, this happens quite often in TDD demonstrations. TDD is used to explore the API and implement it at the same time. To me that´s a violation of the Single Responsibility Principle (SRP) which not only should hold for software functional units but also for tasks or activities. In the case of this kata the API fortunately is obvious. Just one function is needed: string ToRoman(int arabic). And it lives in a class ArabicRomanConversions. Now what about acceptance test cases? There are hardly any stated in the kata descriptions. Roman numerals are explained, but no specific test cases from the point of view of a customer. So I just “invent” some acceptance test cases by picking roman numerals from a wikipedia article. They are supposed to be just “typical examples” without special meaning. Given the acceptance test cases I then try to develop an understanding of the problem domain. I´ll spare you that. The domain is trivial and is explain in almost all kata descriptions. How roman numerals are built is not difficult to understand. What´s more difficult, though, might be to find an efficient solution to convert into them automatically. 2. Solve The usual TDD demonstration skips a solution finding phase. Like the interface exploration it´s mixed in with the implementation. But I don´t think this is how it should be done. I even think this is not how it really works for the people demonstrating TDD. They´re simplifying their true software development process because they want to show a streamlined TDD process. I doubt this is helping anybody. Before you code you better have a plan what to code. This does not mean you have to do “Big Design Up-Front”. It just means: Have a clear picture of the logical solution in your head before you start to build a physical solution (code). Evidently such a solution can only be as good as your understanding of the problem. If that´s limited your solution will be limited, too. Fortunately, in the case of this kata your understanding does not need to be limited. Thus the logical solution does not need to be limited or preliminary or tentative. That does not mean you need to know every line of code in advance. It just means you know the rough structure of your implementation beforehand. Because it should mirror the process described by the logical or conceptual solution. Here´s my solution approach: The arabic “encoding” of numbers represents them as an ordered set of powers of 10. Each digit is a factor to multiply a power of ten with. The “encoding” 123 is the short form for a set like this: {1*10^2, 2*10^1, 3*10^0}. And the number is the sum of the set members. The roman “encoding” is different. There is no base (like 10 for arabic numbers), there are just digits of different value, and they have to be written in descending order. The “encoding” XVI is short for [10, 5, 1]. And the number is still the sum of the members of this list. The roman “encoding” thus is simpler than the arabic. Each “digit” can be taken at face value. No multiplication with a base required. But what about IV which looks like a contradiction to the above rule? It is not – if you accept roman “digits” not to be limited to be single characters only. Usually I, V, X, L, C, D, M are viewed as “digits”, and IV, IX etc. are viewed as nuisances preventing a simple solution. All looks different, though, once IV, IX etc. are taken as “digits”. Then MCMLIV is just a sum: M+CM+L+IV which is 1000+900+50+4. Whereas before it would have been understood as M-C+M+L-I+V – which is more difficult because here some “digits” get subtracted. Here´s the list of roman “digits” with their values: {1, I}, {4, IV}, {5, V}, {9, IX}, {10, X}, {40, XL}, {50, L}, {90, XC}, {100, C}, {400, CD}, {500, D}, {900, CM}, {1000, M} Since I take IV, IX etc. as “digits” translating an arabic number becomes trivial. I just need to find the values of the roman “digits” making up the number, e.g. 1954 is made up of 1000, 900, 50, and 4. I call those “digits” factors. If I move from the highest factor (M=1000) to the lowest (I=1) then translation is a two phase process: Find all the factors Translate the factors found Compile the roman representation Translation is just a look-up. Finding, though, needs some calculation: Find the highest remaining factor fitting in the value Remember and subtract it from the value Repeat with remaining value and remaining factors Please note: This is just an algorithm. It´s not code, even though it might be close. Being so close to code in my solution approach is due to the triviality of the problem. In more realistic examples the conceptual solution would be on a higher level of abstraction. With this solution in hand I finally can do what TDD advocates: find and prioritize test cases. As I can see from the small process description above, there are two aspects to test: Test the translation Test the compilation Test finding the factors Testing the translation primarily means to check if the map of factors and digits is comprehensive. That´s simple, even though it might be tedious. Testing the compilation is trivial. Testing factor finding, though, is a tad more complicated. I can think of several steps: First check, if an arabic number equal to a factor is processed correctly (e.g. 1000=M). Then check if an arabic number consisting of two consecutive factors (e.g. 1900=[M,CM]) is processed correctly. Then check, if a number consisting of the same factor twice is processed correctly (e.g. 2000=[M,M]). Finally check, if an arabic number consisting of non-consecutive factors (e.g. 1400=[M,CD]) is processed correctly. I feel I can start an implementation now. If something becomes more complicated than expected I can slow down and repeat this process. 3. Implement First I write a test for the acceptance test cases. It´s red because there´s no implementation even of the API. That´s in conformance with “TDD lore”, I´d say: Next I implement the API: The acceptance test now is formally correct, but still red of course. This will not change even now that I zoom in. Because my goal is not to most quickly satisfy these tests, but to implement my solution in a stepwise manner. That I do by “faking” it: I just “assume” three functions to represent the transformation process of my solution: My hypothesis is that those three functions in conjunction produce correct results on the API-level. I just have to implement them correctly. That´s what I´m trying now – one by one. I start with a simple “detail function”: Translate(). And I start with all the test cases in the obvious equivalence partition: As you can see I dare to test a private method. Yes. That´s a white box test. But as you´ll see it won´t make my tests brittle. It serves a purpose right here and now: it lets me focus on getting one aspect of my solution right. Here´s the implementation to satisfy the test: It´s as simple as possible. Right how TDD wants me to do it: KISS. Now for the second equivalence partition: translating multiple factors. (It´a pattern: if you need to do something repeatedly separate the tests for doing it once and doing it multiple times.) In this partition I just need a single test case, I guess. Stepping up from a single translation to multiple translations is no rocket science: Usually I would have implemented the final code right away. Splitting it in two steps is just for “educational purposes” here. How small your implementation steps are is a matter of your programming competency. Some “see” the final code right away before their mental eye – others need to work their way towards it. Having two tests I find more important. Now for the next low hanging fruit: compilation. It´s even simpler than translation. A single test is enough, I guess. And normally I would not even have bothered to write that one, because the implementation is so simple. I don´t need to test .NET framework functionality. But again: if it serves the educational purpose… Finally the most complicated part of the solution: finding the factors. There are several equivalence partitions. But still I decide to write just a single test, since the structure of the test data is the same for all partitions: Again, I´m faking the implementation first: I focus on just the first test case. No looping yet. Faking lets me stay on a high level of abstraction. I can write down the implementation of the solution without bothering myself with details of how to actually accomplish the feat. That´s left for a drill down with a test of the fake function: There are two main equivalence partitions, I guess: either the first factor is appropriate or some next. The implementation seems easy. Both test cases are green. (Of course this only works on the premise that there´s always a matching factor. Which is the case since the smallest factor is 1.) And the first of the equivalence partitions on the higher level also is satisfied: Great, I can move on. Now for more than a single factor: Interestingly not just one test becomes green now, but all of them. Great! You might say, then I must have done not the simplest thing possible. And I would reply: I don´t care. I did the most obvious thing. But I also find this loop very simple. Even simpler than a recursion of which I had thought briefly during the problem solving phase. And by the way: Also the acceptance tests went green: Mission accomplished. At least functionality wise. Now I´ve to tidy up things a bit. TDD calls for refactoring. Not uch refactoring is needed, because I wrote the code in top-down fashion. I faked it until I made it. I endured red tests on higher levels while lower levels weren´t perfected yet. But this way I saved myself from refactoring tediousness. At the end, though, some refactoring is required. But maybe in a different way than you would expect. That´s why I rather call it “cleanup”. First I remove duplication. There are two places where factors are defined: in Translate() and in Find_factors(). So I factor the map out into a class constant. Which leads to a small conversion in Find_factors(): And now for the big cleanup: I remove all tests of private methods. They are scaffolding tests to me. They only have temporary value. They are brittle. Only acceptance tests need to remain. However, I carry over the single “digit” tests from Translate() to the acceptance test. I find them valuable to keep, since the other acceptance tests only exercise a subset of all roman “digits”. This then is my final test class: And this is the final production code: Test coverage as reported by NCrunch is 100%: Reflexion Is this the smallest possible code base for this kata? Sure not. You´ll find more concise solutions on the internet. But LOC are of relatively little concern – as long as I can understand the code quickly. So called “elegant” code, however, often is not easy to understand. The same goes for KISS code – especially if left unrefactored, as it is often the case. That´s why I progressed from requirements to final code the way I did. I first understood and solved the problem on a conceptual level. Then I implemented it top down according to my design. I also could have implemented it bottom-up, since I knew some bottom of the solution. That´s the leaves of the functional decomposition tree. Where things became fuzzy, since the design did not cover any more details as with Find_factors(), I repeated the process in the small, so to speak: fake some top level, endure red high level tests, while first solving a simpler problem. Using scaffolding tests (to be thrown away at the end) brought two advantages: Encapsulation of the implementation details was not compromised. Naturally private methods could stay private. I did not need to make them internal or public just to be able to test them. I was able to write focused tests for small aspects of the solution. No need to test everything through the solution root, the API. The bottom line thus for me is: Informed TDD produces cleaner code in a systematic way. It conforms to core principles of programming: Single Responsibility Principle and/or Separation of Concerns. Distinct roles in development – being a researcher, being an engineer, being a craftsman – are represented as different phases. First find what, what there is. Then devise a solution. Then code the solution, manifest the solution in code. Writing tests first is a good practice. But it should not be taken dogmatic. And above all it should not be overloaded with purposes. And finally: moving from top to bottom through a design produces refactored code right away. Clean code thus almost is inevitable – and not left to a refactoring step at the end which is skipped often for different reasons.   PS: Yes, I have done this kata several times. But that has only an impact on the time needed for phases 1 and 2. I won´t skip them because of that. And there are no shortcuts during implementation because of that.

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• xf86OpenConsole: Cannot find a free VT: Invalid argument

  - by Oliver Seeliger

  I'v set up an Ubuntu 12.04 from the precreated OpenVZ template. The host system is configured as follows: # $ cat /etc/issue Debian GNU/Linux 6.0 # $ uname -a Linux openvz-02 2.6.32-16-pve #1 SMP Fri Nov 9 11:42:51 CET 2012 x86_64 GNU/Linux # $ apt-cache showpkg proxmox-ve-2.6.32 Package: proxmox-ve-2.6.32 # $ tail -n 3 /etc/apt/sources.list # PVE packages provided by proxmox.com deb http://download.proxmox.com/debian squeeze pve For a software project I need a minimal xserver and followed the instructions at https://help.ubuntu.com/community/ServerGUI. I simply installed the package xorg (xorg 1:7.6+7ubuntu7.1). Now when I 'startx' I get an error message Fatal server error: xf86OpenConsole: Cannot find a free VT: Invalid argument The complete output of startx # startx X.Org X Server 1.11.3 Release Date: 2011-12-16 X Protocol Version 11, Revision 0 Build Operating System: Linux 2.6.42-23-generic x86_64 Ubuntu Current Operating System: Linux www 2.6.32-16-pve #1 SMP Fri Nov 9 11:42:51 CET 2012 x86_64 Kernel command line: quiet Build Date: 29 August 2012 12:12:33AM xorg-server 2:1.11.4-0ubuntu10.8 (For technical support please see http://www.ubuntu.com/support) Current version of pixman: 0.24.4 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: "/var/log/Xorg.0.log", Time: Tue Nov 20 08:46:04 2012 (==) Using system config directory "/usr/share/X11/xorg.conf.d" Fatal server error: xf86OpenConsole: Cannot find a free VT: Invalid argument Please consult the The X.Org Foundation support at http://wiki.x.org for help. Please also check the log file at "/var/log/Xorg.0.log" for additional information. ddxSigGiveUp: Closing log Server terminated with error (1). Closing log file.

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• Desktop Fun: Battlestar Galactica Wallpapers

  - by Asian Angel

  Are you feeling nostalgic and/or sad now that the Battlestar Galactica series has finished up? Now you can add a bit of that Galactica goodness to your desktop with our Battlestar Galactica Wallpaper collection. If the image links fail for some reason you can download the entire set as a zipped file here. Note: Click on the picture to see the full-size image—these wallpapers vary in size so you may need to crop, stretch, or place them on a colored background in order to best match them to your screen’s resolution. For more fun wallpapers be certain to visit our new Desktop Fun section. If you are looking for some great icons to go with your new Battlestar Galactica wallpaper make certain to check out our Sci-Fi Icon Packs collection here. Similar Articles Productive Geek Tips Desktop Customization: Sci-Fi Icon PacksWindows 7 Welcome Screen Taking Forever? Here’s the Fix (Maybe)Desktop Fun: Starship Theme WallpapersDesktop Fun: Underwater Theme WallpapersDesktop Fun: Starscape Theme Wallpapers TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Acronis Online Backup DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows Tomorrow is Mother’s Day Check the Average Speed of YouTube Videos You’ve Watched OutlookStatView Scans and Displays General Usage Statistics How to Add Exceptions to the Windows Firewall Office 2010 reviewed in depth by Ed Bott FoxClocks adds World Times in your Statusbar (Firefox)

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• WiX 3 Tutorial: Custom EULA License and MSI localization

  - by Mladen Prajdic

  In this part of the ongoing Wix tutorial series we’ll take a look at how to localize your MSI into different languages. We’re still the mighty SuperForm: Program that takes care of all your label color needs. :) Localizing the MSI With WiX 3.0 localizing an MSI is pretty much a simple and straightforward process. First let look at the WiX project Properties->Build. There you can see "Cultures to build" textbox. Put specific cultures to build into the testbox or leave it empty to build all of them. Cultures have to be in correct culture format like en-US, en-GB or de-DE. Next we have to tell WiX which cultures we actually have in our project. Take a look at the first post in the series about Solution/Project structure and look at the Lang directory in the project structure picture. There we have de-de and en-us subfolders each with its own localized stuff. In the subfolders pay attention to the WXL files Loc_de-de.wxl and Loc_en-us.wxl. Each one has a <String Id="LANG"> under the WixLocalization root node. By including the string with id LANG we tell WiX we want that culture built. For English we have <String Id="LANG">1033</String>, for German <String Id="LANG">1031</String> in Loc_de-de.wxl and for French we’d have to create another file Loc_fr-FR.wxl and put <String Id="LANG">1036</String>. WXL files are localization files. Any string we want to localize we have to put in there. To reference it we use loc keyword like this: !(loc.IdOfTheVariable) => !(loc.MustCloseSuperForm) This is our Loc_en-us.wxl. Note that German wxl has an identical structure but values are in German. <?xml version="1.0" encoding="utf-8"?><WixLocalization Culture="en-us" xmlns="http://schemas.microsoft.com/wix/2006/localization" Codepage="1252"> <String Id="LANG">1033</String> <String Id="ProductName">SuperForm</String> <String Id="LicenseRtf" Overridable="yes">\Lang\en-us\EULA_en-us.rtf</String> <String Id="ManufacturerName">My Company Name</String> <String Id="AppNotSupported">This application is is not supported on your current OS. Minimal OS supported is Windows XP SP2</String> <String Id="DotNetFrameworkNeeded">.NET Framework 3.5 is required. Please install the .NET Framework then run this installer again.</String> <String Id="MustCloseSuperForm">Must close SuperForm!</String> <String Id="SuperFormNewerVersionInstalled">A newer version of !(loc.ProductName) is already installed.</String> <String Id="ProductKeyCheckDialog_Title">!(loc.ProductName) setup</String> <String Id="ProductKeyCheckDialogControls_Title">!(loc.ProductName) Product check</String> <String Id="ProductKeyCheckDialogControls_Description">Plese Enter following information to perform the licence check.</String> <String Id="ProductKeyCheckDialogControls_FullName">Full Name:</String> <String Id="ProductKeyCheckDialogControls_Organization">Organization:</String> <String Id="ProductKeyCheckDialogControls_ProductKey">Product Key:</String> <String Id="ProductKeyCheckDialogControls_InvalidProductKey">The product key you entered is invalid. Please call user support.</String> </WixLocalization>   As you can see from the file we can use localization variables in other variables like we do for SuperFormNewerVersionInstalled string. ProductKeyCheckDialog* strings are to localize a custom dialog for Product key check which we’ll look at in the next post. Built in dialog text localization Under the de-de folder there’s also the WixUI_de-de.wxl file. This files contains German translations of all texts that are in WiX built in dialogs. It can be downloaded from WiX 3.0.5419.0 Source Forge site. Download the wix3-sources.zip and go to \src\ext\UIExtension\wixlib. There you’ll find already translated all WiX texts in 12 Languages. Localizing the custom EULA license Here it gets ugly. We can override the default EULA license easily by overriding WixUILicenseRtf WiX variable like this: <WixVariable Id="WixUILicenseRtf" Value="License.rtf" /> where License.rtf is the name of your custom EULA license file. The downside of this method is that you can only have one license file which means no localization for it. That’s why we need to make a workaround. License is checked on a dialog name LicenseAgreementDialog. What we have to do is overwrite that dialog and insert the functionality for localization. This is a code for LicenseAgreementDialogOverwritten.wxs, an overwritten LicenseAgreementDialog that supports localization. LicenseAcceptedOverwritten replaces the LicenseAccepted built in variable. <?xml version="1.0" encoding="UTF-8" ?><Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"> <Fragment> <UI> <Dialog Id="LicenseAgreementDialogOverwritten" Width="370" Height="270" Title="!(loc.LicenseAgreementDlg_Title)"> <Control Id="LicenseAcceptedOverwrittenCheckBox" Type="CheckBox" X="20" Y="207" Width="330" Height="18" CheckBoxValue="1" Property="LicenseAcceptedOverwritten" Text="!(loc.LicenseAgreementDlgLicenseAcceptedCheckBox)" /> <Control Id="Back" Type="PushButton" X="180" Y="243" Width="56" Height="17" Text="!(loc.WixUIBack)" /> <Control Id="Next" Type="PushButton" X="236" Y="243" Width="56" Height="17" Default="yes" Text="!(loc.WixUINext)"> <Publish Event="SpawnWaitDialog" Value="WaitForCostingDlg">CostingComplete = 1</Publish> <Condition Action="disable"> <![CDATA[ LicenseAcceptedOverwritten <> "1" ]]> </Condition> <Condition Action="enable">LicenseAcceptedOverwritten = "1"</Condition> </Control> <Control Id="Cancel" Type="PushButton" X="304" Y="243" Width="56" Height="17" Cancel="yes" Text="!(loc.WixUICancel)"> <Publish Event="SpawnDialog" Value="CancelDlg">1</Publish> </Control> <Control Id="BannerBitmap" Type="Bitmap" X="0" Y="0" Width="370" Height="44" TabSkip="no" Text="!(loc.LicenseAgreementDlgBannerBitmap)" /> <Control Id="LicenseText" Type="ScrollableText" X="20" Y="60" Width="330" Height="140" Sunken="yes" TabSkip="no"> <!-- This is original line --> <!--<Text SourceFile="!(wix.WixUILicenseRtf=$(var.LicenseRtf))" />--> <!-- To enable EULA localization we change it to this --> <Text SourceFile="$(var.ProjectDir)\!(loc.LicenseRtf)" /> <!-- In each of localization files (wxl) put line like this: <String Id="LicenseRtf" Overridable="yes">\Lang\en-us\EULA_en-us.rtf</String>--> </Control> <Control Id="Print" Type="PushButton" X="112" Y="243" Width="56" Height="17" Text="!(loc.WixUIPrint)"> <Publish Event="DoAction" Value="WixUIPrintEula">1</Publish> </Control> <Control Id="BannerLine" Type="Line" X="0" Y="44" Width="370" Height="0" /> <Control Id="BottomLine" Type="Line" X="0" Y="234" Width="370" Height="0" /> <Control Id="Description" Type="Text" X="25" Y="23" Width="340" Height="15" Transparent="yes" NoPrefix="yes" Text="!(loc.LicenseAgreementDlgDescription)" /> <Control Id="Title" Type="Text" X="15" Y="6" Width="200" Height="15" Transparent="yes" NoPrefix="yes" Text="!(loc.LicenseAgreementDlgTitle)" /> </Dialog> </UI> </Fragment></Wix>   Look at the Control with Id "LicenseText” and read the comments. We’ve changed the original license text source to "$(var.ProjectDir)\!(loc.LicenseRtf)". var.ProjectDir is the directory of the project file. The !(loc.LicenseRtf) is where the magic happens. Scroll up and take a look at the wxl localization file example. We have the LicenseRtf declared there and it’s been made overridable so developers can change it if they want. The value of the LicenseRtf is the path to our localized EULA relative to the WiX project directory. With little hacking we’ve achieved a fully localizable installer package.   The final step is to insert the extended LicenseAgreementDialogOverwritten license dialog into the installer GUI chain. This is how it’s done under the <UI> node of course.   <UI> <!-- code to be discussed in later posts –> <!-- BEGIN UI LOGIC FOR CLEAN INSTALLER --> <Publish Dialog="WelcomeDlg" Control="Next" Event="NewDialog" Value="LicenseAgreementDialogOverwritten">1</Publish> <Publish Dialog="LicenseAgreementDialogOverwritten" Control="Back" Event="NewDialog" Value="WelcomeDlg">1</Publish> <Publish Dialog="LicenseAgreementDialogOverwritten" Control="Next" Event="NewDialog" Value="ProductKeyCheckDialog">LicenseAcceptedOverwritten = "1" AND NOT OLDER_VERSION_FOUND</Publish> <Publish Dialog="InstallDirDlg" Control="Back" Event="NewDialog" Value="ProductKeyCheckDialog">1</Publish> <!-- END UI LOGIC FOR CLEAN INSTALLER –> <!-- code to be discussed in later posts --></UI> For a thing that should be simple for the end developer to do, localization can be a bit advanced for the novice WiXer. Hope this post makes the journey easier and that next versions of WiX improve this process. WiX 3 tutorial by Mladen Prajdic navigation WiX 3 Tutorial: Solution/Project structure and Dev resources WiX 3 Tutorial: Understanding main wxs and wxi file WiX 3 Tutorial: Generating file/directory fragments with Heat.exe  WiX 3 Tutorial: Custom EULA License and MSI localization WiX 3 Tutorial: Product Key Check custom action WiX 3 Tutorial: Building an updater WiX 3 Tutorial: Icons and installer pictures WiX 3 Tutorial: Creating a Bootstrapper

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• Problems with SQL Server 2008 - "The client was unable to reuse a session with SPID 62, which had ..

  - by GrZeCh

  Hello, I'm having problems with my SQL Server 2008 installation (10.0.2531.0 - SP1 installed). It works as a database server for small hosting environment (about 500 sites). I'm getting errors like this: The client was unable to reuse a session with SPID 62, which had been reset for connection pooling. The failure ID is 29. This error may have been caused by an earlier operation failing. Check the error logs for failed operations immediately before this error message. in Windows event log and when I run this: SELECT * FROM sys.dm_os_performance_counters WHERE object_name = 'SQLServer:General Statistics' I see that one of counters looks a little odd: Logins/sec 429 Connection Reset/sec 163459 Logouts/sec 399 User Connections 30 Logical Connections 33 any ideas how to check what is causing this problem?

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• Sputnik – Google’s Java script conformance tester now as website

  - by samsudeen

  Sputnik the JavaScript 3 conformance test suite launched by Google last year is now available as Google Labs (Sputnik Test)product. You can browse it like any other  website and run over 5000 java script function tests to check your browser compatibility This product allows you do the following options Run :  You can run the complete test suite on your browser to check the compliance to  ECMA-262 standards.You can also browse trough  the failed test case. Compare : You can compare java script conformance of the various leading browsers in the market. Now web developers can be more cautious while designing websites to make them compatible with multiple browsers. Google is committed to review and release multiple version periodically with updated test cases. According to the latest sputnik test  result released by Google, Opera 10.5 leads the race with only 78 failures. Microsoft IE 8 performed the worst (463 failures) . Next to Opera,  Apple’s Safari (159 failures), Google’s Chrome (218 failures) and Mozilla’s Firefox (259 failures) leads respectively Though the test are about conformance, not performance, the top 3 leading browsers are among the last three in conformance which is something they have to improve Join us on Facebook to read all our stories right inside your Facebook news feed.

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• HAProxy: Display a "BADREQ" | BADREQ's by the thousands

  - by GruffTech

  My HAProxy Configuration. #HA-Proxy version 1.3.22 2009/10/14 Copyright 2000-2009 Willy Tarreau <[email protected]> global maxconn 10000 spread-checks 50 user haproxy group haproxy daemon stats socket /tmp/haproxy log localhost local0 log localhost local1 notice defaults mode http maxconn 50000 timeout client 10000 option forwardfor except 127.0.0.1 option httpclose option httplog listen dcaustin 0.0.0.0:80 mode http timeout connect 12000 timeout server 60000 timeout queue 120000 balance roundrobin option httpchk GET /index.html log global option httplog option dontlog-normal server web1 10.10.10.101:80 maxconn 300 check fall 1 server web2 10.10.10.102:80 maxconn 300 check fall 1 server web3 10.10.10.103:80 maxconn 300 check fall 1 server web4 10.10.10.104:80 maxconn 300 check fall 1 listen stats 0.0.0.0:9000 mode http balance log global timeout client 5000 timeout connect 4000 timeout server 30000 stats uri /haproxy HAProxy is running, and the socket is working... adam@dcaustin:/etc/haproxy# echo "show info" | socat stdio /tmp/haproxy Name: HAProxy Version: 1.3.22 Release_date: 2009/10/14 Nbproc: 1 Process_num: 1 Pid: 6320 Uptime: 0d 0h14m58s Uptime_sec: 898 Memmax_MB: 0 Ulimit-n: 20017 Maxsock: 20017 Maxconn: 10000 Maxpipes: 0 CurrConns: 47 PipesUsed: 0 PipesFree: 0 Tasks: 51 Run_queue: 1 node: dcaustin desiption: Errors show nothing from socket... adam@dcaustin:/etc/haproxy# echo "show errors" | socat stdio /tmp/haproxy adam@dcaustin:/etc/haproxy# However... My Error log is exploding with "badrequests" with the Error code cR. cR (according to 1.3 documentation) is The "timeout http-request" stroke before the client sent a full HTTP request. This is sometimes caused by too large TCP MSS values on the client side for PPPoE networks which cannot transport full-sized packets, or by clients sending requests by hand and not typing fast enough, or forgetting to enter the empty line at the end of the request. The HTTP status code is likely a 408 here. Correct on the 408, but we're getting literally thousands of these requests every hour. (This log snippet is an clip for about 10 seconds of time...) Jun 30 11:08:52 localhost haproxy[6320]: 92.22.213.32:26448 [30/Jun/2011:11:08:42.384] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10002 408 212 - - cR-- 35/35/18/0/0 0/0 "<BADREQ>" Jun 30 11:08:54 localhost haproxy[6320]: 71.62.130.24:62818 [30/Jun/2011:11:08:44.457] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10001 408 212 - - cR-- 39/39/16/0/0 0/0 "<BADREQ>" Jun 30 11:08:55 localhost haproxy[6320]: 84.73.75.236:3589 [30/Jun/2011:11:08:45.021] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10008 408 212 - - cR-- 35/35/15/0/0 0/0 "<BADREQ>" Jun 30 11:08:55 localhost haproxy[6320]: 69.39.20.190:49969 [30/Jun/2011:11:08:45.709] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10000 408 212 - - cR-- 37/37/16/0/0 0/0 "<BADREQ>" Jun 30 11:08:56 localhost haproxy[6320]: 2.29.0.9:58772 [30/Jun/2011:11:08:46.846] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10001 408 212 - - cR-- 43/43/22/0/0 0/0 "<BADREQ>" Jun 30 11:08:57 localhost haproxy[6320]: 212.139.250.242:57537 [30/Jun/2011:11:08:47.568] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10000 408 212 - - cR-- 42/42/21/0/0 0/0 "<BADREQ>" Jun 30 11:08:58 localhost haproxy[6320]: 74.79.195.75:55046 [30/Jun/2011:11:08:48.559] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10000 408 212 - - cR-- 46/46/24/0/0 0/0 "<BADREQ>" Jun 30 11:08:58 localhost haproxy[6320]: 74.79.195.75:55044 [30/Jun/2011:11:08:48.554] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10004 408 212 - - cR-- 45/45/24/0/0 0/0 "<BADREQ>" Jun 30 11:08:58 localhost haproxy[6320]: 74.79.195.75:55045 [30/Jun/2011:11:08:48.554] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10005 408 212 - - cR-- 44/44/24/0/0 0/0 "<BADREQ>" Jun 30 11:09:00 localhost haproxy[6320]: 68.197.56.2:52781 [30/Jun/2011:11:08:50.975] dcaustin dcaustin/<NOSRV> -1/-1/-1/-1/10000 408 212 - - cR-- 49/49/28/0/0 0/0 "<BADREQ>" From what I read on google, if i wanted to see what the bad requests are, I can show errors to the socket and it will spit them out. We do run a pretty heavily trafficed website and the percentage of "BADREQS" to normal requests is quite low, but I'd like to be able to get ahold of what that request WAS so I can debug it. stats # pxname,svname,qcur,qmax,scur,smax,slim,stot,bin,bout,dreq,dresp,ereq,econ,eresp,wretr,wredis,status,weight,act,bck,chkfail,chkdown,lastchg,downtime,qlimit,pid,iid,sid,throttle,lbtot,tracked,type,rate,rate_lim,rate_max, dcaustin,FRONTEND,,,64,120,50000,88433,105889100,2553809875,0,0,4641,,,,,OPEN,,,,,,,,,1,1,0,,,,0,45,0,128, dcaustin,web1,0,0,10,28,300,20941,25402112,633143416,,0,,0,3,0,0,UP,1,1,0,0,0,2208,0,,1,1,1,,20941,,2,11,,30, dcaustin,web2,0,0,9,30,300,20941,25026691,641475169,,0,,0,3,0,0,UP,1,1,0,0,0,2208,0,,1,1,2,,20941,,2,11,,30, dcaustin,web3,0,0,10,27,300,20940,30116527,635015040,,0,,0,9,0,0,UP,1,1,0,0,0,2208,0,,1,1,3,,20940,,2,10,,31, dcaustin,web4,0,0,5,28,300,20940,25343770,643209546,,0,,0,8,0,0,UP,1,1,0,0,0,2208,0,,1,1,4,,20940,,2,11,,31, dcaustin,BACKEND,0,0,34,95,50000,83762,105889100,2553809875,0,0,,0,34,0,0,UP,4,4,0,,0,2208,0,,1,1,0,,83762,,1,43,,122, 88500 "Sessions" and 4500 errors. in the last 20 minutes.

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• SSL connection errors from Apache

  - by Yang

  I'm running a (self-signed) SSL cert site on Apache/2.2.14 on Ubuntu 10.04, but various browsers are giving errors on half the connection attempts. Just now saw this transient error from Chrome: "Error 126 (net::ERR_SSL_BAD_RECORD_MAC_ALERT): Unknown error." Hit refresh and the problem goes away for a while. wget too: $ wget --no-check-certificate https://dev.foo.com/deps/ --2010-09-08 19:30:26-- https://dev.foo.com/deps/ Resolving dev.foo.com... 184.72.53.220 Connecting to dev.foo.com|184.72.53.220|:443... connected. OpenSSL: error:0407006A:rsa routines:RSA_padding_check_PKCS1_type_1:block type is not 01 OpenSSL: error:04067072:rsa routines:RSA_EAY_PUBLIC_DECRYPT:padding check failed OpenSSL: error:1408D07B:SSL routines:SSL3_GET_KEY_EXCHANGE:bad signature Unable to establish SSL connection. Run it right away again and it works: $ wget --no-check-certificate https://dev.foo.com/deps/ --2010-09-08 19:30:29-- https://dev.foo.com/deps/ Resolving dev.foo.com... 184.72.53.220 Connecting to dev.foo.com|184.72.53.220|:443... connected. WARNING: cannot verify dev.foo.com's certificate, issued by `/CN=dev.foo.com': Self-signed certificate encountered. HTTP request sent, awaiting response... 200 OK Length: 3157 (3.1K) [text/html] Saving to: `index.html' 100%[======================================>] 3,157 --.-K/s in 0s 2010-09-08 19:30:29 (48.6 MB/s) - `index.html' saved [3157/3157] In my sites-enabled/default-ssl: SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key The cert: -----BEGIN CERTIFICATE----- MIIBszCCARwCCQCa0TzNwqLgsTANBgkqhkiG9w0BAQUFADAeMRwwGgYDVQQDExNk ZXYucGFydHlvbmRhdGEuY29tMB4XDTEwMDgyNzA2MzA1N1oXDTIwMDgyNDA2MzA1 N1owHjEcMBoGA1UEAxMTZGV2LnBhcnR5b25kYXRhLmNvbTCBnzANBgkqhkiG9w0B AQEFAAOBjQAwgYkCgYEAzXDEULpCUqIc9hV/ESFapkckR2uoYINA81DvG2aQZ9Ot Q30OwX2ae2CC4bSzJEIVlahU8vjVrWpmpa28NEhQbqh4ywwbl1XDrEVYI6Gkfimf snJhOKyaVrEhlwutYtBjmsz3ZIqwymMPm/6smVcSS5dJIynlSmtltxX6ivPcO8UC AwEAATANBgkqhkiG9w0BAQUFAAOBgQBGxHVkpSSOnZjzuySRepjhAlV/yhe9Fx23 fh12WrjQMEi98B7JEuNSLXDWckUN7O6XRc3RzKmazcGHJqzhn0Ov6gAmAE2XjZ/x VW21xmaLwk+KgYKFJbJJaP3jMSpU7I3aa11wqAkR2Zd4Nkm9N0YXYIzcBdfztTVI Et8mEHBFdg== -----END CERTIFICATE----- The cert is in turn generated via: $ make-ssl-cert generate-default-snakeoil --force-overwrite Apache version. $ apache2 -V Server version: Apache/2.2.14 (Ubuntu) Server built: Apr 13 2010 20:22:19 Server's Module Magic Number: 20051115:23 Server loaded: APR 1.3.8, APR-Util 1.3.9 Compiled using: APR 1.3.8, APR-Util 1.3.9 Architecture: 64-bit Server MPM: Worker threaded: yes (fixed thread count) forked: yes (variable process count) Server compiled with.... -D APACHE_MPM_DIR="server/mpm/worker" -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=128 -D HTTPD_ROOT="" -D SUEXEC_BIN="/usr/lib/apache2/suexec" -D DEFAULT_PIDLOG="/var/run/apache2.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="/etc/apache2/mime.types" -D SERVER_CONFIG_FILE="/etc/apache2/apache2.conf" I don't administer the network, hardware, etc. - this is all running on Amazon EC2. I'm not running a load-balancer or anything else in front of the server. I'm making direct TCP connections to that host (AFAIK). Any ideas? Thanks in advance for any help.

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• ASP.NET GZip Encoding Caveats

  - by Rick Strahl

  GZip encoding in ASP.NET is pretty easy to accomplish using the built-in GZipStream and DeflateStream classes and applying them to the Response.Filter property.  While applying GZip and Deflate behavior is pretty easy there are a few caveats that you have watch out for as I found out today for myself with an application that was throwing up some garbage data. But before looking at caveats let’s review GZip implementation for ASP.NET. ASP.NET GZip/Deflate Basics Response filters basically are applied to the Response.OutputStream and transform it as data is written to it through the ASP.NET Response object. So a Response.Write eventually gets written into the output stream which if a filter is also written through the filter stream’s interface. To perform the actual GZip (and Deflate) encoding typically used by Web pages .NET includes the GZipStream and DeflateStream stream classes which can be readily assigned to the Repsonse.OutputStream. With these two stream classes in place it’s almost trivially easy to create a couple of reusable methods that allow you to compress your HTTP output. In my standard WebUtils utility class (from the West Wind West Wind Web Toolkit) created two static utility methods – IsGZipSupported and GZipEncodePage – that check whether the client supports GZip encoding and then actually encodes the current output (note that although the method includes ‘Page’ in its name this code will work with any ASP.NET output). /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } /// <summary> /// Sets up the current page or handler to use GZip through a Response.Filter /// IMPORTANT: /// You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() { HttpResponse Response = HttpContext.Current.Response; if (IsGZipSupported()) { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (AcceptEncoding.Contains("deflate")) { Response.Filter = new System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "deflate"); } else { Response.Filter = new System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "gzip"); } } } As you can see the actual assignment of the Filter is as simple as: Response.Filter = new DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); which applies the filter to the OutputStream. You also need to ensure that your response reflects the new GZip or Deflate encoding and ensure that any pages that are cached in Proxy servers can differentiate between pages that were encoded with the various different encodings (or no encoding). To use this utility function now is trivially easy: In any ASP.NET code that wants to compress its Response output you simply use: protected void Page_Load(object sender, EventArgs e) { WebUtils.GZipEncodePage(); Entry = WebLogFactory.GetEntry(); var entries = Entry.GetLastEntries(App.Configuration.ShowEntryCount, "pk,Title,SafeTitle,Body,Entered,Feedback,Location,ShowTopAd", "TEntries"); if (entries == null) throw new ApplicationException("Couldn't load WebLog Entries: " + Entry.ErrorMessage); this.repEntries.DataSource = entries; this.repEntries.DataBind(); } Here I use an ASP.NET page, but the above WebUtils.GZipEncode() method call will work in any ASP.NET application type including HTTP Handlers. The only requirement is that the filter needs to be applied before any other output is sent to the OutputStream. For example, in my CallbackHandler service implementation by default output over a certain size is GZip encoded. The output that is generated is JSON or XML and if the output is over 5k in size I apply WebUtils.GZipEncode(): if (sbOutput.Length > GZIP_ENCODE_TRESHOLD) WebUtils.GZipEncodePage(); Response.ContentType = ControlResources.STR_JsonContentType; HttpContext.Current.Response.Write(sbOutput.ToString()); Ok, so you probably get the idea: Encoding GZip/Deflate content is pretty easy. Hold on there Hoss –Watch your Caching Or is it? There are a few caveats that you need to watch out for when dealing with GZip content. The fist issue is that you need to deal with the fact that some clients don’t support GZip or Deflate content. Most modern browsers support it, but if you have a programmatic Http client accessing your content GZip/Deflate support is by no means guaranteed. For example, WinInet Http clients don’t support GZip out of the box – it has to be explicitly implemented. Other low level HTTP clients on other platforms too don’t support GZip out of the box. The problem is that your application, your Web Server and Proxy Servers on the Internet might be caching your generated content. If you return content with GZip once and then again without, either caching is not applied or worse the wrong type of content is returned back to the client from a cache or proxy. The result is an unreadable response for *some clients* which is also very hard to debug and fix once in production. You already saw the issue of Proxy servers addressed in the GZipEncodePage() function: // Allow proxy servers to cache encoded and unencoded versions separately Response.AppendHeader("Vary", "Content-Encoding"); This ensures that any Proxy servers also check for the Content-Encoding HTTP Header to cache their content – not just the URL. The same thing applies if you do OutputCaching in your own ASP.NET code. If you generate output for GZip on an OutputCached page the GZipped content will be cached (either by ASP.NET’s cache or in some cases by the IIS Kernel Cache). But what if the next client doesn’t support GZip? She’ll get served a cached GZip page that won’t decode and she’ll get a page full of garbage. Wholly undesirable. To fix this you need to add some custom OutputCache rules by way of the GetVaryByCustom() HttpApplication method in your global_ASAX file: public override string GetVaryByCustomString(HttpContext context, string custom) { // Override Caching for compression if (custom == "GZIP") { string acceptEncoding = HttpContext.Current.Response.Headers["Content-Encoding"]; if (string.IsNullOrEmpty(acceptEncoding)) return ""; else if (acceptEncoding.Contains("gzip")) return "GZIP"; else if (acceptEncoding.Contains("deflate")) return "DEFLATE"; return ""; } return base.GetVaryByCustomString(context, custom); } In a page that use Output caching you then specify: <%@ OutputCache Duration="180" VaryByParam="none" VaryByCustom="GZIP" %> To use that custom rule. It’s all Fun and Games until ASP.NET throws an Error Ok, so you’re up and running with GZip, you have your caching squared away and your pages that you are applying it to are jamming along. Then BOOM, something strange happens and you get a lovely garbled page that look like this: Lovely isn’t it? What’s happened here is that I have WebUtils.GZipEncode() applied to my page, but there’s an error in the page. The error falls back to the ASP.NET error handler and the error handler removes all existing output (good) and removes all the custom HTTP headers I’ve set manually (usually good, but very bad here). Since I applied the Response.Filter (via GZipEncode) the output is now GZip encoded, but ASP.NET has removed my Content-Encoding header, so the browser receives the GZip encoded content without a notification that it is encoded as GZip. The result is binary output. Here’s what Fiddler says about the raw HTTP header output when an error occurs when GZip encoding was applied: HTTP/1.1 500 Internal Server Error Cache-Control: private Content-Type: text/html; charset=utf-8 Date: Sat, 30 Apr 2011 22:21:08 GMT Content-Length: 2138 Connection: close ?`I?%&/m?{J?J??t??` … binary output striped here Notice: no Content-Encoding header and that’s why we’re seeing this garbage. ASP.NET has stripped the Content-Encoding header but left our filter intact. So how do we fix this? In my applications I typically have a global Application_Error handler set up and in this case I’ve been using that. One thing that you can do in the Application_Error handler is explicitly clear out the Response.Filter and set it to null at the top: protected void Application_Error(object sender, EventArgs e) { // Remove any special filtering especially GZip filtering Response.Filter = null; … } And voila I get my Yellow Screen of Death or my custom generated error output back via uncompressed content. BTW, the same is true for Page level errors handled in Page_Error or ASP.NET MVC Error handling methods in a controller. Another and possibly even better solution is to check whether a filter is attached just before the headers are sent to the client as pointed out by Adam Schroeder in the comments: protected void Application_PreSendRequestHeaders() { // ensure that if GZip/Deflate Encoding is applied that headers are set // also works when error occurs if filters are still active HttpResponse response = HttpContext.Current.Response; if (response.Filter is GZipStream && response.Headers["Content-encoding"] != "gzip") response.AppendHeader("Content-encoding", "gzip"); else if (response.Filter is DeflateStream && response.Headers["Content-encoding"] != "deflate") response.AppendHeader("Content-encoding", "deflate"); } This uses the Application_PreSendRequestHeaders() pipeline event to check for compression encoding in a filter and adjusts the content accordingly. This is actually a better solution since this is generic – it’ll work regardless of how the content is cleaned up. For example, an error Response.Redirect() or short error display might get changed and the filter not cleared and this code actually handles that. Sweet, thanks Adam. It’s unfortunate that ASP.NET doesn’t natively clear out Response.Filters when an error occurs just as it clears the Response and Headers. I can’t see where leaving a Filter in place in an error situation would make any sense, but hey - this is what it is and it’s easy enough to fix as long as you know where to look. Riiiight! IIS and GZip I should also mention that IIS 7 includes good support for compression natively. If you can defer encoding to let IIS perform it for you rather than doing it in your code by all means you should do it! Especially any static or semi-dynamic content that can be made static should be using IIS built-in compression. Dynamic caching is also supported but is a bit more tricky to judge in terms of performance and footprint. John Forsyth has a great article on the benefits and drawbacks of IIS 7 compression which gives some detailed performance comparisons and impact reviews. I’ll post another entry next with some more info on IIS compression since information on it seems to be a bit hard to come by. Related Content Built-in GZip/Deflate Compression in IIS 7.x HttpWebRequest and GZip Responses © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET   IIS7  

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• Podcast: The Invisible UI : Natural User Interfaces with Josh Blake

  - by craigshoemaker

  Josh Blake of Infostrat joins Pixel8 to discuss NUI development in .NET. Josh is the author of the upcoming book Multitouch on Windows from Manning. Reaching far beyond theory and the niche market of Microsoft Surface, NUI development is now possible with Silverlight and WPF development on Windows 7 and Windows 7 Mobile devices. Subscribe to the podcast! The Natural User Interface (NUI) was a prominent force at MIX10. What is NUI? Wikipedia defines it as: Natural user interface, or NUI, is the common parlance used by designers and developers of computer interfaces to refer to a user interface that is effectively invisible, or becomes invisible with successive learned interactions, to its users. The word natural is used because most computer interfaces use artificial control devices whose operation has to be learned. A NUI relies on a user being able to carry out relatively natural motions, movements or gestures that they quickly discover control the computer application or manipulate the on-screen content. The most descriptive identifier of a NUI is the lack of a physical keyboard and/or mouse. In our interview Josh demystifies what NUI is, makes a distinction between gestures and manipulations, and talks about what is possible today for NUI development. For more from Josh make sure to check out his book: and watch his MIX Presentation: Developing Natural User Interfaces with Microsoft Silverlight and WPF 4 Touch Resources Mentioned in the Show Check out the following videos that show the roots and future of NUI development: Jeff Han's Multi-Touch TED Presentation Microsoft Surface Project Natal MIX10 Day 2 Keynote A few times during our talk Bill Buxton’s work is mentioned. To see his segment of the MIX10 day 2 keynote, click below:

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• Cannot start session without errors in phpMyAdmin running Nginx with PHP-FPM

  - by Infinity

  Whenever I open phpMyAdmin from my VPS I get the following error: Cannot start session without errors, please check errors given in your PHP and/or webserver log file and configure your PHP installation properly. I have researched it, but cant seem to find a solution, I have done the following: Cleared cache and cookies Checked the php.ini (see below) Checked the logs (found nothing relevant) Given the correct permissions. [by sudo chown -R root:nginx /home/humza/pma] I am running Nginx with PHP-FPM, I have php-mysql and all that working fine but I can't get phpMyAdmin to work. I downloaded it off phpMyAdmin's website and extracted it, that's all. http://pastebin.com/raw.php?i=6n57cW8H - my php.ini sessions bit http://pastebin.com/raw.php?i=VaNP2TLi - my whole php.ini None of my logs have anything relevant. My error logs have other PHP errors but not this one and my access logs don't have anything either. I have checked my nginx logs and my PHP-FPM logs. I tried installing phpMyAdmin via yum and got a whole lot of dependency errors. [root@infinity ~]# yum install phpmyadmin Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package phpMyAdmin.noarch 0:2.11.11.3-1.el5 set to be updated --> Processing Dependency: php-mcrypt >= 4.1.0 for package: phpMyAdmin --> Processing Dependency: php >= 4.1.0 for package: phpMyAdmin --> Processing Dependency: php-mbstring >= 4.1.0 for package: phpMyAdmin --> Running transaction check ---> Package php.i386 0:5.1.6-27.el5_5.3 set to be updated --> Processing Dependency: php-common = 5.1.6-27.el5_5.3 for package: php --> Processing Dependency: php-cli = 5.1.6-27.el5_5.3 for package: php ---> Package php-mbstring.i386 0:5.1.6-27.el5_5.3 set to be updated --> Processing Dependency: php-common = 5.1.6-27.el5_5.3 for package: php-mbstring ---> Package php-mcrypt.i386 0:5.1.6-15.el5.centos.1 set to be updated --> Processing Dependency: php-api = 20041225 for package: php-mcrypt --> Running transaction check ---> Package php.i386 0:5.1.6-27.el5_5.3 set to be updated --> Processing Dependency: php-common = 5.1.6-27.el5_5.3 for package: php ---> Package php-cli.i386 0:5.1.6-27.el5_5.3 set to be updated --> Processing Dependency: php-common = 5.1.6-27.el5_5.3 for package: php-cli ---> Package php-mbstring.i386 0:5.1.6-27.el5_5.3 set to be updated --> Processing Dependency: php-common = 5.1.6-27.el5_5.3 for package: php-mbstring ---> Package php-mcrypt.i386 0:5.1.6-15.el5.centos.1 set to be updated --> Processing Dependency: php-api = 20041225 for package: php-mcrypt --> Finished Dependency Resolution php-5.1.6-27.el5_5.3.i386 from base has depsolving problems --> Missing Dependency: php-common = 5.1.6-27.el5_5.3 is needed by package php-5.1.6-27.el5_5.3.i386 (base) php-cli-5.1.6-27.el5_5.3.i386 from base has depsolving problems --> Missing Dependency: php-common = 5.1.6-27.el5_5.3 is needed by package php-cli-5.1.6-27.el5_5.3.i386 (base) php-mbstring-5.1.6-27.el5_5.3.i386 from base has depsolving problems --> Missing Dependency: php-common = 5.1.6-27.el5_5.3 is needed by package php-mbstring-5.1.6-27.el5_5.3.i386 (base) php-mcrypt-5.1.6-15.el5.centos.1.i386 from extras has depsolving problems --> Missing Dependency: php-api = 20041225 is needed by package php-mcrypt-5.1.6-15.el5.centos.1.i386 (extras) Error: Missing Dependency: php-api = 20041225 is needed by package php-mcrypt-5.1.6-15.el5.centos.1.i386 (extras) Error: Missing Dependency: php-common = 5.1.6-27.el5_5.3 is needed by package php-cli-5.1.6-27.el5_5.3.i386 (base) Error: Missing Dependency: php-common = 5.1.6-27.el5_5.3 is needed by package php-5.1.6-27.el5_5.3.i386 (base) Error: Missing Dependency: php-common = 5.1.6-27.el5_5.3 is needed by package php-mbstring-5.1.6-27.el5_5.3.i386 (base) You could try using --skip-broken to work around the problem You could try running: package-cleanup --problems package-cleanup --dupes rpm -Va --nofiles --nodigest The program package-cleanup is found in the yum-utils package. [root@infinity ~]# Any ideas?

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• How to Make Sure your Company Don't Go Underwater if Your Programmers are Hit by Bus

  - by Graviton

  I have a few programmers under me, they are all doing very great and very smart obviously. Thank you very much. But the problem is that each and every one of them is responsible for one core area, which no one else on the team have foggiest idea on what it is. This means that if anyone of them is taken out, my company as a business is dead because they aren't replaceable. I'm thinking about bringing in new programmers to cover them, just in case they are hit by a bus, or resign or whatever. But I afraid that The old programmers might actively resist the idea of knowledge transfer, fearing that a backup might reduce their value. I don't have a system to facilitate technology transfer between different developers, so even if I ask them to do it, I've no assurance that they will do it properly. My question is, How to put it to the old programmers in such they would agree What are systems that you use, in order to facilitate this kind of "backup"? I can understand that you can do code review, but is there a simple way to conduct this? I think we are not ready for a full blown, check-in by check-in code review.

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• SSL connection errors from Apache

  - by Yang

  I'm running a (self-signed) SSL cert site on Apache/2.2.14 on Ubuntu 10.04, but various browsers are giving errors on half the connection attempts. Just now saw this transient error from Chrome: "Error 126 (net::ERR_SSL_BAD_RECORD_MAC_ALERT): Unknown error." Hit refresh and the problem goes away for a while. wget too: $ wget --no-check-certificate https://dev.partyondata.com/deps/ --2010-09-08 19:30:26-- https://dev.partyondata.com/deps/ Resolving dev.partyondata.com... 184.72.53.220 Connecting to dev.partyondata.com|184.72.53.220|:443... connected. OpenSSL: error:0407006A:rsa routines:RSA_padding_check_PKCS1_type_1:block type is not 01 OpenSSL: error:04067072:rsa routines:RSA_EAY_PUBLIC_DECRYPT:padding check failed OpenSSL: error:1408D07B:SSL routines:SSL3_GET_KEY_EXCHANGE:bad signature Unable to establish SSL connection. Run it right away again and it works: $ wget --no-check-certificate https://dev.partyondata.com/deps/ --2010-09-08 19:30:29-- https://dev.partyondata.com/deps/ Resolving dev.partyondata.com... 184.72.53.220 Connecting to dev.partyondata.com|184.72.53.220|:443... connected. WARNING: cannot verify dev.partyondata.com's certificate, issued by `/CN=dev.partyondata.com': Self-signed certificate encountered. HTTP request sent, awaiting response... 200 OK Length: 3157 (3.1K) [text/html] Saving to: `index.html' 100%[======================================>] 3,157 --.-K/s in 0s 2010-09-08 19:30:29 (48.6 MB/s) - `index.html' saved [3157/3157] In my sites-enabled/default-ssl: SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key The cert: -----BEGIN CERTIFICATE----- MIIBszCCARwCCQCa0TzNwqLgsTANBgkqhkiG9w0BAQUFADAeMRwwGgYDVQQDExNk ZXYucGFydHlvbmRhdGEuY29tMB4XDTEwMDgyNzA2MzA1N1oXDTIwMDgyNDA2MzA1 N1owHjEcMBoGA1UEAxMTZGV2LnBhcnR5b25kYXRhLmNvbTCBnzANBgkqhkiG9w0B AQEFAAOBjQAwgYkCgYEAzXDEULpCUqIc9hV/ESFapkckR2uoYINA81DvG2aQZ9Ot Q30OwX2ae2CC4bSzJEIVlahU8vjVrWpmpa28NEhQbqh4ywwbl1XDrEVYI6Gkfimf snJhOKyaVrEhlwutYtBjmsz3ZIqwymMPm/6smVcSS5dJIynlSmtltxX6ivPcO8UC AwEAATANBgkqhkiG9w0BAQUFAAOBgQBGxHVkpSSOnZjzuySRepjhAlV/yhe9Fx23 fh12WrjQMEi98B7JEuNSLXDWckUN7O6XRc3RzKmazcGHJqzhn0Ov6gAmAE2XjZ/x VW21xmaLwk+KgYKFJbJJaP3jMSpU7I3aa11wqAkR2Zd4Nkm9N0YXYIzcBdfztTVI Et8mEHBFdg== -----END CERTIFICATE----- The cert is in turn generated via: $ make-ssl-cert generate-default-snakeoil --force-overwrite Apache version. $ apache2 -V Server version: Apache/2.2.14 (Ubuntu) Server built: Apr 13 2010 20:22:19 Server's Module Magic Number: 20051115:23 Server loaded: APR 1.3.8, APR-Util 1.3.9 Compiled using: APR 1.3.8, APR-Util 1.3.9 Architecture: 64-bit Server MPM: Worker threaded: yes (fixed thread count) forked: yes (variable process count) Server compiled with.... -D APACHE_MPM_DIR="server/mpm/worker" -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=128 -D HTTPD_ROOT="" -D SUEXEC_BIN="/usr/lib/apache2/suexec" -D DEFAULT_PIDLOG="/var/run/apache2.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="/etc/apache2/mime.types" -D SERVER_CONFIG_FILE="/etc/apache2/apache2.conf" Any ideas? Thanks in advance for any help.

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• New Fusion Community, Community Name Changes and Upcoming Webcasts

  - by cwarticki

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Check out the new MOS Customer Relationship Management (CRM) community. This community has been featured in marketing events and is one of the more active communities so far. Support has also renamed the Fusion HCM community (now Human Capital Management (HCM)) and the Technical – FA community (now Fusion Applications Technology) in order to standardize our naming convention. Finally, we have two upcoming webcasts: 18-OCT-2012 : Fusion Apps Security - User & Role Management using Oracle Identity Manager featured in our Fusion Applications Technology community 01-NOV-2012: Fusion Apps Security – Troubleshoot Data Role Issues featured in our Fusion Applications Technology community. Check out our new Community. Attend our upcoming webcasts. Participate.  Engage. Contribute. ~Chris

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• 10 Essential Tools for building ASP.NET Websites

  - by Stephen Walther

  I recently put together a simple public website created with ASP.NET for my company at Superexpert.com. I was surprised by the number of free tools that I ended up using to put together the website. Therefore, I thought it would be interesting to create a list of essential tools for building ASP.NET websites. These tools work equally well with both ASP.NET Web Forms and ASP.NET MVC. Performance Tools After reading Steve Souders two (very excellent) books on front-end website performance High Performance Web Sites and Even Faster Web Sites, I have been super sensitive to front-end website performance. According to Souders’ Performance Golden Rule: “Optimize front-end performance first, that's where 80% or more of the end-user response time is spent” You can use the tools below to reduce the size of the images, JavaScript files, and CSS files used by an ASP.NET application. 1. Sprite and Image Optimization Framework CSS sprites were first described in an article written for A List Apart entitled CSS sprites: Image Slicing’s Kiss of Death. When you use sprites, you combine multiple images used by a website into a single image. Next, you use CSS trickery to display particular sub-images from the combined image in a webpage. The primary advantage of sprites is that they reduce the number of requests required to display a webpage. Requesting a single large image is faster than requesting multiple small images. In general, the more resources – images, JavaScript files, CSS files – that must be moved across the wire, the slower your website. However, most people avoid using sprites because they require a lot of work. You need to combine all of the images and write just the right CSS rules to display the sub-images. The Microsoft Sprite and Image Optimization Framework enables you to avoid all of this work. The framework combines the images for you automatically. Furthermore, the framework includes an ASP.NET Web Forms control and an ASP.NET MVC helper that makes it easy to display the sub-images. You can download the Sprite and Image Optimization Framework from CodePlex at http://aspnet.codeplex.com/releases/view/50869. The Sprite and Image Optimization Framework was written by Morgan McClean who worked in the office next to mine at Microsoft. Morgan was a scary smart Intern from Canada and we discussed the Framework while he was building it (I was really excited to learn that he was working on it). Morgan added some great advanced features to this framework. For example, the Sprite and Image Optimization Framework supports something called image inlining. When you use image inlining, the actual image is stored in the CSS file. Here’s an example of what image inlining looks like: .Home_StephenWalther_small-jpg { width:75px; height:100px; background: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAEsAAABkCAIAAABB1lpeAAAAB GdBTUEAALGOfPtRkwAAACBjSFJNAACHDwAAjA8AAP1SAACBQAAAfXkAAOmLAAA85QAAGcxzPIV3AAAKL s+zNfREAAAAASUVORK5CYII=) no-repeat 0% 0%; } The actual image (in this case a picture of me that is displayed on the home page of the Superexpert.com website) is stored in the CSS file. If you visit the Superexpert.com website then very few separate images are downloaded. For example, all of the images with a red border in the screenshot below take advantage of CSS sprites: Unfortunately, there are some significant Gotchas that you need to be aware of when using the Sprite and Image Optimization Framework. There are workarounds for these Gotchas. I plan to write about these Gotchas and workarounds in a future blog entry. 2. Microsoft Ajax Minifier Whenever possible you should combine, minify, compress, and cache with a far future header all of your JavaScript and CSS files. The Microsoft Ajax Minifier makes it easy to minify JavaScript and CSS files. Don’t confuse minification and compression. You need to do both. According to Souders, you can reduce the size of a JavaScript file by an additional 20% (on average) by minifying a JavaScript file after you compress the file. When you minify a JavaScript or CSS file, you use various tricks to reduce the size of the file before you compress the file. For example, you can minify a JavaScript file by replacing long JavaScript variables names with short variables names and removing unnecessary white space and comments. You can minify a CSS file by doing such things as replacing long color names such as #ffffff with shorter equivalents such as #fff. The Microsoft Ajax Minifier was created by Microsoft employee Ron Logan. Internally, this tool was being used by several large Microsoft websites. We also used the tool heavily on the ASP.NET team. I convinced Ron to publish the tool on CodePlex so that everyone in the world could take advantage of it. You can download the tool from the ASP.NET Ajax website and read documentation for the tool here. I created the installer for the Microsoft Ajax Minifier. When creating the installer, I also created a Visual Studio build task to make it easy to minify all of your JavaScript and CSS files whenever you do a build within Visual Studio automatically. Read the Ajax Minifier Quick Start to learn how to configure the build task. 3. ySlow The ySlow tool is a free add-on for Firefox created by Yahoo that enables you to test the front-end of your website. For example, here are the current test results for the Superexpert.com website: The Superexpert.com website has an overall score of B (not perfect but not bad). The ySlow tool is not perfect. For example, the Superexpert.com website received a failing grade of F for not using a Content Delivery Network even though the website using the Microsoft Ajax Content Delivery Network for JavaScript files such as jQuery. Uptime After publishing a website live to the world, you want to ensure that the website does not encounter any issues and that it stays live. I use the following tools to monitor the Superexpert.com website now that it is live. 4. ELMAH ELMAH stands for Error Logging Modules and Handlers for ASP.NET. ELMAH enables you to record any errors that happen at your website so you can review them in the future. You can download ELMAH for free from the ELMAH project website. ELMAH works great with both ASP.NET Web Forms and ASP.NET MVC. You can configure ELMAH to store errors in a number of different stores including XML files, the Event Log, an Access database, a SQL database, an Oracle database, or in computer RAM. You also can configure ELMAH to email error messages to you when they happen. By default, you can access ELMAH by requesting the elmah.axd page from a website with ELMAH installed. Here’s what the elmah page looks like from the Superexpert.com website (this page is password-protected because secret information can be revealed in an error message): If you click on a particular error message, you can view the original Yellow Screen ASP.NET error message (even when the error message was never displayed to the actual user). I installed ELMAH by taking advantage of the new package manager for ASP.NET named NuGet (originally named NuPack). You can read the details about NuGet in the following blog entry by Scott Guthrie. You can download NuGet from CodePlex. 5. Pingdom I use Pingdom to verify that the Superexpert.com website is always up. You can sign up for Pingdom by visiting Pingdom.com. You can use Pingdom to monitor a single website for free. At the Pingdom website, you configure the frequency that your website gets pinged. I verify that the Superexpert.com website is up every 5 minutes. I have the Pingdom service verify that it can retrieve the string “Contact Us” from the website homepage. If your website goes down, you can configure Pingdom so that it sends an email, Twitter, SMS, or iPhone alert. I use the Pingdom iPhone app which looks like this: 6. Host Tracker If your website does go down then you need some way of determining whether it is a problem with your local network or if your website is down for everyone. I use a website named Host-Tracker.com to check how badly a website is down. Here’s what the Host-Tracker website displays for the Superexpert.com website when the website can be successfully pinged from everywhere in the world: Notice that Host-Tracker pinged the Superexpert.com website from 68 locations including Roubaix, France and Scranton, PA. Debugging I mean debugging in the broadest possible sense. I use the following tools when building a website to verify that I have not made a mistake. 7. HTML Spell Checker Why doesn’t Visual Studio have a built-in spell checker? Don’t know – I’ve always found this mysterious. Fortunately, however, a former member of the ASP.NET team wrote a free spell checker that you can use with your ASP.NET pages. I find a spell checker indispensible. It is easy to delude yourself that you are capable of perfect spelling. I’m always super embarrassed when I actually run the spell checking tool and discover all of my spelling mistakes. The fastest way to add the HTML Spell Checker extension to Visual Studio is to select the menu option Tools, Extension Manager within Visual Studio. Click on Online Gallery and search for HTML Spell Checker: 8. IIS SEO Toolkit If people cannot find your website through Google then you should not even bother to create it. Microsoft has a great extension for IIS named the IIS Search Engine Optimization Toolkit that you can use to identify issue with your website that would hurt its page rank. You also can use this tool to quickly create a sitemap for your website that you can submit to Google or Bing. You can even generate the sitemap for an ASP.NET MVC website. Here’s what the report overview for the Superexpert.com website looks like: Notice that the Sueprexpert.com website had plenty of violations. For example, there are 65 cases in which a page has a broken hyperlink. You can drill into these violations to identity the exact page and location where these violations occur. 9. LinqPad If your ASP.NET website accesses a database then you should be using LINQ to Entities with the Entity Framework. Using LINQ involves some magic. LINQ queries written in C# get converted into SQL queries for you. If you are not careful about how you write your LINQ queries, you could unintentionally build a really badly performing website. LinqPad is a free tool that enables you to experiment with your LINQ queries. It even works with Microsoft SQL CE 4 and Azure. You can use LinqPad to execute a LINQ to Entities query and see the results. You also can use it to see the resulting SQL that gets executed against the database: 10. .NET Reflector I use .NET Reflector daily. The .NET Reflector tool enables you to take any assembly and disassemble the assembly into C# or VB.NET code. You can use .NET Reflector to see the “Source Code” of an assembly even when you do not have the actual source code. You can download a free version of .NET Reflector from the Redgate website. I use .NET Reflector primarily to help me understand what code is doing internally. For example, I used .NET Reflector with the Sprite and Image Optimization Framework to better understand how the MVC Image helper works. Here’s part of the disassembled code from the Image helper class: Summary In this blog entry, I’ve discussed several of the tools that I used to create the Superexpert.com website. These are tools that I use to improve the performance, improve the SEO, verify the uptime, or debug the Superexpert.com website. All of the tools discussed in this blog entry are free. Furthermore, all of these tools work with both ASP.NET Web Forms and ASP.NET MVC. Let me know if there are any tools that you use daily when building ASP.NET websites.

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• SQL SERVER – Guest Post – Jonathan Kehayias – Wait Type – Day 16 of 28

  - by pinaldave

  Jonathan Kehayias (Blog | Twitter) is a MCITP Database Administrator and Developer, who got started in SQL Server in 2004 as a database developer and report writer in the natural gas industry. After spending two and a half years working in TSQL, in late 2006, he transitioned to the role of SQL Database Administrator. His primary passion is performance tuning, where he frequently rewrites queries for better performance and performs in depth analysis of index implementation and usage. Jonathan blogs regularly on SQLBlog, and was a coauthor of Professional SQL Server 2008 Internals and Troubleshooting. On a personal note, I think Jonathan is extremely positive person. In every conversation with him I have found that he is always eager to help and encourage. Every time he finds something needs to be approved, he has contacted me without hesitation and guided me to improve, change and learn. During all the time, he has not lost his focus to help larger community. I am honored that he has accepted to provide his views on complex subject of Wait Types and Queues. Currently I am reading his series on Extended Events. Here is the guest blog post by Jonathan: SQL Server troubleshooting is all about correlating related pieces of information together to indentify where exactly the root cause of a problem lies. In my daily work as a DBA, I generally get phone calls like, “So and so application is slow, what’s wrong with the SQL Server.” One of the funny things about the letters DBA is that they go so well with Default Blame Acceptor, and I really wish that I knew exactly who the first person was that pointed that out to me, because it really fits at times. A lot of times when I get this call, the problem isn’t related to SQL Server at all, but every now and then in my initial quick checks, something pops up that makes me start looking at things further. The SQL Server is slow, we see a number of tasks waiting on ASYNC_IO_COMPLETION, IO_COMPLETION, or PAGEIOLATCH_* waits in sys.dm_exec_requests and sys.dm_exec_waiting_tasks. These are also some of the highest wait types in sys.dm_os_wait_stats for the server, so it would appear that we have a disk I/O bottleneck on the machine. A quick check of sys.dm_io_virtual_file_stats() and tempdb shows a high write stall rate, while our user databases show high read stall rates on the data files. A quick check of some performance counters and Page Life Expectancy on the server is bouncing up and down in the 50-150 range, the Free Page counter consistently hits zero, and the Free List Stalls/sec counter keeps jumping over 10, but Buffer Cache Hit Ratio is 98-99%. Where exactly is the problem? In this case, which happens to be based on a real scenario I faced a few years back, the problem may not be a disk bottleneck at all; it may very well be a memory pressure issue on the server. A quick check of the system spec’s and it is a dual duo core server with 8GB RAM running SQL Server 2005 SP1 x64 on Windows Server 2003 R2 x64. Max Server memory is configured at 6GB and we think that this should be enough to handle the workload; or is it? This is a unique scenario because there are a couple of things happening inside of this system, and they all relate to what the root cause of the performance problem is on the system. If we were to query sys.dm_exec_query_stats for the TOP 10 queries, by max_physical_reads, max_logical_reads, and max_worker_time, we may be able to find some queries that were using excessive I/O and possibly CPU against the system in their worst single execution. We can also CROSS APPLY to sys.dm_exec_sql_text() and see the statement text, and also CROSS APPLY sys.dm_exec_query_plan() to get the execution plan stored in cache. Ok, quick check, the plans are pretty big, I see some large index seeks, that estimate 2.8GB of data movement between operators, but everything looks like it is optimized the best it can be. Nothing really stands out in the code, and the indexing looks correct, and I should have enough memory to handle this in cache, so it must be a disk I/O problem right? Not exactly! If we were to look at how much memory the plan cache is taking by querying sys.dm_os_memory_clerks for the CACHESTORE_SQLCP and CACHESTORE_OBJCP clerks we might be surprised at what we find. In SQL Server 2005 RTM and SP1, the plan cache was allowed to take up to 75% of the memory under 8GB. I’ll give you a second to go back and read that again. Yes, you read it correctly, it says 75% of the memory under 8GB, but you don’t have to take my word for it, you can validate this by reading Changes in Caching Behavior between SQL Server 2000, SQL Server 2005 RTM and SQL Server 2005 SP2. In this scenario the application uses an entirely adhoc workload against SQL Server and this leads to plan cache bloat, and up to 4.5GB of our 6GB of memory for SQL can be consumed by the plan cache in SQL Server 2005 SP1. This in turn reduces the size of the buffer cache to just 1.5GB, causing our 2.8GB of data movement in this expensive plan to cause complete flushing of the buffer cache, not just once initially, but then another time during the queries execution, resulting in excessive physical I/O from disk. Keep in mind that this is not the only query executing at the time this occurs. Remember the output of sys.dm_io_virtual_file_stats() showed high read stalls on the data files for our user databases versus higher write stalls for tempdb? The memory pressure is also forcing heavier use of tempdb to handle sorting and hashing in the environment as well. The real clue here is the Memory counters for the instance; Page Life Expectancy, Free List Pages, and Free List Stalls/sec. The fact that Page Life Expectancy is fluctuating between 50 and 150 constantly is a sign that the buffer cache is experiencing constant churn of data, once every minute to two and a half minutes. If you add to the Page Life Expectancy counter, the consistent bottoming out of Free List Pages along with Free List Stalls/sec consistently spiking over 10, and you have the perfect memory pressure scenario. All of sudden it may not be that our disk subsystem is the problem, but is instead an innocent bystander and victim. Side Note: The Page Life Expectancy counter dropping briefly and then returning to normal operating values intermittently is not necessarily a sign that the server is under memory pressure. The Books Online and a number of other references will tell you that this counter should remain on average above 300 which is the time in seconds a page will remain in cache before being flushed or aged out. This number, which equates to just five minutes, is incredibly low for modern systems and most published documents pre-date the predominance of 64 bit computing and easy availability to larger amounts of memory in SQL Servers. As food for thought, consider that my personal laptop has more memory in it than most SQL Servers did at the time those numbers were posted. I would argue that today, a system churning the buffer cache every five minutes is in need of some serious tuning or a hardware upgrade. Back to our problem and its investigation: There are two things really wrong with this server; first the plan cache is excessively consuming memory and bloated in size and we need to look at that and second we need to evaluate upgrading the memory to accommodate the workload being performed. In the case of the server I was working on there were a lot of single use plans found in sys.dm_exec_cached_plans (where usecounts=1). Single use plans waste space in the plan cache, especially when they are adhoc plans for statements that had concatenated filter criteria that is not likely to reoccur with any frequency.  SQL Server 2005 doesn’t natively have a way to evict a single plan from cache like SQL Server 2008 does, but MVP Kalen Delaney, showed a hack to evict a single plan by creating a plan guide for the statement and then dropping that plan guide in her blog post Geek City: Clearing a Single Plan from Cache. We could put that hack in place in a job to automate cleaning out all the single use plans periodically, minimizing the size of the plan cache, but a better solution would be to fix the application so that it uses proper parameterized calls to the database. You didn’t write the app, and you can’t change its design? Ok, well you could try to force parameterization to occur by creating and keeping plan guides in place, or we can try forcing parameterization at the database level by using ALTER DATABASE <dbname> SET PARAMETERIZATION FORCED and that might help. If neither of these help, we could periodically dump the plan cache for that database, as discussed as being a problem in Kalen’s blog post referenced above; not an ideal scenario. The other option is to increase the memory on the server to 16GB or 32GB, if the hardware allows it, which will increase the size of the plan cache as well as the buffer cache. In SQL Server 2005 SP1, on a system with 16GB of memory, if we set max server memory to 14GB the plan cache could use at most 9GB  [(8GB*.75)+(6GB*.5)=(6+3)=9GB], leaving 5GB for the buffer cache.  If we went to 32GB of memory and set max server memory to 28GB, the plan cache could use at most 16GB [(8*.75)+(20*.5)=(6+10)=16GB], leaving 12GB for the buffer cache. Thankfully we have SQL Server 2005 Service Pack 2, 3, and 4 these days which include the changes in plan cache sizing discussed in the Changes to Caching Behavior between SQL Server 2000, SQL Server 2005 RTM and SQL Server 2005 SP2 blog post. In real life, when I was troubleshooting this problem, I spent a week trying to chase down the cause of the disk I/O bottleneck with our Server Admin and SAN Admin, and there wasn’t much that could be done immediately there, so I finally asked if we could increase the memory on the server to 16GB, which did fix the problem. It wasn’t until I had this same problem occur on another system that I actually figured out how to really troubleshoot this down to the root cause.  I couldn’t believe the size of the plan cache on the server with 16GB of memory when I actually learned about this and went back to look at it. SQL Server is constantly telling a story to anyone that will listen. As the DBA, you have to sit back and listen to all that it’s telling you and then evaluate the big picture and how all the data you can gather from SQL about performance relate to each other. One of the greatest tools out there is actually a free in the form of Diagnostic Scripts for SQL Server 2005 and 2008, created by MVP Glenn Alan Berry. Glenn’s scripts collect a majority of the information that SQL has to offer for rapid troubleshooting of problems, and he includes a lot of notes about what the outputs of each individual query might be telling you. When I read Pinal’s blog post SQL SERVER – ASYNC_IO_COMPLETION – Wait Type – Day 11 of 28, I noticed that he referenced Checking Memory Related Performance Counters in his post, but there was no real explanation about why checking memory counters is so important when looking at an I/O related wait type. I thought I’d chat with him briefly on Google Talk/Twitter DM and point this out, and offer a couple of other points I noted, so that he could add the information to his blog post if he found it useful.  Instead he asked that I write a guest blog for this. I am honored to be a guest blogger, and to be able to share this kind of information with the community. The information contained in this blog post is a glimpse at how I do troubleshooting almost every day of the week in my own environment. SQL Server provides us with a lot of information about how it is running, and where it may be having problems, it is up to us to play detective and find out how all that information comes together to tell us what’s really the problem. This blog post is written by Jonathan Kehayias (Blog | Twitter). Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: MVP, Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• Unable to delete a file using bash script

  - by user3719091

  I'm having problems removing a file in a bash script. I saw the other post with the same problem but none of those solutions solved my problem. The bash script is an OP5 surveillance check and it calls an Expect process that saves a temporary file to the local drive which the bash script reads from. Once it has read the file and checked its status I would like to remove the temporary file. I'm pretty new to scripting so my script may not be as optimal as it can be. Either way it does the job except removing the file once it's done. I will post the entire code below: #!/bin/bash #GET FLAGS while getopts H:c:w: option do case "${option}" in H) HOSTADDRESS=${OPTARG};; c) CRITICAL=${OPTARG};; w) WARNING=${OPTARG};; esac done ./expect.vpn.check.sh $HOSTADDRESS #VARIABLES VPNCount=$(grep -o '[0-9]\+' $HOSTADDRESS.op5.vpn.results) # Check if the temporary results file exists if [ -f $HOSTADDRESS.op5.vpn.results ] then # If the file exist, Print "File Found" message echo Temporary results file exist. Analyze results. else # If the file does NOT exist, print "File NOT Found" message and send message to OP5 echo Temporary results file does NOT exist. Unable to analyze. # Exit with status Critical (exit code 2) exit 2 fi if [[ "$VPNCount" > $CRITICAL ]] then # If the amount of tunnels exceeds the critical threshold, echo out a warning message and current threshold and send warning to OP5 echo "The amount of VPN tunnels exceeds the critical threshold - ($VPNCount)" # Exit with status Critical (exit code 2) exit 2 elif [[ "$VPNCount" > $WARNING ]] then # If the amount of tunnels exceeds the warning threshold, echo out a warning message and current threshold and send warning to OP5 echo "The amount of VPN tunnels exceeds the warning threshold - ($VPNCount)" # Exit with status Warning (exit code 1) exit 1 else # The amount of tunnels do not exceed the warning threshold. # Print an OK message echo OK - $VPNCount # Exit with status OK exit 0 fi #Clean up temporary files. rm -f $HOSTADDRESS.op5.vpn.results I have tried the following solutions: Create a separate variable called TempFile that specifies the file. And specify that in the rm command. I tried creating another if statement similar to the one I use to verify that file exist and then rm the filename. I tried adding the complete name of the file (no variables, just plain text of the file) I can: Remove the file using the full name in both a separate script and directly in the CLI. Is there something in my script that locks the file that prevents me from removing it? I'm not sure what to try next. Thanks in advance!

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• With Ubuntu Linux (10+), how do I connect to remote to my machine from Windows

  - by Berlin Brown

  I tried to to remote into my Ubuntu machine. I enabled the setting on Ubuntu and that side seems to work. But I get a connection time out when I use RealVNC on the Windows box. I believe it is a firewall issue. I disabled the firewall for that application on Windows but I don't know how to check if the firewall is enabled on the windows machine. I am on a local network with a router. Ideally, I would want to block that remote control port at the Internet level/router level but "enable" that port on the Windows box and the Ubuntu box. How do I check those settings.

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• Best available technology for layered disk cache in linux

  - by SpliFF

  I've just bought a 6-core Phenom with 16G of RAM. I use it primarily for compiling and video encoding (and occassional web/db). I'm finding all activities get disk-bound and I just can't keep all 6 cores fed. I'm buying an SSD raid to sit between the HDD and tmpfs. I want to setup a "layered" filesystem where reads are cached on tmpfs but writes safely go through to the SSD. I want files (or blocks) that haven't been read lately on the SSD to then be written back to a HDD using a compressed FS or block layer. So basically reads: - Check tmpfs - Check SSD - Check HD And writes: - Straight to SSD (for safety), then tmpfs (for speed) And periodically, or when space gets low: - Move least frequently accessed files down one layer. I've seen a few projects of interest. CacheFS, cachefsd, bcache seem pretty close but I'm having trouble determining which are practical. bcache seems a little risky (early adoption), cachefs seems tied to specific network filesystems. There are "union" projects unionfs and aufs that let you mount filesystems over each other (USB device over a DVD usually) but both are distributed as a patch and I get the impression this sort of "transparent" mounting was going to become a kernel feature rather than a FS. I know the kernel has a built-in disk cache but it doesn't seem to work well with compiling. I see a 20x speed improvement when I move my source files to tmpfs. I think it's because the standard buffers are dedicated to a specific process and compiling creates and destroys thousands of processes during a build (just guessing there). It looks like I really want those files precached. I've read tmpfs can use virtual memory. In that case is it practical to create a giant tmpfs with swap on the SSD? I don't need to boot off the resulting layered filesystem. I can load grub, kernel and initrd from elsewhere if needed. So that's the background. The question has several components I guess: Recommended FS and/or block layer for the SSD and compressed HDD. Recommended mkfs parameters (block size, options etc...) Recommended cache/mount technology to bind the layers transparently Required mount parameters Required kernel options / patches, etc..

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• Collaborate 2010: Spotlight on Oracle Content Management

  - by [email protected]

  Excitement is building for the Collaborate conference April 18th through the 22nd. Outside of the event being in Las Vegas, which for me often seems to add to the excitement, there will be a great lineup of Oracle Content Management focused sessions. In fact, there are currently over 30 content management sessions scheduled, and attendees will get to hear from customers, partners, as well as Oracle experts. Attendees should expect to hear a lot about Oracle Content Management 11g at Collaborate 2010. Roel Stalman and Andy MacMillan will kick off these discussions on Monday, April 19th as they present Oracle Content Management's product strategy and roadmap (10:45 - 11:45). Monday's lineup also includes sessions on Oracle Imaging and Process Management (I/PM) 11g and Oracle Forms Recognition (2:30 - 3:30), which were both released in January. For those customers using older versions of I/PM or Stellent IBPM, be sure not to miss the "migrating to I/PM 11g" session on Monday as well (1:15 - 2:15) as this should give you some insight into the migration process. Check out the entire list of Oracle Content Management sessions here. Another focus at Collaborate this year is to discuss the benefits of using Oracle Content Management with Oracle Applications - Oracle E-Business Suite, PeopleSoft, and Siebel - so be sure to check out these sessions too: Accelerating Accounts Payable Processes with Integrated Document Imaging(Monday, April 19th, 3:45 - 4:45)Supercharge Your Siebel Sales and Marketing with Integrated Document Management(Tuesday, April 20th, 2:00 - 3:00)Oracle Enterprise 2.0 for Oracle Applications: The Value of an Integrated E2.0 Platform(Tuesday, April 20th, 3:15 - 4:15)Comprehensive Human Resources Automation with Oracle Content Management(Wednesday, April 21st, 1:00 - 2:00) Collaborate is also the perfect opportunity to meet Oracle executives and product experts. Attendees can sign up for 1 on 1 meetings at the event, and there will be someone representing each Oracle Content Management product. These meetings are probably the best way to get your product questions answered in a face-to-face manner. It seems more and more to me that Oracle Content Management customers are viewing Collaborate as "the" conference to attend each year. I hope you have plans to attend and I will see you there.

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• How to Make Sure Your Company Doesn't Go Underwater If Your Programmers Win the Lottery

  - by Graviton

  I have a few programmers under me, they are all doing very great and very smart obviously. Thank you very much. But the problem is that each and every one of them is responsible for one core area, which no one else on the team have foggiest idea on what it is. This means that if anyone of them is taken out, my company as a business is dead because they aren't replaceable. I'm thinking about bringing in new programmers to cover them, just in case they are hit by a bus, or resign or whatever. But I afraid that The old programmers might actively resist the idea of knowledge transfer, fearing that a backup might reduce their value. I don't have a system to facilitate technology transfer between different developers, so even if I ask them to do it, I've no assurance that they will do it properly. My question is, How to put it to the old programmers in such they would agree What are systems that you use, in order to facilitate this kind of "backup"? I can understand that you can do code review, but is there a simple way to conduct this? I think we are not ready for a full blown, check-in by check-in code review.

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• Trace Your Browser’s Roots on the Browser Family Tree [Infographic]

  - by ETC

  The world of browsers is far more diverse than a glance at the big four browsers might lead you to believe. Check out the roots of your browser in the Browser Family Tree. You’re likely aware of mainstream browsers like Internet Explorer, Firefox, Chrome, and Opera, but do you know where they came from? That many of them share a common forefather? Not only that but what about lesser known browsers like Tamaya and OmniWeb? The browser family tree is a diverse thing. Hit up the link below to check out the full Browser Family Tree. Browser Family Tree [Wikipedia via Hotlinks] Latest Features How-To Geek ETC Macs Don’t Make You Creative! So Why Do Artists Really Love Apple? MacX DVD Ripper Pro is Free for How-To Geek Readers (Time Limited!) HTG Explains: What’s a Solid State Drive and What Do I Need to Know? How to Get Amazing Color from Photos in Photoshop, GIMP, and Paint.NET Learn To Adjust Contrast Like a Pro in Photoshop, GIMP, and Paint.NET Have You Ever Wondered How Your Operating System Got Its Name? Sync Blocker Stops iTunes from Automatically Syncing The Journey to the Mystical Forest [Wallpaper] Trace Your Browser’s Roots on the Browser Family Tree [Infographic] Save Files Directly from Your Browser to the Cloud in Chrome and Iron The Steve Jobs Chronicles – Charlie and the Apple Factory [Video] Google Chrome Updates; Faster, Cleaner Menus, Encrypted Password Syncing, and More

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