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• Oracle GoldenGate 12c - Leading Enterprise Replication

  - by Doug Reid

  Oracle GoldenGate 12c released  on October 17th and includes several new cutting edge features that firmly establishes GoldenGate's leader position in the data replication space.   In fact, this release more than doubles the performance of data delivery, supports Oracle's new multitenant database feature,  it's more secure, has more options for high availability, and has made great strides to simplify the configuration and deployment of the product.     Read through the press release if you haven't already and do not miss the quote from Cern's Eva Dafonte Perez, regarding Oracle GoldenGate 12c "….performs five times faster compared to previous GoldenGate versions and simplifies the management of a multi-tier environment" There are a variety of new and improved features in the Oracle GoldenGate 12c.  Here are the highlights: Optimized for Oracle Database 12c -  GoldenGate 12c is custom tailored to the unique capabilities of Oracle database 12c and out of the box GoldenGate 12c supports multitenant (pluggable database (PDB)) and non-consolidated deployments of Oracle Database 12c.   The naming convention used by database 12c is now in three parts (PDB-name, schema-name, and object name).  We have made changes to the GoldenGate capture process to support the new naming convention and streamlined the whole process so a single GoldenGate capture process is being used at the container level rather than at each individual PDB.  By having the capture process at the container level resource usage and the number of processes are reduced. To view a conceptual architecture diagram click here. Integrated Delivery for the Oracle Database - Leveraging a lightweight streaming API built exclusively for Oracle GoldenGate 12c, this process distributes load, auto tunes the degree of parallelism, scales better, and delivers blinding rates of changed data delivery to the Oracle database.  One of the goals for Oracle GoldenGate 12c was to reduce IT costs by simplifying the configuration and reduce the time to manage complex infrastructures.  In previous versions of Oracle GoldenGate, customers would split transaction loads by grouping tables into multiple different delivery processes (click here to view the previous method). Each delivery process executed independently and without any interaction or knowledge of other delivery processes.  This setup was complicated to configure and time consuming as the developer needed in-depth knowledge of the source and target schemas and the transaction profile. With GoldenGate 12c and Integrated Delivery we have made it easier to configure and faster to deploy.  To view a conceptual architecture diagram of integrated delivery click here Coordinated Delivery for Non-Oracle Databases - Coordinated Delivery orchestrates high-speed apply processes and simplifies the configuration of GoldenGate for non-Oracle targets. In Oracle GoldenGate 12c a single delivery process is used with multiple threads (click here) and key events, such as primary key updates, event markers, DDL, etc, are coordinated between the various threads to insure that the transactions are applied in the same sequence as they were captured, all while delivery improved performance.  Replication Between On-Premises and Cloud-Based systems. - The trend for business to utilize both on-premises and cloud-based systems is rising and businesses need to replicate data back and forth.   GoldenGate 12c can be configured in a variety of ways to provide real-time replication when unrestricted or restricted (limited ports or HTTP tunneling) networks are between on-premises and cloud-based systems.    Expanded Heterogeneity - It wouldn't be a GoldenGate release without new and improved platform support.   Release 1 includes support for MySQL 5.6 and Sybase 15.7.   Upcoming in the next release GoldenGate, support will be expanded for MS SQL Server, DB2, and Teradata. Tighter Security - Oracle GoldenGate 12c is integrated with the Oracle wallet to shield usernames and passwords using strong encryption and aliases.   Customers accustomed to using the Oracle Wallet with other Oracle products will instantly be familiar with how to use this great new feature Expanded Oracle Application and Technology Support -   GoldenGate can be used along with Oracle Coherence to enable real-time changed data feeds to the Coherence cache using Toplink and the Oracle GoldenGate JMS adapter.     Plus,  Oracle Advanced Customer Services (ACS) now offers a low downtime E-Business Suite platform and database migrations using GoldenGate as the enabling technology.  Keep tuned for more blogs on the new features and the upcoming launch webcast where we will go into these new features in more detail.   In the mean time make sure to read through our white paper "Oracle GoldenGate 12c Release 1 New Features Overview"

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• Phones, Nokia, Microsoft and More

  - by Bill Evjen

  The phone revolution that is under way at the moment is insanely interesting and continuously full of buzz about directions, failures, and promises. The movement started with Apple completely reinventing what a smart phone was all about and now we have the followers. Though – don’t dismiss the followers, they are usually the ones that come out with the leap frog products when most of the world is thinking about jumping on. Remember the often used analogy – the USA invented the TV – but it was Japan that took it to the next level and now all TVs are from somewhere else other than the USA. Really there are two camps for the phones – the Cool Kids and other kids that no one wants to hang out with anymore. When it comes to cool – for some reason, the phone is an important part of that factor. Everyone wants to show their phone and its configuration (apps installed, etc) to their friends as a sign of (1) “I have money” and (2) I have smarts/tastes/style/etc when it comes to my applications that are on my phone. For those that don’t know – the Cool Kids include: Apple – this is quite obvious as everything Apple produces is in the cool camp. Just having an Apple product on your person means you can dance. Google – this is one of the more interesting releases as they have created something called Android (which in it’s own right is a major brand in itself). Microsoft – you might be saying “Really, Microsoft is cool?”. I would argue that they are indeed cool as it is now associated with XBOX 360, Kinect, and Windows 7. Gone are the days of Bob and that silly paperclip. Well – that’s it. There is nobody else I would stick in that camp. The other kids that weren’t picked for that dodgeball team include: Nokia Motorola Palm Blackberry and many many more The sad part of all this is that no matter what this second camp does now, it won’t be able to get out of this bucket easily. They will always be associated as yesterday’s technology and that association will drive the sales of the phone purchasers of the world. For those in that group, the only possible way out is to get invited to the cool club by one of the cool club members in the hope that their coolness somehow rubs off. To me, this is the move that Nokia is making. They are at this point where they have realized that they don’t have the full scope of the required end to end solution to make this all work. They have the plants to build the phones and the reach of the retailers that sell what they have. What they are missing is the proper operating system for the new world of multi-touch form factor phones. Even the companies that come up with some sort of new operating system for this type of new device, they are still associated with the yesterday and lack the developer community behind them to be the real wave of adoption that this market needs. Think about that – this is a major different between Nokia/Blackberry when you compare it to the likes of Apple, Google, and Microsoft. These three powerhouses having a very large and strong development community that will eagerly take on new initiatives using the skillsets that they have already cultivated over the years of already working with the company. This then results in a plethora of applications that are then placed on an app store of some kind. The developer gets a cut and then Apple/Google/Microsoft then get their cut. It is definitely a win-win. None of the other phone companies and wannabies can provide the same results. What Microsoft was missing was the major phone manufactures coming on board to create and push forward with the phones that are required to start the wave. This is where Nokia can come in and help Microsoft. They have the ability to promote the Windows Phone operating system on a new wave of phones. This does mean that Nokia will sell phones, but they lose out on the application store that they might have been thinking about making some money on as well as controlling the end to end solution. What is interesting is in questioning to oneself if Microsoft will purchase Nokia. It really depends upon how they want to compete and with whom Microsoft views as the major competitor. For instance, they can purchase Nokia and have their own hardware company and distribution network for phones – thereby taking on a model that is quite similar to Apple. On the other hand, they could just leave it up to the phone hardware companies such as Nokia and others to build and promote phones in a model that is similar to Google. Both ways have pluses and minuses. If they own the phone manufacturer, they really can put some thought into the design and technical specifications of the phone that is really designed to exactly how they want it. Microsoft has shown that they have this ability – especially with the XBOX initiative they have done over the years. Think about how good and powerful they have moved forward with XBOX – and I am not talking about just copying what others are doing, but coming up with leapfrog products that are steps ahead of everyone else. Though, if they didn’t do it themselves, they could then leave it up to the phone manufacturers to drive each other to build better and better phones that run the Microsoft OS – competition drives better products. We have seen this with the Android line of phones that are out there on the market. I have read a lot about Nokia investors really upset about the new Microsoft relationship – but really, this is a great thing. I for one am a fan of this relationship (I am also a Nokia stock holder btw). This will mean better days for Nokia.

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• Odd performance with C# Asynchronous server socket

  - by The.Anti.9

  I'm working on a web server in C# and I have it running on Asynchronous socket calls. The weird thing is that for some reason, when you start loading pages, the 3rd request is where the browser won't connect. It just keeps saying "Connecting..." and doesn't ever stop. If I hit stop. and then refresh, it will load again, but if I try another time after that it does the thing where it doesn't load again. And it continues in that cycle. I'm not really sure what is making it do that. The code is kind of hacked together from a couple of examples and some old code I had. Any miscellaneous tips would be helpful as well. Heres my little Listener class that handles everything (pastied here. thought it might be easier to read this way) using System; using System.Collections.Generic; using System.Net; using System.Net.Sockets; using System.Text; using System.Threading; namespace irek.Server { public class Listener { private int port; private Socket server; private Byte[] data = new Byte[2048]; static ManualResetEvent allDone = new ManualResetEvent(false); public Listener(int _port) { port = _port; } public void Run() { server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); IPEndPoint iep = new IPEndPoint(IPAddress.Any, port); server.Bind(iep); Console.WriteLine("Server Initialized."); server.Listen(5); Console.WriteLine("Listening..."); while (true) { allDone.Reset(); server.BeginAccept(new AsyncCallback(AcceptCon), server); allDone.WaitOne(); } } private void AcceptCon(IAsyncResult iar) { allDone.Set(); Socket s = (Socket)iar.AsyncState; Socket s2 = s.EndAccept(iar); SocketStateObject state = new SocketStateObject(); state.workSocket = s2; s2.BeginReceive(state.buffer, 0, SocketStateObject.BUFFER_SIZE, 0, new AsyncCallback(Read), state); } private void Read(IAsyncResult iar) { try { SocketStateObject state = (SocketStateObject)iar.AsyncState; Socket s = state.workSocket; int read = s.EndReceive(iar); if (read > 0) { state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, read)); if (s.Available > 0) { s.BeginReceive(state.buffer, 0, SocketStateObject.BUFFER_SIZE, 0, new AsyncCallback(Read), state); return; } } if (state.sb.Length > 1) { string requestString = state.sb.ToString(); // HANDLE REQUEST HERE // Temporary response string resp = "<h1>It Works!</h1>"; string head = "HTTP/1.1 200 OK\r\nContent-Type: text/html;\r\nServer: irek\r\nContent-Length:"+resp.Length+"\r\n\r\n"; byte[] answer = Encoding.ASCII.GetBytes(head+resp); // end temp. state.workSocket.BeginSend(answer, 0, answer.Length, SocketFlags.None, new AsyncCallback(Send), state.workSocket); } } catch (Exception) { return; } } private void Send(IAsyncResult iar) { try { SocketStateObject state = (SocketStateObject)iar.AsyncState; int sent = state.workSocket.EndSend(iar); state.workSocket.Shutdown(SocketShutdown.Both); state.workSocket.Close(); } catch (Exception) { } return; } } } And my SocketStateObject: public class SocketStateObject { public Socket workSocket = null; public const int BUFFER_SIZE = 1024; public byte[] buffer = new byte[BUFFER_SIZE]; public StringBuilder sb = new StringBuilder(); }

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• Testing a Non-blocking Queue

  - by jsw

  I've ported the non-blocking queue psuedocode here to C#. The code below is meant as a near verbatim copy of the paper. What approach would you take to test the implementation? Note: I'm running in VS2010 so I don't have CHESS support yet. using System.Threading; #pragma warning disable 0420 namespace ConcurrentCollections { class QueueNodePointer<T> { internal QueueNode<T> ptr; internal QueueNodePointer() : this(null) { } internal QueueNodePointer(QueueNode<T> ptr) { this.ptr = ptr; } } class QueueNode<T> { internal T value; internal QueueNodePointer<T> next; internal QueueNode() : this(default(T)) { } internal QueueNode(T value) { this.value = value; this.next = new QueueNodePointer<T>(); } } public class ConcurrentQueue<T> { private volatile int count = 0; private QueueNodePointer<T> qhead = new QueueNodePointer<T>(); private QueueNodePointer<T> qtail = new QueueNodePointer<T>(); public ConcurrentQueue() { var node = new QueueNode<T>(); node.next.ptr = null; this.qhead.ptr = this.qtail.ptr = node; } public int Count { get { return this.count; } } public void Enqueue(T value) { var node = new QueueNode<T>(value); node.next.ptr = null; QueueNodePointer<T> tail; QueueNodePointer<T> next; while (true) { tail = this.qtail; next = tail.ptr.next; if (tail == this.qtail) { if (next.ptr == null) { var newtail = new QueueNodePointer<T>(node); if (Interlocked.CompareExchange(ref tail.ptr.next, newtail, next) == next) { Interlocked.Increment(ref this.count); break; } else { Interlocked.CompareExchange(ref this.qtail, new QueueNodePointer<T>(next.ptr), tail); } } } } Interlocked.CompareExchange(ref this.qtail, new QueueNodePointer<T>(node), tail); } public T Dequeue() { T value; while (true) { var head = this.qhead; var tail = this.qtail; var next = head.ptr.next; if (head == this.qhead) { if (head.ptr == tail.ptr) { if (next.ptr == null) { return default(T); } Interlocked.CompareExchange(ref this.qtail, new QueueNodePointer<T>(next.ptr), tail); } else { value = next.ptr.value; var newhead = new QueueNodePointer<T>(next.ptr); if (Interlocked.CompareExchange(ref this.qhead, newhead, head) == head) { Interlocked.Decrement(ref this.count); break; } } } } return value; } } } #pragma warning restore 0420

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• Memento with optional state?

  - by Korey Hinton

  EDIT: As pointed out by Steve Evers and pdr, I am not correctly implementing the Memento pattern, my design is actually State pattern. Menu Program I built a console-based menu program with multiple levels that selects a particular test to run. Each level more precisely describes the operation. At any level you can type back to go back one level (memento). Level 1: Server Type? [1] Server A [2] Server B Level 2: Server environment? [1] test [2] production Level 3: Test type? [1] load [2] unit Level 4: Data Collection? [1] Legal docs [2] Corporate docs Level 4.5 (optional): Load Test Type [2] Multi TIF [2] Single PDF Level 5: Command Type? [1] Move [2] Copy [3] Remove [4] Custom Level 6: Enter a keyword [setup, cleanup, run] Design States PROBLEM: Right now the STATES enum is the determining factor as to what state is BACK and what state is NEXT yet it knows nothing about what the current memento state is. Has anyone experienced a similar issue and found an effective way to handle mementos with optional state? static enum STATES { SERVER, ENVIRONMENT, TEST_TYPE, COLLECTION, COMMAND_TYPE, KEYWORD, FINISHED } Possible Solution (Not-flexible) In reference to my code below, every case statement in the Menu class could check the state of currentMemo and then set the STATE (enum) accordingly to pass to the Builder. However, this doesn't seem flexible very flexible to change and I'm struggling to see an effective way refactor the design. class Menu extends StateConscious { private State state; private Scanner reader; private ServerUtils utility; Menu() { state = new State(); reader = new Scanner(System.in); utility = new ServerUtils(); } // Recurring menu logic public void startPromptingLoop() { List<State> states = new ArrayList<>(); states.add(new State()); boolean redoInput = false; boolean userIsDone = false; while (true) { // get Memento from last loop Memento currentMemento = states.get(states.size() - 1) .saveMemento(); if (currentMemento == null) currentMemento = new Memento.Builder(0).build(); if (!redoInput) System.out.println(currentMemento.prompt); redoInput = false; // prepare Memento for next loop Memento nextMemento = null; STATES state = STATES.values()[states.size() - 1]; // get user input String selection = reader.nextLine(); switch (selection) { case "exit": reader.close(); return; // only escape case "quit": nextMemento = new Memento.Builder(first(), currentMemento, selection).build(); states.clear(); break; case "back": nextMemento = new Memento.Builder(previous(state), currentMemento, selection).build(); if (states.size() <= 1) { states.remove(0); } else { states.remove(states.size() - 1); states.remove(states.size() - 1); } break; case "1": nextMemento = new Memento.Builder(next(state), currentMemento, selection).build(); break; case "2": nextMemento = new Memento.Builder(next(state), currentMemento, selection).build(); break; case "3": nextMemento = new Memento.Builder(next(state), currentMemento, selection).build(); break; case "4": nextMemento = new Memento.Builder(next(state), currentMemento, selection).build(); break; default: if (state.equals(STATES.CATEGORY)) { String command = selection; System.out.println("Executing " + command + " command on: " + currentMemento.type + " " + currentMemento.environment); utility.executeCommand(currentMemento.nickname, command); userIsDone = true; states.clear(); nextMemento = new Memento.Builder(first(), currentMemento, selection).build(); } else if (state.equals(STATES.KEYWORD)) { nextMemento = new Memento.Builder(next(state), currentMemento, selection).build(); states.clear(); nextMemento = new Memento.Builder(first(), currentMemento, selection).build(); } else { redoInput = true; System.out.println("give it another try"); continue; } break; } if (userIsDone) { // start the recurring menu over from the beginning for (int i = 0; i < states.size(); i++) { if (i != 0) { states.remove(i); // remove all except first } } reader = new Scanner(System.in); this.state = new State(); userIsDone = false; } if (!redoInput) { this.state.restoreMemento(nextMemento); states.add(this.state); } } } }

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• A Visual Studio Release Grows in Brooklyn

  - by andrewbrust

  Yesterday, Microsoft held its flagship launch event for Office 2010 in Manhattan.  Today, the Redmond software company is holding a local launch event for Visual Studio (VS) 2010, in Brooklyn.  How come information workers get the 212 treatment and developers are relegated to 718? Well, here’s the thing: the Brooklyn Marriott is actually a great place for an event, but you need some intimate knowledge of New York City to know that.  NBC’s Studio 8H, where the Office launch was held yesterday (and from where SNL is broadcast) is a pretty small venue, but you’d need some inside knowledge to recognize that.  Likewise, while Office 2010 is a product whose value is apparent.  Appreciating VS 2010’s value takes a bit more savvy.  Setting aside its year-based designation, this release of VS, counting the old Visual Basic releases, is the 10th version of the product.  How can a developer audience get excited about an integrated development environment when it reaches double-digit version numbers?  Well, it can be tough.  Luckily, Microsoft sent Jay Schmelzer, a Group Program Manager from the Visual Studio team in Redmond, to come tell the Brooklyn audience why they should be excited. Turns out there’s a lot of reasons.  Support fro SharePoint development is a big one.  In previous versions of VS, that support has been anemic, at best.  Shortage of SharePoint developers is a huge issue in the industry, and this should help.  There’s also built in support for Windows Azure (Microsoft’s cloud platform) and, through a download, support for the forthcoming Windows Phone 7 platform.  ASP.NET MVC, a “close-to-the-metal” Web development option that does away with the Web Forms abstraction layer, has a first-class presence in VS.  So too does jQuery, the Open Source environment that makes JavaScript development a breeze.  The jQuery support is so good that Microsoft now contributes to that Open Source project and offers IntelliSense support for it in the code editor. Speaking of the VS code editor, it now supports multi-monitor setups, zoom-in, and block selection.  If you’re not a developer, this may sound confusing and minute.  I’ll just say that for people who are developers these are little things that really contribute to productivity, and that translates into lower development costs. The really cool demo, though, was around Visual Studio 2010’s new debugging features.  This stuff is hard to showcase, but I believe it’s truly breakthrough technology: imagine being able to step backwards in time to see what might have caused a bug.  Cool?  Now imagine being able to do that, even if you weren’t the tester and weren’t present while the testing was being done.  Then imagine being able to see a video screen capture of what the tester was doing with your app when the bug occurred.  VS 2010 allows all that.  This could be the demise of the IWOMM (“it works on my machine”) syndrome. After the keynote, I asked Schmelzer if any of Microsoft’s competitors have debugging tools that come close to VS 2010’s.  His answer was an earnest “we don’t think so.”  If that’s true, that’s a big deal, and a huge advantage for developer teams who adopt it.  It will make software development much cheaper and more efficient.  Kind of like holding a launch event at the Brooklyn Marriott instead of 30 Rock in Manhattan! VS 2010 (version 10) and Office 2010 (version 14) aren’t the only new product versions Microsoft is releasing right now.  There’s also SQL Server 2008 R2 (version 10.5), Exchange 2010 (version 8, I believe), SharePoint 2010 (version 4) and, of course, Windows 7.  With so many new versions at such levels of maturity, I think it’s fair to say Microsoft has reached middle-age.  How does a company stave off a potential mid-life crisis, especially when with young Turks like Google coming along and competing so fiercely?  Hard to say.  But if focusing on core value, including value that’s hard to play into a sexy demo, is part oft the answer, then Microsoft’s doing OK.  And if some new tricks, like Windows Phone 7, can gain some traction, that might round things out nicely. Are the legacy products old tricks, or are they revised classics?  I honestly don’t know, because it’s the market’s prerogative to pass that judgement.  I can say this though: based on today’s show, I think Microsoft’s been doing its homework.

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• Computer Networks UNISA - Chap 15 &ndash; Network Management

  - by MarkPearl

  After reading this section you should be able to Understand network management and the importance of documentation, baseline measurements, policies, and regulations to assess and maintain a network’s health. Manage a network’s performance using SNMP-based network management software, system and event logs, and traffic-shaping techniques Identify the reasons for and elements of an asset managements system Plan and follow regular hardware and software maintenance routines Fundamentals of Network Management Network management refers to the assessment, monitoring, and maintenance of all aspects of a network including checking for hardware faults, ensuring high QoS, maintaining records of network assets, etc. Scope of network management differs depending on the size and requirements of the network. All sub topics of network management share the goals of enhancing the efficiency and performance while preventing costly downtime or loss. Documentation The way documentation is stored may vary, but to adequately manage a network one should at least record the following… Physical topology (types of LAN and WAN topologies – ring, star, hybrid) Access method (does it use Ethernet 802.3, token ring, etc.) Protocols Devices (Switches, routers, etc) Operating Systems Applications Configurations (What version of operating system and config files for serve / client software) Baseline Measurements A baseline is a report of the network’s current state of operation. Baseline measurements might include the utilization rate for your network backbone, number of users logged on per day, etc. Baseline measurements allow you to compare future performance increases or decreases caused by network changes or events with past network performance. Obtaining baseline measurements is the only way to know for certain whether a pattern of usage has changed, or whether a network upgrade has made a difference. There are various tools available for measuring baseline performance on a network. Policies, Procedures, and Regulations Following rules helps limit chaos, confusion, and possibly downtime. The following policies and procedures and regulations make for sound network management. Media installations and management (includes designing physical layout of cable, etc.) Network addressing policies (includes choosing and applying a an addressing scheme) Resource sharing and naming conventions (includes rules for logon ID’s) Security related policies Troubleshooting procedures Backup and disaster recovery procedures In addition to internal policies, a network manager must consider external regulatory rules. Fault and Performance Management After documenting every aspect of your network and following policies and best practices, you are ready to asses you networks status on an on going basis. This process includes both performance management and fault management. Network Management Software To accomplish both fault and performance management, organizations often use enterprise-wide network management software. There various software packages that do this, each collect data from multiple networked devices at regular intervals, in a process called polling. Each managed device runs a network management agent. So as not to affect the performance of a device while collecting information, agents do not demand significant processing resources. The definition of a managed devices and their data are collected in a MIB (Management Information Base). Agents communicate information about managed devices via any of several application layer protocols. On modern networks most agents use SNMP which is part of the TCP/IP suite and typically runs over UDP on port 161. Because of the flexibility and sophisticated network management applications are a challenge to configure and fine-tune. One needs to be careful to only collect relevant information and not cause performance issues (i.e. pinging a device every 5 seconds can be a problem with thousands of devices). MRTG (Multi Router Traffic Grapher) is a simple command line utility that uses SNMP to poll devices and collects data in a log file. MRTG can be used with Windows, UNIX and Linux. System and Event Logs Virtually every condition recognized by an operating system can be recorded. This is typically done using event logs. In Windows there is a GUI event log viewer. Similar information is recorded in UNIX and Linux in a system log. Much of the information collected in event logs and syslog files does not point to a problem, even if it is marked with a warning so it is important to filter your logs appropriately to reduce the noise. Traffic Shaping When a network must handle high volumes of network traffic, users benefit from performance management technique called traffic shaping. Traffic shaping involves manipulating certain characteristics of packets, data streams, or connections to manage the type and amount of traffic traversing a network or interface at any moment. Its goals are to assure timely delivery of the most important traffic while offering the best possible performance for all users. Several types of traffic prioritization exist including prioritizing traffic according to any of the following characteristics… Protocol IP address User group DiffServr VLAN tag in a Data Link layer frame Service or application Caching In addition to traffic shaping, a network or host might use caching to improve performance. Caching is the local storage of frequently needed files that would otherwise be obtained from an external source. By keeping files close to the requester, caching allows the user to access those files quickly. The most common type of caching is Web caching, in which Web pages are stored locally. To an ISP, caching is much more than just convenience. It prevents a significant volume of WAN traffic, thus improving performance and saving money. Asset Management Another key component in managing networks is identifying and tracking its hardware. This is called asset management. The first step to asset management is to take an inventory of each node on the network. You will also want to keep records of every piece of software purchased by your organization. Asset management simplifies maintaining and upgrading the network chiefly because you know what the system includes. In addition, asset management provides network administrators with information about the costs and benefits of certain types of hardware or software. Change Management Networks are always in a stage of flux with various aspects including… Software changes and patches Client Upgrades Shared Application Upgrades NOS Upgrades Hardware and Physical Plant Changes Cabling Upgrades Backbone Upgrades For a detailed explanation on each of these read the textbook (Page 750 – 761)

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• SPARC T4-4 Delivers World Record Performance on Oracle OLAP Perf Version 2 Benchmark

  - by Brian

  Oracle's SPARC T4-4 server delivered world record performance with subsecond response time on the Oracle OLAP Perf Version 2 benchmark using Oracle Database 11g Release 2 running on Oracle Solaris 11. The SPARC T4-4 server achieved throughput of 430,000 cube-queries/hour with an average response time of 0.85 seconds and the median response time of 0.43 seconds. This was achieved by using only 60% of the available CPU resources leaving plenty of headroom for future growth. The SPARC T4-4 server operated on an Oracle OLAP cube with a 4 billion row fact table of sales data containing 4 dimensions. This represents as many as 90 quintillion aggregate rows (90 followed by 18 zeros). Performance Landscape Oracle OLAP Perf Version 2 Benchmark 4 Billion Fact Table Rows System Queries/hour Users* Response Time (sec) Average Median SPARC T4-4 430,000 7,300 0.85 0.43 * Users - the supported number of users with a given think time of 60 seconds Configuration Summary and Results Hardware Configuration: SPARC T4-4 server with 4 x SPARC T4 processors, 3.0 GHz 1 TB memory Data Storage 1 x Sun Fire X4275 (using COMSTAR) 2 x Sun Storage F5100 Flash Array (each with 80 FMODs) Redo Storage 1 x Sun Fire X4275 (using COMSTAR with 8 HDD) Software Configuration: Oracle Solaris 11 11/11 Oracle Database 11g Release 2 (11.2.0.3) with Oracle OLAP option Benchmark Description The Oracle OLAP Perf Version 2 benchmark is a workload designed to demonstrate and stress the Oracle OLAP product's core features of fast query, fast update, and rich calculations on a multi-dimensional model to support enhanced Data Warehousing. The bulk of the benchmark entails running a number of concurrent users, each issuing typical multidimensional queries against an Oracle OLAP cube consisting of a number of years of sales data with fully pre-computed aggregations. The cube has four dimensions: time, product, customer, and channel. Each query user issues approximately 150 different queries. One query chain may ask for total sales in a particular region (e.g South America) for a particular time period (e.g. Q4 of 2010) followed by additional queries which drill down into sales for individual countries (e.g. Chile, Peru, etc.) with further queries drilling down into individual stores, etc. Another query chain may ask for yearly comparisons of total sales for some product category (e.g. major household appliances) and then issue further queries drilling down into particular products (e.g. refrigerators, stoves. etc.), particular regions, particular customers, etc. Results from version 2 of the benchmark are not comparable with version 1. The primary difference is the type of queries along with the query mix. Key Points and Best Practices Since typical BI users are often likely to issue similar queries, with different constants in the where clauses, setting the init.ora prameter "cursor_sharing" to "force" will provide for additional query throughput and a larger number of potential users. Except for this setting, together with making full use of available memory, out of the box performance for the OLAP Perf workload should provide results similar to what is reported here. For a given number of query users with zero think time, the main measured metrics are the average query response time, the median query response time, and the query throughput. A derived metric is the maximum number of users the system can support achieving the measured response time assuming some non-zero think time. The calculation of the maximum number of users follows from the well-known response-time law N = (rt + tt) * tp where rt is the average response time, tt is the think time and tp is the measured throughput. Setting tt to 60 seconds, rt to 0.85 seconds and tp to 119.44 queries/sec (430,000 queries/hour), the above formula shows that the T4-4 server will support 7,300 concurrent users with a think time of 60 seconds and an average response time of 0.85 seconds. For more information see chapter 3 from the book "Quantitative System Performance" cited below. -- See Also Quantitative System Performance Computer System Analysis Using Queueing Network Models Edward D. Lazowska, John Zahorjan, G. Scott Graham, Kenneth C. Sevcik external local Oracle Database 11g – Oracle OLAP oracle.com OTN SPARC T4-4 Server oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 11/2/2012.

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• Variable mysteriously changing value

  - by Eitan

  I am making a simple tcp/ip chat program for practicing threads and tcp/ip. I was using asynchronous methods but had a problem with concurrency so I went to threads and blocking methods (not asynchronous). I have two private variables defined in the class, not static: string amessage = string.Empty; int MessageLength; and a Thread private Thread BeginRead; Ok so I call a function called Listen ONCE when the client starts: public virtual void Listen(int byteLength) { var state = new StateObject {Buffer = new byte[byteLength]}; BeginRead = new Thread(ReadThread); BeginRead.Start(state); } and finally the function to receive commands and process them, I'm going to shorten it because it is really long: private void ReadThread(object objectState) { var state = (StateObject)objectState; int byteLength = state.Buffer.Length; while (true) { var buffer = new byte[byteLength]; int len = MySocket.Receive(buffer); if (len <= 0) return; string content = Encoding.ASCII.GetString(buffer, 0, len); amessage += cleanMessage.Substring(0, MessageLength); if (OnRead != null) { var e = new CommandEventArgs(amessage); OnRead(this, e); } } } Now, as I understand it only one thread at a time will enter BeginRead, I call Receive, it blocks until I get data, and then I process it. The problem: the variable amessage will change it's value between statements that do not touch or alter the variable at all, for example at the bottom of the function at: if (OnRead != null) "amessage" will be equal to 'asdf' and at if (OnRead != null) "amessage" will be equal to qwert. As I understand it this is indicative of another thread changing the value/running asynchronously. I only spawn one thread to do the receiving and the Receive function is blocking, how could there be two threads in this function and if there is only one thread how does amessage's value change between statements that don't affect it's value. As a side note sorry for spamming the site with these questions but I'm just getting a hang of this threading story and it's making me want to sip cyanide. Thanks in advance. EDIT: Here is my code that calls the Listen Method in the client: public void ConnectClient(string ip,int port) { client.Connect(ip,port); client.Listen(5); } and in the server: private void Accept(IAsyncResult result) { var client = new AbstractClient(MySocket.EndAccept(result)); var e = new CommandEventArgs(client, null); Clients.Add(client); client.Listen(5); if (OnClientAdded != null) { var target = (Control) OnClientAdded.Target; if (target != null && target.InvokeRequired) target.Invoke(OnClientAdded, this, e); else OnClientAdded(this, e); } client.OnRead += OnRead; MySocket.BeginAccept(new AsyncCallback(Accept), null); } All this code is in a class called AbstractClient. The client inherits the Abstract client and when the server accepts a socket it create's it's own local AbstractClient, in this case both modules access the functions above however they are different instances and I couldn't imagine threads from different instances combining especially as no variable is static.

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• grid layout default on wordpress theme

  - by nathan philpott

  I'm having trouble with a multi-layout option on a wordpress theme sight http://sight.wpshower.com/ the traffic have the option of a grid or a list layout at the click of a button. at present the list layout is default. I am interested in making the grid layout default . this is some of the php, i tried simply swapping the word grid for list but although this does work to an extent , if done on the loop.php page it removes the a:hover functions on the post boxes in the grid format. also if done on the index.php it switches buttons on the main index page. any ideas?? loop.php <div id="loop" class="<?php if ($_COOKIE['mode'] == 'grid') echo 'grid'; else echo 'list'; ?> clear"> <?php while ( have_posts() ) : the_post(); ?> <div <?php post_class('post clear'); ?> id="post_<?php the_ID(); ?>"> <?php if ( has_post_thumbnail() ) :?> <a href="<?php the_permalink() ?>" class="thumb"><?php the_post_thumbnail('thumbnail', array( 'alt' => trim(strip_tags( $post->post_title )), 'title' => trim(strip_tags( $post->post_title )), )); ?></a> <?php endif; ?> <div class="post-category"><?php the_category(' / '); ?></div> <h2><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h2> <!-- <div class="post-meta">by <span class="post-author"><a href="<?php echo get_author_posts_url(get_the_author_meta('ID')); ?>" title="Posts by <?php the_author(); ?>"><?php the_author(); ?></a></span> on <span class="post-date"><?php the_time(__('M j, Y')) ?></span> <em>&bull; </em><?php comments_popup_link(__('No Comments'), __('1 Comment'), __('% Comments'), '', __('Comments Closed')); ?> <?php edit_post_link( __( 'Edit entry'), '<em>&bull; </em>'); ?> </div> --> <?php edit_post_link( __( 'Edit entry'), '<em>&bull; </em>'); ?> <div class="post-content"><?php if (function_exists('smart_excerpt')) smart_excerpt(get_the_excerpt(), 55); ?></div> </div> <?php endwhile; ?> </div> <?php endif; ?> index.php <?php get_header(); ?> <div class="content-title"> Projects <a href="javascript: void(0);" id="mode"<?php if ($_COOKIE['mode'] == 'grid') echo ' class="flip"'; ?>></a> </div> <?php query_posts(array( 'post__not_in' => $exl_posts, 'paged' => $paged, ) ); ?> <?php get_template_part('loop'); ?> <?php wp_reset_query(); ?> <?php get_template_part('pagination'); ?> <?php get_footer(); ?>

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• Why isn't my algorithm for find the biggest and smallest inputs working?

  - by Matt Ellen

  I have started a new job, and with it comes a new language: Ironpython. Thankfully a good language :D Before starting I got to grips with Python on the whole, but that was only a week's worth of learning. Now I'm writing actual code. I've been charged with writing an algorithm that finds the best input parameter to collect data with. The basic algorithm is (as I've been instructed): Set the input parameter to a good guess Start collecting data When data is available stop collecting find the highest point If the point before this (i.e. for the previous parameter value) was higher and the point before that was lower then we've found the max otherwise the input parameter is increased by the initial guess. goto 2 If the max is found then the min needs to be found. To do this the algorithm carries on increasing the input, but by 1/10 of the max, until the current point is greater than the previous point and the point before that is also greater. Once the min is found then the algorithm stops. Currently I have a simplified data generator outputting the sin of the input, so that I know that the min value should be PI and the max value should be PI/2 The main Python code looks like this (don't worry, this is just for my edification, I don't write real code like this): import sys sys.path.append(r"F:\Programming Source\C#\PythonHelp\PythonHelp\bin\Debug") import clr clr.AddReferenceToFile("PythonHelpClasses.dll") import PythonHelpClasses from PHCStruct import Helper from System import Math helper = Helper() def run(): b = PythonHelpClasses.Executor() a = PythonHelpClasses.HasAnEvent() b.Input = 0.0 helper.__init__() def AnEventHandler(e): b.Stop() h = helper h.lastLastVal, h.lastVal, h.currentVal = h.lastVal, h.currentVal, e.Number if h.lastLastVal < h.lastVal and h.currentVal < h.lastVal and h.NotPast90: h.NotPast90 = False h.bestInput = h.lastInput inputInc = 0.0 if h.NotPast90: inputInc = Math.PI/10.0 else: inputInc = h.bestInput/10.0 if h.lastLastVal > h.lastVal and h.currentVal > h.lastVal and h.NotPast180: h.NotPast180 = False if h.NotPast180: h.lastInput, b.Input = b.Input, b.Input + inputInc b.Start(a) else: print "Best input:", h.bestInput print "Last input:", h.lastInput b.Stop() a.AnEvent += AnEventHandler b.Start(a) PHCStruct.py: class Helper(): def __init__(self): self.currentVal = 0 self.lastVal = 0 self.lastLastVal = 0 self.NotPast90 = True self.NotPast180 = True self.bestInput = 0 self.lastInput = 0 PythonHelpClasses has two small classes I wrote in C# before I realised how to do it in Ironpython. Executor runs a delegate asynchronously while it's running member is true. The important code: public void Start(HasAnEvent hae) { running = true; RunDelegate r = new RunDelegate(hae.UpdateNumber); AsyncCallback ac = new AsyncCallback(UpdateDone); IAsyncResult ar = r.BeginInvoke(Input, ac, null); } public void Stop() { running = false; } public void UpdateDone(IAsyncResult ar) { RunDelegate r = (RunDelegate)((AsyncResult)ar).AsyncDelegate; r.EndInvoke(ar); if (running) { AsyncCallback ac = new AsyncCallback(UpdateDone); IAsyncResult ar2 = r.BeginInvoke(Input, ac, null); } } HasAnEvent has a function that generates the sin of its input and fires an event with that result as its argument. i.e.: public void UpdateNumber(double val) { AnEventArgs e = new AnEventArgs(Math.Sin(val)); System.Threading.Thread.Sleep(1000); if (null != AnEvent) { AnEvent(e); } } The sleep is in there just to slow things down a bit. The problem I am getting is that the algorithm is not coming up with the best input being PI/2 and the final input being PI, but I can't see why. Also the best and final inputs are different each time I run the programme. Can anyone see why? Also when the algorithm terminates the best and final inputs are printed to the screen multiple times, not just once. Can someone explain why?

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• C# Asynchronous Network IO and OutOfMemoryException

  - by The.Anti.9

  I'm working on a client/server application in C#, and I need to get Asynchronous sockets working so I can handle multiple connections at once. Technically it works the way it is now, but I get an OutOfMemoryException after about 3 minutes of running. MSDN says to use a WaitHandler to do WaitOne() after the socket.BeginAccept(), but it doesn't actually let me do that. When I try to do that in the code it says WaitHandler is an abstract class or interface, and I can't instantiate it. I thought maybe Id try a static reference, but it doesnt have teh WaitOne() method, just WaitAll() and WaitAny(). The main problem is that in the docs it doesn't give a full code snippet, so you can't actually see what their "wait handler" is coming from. its just a variable called allDone, which also has a Reset() method in the snippet, which a waithandler doesn't have. After digging around in their docs, I found some related thing about an AutoResetEvent in the Threading namespace. It has a WaitOne() and a Reset() method. So I tried that around the while(true) { ... socket.BeginAccept( ... ); ... }. Unfortunately this makes it only take one connection at a time. So I'm not really sure where to go. Here's my code: class ServerRunner { private Byte[] data = new Byte[2048]; private int size = 2048; private Socket server; static AutoResetEvent allDone = new AutoResetEvent(false); public ServerRunner() { server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); IPEndPoint iep = new IPEndPoint(IPAddress.Any, 33333); server.Bind(iep); Console.WriteLine("Server initialized.."); } public void Run() { server.Listen(100); Console.WriteLine("Listening..."); while (true) { //allDone.Reset(); server.BeginAccept(new AsyncCallback(AcceptCon), server); //allDone.WaitOne(); } } void AcceptCon(IAsyncResult iar) { Socket oldserver = (Socket)iar.AsyncState; Socket client = oldserver.EndAccept(iar); Console.WriteLine(client.RemoteEndPoint.ToString() + " connected"); byte[] message = Encoding.ASCII.GetBytes("Welcome"); client.BeginSend(message, 0, message.Length, SocketFlags.None, new AsyncCallback(SendData), client); } void SendData(IAsyncResult iar) { Socket client = (Socket)iar.AsyncState; int sent = client.EndSend(iar); client.BeginReceive(data, 0, size, SocketFlags.None, new AsyncCallback(ReceiveData), client); } void ReceiveData(IAsyncResult iar) { Socket client = (Socket)iar.AsyncState; int recv = client.EndReceive(iar); if (recv == 0) { client.Close(); server.BeginAccept(new AsyncCallback(AcceptCon), server); return; } string receivedData = Encoding.ASCII.GetString(data, 0, recv); //process received data here byte[] message2 = Encoding.ASCII.GetBytes("reply"); client.BeginSend(message2, 0, message2.Length, SocketFlags.None, new AsyncCallback(SendData), client); } }

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• .NET Programmatically invoke screenclick doesn't work?

  - by ropstah

  I'm trying to programmatically invoke an onclick event however the click is not received/handled. Am I missing something, or is security preventing the click to be executed? I have a forms application which is invisible. Basically I would like to say: DoDoubleClick(wait, x, y) This should raise two click (mousedown+mouseup) events on screen with the specified wait interval. However the click isn't received in a Flash application in Firefox (which is running at that moment). Here's my code: Form: Public Class Form1 Private WithEvents gmh As GlobalMouseHook Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load gmh = New GlobalMouseHook() Me.Visible = false gmh.DoDoubleClick(50, 800, 600) End Sub Private Sub Form1_FormClosed(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles MyBase.FormClosed gmh.Dispose() End Sub Private Sub gmh_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles gmh.MouseDown End Sub Private Sub gmh_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles gmh.MouseMove End Sub Private Sub gmh_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles gmh.MouseUp End Sub End Class GlobalMouseHook class: Friend Class GlobalMouseHook Implements IDisposable Private hhk As IntPtr = IntPtr.Zero Private disposedValue As Boolean = False Public Event MouseDown As MouseEventHandler Public Event MouseUp As MouseEventHandler Public Event MouseMove As MouseEventHandler Public Sub New() Hook() End Sub Private Sub Hook() Dim hInstance As IntPtr = LoadLibrary("User32") hhk = SetWindowsHookEx(WH_MOUSE_LL, AddressOf Me.HookProc, hInstance, 0) End Sub Private Sub Unhook() UnhookWindowsHookEx(hhk) End Sub Public Sub DoDoubleClick(ByVal wait As Integer, ByVal x As Integer, ByVal y As Integer) RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Left, 1, x, y, 0)) RaiseEvent MouseUp(Me, Nothing) System.Threading.Thread.Sleep(wait) RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Left, 1, x, y, 0)) RaiseEvent MouseUp(Me, Nothing) End Sub Private Function HookProc(ByVal nCode As Integer, ByVal wParam As UInteger, ByRef lParam As MSLLHOOKSTRUCT) As Integer If nCode >= 0 Then Select Case wParam Case WM_LBUTTONDOWN RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Left, 0, lParam.pt.x, lParam.pt.y, 0)) Case WM_RBUTTONDOWN RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Right, 0, lParam.pt.x, lParam.pt.y, 0)) Case WM_MBUTTONDOWN RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Middle, 0, lParam.pt.x, lParam.pt.y, 0)) Case WM_LBUTTONUP, WM_RBUTTONUP, WM_MBUTTONUP RaiseEvent MouseUp(Nothing, Nothing) Case WM_MOUSEMOVE RaiseEvent MouseMove(Nothing, Nothing) Case WM_MOUSEWHEEL, WM_MOUSEHWHEEL Case Else Console.WriteLine(wParam) End Select End If Return CallNextHookEx(hhk, nCode, wParam, lParam) End Function Private Structure API_POINT Public x As Integer Public y As Integer End Structure Private Structure MSLLHOOKSTRUCT Public pt As API_POINT Public mouseData As UInteger Public flags As UInteger Public time As UInteger Public dwExtraInfo As IntPtr End Structure Private Const WM_MOUSEWHEEL As UInteger = &H20A Private Const WM_MOUSEHWHEEL As UInteger = &H20E Private Const WM_MOUSEMOVE As UInteger = &H200 Private Const WM_LBUTTONDOWN As UInteger = &H201 Private Const WM_LBUTTONUP As UInteger = &H202 Private Const WM_MBUTTONDOWN As UInteger = &H207 Private Const WM_MBUTTONUP As UInteger = &H208 Private Const WM_RBUTTONDOWN As UInteger = &H204 Private Const WM_RBUTTONUP As UInteger = &H205 Private Const WH_MOUSE_LL As Integer = 14 Private Delegate Function LowLevelMouseHookProc(ByVal nCode As Integer, ByVal wParam As UInteger, ByRef lParam As MSLLHOOKSTRUCT) As Integer Private Declare Auto Function LoadLibrary Lib "kernel32" (ByVal lpFileName As String) As IntPtr Private Declare Auto Function SetWindowsHookEx Lib "user32.dll" (ByVal idHook As Integer, ByVal lpfn As LowLevelMouseHookProc, ByVal hInstance As IntPtr, ByVal dwThreadId As UInteger) As IntPtr Private Declare Function CallNextHookEx Lib "user32" (ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As UInteger, ByRef lParam As MSLLHOOKSTRUCT) As Integer Private Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hhk As IntPtr) As Boolean ' IDisposable Protected Overridable Sub Dispose(ByVal disposing As Boolean) If Not Me.disposedValue Then If disposing Then ' TODO: free other state (managed objects). End If Unhook() End If Me.disposedValue = True End Sub ' This code added by Visual Basic to correctly implement the disposablepattern. Public Sub Dispose() Implements IDisposable.Dispose ' Do not change this code. Put cleanup code in Dispose(ByValdisposing As Boolean) above. Dispose(True) GC.SuppressFinalize(Me) End Sub End Class

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• Unexpected advantage of Engineered Systems

  - by user12244672

  It's not surprising that Engineered Systems accelerate the debugging and resolution of customer issues. But what has surprised me is just how much faster issue resolution is with Engineered Systems such as SPARC SuperCluster. These are powerful, complex, systems used by customers wanting extreme database performance, app performance, and cost saving server consolidation. A SPARC SuperCluster consists or 2 or 4 powerful T4-4 compute nodes, 3 or 6 extreme performance Exadata Storage Cells, a ZFS Storage Appliance 7320 for general purpose storage, and ultra fast Infiniband switches.  Each with its own firmware. It runs Solaris 11, Solaris 10, 11gR2, LDoms virtualization, and Zones virtualization on the T4-4 compute nodes, a modified version of Solaris 11 in the ZFS Storage Appliance, a modified and highly tuned version of Oracle Linux running Exadata software on the Storage Cells, another Linux derivative in the Infiniband switches, etc. It has an Infiniband data network between the components, a 10Gb data network to the outside world, and a 1Gb management network. And customers can run whatever middleware and apps they want on it, clustered in whatever way they want. In one word, powerful.  In another, complex. The system is highly Engineered.  But it's designed to run general purpose applications. That is, the physical components, configuration, cabling, virtualization technologies, switches, firmware, Operating System versions, network protocols, tunables, etc. are all preset for optimum performance and robustness. That improves the customer experience as what the customer runs leverages our technical know-how and best practices and is what we've tested intensely within Oracle. It should also make debugging easier by fixing a large number of variables which would otherwise be in play if a customer or Systems Integrator had assembled such a complex system themselves from the constituent components.  For example, there's myriad network protocols which could be used with Infiniband.  Myriad ways the components could be interconnected, myriad tunable settings, etc. But what has really surprised me - and I've been working in this area for 15 years now - is just how much easier and faster Engineered Systems have made debugging and issue resolution. All those error opportunities for sub-optimal cabling, unusual network protocols, sub-optimal deployment of virtualization technologies, issues with 3rd party storage, issues with 3rd party multi-pathing products, etc., are simply taken out of the equation. All those error opportunities for making an issue unique to a particular set-up, the "why aren't we seeing this on any other system ?" type questions, the doubts, just go away when we or a customer discover an issue on an Engineered System. It enables a really honed response, getting to the root cause much, much faster than would otherwise be the case. Here's a couple of examples from the last month, one found in-house by my team, one found by a customer: Example 1: We found a node eviction issue running 11gR2 with Solaris 11 SRU 12 under extreme load on what we call our ExaLego test system (mimics an Exadata / SuperCluster 11gR2 Exadata Storage Cell set-up).  We quickly established that an enhancement in SRU12 enabled an 11gR2 process to query Infiniband's Subnet Manager, replacing a fallback mechanism it had used previously.  Under abnormally heavy load, the query could return results which were misinterpreted resulting in node eviction.  In several daily joint debugging sessions between the Solaris, Infiniband, and 11gR2 teams, the issue was fully root caused, evaluated, and a fix agreed upon.  That fix went back into all Solaris releases the following Monday.  From initial issue discovery to the fix being put back into all Solaris releases was just 10 days. Example 2: A customer reported sporadic performance degradation.  The reasons were unclear and the information sparse.  The SPARC SuperCluster Engineered Systems support teams which comprises both SPARC/Solaris and Database/Exadata experts worked to root cause the issue.  A number of contributing factors were discovered, including tunable parameters.  An intense collaborative investigation between the engineering teams identified the root cause to a CPU bound networking thread which was being starved of CPU cycles under extreme load.  Workarounds were identified.  Modifications have been put back into 11gR2 to alleviate the issue and a development project already underway within Solaris has been sped up to provide the final resolution on the Solaris side.  The fixed SPARC SuperCluster configuration greatly aided issue reproduction and dramatically sped up root cause analysis, allowing the correct workarounds and fixes to be identified, prioritized, and implemented.  The customer is now extremely happy with performance and robustness.  Since the configuration is common to other customers, the lessons learned are being proactively rolled out to other customers and incorporated into the installation procedures for future customers.  This effectively acts as a turbo-boost to performance and reliability for all SPARC SuperCluster customers.  If this had occurred in a "home grown" system of this complexity, I expect it would have taken at least 6 months to get to the bottom of the issue.  But because it was an Engineered System, known, understood, and qualified by both the Solaris and Database teams, we were able to collaborate closely to identify cause and effect and expedite a solution for the customer.  That is a key advantage of Engineered Systems which should not be underestimated.  Indeed, the initial issue mitigation on the Database side followed by final fix on the Solaris side, highlights the high degree of collaboration and excellent teamwork between the Oracle engineering teams.  It's a compelling advantage of the integrated Oracle Red Stack in general and Engineered Systems in particular.

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• surfaceDestroyed called out of turn

  - by Avasulthiris

  I'm currently developing on minimum sdk version 3 (Android 1.5 - cupcake) and I'm having a strange unexplained issue that I have not been able to solve on my own. It is now becoming a rather urgent issue as I've already missed 1 deadline... I'm writing a high-level library to make long term android development easier and quicker. The one specific module has to capture images for a application... I've gotten everything right so far over the last couple months, except this one little thing and I don't know what to do any more: When I use the Camera object and implement a SurfaceHolder.Callback, the methods surfaceCreated() and surfaceChanged() are called one after the other. Then when the activity finishes, surfaceDestroyed() is called. This is how it should be, but when I stick the exact same code in my library (plain Java library that references the Android API - not in an activity), surfaceDestroyed() is called directly after created and changed. As a result - the camera object is closed before I can use it and the application force closes. What a pain. I can't do anything! This method call is controlled by the device.. Why does the surface close for no reason? Even when I post it to run on the activity thread through my own invokeAndWait(Runnable) method, like I do for many other things. I have 5 different working examples of different ways and implementations of capturing images in android but I still get the same issue when I plug it into my library. I don't understand what the difference is. The code is pretty much the same - and I post all the related code to the UI thread so its not a thread handling issue or anything like that. I've rewritten it about 20 times in different ways - same issue every time.. The only other way to approach it that I know of is creating a new Camera and setting it to the VideoView. The android source (c++ native code) however provides no Camera constructor, only an open() method which automatically forwards the camera's state to 'prepared' but I can only set the camera to the VideoView from the 'initialized' state. Pretty silly, I know, but there is no way around it unless I modify the Android library source code haha. not an option! The API does not allow for this method - you are expected to use it like my first example. So essentially - i just need to understand exactly why surfaceDestroyed() is called out of turn and if there is anything I can do to avoid it closing? If i can just understand the exact logic behind it and how it works! The documentation isn't much help! Secondly, if someone knows of any alternative ways to do it, as my second example, but hopefully one which the API actually allows for? haha Thanks guys. I would post code, but its fairly complicated, a couple thousand lines for this specific class and it would probably take a couple days to explain with all the threading and event listeners and what not. I just need help with this 1 single thing. Please let me know if you have any questions.

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• Microsoft BUILD 2013 Day 1&ndash;Keynote

  - by Tim Murphy

  Originally posted on: http://geekswithblogs.net/tmurphy/archive/2013/06/27/microsoft-build-2013-day-1ndashkeynote.aspx This one is going to be a little long because the keynote was jam-packed so bare with me. The keynote for the first day of BUILD 2013 was kicked off by Steve Balmer.  He made it very clear that Microsoft’s focus is on accelerating its time to market with products and product updates.  His quote was that “Rapid release” is the new norm.  He continued by showing off several new Lumias that have been buzzing around the internet for a while and announce that Sprint will now be carrying the HTC 8XT and Samsung ATIV. Balmer is known for repeating words or phrase for affect.  This time it was “Rapid release, rapid release” and “Touch, touch, touch, touch, touch, …”.  This was fun, but even more fun was when he announce that all attendees would receive an Acer Iconia 8” tablet. SCORE! The next subject Balmer focused on is new apps.  The three new ones were Flipboard, Facebook and NFL Fantasy Football.  I liked the first two because these are ones that people coming from other platforms are missing.  The NFL app is great just because it targets a demographic that can be fanatical.  If these types of apps keep coming than the missing app argument goes away. While many Negative Nancy’s are describing Windows 8.1 as Windows 180 Steve Balmer chose to call it a “refined blend” as in a coffee that has been improved with a new mix.  This includes more multi-tasking options and leveraging Bing straight throughout the entire ecosystem. He ended this first section by explaining that this will also bring more Bing development opportunities to the community. Steve Balmer was followed by Julie Larson-Green who spent her time on stage selling us on Windows 8 all over again from my point of view.  Something that I would not have thought was needed until I had listened to some other attendees who had a number of concerns and complaints.  She showed a number of new gestures that will come with Windows 8.1, and while they were cool I was left wondering if they really improved the experience.  I guess only time will tell. I did like the fact that it the UI implementation to bring up “All Apps” now mirrors that of Windows Phone.  The consistency is a big step forward that I hope to see continue.  The cool factor went up from there as she swiped content from a desktop (mega-tablet) to the XBox One.  This seamless experience I believe is what is really needed for any future platform to be relevant. I was much more enthused by the presentation of Antoine Leblond who humbled us by letting us know that there are 5k new API.  How that can be or how anyone would ever use all of them is another question.  His announcement was that the Visual Studio 2013 preview would be available today along with the Windows 8.1 bits.  One of the features of VS2013 that he demonstrated is the power consumption profiler.  With battery life being a key factor with consumer consumption devices this is a welcome addition. He didn’t limit his presentation to VS2013 features though.  He showed how the Store has been redesigned to enable better search and discoverability of apps and how Win 8.1 can perform multiple screen scales depending on the resolution of the device automatically.  The last feature he demoed was the real time video streaming API which he made sure we understood by attaching a Surface to a little robot.  Oh, but there was one more thing.  Antoine and Julie announce that all attendees would also be getting Surface Pros.  BONUS! How much more could there be?  Gurdeep Singh Pall was about to pile on.  He introduced us to Bing as a platform (BaaP?).  He said if they (Microsoft) could do something with and API that is good 3rd party developers can do something that is dynamite and showed us some of the tools they had produced.  These included natural user interface improvements such as voice commands that looked to put Siri to shame.  Add to that 3D, OCR and translation capabilities and the future looks to be full of opportunities. Balmer then came out to show us one last thing.  Project Spark is a game design environment that will be available for Windows 8.1, XBox 360 and XBox One.  All I can say is that if my kids get their hands on this they are going to be able to learn some of what dad does in a much more enjoyable way. At the end of it all I was both exhausted and energized by what I saw.  What could they have possibly left for the day 2 keynote?  I hear it will feature Scott Hanselman.  If that is right we are in for a treat.  See you there. del.icio.us Tags: BUILD 2013,Windows 8.1,Winodws Phone,XAML,Keynote,Bing,Visual Studio 2013,Project Spark

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• #OOW 2012 @PARIS...talking Oracle and Clouds, and Optimized Datacenter

  - by Eric Bezille

  For those of you who want to get most out of Oracle technologies to evolve your IT to the Next Wave, I encourage you to register to the up coming Oracle Optimized Datacenter event that will take place in Paris on November 28th. You will get the opportunity to exchange with Oracle experts and customers having successfully evolve their IT by leveraging Oracle technologies. You will also get the latest news on some of the Oracle systems announcements made during OOW 2012. During this event we will make an update about Oracle and Clouds, from private to public and hybrid models. So in preparing this session, I thought it was a good start to make a status of Cloud Computing in France, and CIO requirements in particular. Starting in 2009 with the first Cloud Camp in Paris, the market has evolved, but the basics are still the same : think hybrid. From Traditional IT to Clouds One size doesn't fit all, and for big companies having already an IT in place, there will be parts eligible to external (public) cloud, and parts that would be required to stay inside the firewalls, so ability to integrate both side is key.  None the less, one of the major impact of Cloud Computing trend on IT, reported by Forrester, is the pressure it makes on CIO to evolve towards the same model that end-users are now used to in their day to day life, where self-service and flexibility are paramount. This is what is driving IT to transform itself toward "a Global Service Provider", or for some as "IT "is" the Business" (see : Gartner Identifies Four Futures for IT and CIO), and for both models toward a Private Cloud Service Provider. In this journey, there is still a big difference between most of existing external Cloud and a firm IT : the number of applications that a CIO has to manage. Most cloud providers today are overly specialized, but at the end of the day, there are really few business processes that rely on only one application. So CIOs has to combine everything together external and internal. And for the internal parts that they will have to make them evolve to a Private Cloud, the scope can be very large. This will often require CIOs to evolve from their traditional approach to more disruptive ones, the time has come to introduce new standards and processes, if they want to succeed. So let's have a look at the different Cloud models, what type of users they are addressing, what value they bring and most importantly what needs to be done by the  Cloud Provider, and what is left over to the user. IaaS, PaaS, SaaS : what's provided and what needs to be done First of all the Cloud Provider will have to provide all the infrastructure needed to deliver the service. And the more value IT will want to provide, the more IT will have to deliver and integrate : from disks to applications. As we can see in the above picture, providing pure IaaS, left a lot to cover for the end-user, that’s why the end-user targeted by this Cloud Service is IT people. If you want to bring more value to developers, you need to provide to them a development platform ready to use, which is what PaaS is standing for, by providing not only the processors power, storage and OS, but also the Database and Middleware platform. SaaS being the last mile of the Cloud, providing an application ready to use by business users, the remaining part for the end-users being configuring and specifying the application for their specific usage. In addition to that, there are common challenges encompassing all type of Cloud Services : Security : covering all aspect, not only of users management but also data flows and data privacy Charge back : measuring what is used and by whom Application management : providing capabilities not only to deploy, but also to upgrade, from OS for IaaS, Database, and Middleware for PaaS, to a full Business Application for SaaS. Scalability : ability to evolve ALL the components of the Cloud Provider stack as needed Availability : ability to cover “always on” requirements Efficiency : providing a infrastructure that leverage shared resources in an efficient way and still comply to SLA (performances, availability, scalability, and ability to evolve) Automation : providing the orchestration of ALL the components in all service life-cycle (deployment, growth & shrink (elasticity), upgrades,...) Management : providing monitoring, configuring and self-service up to the end-users Oracle Strategy and Clouds For CIOs to succeed in their Private Cloud implementation, means that they encompass all those aspects for each component life-cycle that they selected to build their Cloud. That’s where a multi-vendors layered approach comes short in terms of efficiency. That’s the reason why Oracle focus on taking care of all those aspects directly at Engineering level, to truly provide efficient Cloud Services solutions for IaaS, PaaS and SaaS. We are going as far as embedding software functions in hardware (storage, processor level,...) to ensure the best SLA with the highest efficiency. The beauty of it, as we rely on standards, is that the Oracle components that you are running today in-house, are exactly the same that we are using to build Clouds, bringing you flexibility, reversibility and fast path to adoption. With Oracle Engineered Systems (Exadata, Exalogic & SPARC SuperCluster, more specifically, when talking about Cloud), we are delivering all those components hardware and software already engineered together at Oracle factory, with a single pane of glace for the management of ALL the components through Oracle Enterprise Manager, and with high-availability, scalability and ability to evolve by design. To give you a feeling of what does that bring in terms just of implementation project timeline, for example with Oracle SPARC SuperCluster, we have a consistent track of record to have the system plug into existing Datacenter and ready in a week. This includes Oracle Database, OS, virtualization, Database Storage (Exadata Storage Cells in this case), Application Storage, and all network configuration. This strategy enable CIOs to very quickly build Cloud Services, taking out not only the complexity of integrating everything together but also taking out the automation and evolution complexity and cost. I invite you to discuss all those aspect in regards of your particular context face2face on November 28th.

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• Why do I get a segmentation fault while redirecting sys.stdout to Tkinter.Text widget in Python?

  - by Brent Nash

  I'm in the process of building a GUI-based application with Python/Tkinter that builds on top of the existing Python bdb module. In this application, I want to silence all stdout/stderr from the console and redirect it to my GUI. To accomplish this purpose, I've written a specialized Tkinter.Text object (code at the end of the post). The basic idea is that when something is written to sys.stdout, it shows up as a line in the "Text" with the color black. If something is written to sys.stderr, it shows up as a line in the "Text" with the color red. As soon as something is written, the Text always scrolls down to view the most recent line. I'm using Python 2.6.1 at the moment. On Mac OS X 10.5, this seems to work great. I have had zero problems with it. On RedHat Enterprise Linux 5, however, I pretty reliably get a segmentation fault during the run of a script. The segmentation fault doesn't always occur in the same place, but it pretty much always occurs. If I comment out the sys.stdout= and sys.stderr= lines from my code, the segmentation faults seem to go away. I'm sure there are other ways around this that I will probably have to resort to, but can anyone see anything I'm doing blatantly wrong here that could be causing these segmentation faults? It's driving me nuts. Thanks! PS - I realize redirecting sys.stderr to the GUI might not be a great idea, but I still get segmentation faults even when I only redirect sys.stdout and not sys.stderr. I also realize that I'm allowing the Text to grow indefinitely at the moment. class ConsoleText(tk.Text): '''A Tkinter Text widget that provides a scrolling display of console stderr and stdout.''' class IORedirector(object): '''A general class for redirecting I/O to this Text widget.''' def __init__(self,text_area): self.text_area = text_area class StdoutRedirector(IORedirector): '''A class for redirecting stdout to this Text widget.''' def write(self,str): self.text_area.write(str,False) class StderrRedirector(IORedirector): '''A class for redirecting stderr to this Text widget.''' def write(self,str): self.text_area.write(str,True) def __init__(self, master=None, cnf={}, **kw): '''See the __init__ for Tkinter.Text for most of this stuff.''' tk.Text.__init__(self, master, cnf, **kw) self.started = False self.write_lock = threading.Lock() self.tag_configure('STDOUT',background='white',foreground='black') self.tag_configure('STDERR',background='white',foreground='red') self.config(state=tk.DISABLED) def start(self): if self.started: return self.started = True self.original_stdout = sys.stdout self.original_stderr = sys.stderr stdout_redirector = ConsoleText.StdoutRedirector(self) stderr_redirector = ConsoleText.StderrRedirector(self) sys.stdout = stdout_redirector sys.stderr = stderr_redirector def stop(self): if not self.started: return self.started = False sys.stdout = self.original_stdout sys.stderr = self.original_stderr def write(self,val,is_stderr=False): #Fun Fact: The way Tkinter Text objects work is that if they're disabled, #you can't write into them AT ALL (via the GUI or programatically). Since we want them #disabled for the user, we have to set them to NORMAL (a.k.a. ENABLED), write to them, #then set their state back to DISABLED. self.write_lock.acquire() self.config(state=tk.NORMAL) self.insert('end',val,'STDERR' if is_stderr else 'STDOUT') self.see('end') self.config(state=tk.DISABLED) self.write_lock.release()

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• what's wrong with my producer-consumer queue design?

  - by toasteroven

  I'm starting with the C# code example here. I'm trying to adapt it for a couple reasons: 1) in my scenario, all tasks will be put in the queue up-front before consumers will start, and 2) I wanted to abstract the worker into a separate class instead of having raw Thread members within the WorkerQueue class. My queue doesn't seem to dispose of itself though, it just hangs, and when I break in Visual Studio it's stuck on the _th.Join() line for WorkerThread #1. Also, is there a better way to organize this? Something about exposing the WaitOne() and Join() methods seems wrong, but I couldn't think of an appropriate way to let the WorkerThread interact with the queue. Also, an aside - if I call q.Start(#) at the top of the using block, only some of the threads every kick in (e.g. threads 1, 2, and 8 process every task). Why is this? Is it a race condition of some sort, or am I doing something wrong? using System; using System.Collections.Generic; using System.Text; using System.Messaging; using System.Threading; using System.Linq; namespace QueueTest { class Program { static void Main(string[] args) { using (WorkQueue q = new WorkQueue()) { q.Finished += new Action(delegate { Console.WriteLine("All jobs finished"); }); Random r = new Random(); foreach (int i in Enumerable.Range(1, 10)) q.Enqueue(r.Next(100, 500)); Console.WriteLine("All jobs queued"); q.Start(8); } } } class WorkQueue : IDisposable { private Queue _jobs = new Queue(); private int _job_count; private EventWaitHandle _wh = new AutoResetEvent(false); private object _lock = new object(); private List _th; public event Action Finished; public WorkQueue() { } public void Start(int num_threads) { _job_count = _jobs.Count; _th = new List(num_threads); foreach (int i in Enumerable.Range(1, num_threads)) { _th.Add(new WorkerThread(i, this)); _th[_th.Count - 1].JobFinished += new Action(WorkQueue_JobFinished); } } void WorkQueue_JobFinished(int obj) { lock (_lock) { _job_count--; if (_job_count == 0 && Finished != null) Finished(); } } public void Enqueue(int job) { lock (_lock) _jobs.Enqueue(job); _wh.Set(); } public void Dispose() { Enqueue(Int32.MinValue); _th.ForEach(th = th.Join()); _wh.Close(); } public int GetNextJob() { lock (_lock) { if (_jobs.Count 0) return _jobs.Dequeue(); else return Int32.MinValue; } } public void WaitOne() { _wh.WaitOne(); } } class WorkerThread { private Thread _th; private WorkQueue _q; private int _i; public event Action JobFinished; public WorkerThread(int i, WorkQueue q) { _i = i; _q = q; _th = new Thread(DoWork); _th.Start(); } public void Join() { _th.Join(); } private void DoWork() { while (true) { int job = _q.GetNextJob(); if (job != Int32.MinValue) { Console.WriteLine("Thread {0} Got job {1}", _i, job); Thread.Sleep(job * 10); // in reality would to actual work here if (JobFinished != null) JobFinished(job); } else { Console.WriteLine("Thread {0} no job available", _i); _q.WaitOne(); } } } } }

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• HttpClient multithread performance

  - by pepper

  I have an application which downloads more than 4500 html pages from 62 target hosts using HttpClient (4.1.3 or 4.2-beta). It runs on Windows 7 64-bit. Processor - Core i7 2600K. Network bandwidth - 54 Mb/s. At this moment it uses such parameters: DefaultHttpClient and PoolingClientConnectionManager; Also it hasIdleConnectionMonitorThread from http://hc.apache.org/httpcomponents-client-ga/tutorial/html/connmgmt.html; Maximum total connections = 80; Default maximum connections per route = 5; For thread management it uses ForkJoinPool with the parallelism level = 5 (Do I understand correctly that it is a number of working threads?) In this case my network usage (in Windows task manager) does not rise above 2.5%. To download 4500 pages it takes 70 minutes. And in HttpClient logs I have such things: DEBUG ForkJoinPool-2-worker-1 [org.apache.http.impl.conn.PoolingClientConnectionManager]: Connection released: [id: 209][route: {}-http://stackoverflow.com][total kept alive: 6; route allocated: 1 of 5; total allocated: 10 of 80] Total allocated connections do not raise above 10-12, in spite of that I've set it up to 80 connections. If I'll try to rise parallelism level to 20 or 80, network usage remains the same but a lot connection time-outs will be generated. I've read tutorials on hc.apache.org (HttpClient Performance Optimization Guide and HttpClient Threading Guide) but they does not help. Task's code looks like this: public class ContentDownloader extends RecursiveAction { private final HttpClient httpClient; private final HttpContext context; private List<Entry> entries; public ContentDownloader(HttpClient httpClient, List<Entry> entries){ this.httpClient = httpClient; context = new BasicHttpContext(); this.entries = entries; } private void computeDirectly(Entry entry){ final HttpGet get = new HttpGet(entry.getLink()); try { HttpResponse response = httpClient.execute(get, context); int statusCode = response.getStatusLine().getStatusCode(); if ( (statusCode >= 400) && (statusCode <= 600) ) { logger.error("Couldn't get content from " + get.getURI().toString() + "\n" + response.toString()); } else { HttpEntity entity = response.getEntity(); if (entity != null) { String htmlContent = EntityUtils.toString(entity).trim(); entry.setHtml(htmlContent); EntityUtils.consumeQuietly(entity); } } } catch (Exception e) { } finally { get.releaseConnection(); } } @Override protected void compute() { if (entries.size() <= 1){ computeDirectly(entries.get(0)); return; } int split = entries.size() / 2; invokeAll(new ContentDownloader(httpClient, entries.subList(0, split)), new ContentDownloader(httpClient, entries.subList(split, entries.size()))); } } And the question is - what is the best practice to use multi threaded HttpClient, may be there is a some rules for setting up ConnectionManager and HttpClient? How can I use all of 80 connections and raise network usage? If necessary, I will provide more code.

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• Help with Silverlight Sockets and Message delivery

  - by pixel3cs

  There are 4 months since I stopped developing my Silverlight Multiplayer Chess game. The problem was a bug wich I couldn't reproduce. Sice I got some free time this week I managed to discover the problem and I am now able to reproduce the bug. It seems that if I send 10 messages from client, one after another, with no delay between them, just like in the below example // when I press Enter, the client will 10 messages with no delay between them private void textBox_KeyDown(object sender, KeyEventArgs e) { if (e.Key == Key.Enter && textBox.Text.Length > 0) { for (int i = 0; i < 10; i++) { MessageBuilder mb = new MessageBuilder(); mb.Writer.Write((byte)GameCommands.NewChatMessageInTable); mb.Writer.Write(string.Format("{0}{2}: {1}", ClientVars.PlayerNickname, textBox.Text, i)); SendChatMessageEvent(mb.GetMessage()); //System.Threading.Thread.Sleep(100); } textBox.Text = string.Empty; } } // the method used by client to send a message to server public void SendData(Message message) { if (socket.Connected) { SocketAsyncEventArgs myMsg = new SocketAsyncEventArgs(); myMsg.RemoteEndPoint = socket.RemoteEndPoint; byte[] buffer = message.Buffer; myMsg.SetBuffer(buffer, 0, buffer.Length); socket.SendAsync(myMsg); } else { string err = "Server does not respond. You are disconnected."; socket.Close(); uiContext.Post(this.uiClient.ProcessOnErrorData, err); } } // the method used by server to receive data from client private void OnDataReceived(IAsyncResult async) { ClientSocketPacket client = async.AsyncState as ClientSocketPacket; int count = 0; try { if (client.Socket.Connected) count = client.Socket.EndReceive(async); // THE PROBLEM IS HERE // IF SERVER WAS RECEIVE ALL MESSAGES SEPARATELY, ONE BY ONE, THE COUNT // WAS ALWAYS 15, BUT BECAUSE THE SERVER RECEIVE 3 MESSAGES IN 1, THE COUNT // IS SOMETIME 45 } catch { HandleException(client); } client.MessageStream.Write(client.Buffer, 0, count); Message message; while (client.MessageStream.Read(out message)) { message.Tag = client; ThreadPool.QueueUserWorkItem(new WaitCallback(this.processingThreadEvent.ServerGotData), message); totalReceivedBytes += message.Buffer.Length; } try { if (client.Socket.Connected) client.Socket.BeginReceive(client.Buffer, 0, client.Buffer.Length, 0, new AsyncCallback(OnDataReceived), client); } catch { HandleException(client); } } there are sent only 3 big messages, and every big message contain 3 or 4 small messages. This is not the behavior I want. If I put a 100 milliseconds delay between message delivery, everything is work fine, but in a real world scenario users can send messages to server even at 1 millisecond between them. Are there any settings to be done in order to make the client send only one message at a time, or Even if I receive 3 messages in 1, are they full messages all the time (I dont't want to receive 2.5 messages in one big message) ? because if they are, I can read them and treat this new situation

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• Why won't USB 3.0 external hard drive run at USB 3.0 speeds?

  - by jgottula

  I recently purchased a PCI Express x1 USB 3.0 controller card (containing the NEC USB 3.0 controller) with the intent of using a USB 3.0 external hard drive with my Linux box. I installed the card in an empty PCIe slot on my motherboard, connected the card to a power cable, strung a USB 3.0 cable between one of the new ports and my external HDD, and connected the HDD to a wall socket for power. Booting the system, the drive works 100% as intended, with the one exception of throughput: rather than using SuperSpeed 4.8 Gbps connectivity, it seems to be falling back to High Speed 480 Mbps USB 2.0-style throughput. Disk Utility shows it as a 480 Mbps device, and running a couple Disk Utility and dd benchmarks confirms that the drive fails to exceed ~40 MB/s (the approximate limit of USB 2.0), despite it being an SSD capable of far more than that. When I connect my USB 3.0 HDD, dmesg shows this: [ 3923.280018] usb 3-2: new high speed USB device using ehci_hcd and address 6 where I would expect to find this: [ 3923.280018] usb 3-2: new SuperSpeed USB device using xhci_hcd and address 6 My system was running on kernel 2.6.35-25-generic at the time. Then, I stumbled upon this forum thread by an individual who found that a bug, which was present in kernels prior to 2.6.37-rc5, could be the culprit for this type of problem. Consequently, I installed the 2.6.37-generic mainline Ubuntu kernel to determine if the problem would go away. It didn't, so I tried 2.6.38-rc3-generic, and even the 2.6.38 nightly from 2010.02.01, to no avail. In short, I'm trying to determine why, with USB 3.0 support in the kernel, my USB 3.0 drive fails to run at full SuperSpeed throughput. See the comments under this question for additional details. Output that might be relevant to the problem (when booting from 2.6.38-rc3): Relevant lines from dmesg: [ 19.589491] xhci_hcd 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17 [ 19.589512] xhci_hcd 0000:03:00.0: setting latency timer to 64 [ 19.589516] xhci_hcd 0000:03:00.0: xHCI Host Controller [ 19.589623] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 12 [ 19.650492] xhci_hcd 0000:03:00.0: irq 17, io mem 0xf8100000 [ 19.650556] xhci_hcd 0000:03:00.0: irq 47 for MSI/MSI-X [ 19.650560] xhci_hcd 0000:03:00.0: irq 48 for MSI/MSI-X [ 19.650563] xhci_hcd 0000:03:00.0: irq 49 for MSI/MSI-X [ 19.653946] xHCI xhci_add_endpoint called for root hub [ 19.653948] xHCI xhci_check_bandwidth called for root hub Relevant section of sudo lspci -v: 03:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03) (prog-if 30) Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at f8100000 (64-bit, non-prefetchable) [size=8K] Capabilities: [50] Power Management version 3 Capabilities: [70] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [90] MSI-X: Enable+ Count=8 Masked- Capabilities: [a0] Express Endpoint, MSI 00 Capabilities: [100] Advanced Error Reporting Capabilities: [140] Device Serial Number ff-ff-ff-ff-ff-ff-ff-ff Capabilities: [150] #18 Kernel driver in use: xhci_hcd Kernel modules: xhci-hcd Relevant section of sudo lsusb -v: Bus 012 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.00 bDeviceClass 9 Hub bDeviceSubClass 0 Unused bDeviceProtocol 3 bMaxPacketSize0 9 idVendor 0x1d6b Linux Foundation idProduct 0x0003 3.0 root hub bcdDevice 2.06 iManufacturer 3 Linux 2.6.38-020638rc3-generic xhci_hcd iProduct 2 xHCI Host Controller iSerial 1 0000:03:00.0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 25 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xe0 Self Powered Remote Wakeup MaxPower 0mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 9 Hub bInterfaceSubClass 0 Unused bInterfaceProtocol 0 Full speed (or root) hub iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0004 1x 4 bytes bInterval 12 Hub Descriptor: bLength 9 bDescriptorType 41 nNbrPorts 4 wHubCharacteristic 0x0009 Per-port power switching Per-port overcurrent protection TT think time 8 FS bits bPwrOn2PwrGood 10 * 2 milli seconds bHubContrCurrent 0 milli Ampere DeviceRemovable 0x00 PortPwrCtrlMask 0xff Hub Port Status: Port 1: 0000.0100 power Port 2: 0000.0100 power Port 3: 0000.0100 power Port 4: 0000.0100 power Device Status: 0x0003 Self Powered Remote Wakeup Enabled Full, non-verbose lsusb: Bus 012 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 011 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 010 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 009 Device 003: ID 04d9:0702 Holtek Semiconductor, Inc. Bus 009 Device 002: ID 046d:c068 Logitech, Inc. G500 Laser Mouse Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 006: ID 174c:5106 ASMedia Technology Inc. Bus 003 Device 004: ID 0bda:0151 Realtek Semiconductor Corp. Mass Storage Device (Multicard Reader) Bus 003 Device 002: ID 058f:6366 Alcor Micro Corp. Multi Flash Reader Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 006: ID 1687:0163 Kingmax Digital Inc. Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 046d:081b Logitech, Inc. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Full output: full dmesg full lspci full lsusb

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• jQuery pop up problems

  - by user327137

  Hi all, I am creating a site from a template i purchased from TM for a beauty salon! I want to create an online booking form with the validations of name number service type but i'm having trouble getting a link to open that will pop up also using jquery NOT html how do i fix this... what is the code i have to insert so that when you click "BOOK NOW" a jquery pop up appears in the centre of the page and it has a booking form on it.... i have googled and googled but it is all new to me as in a NOOB at jquery.... here is a live demo of the template (template link for demo http://osc4.template-help.com/wt_31562/index.html#) and here is the code for where i am trying to place a pop up jquery <dt class="dt3"><a href="#"></a><img src="images/shadow.png" alt="" class="shadow"></dt> <dd id="page3"> <div class="inner"> <div class="content"> <section class="col-1"> <h2>our services</h2> <p>Vintage Beauty</p> <p class="dark">We offer Free Consultation for Botox, Fillers, Medical Skin Peels, Cosmetic Surgery <br> & also specialise n body and skin care. </p> <img src="images/page2-img1.png" alt="" class="p2"> <a href="#" class="more">view more</a> </section> <section class="col-2"> <h2>services</h2> <ul class="list p2"> <li><a href="#">Fish Pedicures</a></li> <li><a href="#">Manicures</a></li> <li><a href="#">Pedicures</a></li> <li><a href="#">Waxing</a></li> <li><a href="#">Threading</a></li> <li><a href="#">Tanning</a></li> <li><a href="#">Body Massage</a></li> <li><a href="#">Nail/Eye Extensions</a></li> <li><a href="#">Eye Lash/Brow Tinting</a></li> <li><a href="#">Twinkle Toes</a></li> <li><a href="#">Teeth Whitening Kits</a></li> <li><a href="#">Hot Wax Specialists</a></li> </ul> **<a href="#" class="more">BOOK ONLINE NOW</a> </section>** </div> </div> </dd>

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• LINQ and ArcObjects

  - by Marko Apfel

  Motivation LINQ (language integrated query) is a component of the Microsoft. NET Framework since version 3.5. It allows a SQL-like query to various data sources such as SQL, XML etc. Like SQL also LINQ to SQL provides a declarative notation of problem solving – i.e. you don’t need describe in detail how a task could be solved, you describe what to be solved at all. This frees the developer from error-prone iterator constructs. Ideally, of course, would be to access features with this way. Then this construct is conceivable: var largeFeatures = from feature in features where (feature.GetValue("SHAPE_Area").ToDouble() > 3000) select feature; or its equivalent as a lambda expression: var largeFeatures = features.Where(feature => (feature.GetValue("SHAPE_Area").ToDouble() > 3000)); This requires an appropriate provider, which manages the corresponding iterator logic. This is easier than you might think at first sight - you have to deliver only the desired entities as IEnumerable<IFeature>. LINQ automatically establishes a state machine in the background, whose execution is delayed (deferred execution) - when you are really request entities (foreach, Count (), ToList (), ..) an instantiation processing takes place, although it was already created at a completely different place. Especially in multiple iteration through entities in the first debuggings you are rubbing your eyes when the execution pointer jumps magically back in the iterator logic. Realization A very concise logic for constructing IEnumerable<IFeature> can be achieved by running through a IFeatureCursor. You return each feature via yield. For an easier usage I have put the logic in an extension method Getfeatures() for IFeatureClass: public static IEnumerable<IFeature> GetFeatures(this IFeatureClass featureClass, IQueryFilter queryFilter, RecyclingPolicy policy) { IFeatureCursor featureCursor = featureClass.Search(queryFilter, RecyclingPolicy.Recycle == policy); IFeature feature; while (null != (feature = featureCursor.NextFeature())) { yield return feature; } //this is skipped in unit tests with cursor-mock if (Marshal.IsComObject(featureCursor)) { Marshal.ReleaseComObject(featureCursor); } } So you can now easily generate the IEnumerable<IFeature>: IEnumerable<IFeature> features = _featureClass.GetFeatures(RecyclingPolicy.DoNotRecycle); You have to be careful with the recycling cursor. After a delayed execution in the same context it is not a good idea to re-iterated on the features. In this case only the content of the last (recycled) features is provided and all the features are the same in the second set. Therefore, this expression would be critical: largeFeatures.ToList(). ForEach(feature => Debug.WriteLine(feature.OID)); because ToList() iterates once through the list and so the the cursor was once moved through the features. So the extension method ForEach() always delivers the same feature. In such situations, you must not use a recycling cursor. Repeated executions of ForEach() is not a problem, because for every time the state machine is re-instantiated and thus the cursor runs again - that's the magic already mentioned above. Perspective Now you can also go one step further and realize your own implementation for the interface IEnumerable<IFeature>. This requires that only the method and property to access the enumerator have to be programmed. In the enumerator himself in the Reset() method you organize the re-executing of the search. This could be archived with an appropriate delegate in the constructor: new FeatureEnumerator<IFeatureclass>(_featureClass, featureClass => featureClass.Search(_filter, isRecyclingCursor)); which is called in Reset(): public void Reset() { _featureCursor = _resetCursor(_t); } In this manner, enumerators for completely different scenarios could be implemented, which are used on the client side completely identical like described above. Thus cursors, selection sets, etc. merge into a single matter and the reusability of code is increasing immensely. On top of that in automated unit tests an IEnumerable could be mocked very easily - a major step towards better software quality. Conclusion Nevertheless, caution should be exercised with these constructs in performance-relevant queries. Because of managing a state machine in the background, a lot of overhead is created. The processing costs additional time - about 20 to 100 percent. In addition, working without a recycling cursor is fast a performance gap. However declarative LINQ code is much more elegant, flawless and easy to maintain than manually iterating, compare and establish a list of results. The code size is reduced according to experience an average of 75 to 90 percent! So I like to wait a few milliseconds longer. As so often it has to be balanced between maintainability and performance - which for me is gaining in priority maintainability. In times of multi-core processors, the processing time of most business processes is anyway not dominated by code execution but by waiting for user input. Demo source code The source code for this prototype with several unit tests, you can download here: https://github.com/esride-apf/Linq2ArcObjects. .

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• Thread locking issue with FileHelpers between calling engine.ReadNext() method and readign engine.Li

  - by Rad

  I use producer/consumer pattern with FileHelpers library to import data from one file (which can be huge) using multiple threads. Each thread is supposed to import a chunk of that file and I would like to use LineNumber property of the FileHelperAsyncEngine instance that is reading the file as primary key for imported rows. FileHelperAsyncEngine internally has an IEnumerator IEnumerable.GetEnumerator(); which is iterated over using engine.ReadNext() method. That internally sets LineNumber property (which seems is not thread safe). Consumers will have Producers assiciated with them that will supply DataTables to Consumers which will consume them via SqlBulkLoad class which will use IDataReader implementation which will iterate over a collection of DataTables which are internal to a Consumer instance. Each instance of will have one SqlBulkCopy instance associate with it. I have thread locking issue. Below is how I create multiple Producer threads. I start each thread afterwords. Produce method on a producer instance will be called determining which chunk of input file will be processed. It seems that engine.LineNumber is not thread safe and I doesn't import a proper LineNumber in the database. It seems that by the time engine.LineNumber is read some other thread called engine.ReadNext() and changed engine.LineNumber property. I don't want to lock the loop that is supposed to process a chunk of input file because I loose parallelism. How to reorganize the code to solve this threading issue? Thanks Rad for (int i = 0; i < numberOfProducerThreads; i++) DataConsumer consumer = dataConsumers[i]; //create a new producer DataProducer producer = new DataProducer(); //consumer has already being created consumer.Subscribe(producer); FileHelperAsyncEngine orderDetailEngine = new FileHelperAsyncEngine(recordType); orderDetailEngine.Options.RecordCondition.Condition = RecordCondition.ExcludeIfBegins; orderDetailEngine.Options.RecordCondition.Selector = STR_ORDR; int skipLines = i * numberOfBufferTablesToProcess * DataBuffer.MaxBufferRowCount; Thread newThread = new Thread(() => { producer.Produce(consumer, inputFilePath, lineNumberFieldName, dict, orderDetailEngine, skipLines, numberOfBufferTablesToProcess); consumer.SetEndOfData(producer); }); producerThreads.Add(newThread); thread.Start();} public void Produce(DataConsumer consumer, string inputFilePath, string lineNumberFieldName, Dictionary<string, object> dict, FileHelperAsyncEngine engine, int skipLines, int numberOfBufferTablesToProcess) { lock (this) { engine.Options.IgnoreFirstLines = skipLines; engine.BeginReadFile(inputFilePath); } int rowCount = 1; DataTable buffer = consumer.BufferDataTable; while (engine.ReadNext() != null) { lock (this) { dict[lineNumberFieldName] = engine.LineNumber; buffer.Rows.Add(ObjectFieldsDataRowMapper.MapObjectFieldsToDataRow(engine.LastRecord, dict, buffer)); if (rowCount % DataBuffer.MaxBufferRowCount == 0) { consumer.AddBufferDataTable(buffer); buffer = consumer.BufferDataTable; } if (rowCount % (numberOfBufferTablesToProcess * DataBuffer.MaxBufferRowCount) == 0) { break; } rowCount++; } } if (buffer.Rows.Count > 0) { consumer.AddBufferDataTable(buffer); } engine.Close(); }

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