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• Azure Mobile Services: lessons learned

  - by svdoever

  When I first started using Azure Mobile Services I thought of it as a nice way to: authenticate my users - login using Twitter, Google, Facebook, Windows Live create tables, and use the client code to create the columns in the table because that is not possible in the Azure Mobile Services UI run some Javascript code on the table crud actions (Insert, Update, Delete, Read) schedule a Javascript to run any 15 or more minutes I had no idea of the magic that was happening inside… where is the data stored? Is it a kind of big table, are relationships between tables possible? those Javascripts on the table crud actions, is that interpreted, what is that exactly? After working for some time with Azure Mobile Services I became a lot wiser: Those tables are just normal tables in an Azure SQL Server 2012 Creating the table columns through client code sucks, at least from my Javascript code, because the columns are deducted from the sent JSON data, and a datetime field is sent as string in JSON, so a string type column is created instead of a datetime column You can connect with SQL Management Studio to the Azure SQL Server, and although you can’t manage your columns through the SQL Management Studio UI, it is possible to just run SQL scripts to drop and create tables and indices When you create a table through SQL script, add the table with the same name in the Azure Mobile Services UI to hook it up and be able to access the table through the provided abstraction layer You can also go to the SQL Database through the Azure Mobile Services UI, and from there get in a web based SQL management studio where you can create columns and manage your data The table crud scripts and the scheduler scripts are full blown node.js scripts, introducing a lot of power with great performance The web based script editor is really powerful, I do most of my editing currently in the editor which has syntax highlighting and code completing. While editing the code JsHint is used for script validation. The documentation on Azure Mobile Services is… suboptimal. It is such a pity that there is no way to comment on it so the community could fill in the missing holes, like which node modules are already loaded, and which modules are available on Azure Mobile Services. Soon I was hacking away on Azure Mobile Services, creating my own database tables through script, and abusing the read script of an empty table named query to implement my own set of “services”. The latest updates to Azure Mobile Services described in the following posts added some great new features like creating web API’s, use shared code from your scripts, command line tools for managing Azure Mobile Services (upload and download scripts for example), support for node modules and git support: http://weblogs.asp.net/scottgu/archive/2013/06/14/windows-azure-major-updates-for-mobile-backend-development.aspx http://blogs.msdn.com/b/carlosfigueira/archive/2013/06/14/custom-apis-in-azure-mobile-services.aspx http://blogs.msdn.com/b/carlosfigueira/archive/2013/06/19/custom-api-in-azure-mobile-services-client-sdks.aspx In the mean time I rewrote all my “service-like” table scripts to API scripts, which works like a breeze. Bad thing with the current state of Azure Mobile Services is that the git support is not working if you are a co-administrator of your Azure subscription, and not and administrator (as in my case). Another bad thing is that Cross Origin Request Sharing (CORS) is not supported for the API yet, so no go yet from the browser client for API’s, which is my case. See http://social.msdn.microsoft.com/Forums/windowsazure/en-US/2b79c5ea-d187-4c2b-823a-3f3e0559829d/known-limitations-for-source-control-and-custom-api-features for more on these and other limitations. In his talk at Build 2013 Josh Twist showed that there is a work-around for accessing shared script code from the table scripts as well (another limitation mentioned in the post above). I could not find that code in the Votabl2 code example from the presentation at https://github.com/joshtwist/votabl2, but we can grab it from the presentation when it comes online on Channel9. By the way: you can always express your needs and ideas at http://mobileservices.uservoice.com, that’s the place they are listening to (I hope!).

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• Multitenant Design for SQL Azure: White Paper Available

  - by Herve Roggero

  Cloud computing is about scaling out all your application tiers, from web application to the database layer. In fact, the whole promise of Azure is to pay for just what you need. You need more IIS servers? No problemo... just spin another web server. You expect to double your storage needs for Azure Tables? No problemo; you are covered there too... just pay for your storage needs. But what about the database tier, SQL Azure? How do you add new databases easily, and transparently, so that your application simply uses more of SQL Azure if its needs to? Without changing a single line of code? And what if you need to scale back down? Welcome to the world of database scalability. There are many terms that describe database scalability, including data federation, multitenant designs, and even NoSQL depending on the technical solution you are implementing.  Because SQL Azure is a transactional database system, NoSQL is not really an option. However data federation and multitenant designs offer some very interesting scalability options that are worth considering. Data federation, a feature of SQL Azure that will be offered in the future, offers very interesting capabilities available natively on the SQL Azure platform. More to come in a few weeks... Multitenant designs on the other hand are design practices and technologies designed to help you reach flexible scalability options not available otherwise. The first incarnation of such a method was made available on CodePlex as an open source project (http://enzosqlshard.codeplex.com).  This project was an attempt to provide a sharding library for educational purposes.  All that sounds really cool... and really esoteric... almost a form of database "voodoo"... However after being on multiple Azure projects I am starting to see a real need. Customers want to be able to free themselves from the database tier, so that if they have 10 new customers tomorrow, all they need to do is add 2 more SQL Azure instances. It's that simple. How you achieve this, and suggested application design guidelines, are available in a white paper I just published.  The white paper offers two primary sections. The first section describes the business and technical problem at hand, and how to classify it according to specific design patterns. For example, I discuss compressed shards through schema separation. The second section offers a method for addressing the needs of a multitenant design using a new library, the big bother of the codeplex project mentioned previously (that I created earlier this year), complete with management interface and such. A Beta of this platform will be made available within weeks; as soon as the documentation will be ready.   I would like to ask you to drop me a quick email at [email protected] if you are going to download the white paper. It's not required, but it would help me get in touch with you for feedback.  You can download this white paper here:   http://www.bluesyntax.net/files/EnzoFramework.pdf . Thank you, and I am looking for feedback, thoughts and implementation opportunities.

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• Critical Threads Optimization

  - by Rafael Vanoni

  Background One of the more common issues we've been seeing in the field is the growing difficulty in optimizing performance of multi-threaded applications. A good portion of this difficulty is due to the increasing complexity of modern processors that present various degrees of sharing relationships between hardware components. Take any current CMT processor and you'll find any number of CPUs sharing execution pipelines, floating point units, caches, etc. Consequently, applying the traditional recipe of one software thread for each CPU will have varying degrees of success, according to the layout of the underlying hardware. On top of this increasing complexity we've also seen processors with features that aim at dynamically resourcing software threads according to their utilization. Intel's Turbo Boost allows processors to increase their operating frequency if there is enough thermal headroom available and the processor isn't fully utilized. More recently, the SPARC T4 processor introduced dynamic threading, allowing each core to dynamically allocate more resources to its active CPUs. Both cases are in essence recognizing that current processors will be running a wide mix of workloads, some will be designed for throughput, others for low latency. The hardware is providing mechanisms to dynamically resource threads according to their runtime behavior. We're very aware of these challenges in Solaris, and have been working to provide the best out of box performance while providing mechanisms to further optimize applications when necessary. The Critical Threads Optimzation was introduced in Solaris 10 8/11 and Solaris 11 as one such mechanism that allows customers to both address issues caused by contention over shared hardware resources and explicitly take advantage of features such as T4's dynamic threading. What it is The basic idea is to allow performance critical threads to execute with more exclusive access to hardware resources. For example, when deploying an application that implements a producer/consumer model, it'll likely be advantageous to give the producer more exclusive access to the hardware instead of having it competing for resources with all the consumers. In the case of a T4 based system, we may want to have a producer running by itself on a single core and create one consumer for each of the remaining CPUs. With the Critical Threads Optimization we're extending the semantics of scheduling priorities (which thread should run first) to include priority over shared resources (which thread should have more "space"). Now the scheduler will not only run higher priority threads first: it will also provide them with more exclusive access to hardware resources if they are available. How does it work ? Using the previous example in Solaris 11, all you'd have to do would be to place the producer in the Fixed Priority (FX) scheduling class at priority 60, or in the Real Time (RT) class at any priority and Solaris will try to give it more "hardware space". On both Solaris 10 8/11 and Solaris 11 this can be achieved through the existing priocntl(1,2) and priocntlset(2) interfaces. If your application already assigns these priorities to performance critical threads, there's no additional step you need to take. One important aspect of this optimization is that it requires some level of idleness in the system, either as a result of sizing the application before hand or through periods of transient idleness during runtime. If the system is fully committed, the scheduler will put all the available CPUs to work.Best practices If you're an application developer, we encourage you to look into assigning the right priorities for the different threads in your application. Solaris provides different scheduling classes (Time Share, Interactive, Fair Share, Fixed Priority and Real Time) that offer different policies and behaviors. It is not always simple to figure out which set of threads are critical to the performance of a workload, and it may not always be feasible to take advantage of this optimization, but we believe that this can be correctly (and safely) done during development. Overall, the out of box performance in Solaris should meet your workload's requirements. If you are looking into that extra bit of performance, then the Critical Threads Optimization may be what you're looking for.

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• Oracle Enterprise Manager Ops Center 12c Update 1 is available now

  - by Anand Akela

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Following the announcement of Oracle Enterprise Manager Ops Center 12c on April 4th, we are happy to announce the release of Oracle Enterprise Manager Ops Center 12c update 1. This is a bundled patch release for Oracle Enterprise Manager Ops Center.  Here are the key features of the Oracle Enterprise Manager Ops Center 12c update 1 : Oracle VM SPARC Server Pool HA Policy  Automatically Upgrade from Ops Center 11g update 3 and Ops Center 12c  Oracle Linux 5.8 and 6.x Support  Oracle VM SPARC IaaS (Virtual Datacenters) WANBoot Improvements with OBP Handling Enhancements SPARC SuperCluster Support Stability fixes This new release contains significant enhancements in the update provisioning, bare metal OS provisioning, shared storage management, cloud/virtual datacenter, and networking management sections of the product.  With this update, customers can achieve better handling of ASR faults, add networks and storage to virtual guests more easily, understand IPMP and VLAN configurations better, get a more robust LDAP integration, get  virtualization aware firmware patching, and observe improved product performance across the board.  Customers can now accelerate Oracle VM SPARC and T4 deployments into production . Oracle Enterprise Manager Ops Center 11g and Ops Center 12c customers will now notice the availability of new product update under the Administration tab within the  Browser User Interface (BUI) .  Upgrade process is explained in detail within the Ops Center Administration Guide under “Chapter 10: Upgrading”.  Please be sure to read over that chapter and the Release Notes before upgrading.  During the week of July 9th,  the full download of the product will be available from the Oracle Enterprise Manager Ops Center download website.  Based on the customer feedback, we have changed the updates to include the entire product. Customers no longer need to install Ops Center 12c and then upgrade to the update 1 release.  The can simply install Ops Center 12c update 1 directly.  Here are some of the resources that can help you learn more about the Oracle Enterprise Manager Ops Center and the new update 1. Oracle Enterprise Manager Ops Center OTN site Bi-Monthly Product Demos Oracle Enterprise Manager Ops Center Forum Oracle Enterprise Manager Ops Center MOS Community Watch the recording of Oracle Enterprise Manager 12c launch webcast by clicking the following banner. Stay Connected: Twitter |  Face book |  You Tube |  Linked in |  Newsletter

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• Wisdom Lies in Collaborative Power and Intelligence

  - by kellsey.ruppel

  By Alakh Verma, Director, Platform Technology Solutions   In my recent blog posts, I shared insights on Predictive Analytics (Will Predictive Analytics at 'Speed of Thoughts' Help Businesses?), Real Time Decisions (How critical are Real Time decisions in business today?) and their significance in our lives in general and in businesses today. In the current business paradigm shift- with evolutionary social business, it is paramount that businesses look for wisdom in collaborative power and intelligence and equip their employees with the tools to engage with one another. There is an old time saying that 5 sticks tied together are stronger and unable to break as opposed to an individual stick. We have recently witnessed the power of ordinary people uniting together and fought collaboratively using Facebook and Twitter to topple down dictators in Tunisia, Egypt and Libya—and are threatening absolute rule in Syria. And an India one man’s (Anna Hazare) campaign against corruption went viral, bringing thousands to the streets in support. As anyone who has worked in a sizeable organization knows, there is no guarantee that the organization as a whole will perform efficiently and achieve its goals, even if each employee is individually efficient and every team has a high level of productivity. To achieve enterprise productivity, it is necessary not only for individuals and groups to “do things right” by working productively but also for the enterprise as a whole to “do the right things” - form the right teams, make the right decisions, allocate resources correctly, and effectively coordinate activities across the entire organization. Most organizations fall short of the optimal level of enterprise productivity because of one or more of these reasons, all at a great cost to the business.  They are disconnected from themselves with various parts of the organization unintentionally working at cross-purposes with each other.  Information that exists is not getting shared or reused.  Human talent is not being applied where it is most needed.  The same problems are being solved repeatedly by multiple groups. Intelligent collaboration through automated business processes has the ability to alter the course of any important business activity, with a potentially dramatic impact on the financial performance of the business. Whether it is a simple email exchange, a physical or virtual meeting, a task force, or a large-scale project, the activity is inherently collaborative.  In fact, collaboration can be defined as the work that takes place among people when a business process is not pre-determining how the work should take place. Collaboration is many things: information sharing, brainstorming, problem solving, best practice negotiation, innovation, coordination of activity, alignment of purpose, and so forth.  Collaboration is the “white space” between the business processes; it is the glue that holds an organization together, and the lubricant that allows the machinery to keep running.  Real time search and collaborative capabilities of the right people with the right content supported by defined processes will provide unparallel wisdom in the organization in the most competitive business environment today. Interestingly, technologies such as Oracle WebCenter offer these capabilities in our Web based business transactions and compliment in the overall collaborative intelligence and power to truly transform organizations to social businesses. Looking to learn more about engaging your employees to collaborate together and providing a complete user experience for your customers? You won't want to miss our webcast today! Drive Online Engagement with Intuitive Portals and Websites

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• EPM troubleshooting Utilities

  - by THE

  (in via Maurice) "Are you keeping up-to-date with the latest troubleshooting utilities introduced from EPM 11.1.2.2? These are typically not described in product documentation, so you might miss references to them. The following five utilities may be run from the command line.(1) Deployment Report was introduced with EPM 11.1.2.2 (11 April 2012). It details logical web addresses, web servers, application ports, database connections, user directories, database repositories configured for the EPM system, data directories used by EPM system products, instance directories, FMW homes, deployment distory, et cetera. It also helps to keep you honest about whether you made changes to the system and at what times! Download Shared Services patch 13530721 to get the backported functionality in EPM 11.1.2.1. Run it from /Oracle/Middleware/user_projects/epmsystem1/bin/epmsys_registry.sh report deployment (on Unix/Linux)\Oracle\Middleware\user_projects\epmsystem1\bin\epmsys_registry.bat report deployment (on Microsoft Windows). The output is saved under \Oracle\Middleware\user_projects\epmsystem1\diagnostics\reports\deployment_report.html (2) Log Analysis has received more "press". It was released with EPM 11.1.2.3 and helps the user to slice and dice EPM logs. It has many parameters which are documented when run without parameters, when run with the -h parameter, or in the 'Readme' file. It has also been released as a standalone utility for EPM 11.1.2.3 and earlier versions. (Sign in to  My Oracle Support, click the 'Patches & Updates' tab, enter the patch number 17425397, and click the Search button. Download the appropriate platform-specific zip file, unzip, and read the 'Readme' file. Note that you must provide a proper value to a JAVA_HOME environment variable [pointer to the mother directory of the Java /bin subdirectory] in the loganalysis.bat | .sh file and use the -d parameter when running standalone.) Run it from /Oracle/Middleware/user_projects/epmsystem1/bin/loganalysis.sh -h (on Unix/Linux)\Oracle\Middleware\user_projects\epmsystem1\bin\loganalysis.bat -h (on Microsoft Windows). The output is saved under the \Oracle\Middleware\user_projects\epmsystem1\diagnostics\reports\ subdirectory. (3) The Registry Cleanup command may be used (without fear!) to clean up various corruptions which can  affect the Hyperion (database-based) Repository. Run it from /Oracle/Middleware/user_projects/epmsystem1/bin/registry-cleanup.sh (on Unix/Linux)\Oracle\Middleware\user_projects\epmsystem1\bin\registry-cleanup.bat (on Microsoft Windows). The actions are described on the command line. (4) The Remove Instance Command is only used if there are two or more instances configured on one computer and one of those should be deleted. Run it from /Oracle/Middleware/user_projects/epmsystem1/bin/remove-instance.sh (on Unix/Linux)\Oracle\Middleware\user_projects\epmsystem1\bin\remove-instance.bat (on Microsoft Windows). (5) The Reset Configuration Tool was introduced with EPM 11.1.2.2. It nullifies Shared Services Hyperion Registry settings so that a service may be reconfigured. You may locate the values to substitute for <product> or <task> by scanning registry.html (generated by running epmsys_registry.bat | .sh). Find productNAME in INSTANCE_TASKS_CONFIGURATION and SYSTEM_TASKS_CONFIGURATION nodes and identify tasks by property pairs that have values of 'Configurated' or 'Pending'. Run it from /Oracle/Middleware/user_projects/epmsystem1/bin/resetConfigTask.sh -product <product> -task <task> (on Unix/Linux)\Oracle\Middleware\user_projects\epmsystem1\bin\resetConfigTask.bat -product <product> -task <task> (on Microsoft Windows). "Thanks to Maurice for this collection of utilities.

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• SQL Server IO handling mechanism can be severely affected by high CPU usage

  - by sqlworkshops

  Are you using SSD or SAN / NAS based storage solution and sporadically observe SQL Server experiencing high IO wait times or from time to time your DAS / HDD becomes very slow according to SQL Server statistics? Read on… I need your help to up vote my connect item – https://connect.microsoft.com/SQLServer/feedback/details/744650/sql-server-io-handling-mechanism-can-be-severely-affected-by-high-cpu-usage. Instead of taking few seconds, queries could take minutes/hours to complete when CPU is busy.In SQL Server when a query / request needs to read data that is not in data cache or when the request has to write to disk, like transaction log records, the request / task will queue up the IO operation and wait for it to complete (task in suspended state, this wait time is the resource wait time). When the IO operation is complete, the task will be queued to run on the CPU. If the CPU is busy executing other tasks, this task will wait (task in runnable state) until other tasks in the queue either complete or get suspended due to waits or exhaust their quantum of 4ms (this is the signal wait time, which along with resource wait time will increase the overall wait time). When the CPU becomes free, the task will finally be run on the CPU (task in running state).The signal wait time can be up to 4ms per runnable task, this is by design. So if a CPU has 5 runnable tasks in the queue, then this query after the resource becomes available might wait up to a maximum of 5 X 4ms = 20ms in the runnable state (normally less as other tasks might not use the full quantum).In case the CPU usage is high, let’s say many CPU intensive queries are running on the instance, there is a possibility that the IO operations that are completed at the Hardware and Operating System level are not yet processed by SQL Server, keeping the task in the resource wait state for longer than necessary. In case of an SSD, the IO operation might even complete in less than a millisecond, but it might take SQL Server 100s of milliseconds, for instance, to process the completed IO operation. For example, let’s say you have a user inserting 500 rows in individual transactions. When the transaction log is on an SSD or battery backed up controller that has write cache enabled, all of these inserts will complete in 100 to 200ms. With a CPU intensive parallel query executing across all CPU cores, the same inserts might take minutes to complete. WRITELOG wait time will be very high in this case (both under sys.dm_io_virtual_file_stats and sys.dm_os_wait_stats). In addition you will notice a large number of WAITELOG waits since log records are written by LOG WRITER and hence very high signal_wait_time_ms leading to more query delays. However, Performance Monitor Counter, PhysicalDisk, Avg. Disk sec/Write will report very low latency times.Such delayed IO handling also occurs to read operations with artificially very high PAGEIOLATCH_SH wait time (with number of PAGEIOLATCH_SH waits remaining the same). This problem will manifest more and more as customers start using SSD based storage for SQL Server, since they drive the CPU usage to the limits with faster IOs. We have a few workarounds for specific scenarios, but we think Microsoft should resolve this issue at the product level. We have a connect item open – https://connect.microsoft.com/SQLServer/feedback/details/744650/sql-server-io-handling-mechanism-can-be-severely-affected-by-high-cpu-usage - (with example scripts) to reproduce this behavior, please up vote the item so the issue will be addressed by the SQL Server product team soon.Thanks for your help and best regards,Ramesh MeyyappanHome: www.sqlworkshops.comLinkedIn: http://at.linkedin.com/in/rmeyyappan

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• Organization &amp; Architecture UNISA Studies &ndash; Chap 6

  - by MarkPearl

  Learning Outcomes Discuss the physical characteristics of magnetic disks Describe how data is organized and accessed on a magnetic disk Discuss the parameters that play a role in the performance of magnetic disks Describe different optical memory devices Magnetic Disk The way data is stored on and retried from magnetic disks Data is recorded on and later retrieved form the disk via a conducting coil named the head (in many systems there are two heads) The writ mechanism exploits the fact that electricity flowing through a coil produces a magnetic field. Electric pulses are sent to the write head, and the resulting magnetic patterns are recorded on the surface below with different patterns for positive and negative currents The physical characteristics of a magnetic disk   Summarize from book   The factors that play a role in the performance of a disk Seek time – the time it takes to position the head at the track Rotational delay / latency – the time it takes for the beginning of the sector to reach the head Access time – the sum of the seek time and rotational delay Transfer time – the time it takes to transfer data RAID The rate of improvement in secondary storage performance has been considerably less than the rate for processors and main memory. Thus secondary storage has become a bit of a bottleneck. RAID works on the concept that if one disk can be pushed so far, additional gains in performance are to be had by using multiple parallel components. Points to note about RAID… RAID is a set of physical disk drives viewed by the operating system as a single logical drive Data is distributed across the physical drives of an array in a scheme known as striping Redundant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure (not supported by RAID 0 or RAID 1) Interesting to note that the increase in the number of drives, increases the probability of failure. To compensate for this decreased reliability RAID makes use of stored parity information that enables the recovery of data lost due to a disk failure.   The RAID scheme consists of 7 levels…   Category Level Description Disks Required Data Availability Large I/O Data Transfer Capacity Small I/O Request Rate Striping 0 Non Redundant N Lower than single disk Very high Very high for both read and write Mirroring 1 Mirrored 2N Higher than RAID 2 – 5 but lower than RAID 6 Higher than single disk Up to twice that of a signle disk for read Parallel Access 2 Redundant via Hamming Code N + m Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Parallel Access 3 Bit interleaved parity N + 1 Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Independent Access 4 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, significantly lower than single disk for write Similar to RAID 0 for read, significantly lower than single disk for write Independent Access 5 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, lower than single disk for write Similar to RAID 0 for read, generally  lower than single disk for write Independent Access 6 Block interleaved parity N + 2 Highest of all listed alternatives Similar to RAID 0 for read; lower than RAID 5 for write Similar to RAID 0 for read, significantly lower than RAID 5  for write   Read page 215 – 221 for detailed explanation on RAID levels Optical Memory There are a variety of optical-disk systems available. Read through the table on page 222 – 223 Some of the devices include… CD CD-ROM CD-R CD-RW DVD DVD-R DVD-RW Blue-Ray DVD Magnetic Tape Most modern systems use serial recording – data is lade out as a sequence of bits along each track. The typical recording used in serial is referred to as serpentine recording. In this technique when data is being recorded, the first set of bits is recorded along the whole length of the tape. When the end of the tape is reached the heads are repostioned to record a new track, and the tape is again recorded on its whole length, this time in the opposite direction. That process continued back and forth until the tape is full. To increase speed, the read-write head is capable of reading and writing a number of adjacent tracks simultaneously. Data is still recorded serially along individual tracks, but blocks in sequence are stored on adjacent tracks as suggested. A tape drive is a sequential access device. Magnetic tape was the first kind of secondary memory. It is still widely used as the lowest-cost, slowest speed member of the memory hierarchy.

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• ArchBeat Link-o-Rama Top 10 for November 2012

  - by Bob Rhubart

  Every day ArchBeat searches the web for content created by and for community members, and then shares that content via social media. Here's the list of the Top 10 most popular items posted on the OTN ArchBeat Facebook Page for November 2012. One-Stop Shop for Oracle Webcasts Webcasts can be a great way to get information about Oracle products without having to go cross-eyed reading yet another document off your computer screen. Oracle's new Webcast Center offers selectable filtering to make it easy to get to the information you want. Yes, you have to register to gain access, but that process is quick, and with over 200 webcasts to choose from you know you'll find useful content. OAM/OVD JVM Tuning Vinay from the Oracle Fusion Middleware Architecture Group (otherwise known as the A-Team) shares a process for analyzing and improving performance in Oracle Virtual Directory and Oracle Access Manager. White Paper: Oracle Exalogic Elastic Cloud: Advanced I/O Virtualization Architecture for Consolidating High-Performance Workloads This new white paper by Adam Hawley (with contributions from Yoav Eilat) describes in great detail the incorporation into Oracle Exalogic of virtualized InfiniBand I/O interconnects using Single Root I/O Virtualization (SR-IOV) technology. Architected Systems: "If you don't develop an architecture, you will get one anyway..." "Can you build a system without taking care of architecture?," asks Manuel Ricca. "You certainly can. But inevitably the system will be unbalanced, neglecting the interests of key stakeholders, and problems will soon emerge." Backup and Recovery of an Exalogic vServer via rsync "On Exalogic a vServer will consist of a number of resources from the underlying machine," says the man known only as Donald. "These resources include compute power, networking and storage. In order to recover a vServer from a failure in the underlying rack all of these components have to be thoughts about. This article only discusses the backup and recovery strategies that apply to the storage system of a vServer." This Week on the OTN Architect Community Home Page Make time to check out this week's features on the OTN Solution Architect Homepage, including: SOA Practitioner Guide: Identifying and Discovering Services Technical article by Yuli Vasiliev on Setting Up, Configuring, and Using an Oracle WebLogic Server Cluster Podcast: Are You Future Proof? Clustering ODI11g for High-Availability Part 1: Introduction and Architecture | Richard Yeardley "JEE agents can be deployed alongside, or instead of, standalone agents," says Rittman Meade's Richard Yeardley. "But there is one key advantage in using JEE agents and WebLogic – when you deploy JEE agents as part of a WebLogic cluster they can be configured together to form a high availability cluster." Learn more in Yeardley's extensive post. OIM 11g : Multi-thread approach for writing custom scheduled job | Saravanan V S Saravanan shares insight and expertise relevant to "designing and developing an OIM schedule job that uses multi threaded approach for updating data in OIM using APIs." How to Create Virtual Directory in Weblogic Server | Zeeshan Baig Oracle ACE Zeeshan Baig shows you how in six easy steps. SOA Galore: New Books for Technical Eyes Only Shake up up your technical skills with this trio of new technical books from community members covering SOA and BPM. Thought for the Day "Humans are the best value in computers -- where else can you get a non-linear computer weighing only about 160lbs, having a billion binary decision elements, that can be mass-produced by unskilled labour?" — Anonymous Source: SoftwareQuotes.com

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• World Record Siebel PSPP Benchmark on SPARC T4 Servers

  - by Brian

  Oracle's SPARC T4 servers set a new World Record for Oracle's Siebel Platform Sizing and Performance Program (PSPP) benchmark suite. The result used Oracle's Siebel Customer Relationship Management (CRM) Industry Applications Release 8.1.1.4 and Oracle Database 11g Release 2 running Oracle Solaris on three SPARC T4-2 and two SPARC T4-1 servers. The SPARC T4 servers running the Siebel PSPP 8.1.1.4 workload which includes Siebel Call Center and Order Management System demonstrates impressive throughput performance of the SPARC T4 processor by achieving 29,000 users. This is the first Siebel PSPP 8.1.1.4 benchmark supporting 29,000 concurrent users with a rate of 239,748 Business Transactions/hour. The benchmark demonstrates vertical and horizontal scalability of Siebel CRM Release 8.1.1.4 on SPARC T4 servers. Performance Landscape Systems Txn/hr Users Call Center Order Management Response Times (sec) 1 x SPARC T4-1 (1 x SPARC T4 2.85 GHz) – Web 3 x SPARC T4-2 (2 x SPARC T4 2.85 GHz) – App/Gateway 1 x SPARC T4-1 (1 x SPARC T4 2.85 GHz) – DB 239,748 29,000 0.165 0.925 Oracle: Call Center + Order Management Transactions: 197,128 + 42,620 Users: 20300 + 8700 Configuration Summary Web Server Configuration: 1 x SPARC T4-1 server 1 x SPARC T4 processor, 2.85 GHz 128 GB memory Oracle Solaris 10 8/11 iPlanet Web Server 7 Application Server Configuration: 3 x SPARC T4-2 servers, each with 2 x SPARC T4 processor, 2.85 GHz 256 GB memory 3 x 300 GB SAS internal disks Oracle Solaris 10 8/11 Siebel CRM 8.1.1.5 SIA Database Server Configuration: 1 x SPARC T4-1 server 1 x SPARC T4 processor, 2.85 GHz 128 GB memory Oracle Solaris 11 11/11 Oracle Database 11g Release 2 (11.2.0.2) Storage Configuration: 1 x Sun Storage F5100 Flash Array 80 x 24 GB flash modules Benchmark Description Siebel 8.1 PSPP benchmark includes Call Center and Order Management: Siebel Financial Services Call Center – Provides the most complete solution for sales and service, allowing customer service and telesales representatives to provide superior customer support, improve customer loyalty, and increase revenues through cross-selling and up-selling. High-level description of the use cases tested: Incoming Call Creates Opportunity, Quote and Order and Incoming Call Creates Service Request . Three complex business transactions are executed simultaneously for specific number of concurrent users. The ratios of these 3 scenarios were 30%, 40%, 30% respectively, which together were totaling 70% of all transactions simulated in this benchmark. Between each user operation and the next one, the think time averaged approximately 10, 13, and 35 seconds respectively. Siebel Order Management – Oracle's Siebel Order Management allows employees such as salespeople and call center agents to create and manage quotes and orders through their entire life cycle. Siebel Order Management can be tightly integrated with back-office applications allowing users to perform tasks such as checking credit, confirming availability, and monitoring the fulfillment process. High-level description of the use cases tested: Order & Order Items Creation and Order Updates. Two complex Order Management transactions were executed simultaneously for specific number of concurrent users concurrently with aforementioned three Call Center scenarios above. The ratio of these 2 scenarios was 50% each, which together were totaling 30% of all transactions simulated in this benchmark. Between each user operation and the next one, the think time averaged approximately 20 and 67 seconds respectively. Key Points and Best Practices No processor cores or cache were activated or deactivated on the SPARC T-Series systems to achieve special benchmark effects. See Also Siebel White Papers SPARC T4-1 Server oracle.com OTN SPARC T4-2 Server oracle.com OTN Siebel CRM oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition 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 30 September 2012.

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• Let Me Show You Something: Instagram, Vine and Snapchat for Brands

  - by Mike Stiles

  While brands are well aware of how much more impactful images are than text-only posts on social channels, today you’re additionally being presented with platform after additional platform for hosting, doctoring and sharing photos and videos.  Can you play in every sandbox? And if you do, can you be brilliant on all of them? As has usually been the case, so far brands are sticking their toes into new platforms while not actually committing to them, or strategizing for them, or resourcing them. TrackMaven found of the 123 F500 companies using Instagram, only 22% of them are active on it. Likewise, research from Simply Measured found brands are indeed jumping in, with the number establishing a presence on Instagram up 55% over the past year. Users want them there…brand engagement has exploded 350%, and over 1/3 of the top brands have at least 10,000 followers. BUT…the top 10 brands are generating 33% of all posts, reaping 83% of all engagement. Things are also growing on Twitter’s Vine, the 6-second looping video app that hit 40 million users in August. The 7th Chamber says 5 tweets a second contain a Vine link. Other studies say branded Vines are 4 times more likely to be shared and seen than rank-and-file branded videos. Why? Users know that even if a video is pure junk, they won’t get robbed of too much of their valuable time. Vine is always upgrading so you can make sure your videos are worth viewers’ time. You can now edit videos, and save & work on several projects concurrently. What you can’t do is upload a finely crafted video into Vine, but you can do that with Instagram. The key to success? Same as with all other content; make it of value. Deliver a laugh or a lesson or both. How-to, behind the scenes peeks, contests, demos, all make sense in the short video format. Or follow Nash Grier’s example, which is to just have fun with and connect to your viewers, earning their trust that your next Vine will be as good as the last. Nash is only 15, has over 1.4 million followers, and adds about 100,000 a week. He broke out when one of his videos was re-Vined by some other kid with 300,000 followers. Make good stuff, get it in front of influencers, and your brand Vines could break out as well. Then there’s Snapchat, the “this photo will self destruct” platform. How can that be of use to brands besides offering coupons that really expire? The jury is out. But with an audience of over 100 million and a valuation of $800 million, media-with-a-time-limit is compelling. Now there’s “Snapchat Stories” that can last 24 hours and be shared to the public at large. You might be able to capitalize on how much more focus gets put on content when there’s a time limit on its availability. The underlying truth to all of this is, these are all tools. Very cool, feature rich tools, but tools. You can give the exact same art kit to 5 different people and you’d get back 5 very different works, ranging from worthless garbage to masterpiece. Brands are being called upon to be still and moving image artists. That’s what your customers are used to seeing, from a variety of sources. Commit to communicating with them accordingly. @mikestiles Photo: stock.xchng

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• How to safely copy an object?

  - by Prog

  This question is going to be a little long. Please bear with me. Something that happened in a project of mine made me think about how to safely copy objects. I'll present the situation I had and then ask a question. There was a class SomeClass: class SomeClass{ Thing[] things; public SomeClass(Thing[] things){ this.things = things; } // irrelevant stuff omitted public SomeClass copy(){ return new SomeClass(things); } } There was another class Processor that takes SomeClass objects, copies them (via someClassInstance.copy()), manipulates the copy's state, and returns the copy. Here it is: class Processor{ public SomeClass processObject(SomeClass object){ SomeClass copy = object.copy(); manipulateTheCopy(copy); return copy; } // irrelevant stuff omitted } I ran this, and it had bugs. I looked into these bugs, and it turned out that the manipulations Processor does on copy actually affect not only the copy, but also the original SomeClass object that was passed into processObject. I found out that it was because the original and the copy shared state - because the original passed it's field things into the copy when creating it. This made me realize that copying objects is harder than simply instantiating them with the same fields as the original. For the two objects to be completely disconnected, without any shared state, each of the fields passed to the copy also has to be copied. And if that object contains other objects - they have to be copied too. And so on. So basically, in order to be able to actually copy an object, each class in the system must have a copy() method, that also invokes copy() on all of it's fields, and so on. So for example, for copy() in SomeClass to work, it needs to look like this: public SomeClass copy(){ Thing[] copyThings = new Thing[things.length]; for(int i=0; i<things.length; i++) copyThings[i] = things[i].copy(); return new SomeClass(copyThings); } And if Thing has object fields of it's own, than it's own copy() method must be appropriate: class Thing{ Apple apple; Pencil pencil; int number; public Thing(Apple apple, Pencil pencil, int number){ this.apple = apple; this.pencil = pencil; this.number = number; } public Thing copy(){ // 'number' is a primitve. return new Thing(apple.getCopy(), pencil.getCopy(), number); } } And so on. Of course, instead of all classes having a copy() method, the copying mechanism can happen in all of the getters and the constructors of classes (unless places where it isn't suitable, for example when the field points to an external object, not to an object that 'is part' of this object). Still, that means that in order to be able to safely copy an object - most classes would have to have copying mechanisms in their getters. My question is divided into two parts: How frequently do you need to get a copy of an object? Is this a regular issue? Is the technique described common and/or reasonable? Or is there a better way to make safe copies of objects? Or is there an easier way to safely copy objects, without them sharing any state?

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• DBA Best Practices - A Blog Series: Episode 2 - Password Lists

  - by Argenis

    Digital World, Digital Locks One of the biggest digital assets that any company has is its secrets. These include passwords, key rings, certificates, and any other digital asset used to protect another asset from tampering or unauthorized access. As a DBA, you are very likely to manage some of these assets for your company - and your employer trusts you with keeping them safe. Probably one of the most important of these assets are passwords. As you well know, the can be used anywhere: for service accounts, credentials, proxies, linked servers, DTS/SSIS packages, symmetrical keys, private keys, etc., etc. Have you given some thought to what you're doing to keep these passwords safe? Are you backing them up somewhere? Who else besides you can access them? Good-Ol’ Post-It Notes Under Your Keyboard If you have a password-protected Excel sheet for your passwords, I have bad news for you: Excel's level of encryption is good for your grandma's budget spreadsheet, not for a list of enterprise passwords. I will try to summarize the main point of this best practice in one sentence: You should keep your passwords on an encrypted, access and version-controlled, backed-up, well-known shared location that every DBA on your team is aware of, and maintain copies of this password "database" on your DBA's workstations. Now I have to break down that statement to you: - Encrypted: what’s the point of saving your passwords on a file that any Windows admin with enough privileges can read? - Access controlled: This one is pretty much self-explanatory. - Version controlled: Passwords change (and I’m really hoping you do change them) and version control would allow you to track what a previous password was if the utility you’ve chosen doesn’t handle that for you. - Backed-up: You want a safe copy of the password list to be kept offline, preferably in long term storage, with relative ease of restoring. - Well-known shared location: This is critical for teams: what good is a password list if only one person in the team knows where it is? I have seen multiple examples of this that work well. They all start with an encrypted database. Certainly you could leverage SQL Server's native encryption solutions like cell encryption for this. I have found such implementations to be impractical, for the most part. Enter The World Of Utilities There are a myriad of open source/free software solutions to help you here. One of my favorites is KeePass, which creates encrypted files that can be saved to a network share, Sharepoint, etc. KeePass has UIs for most operating systems, including Windows, MacOS, iOS, Android and Windows Phone. Other solutions I've used before worth mentioning include PasswordSafe and 1Password, with the latter one being a paid solution – but wildly popular in mobile devices. There are, of course, even more "enterprise-level" solutions available from 3rd party vendors. The truth is that most of the customers that I work with don't need that level of protection of their digital assets, and something like a KeePass database on Sharepoint suits them very well. What are you doing to safeguard your passwords? Leave a comment below, and join the discussion! Cheers, -Argenis

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• Free hosting solution for a very low-traffic website [duplicate]

  - by user966939

  This question already has an answer here: How to find web hosting that meets my requirements? 4 answers I run a very low-traffic website (about 40 users, basically all of which are daily active on the site). I don't see it changing anytime soon either, as there is no way to sign up on the site right now. Until now I have just been using a sub-directory on a friend's host (shared), to host the web site. But in only a few weeks from now, his subscription will end, and he has no plans on renewing it. So of course this means I'll have to move on to something else. But I don't think I'll find someone who'd be willing to share a... shared host with me again. And besides, the software used on that server is ancient (PHP 4.4.9 + MySQL 4.1.22). There's one obvious solution that comes to mind, I guess: choose a better host and pay for it myself. The problem here is that I have no real fixed income, as I'm only a student. So even if the pricing is dirt cheap, I just can't be certain I will be able to afford it, every single month, for... at least 2 years maybe? So I've looked at free hosting solutions instead. The least requirement I had was that it was completely free of ads. But no matter where I look, I always find something in a corner or two ("what can you expect from a free host?" - yeah I know, but I guess it was worth a shot). For example, on Byethost (one of the free hosts I tried), if you trigger a PHP error while error reporting is set to E_ALL, you will spawn some hidden ad... Besides Byethost, I've tried 000Webhost, x10Hosting, 2Freehosting/1Freehosting, Wink.ws, and they are only worse. Okay, I'm running low on ideas. But! What if I just hosted the site myself, on my own computer? That could work. I actually do have my computer on practically 24/7. But not really. Sometimes I need to reboot it, and sometimes we even have power outages. And what if the hardware needs an upgrade? It's not such a big deal for me if the site went down, because I know what's going on; but what about the users? If I do decide to host it myself, is there some way to show users an alternate page instead of them just seeing a generic "server not found" page in the browser when the site is not accessible? Or is there something I have been missing out on? Is there a different kind of "web hosting" solution out there that I haven't heard of? Here is what I'm really looking for: Free (as in, no costs) NO ads Bandwidth enough for a low-traffic forum with roughly 40 users (Semi-)Up-to-date PHP and MySQL (at least not older than a year) No standard (non-extension) PHP functions turned off - such as sleep() The mbstring extension is enabled Disk space: at least 5 MB At least one MySQL database Some bonus points would be: Max execution time of PHP scripts can be set Remote access to MySQL database What would be the best solution for me? Is there one?

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• Moving StarterSTS to the (Azure) Cloud

  - by Your DisplayName here!

  Quite some people asked me about an Azure version of StarterSTS. While I kinda knew what I had to do to make the move, I couldn’t find the time. Until recently. This blog post briefly documents the necessary changes and design decisions for the next version of StarterSTS which will work both on-premise and on Azure. Provider Fortunately StarterSTS is already based on the idea of “providers”. Authentication, roles and claims generation is based on the standard ASP.NET provider infrastructure. This makes the migration to different data stores less painful. In my case I simply moved the ASP.NET provider database to SQL Azure and still use the standard SQL Server based membership, roles and profile provider. In addition StarterSTS has its own providers to abstract resource access for certificates, relying party registration, client certificate registration and delegation. So I only had to provide new implementations. Signing and SSL keys now go in the Azure certificate store and user mappings (client certificates and delegation settings) have been moved to Azure table storage. The one thing I didn’t anticipate when I originally wrote StarterSTS was the need to also encapsulate configuration. Currently configuration is “locked” to the standard .NET configuration system. The new version will have a pluggable SettingsProvider with versions for .NET configuration as well as Azure service configuration. If you want to externalize these settings into e.g. a database, it is now just a matter of supplying a corresponding provider. Moving between the on-premise and Azure version will be just a matter of using different providers. URL Handling Another thing that’s substantially different on Azure (and load balanced scenarios in general) is the handling of URLs. In farm scenarios, the standard APIs like ASP.NET’s Request.Url return the current (internal) machine name, but you typically need the address of the external facing load balancer. There’s a hotfix for WCF 3.5 (included in v4) that fixes this for WCF metadata. This was accomplished by using the HTTP Host header to generate URLs instead of the local machine name. I now use the same approach for generating WS-Federation metadata as well as information card files. New Features I introduced a cache provider. Since we now have slightly more expensive lookups (e.g. relying party data from table storage), it makes sense to cache certain data in the front end. The default implementation uses the ASP.NET web cache and can be easily extended to use products like memcached or AppFabric Caching. Starting with the relying party provider, I now also provide a read/write interface. This allows building management interfaces on top of this provider. I also include a (very) simple web page that allows working with the relying party provider data. I guess I will use the same approach for other providers in the future as well. I am also doing some work on the tracing and health monitoring area. Especially important for the Azure version. Stay tuned.

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• The Growing Importance of Network Virtualization

  - by user12608550

  The Growing Importance of Network Virtualization We often focus on server virtualization when we discuss cloud computing, but just as often we neglect to consider some of the critical implications of that technology. The ability to create virtual environments (or VEs [1]) means that we can create, destroy, activate and deactivate, and more importantly, MOVE them around within the cloud infrastructure. This elasticity and mobility has profound implications for how network services are defined, managed, and used to provide cloud services. It's not just servers that benefit from virtualization, it's the network as well. Network virtualization is becoming a hot topic, and not just for discussion but for companies like Oracle and others who have recently acquired net virtualization companies [2,3]. But even before this topic became so prominent, Solaris engineers were working on technologies in Solaris 11 to virtualize network services, known as Project Crossbow [4]. And why is network virtualization so important? Because old assumptions about network devices, topology, and management must be re-examined in light of the self-service, elasticity, and resource sharing requirements of cloud computing infrastructures. Static, hierarchical network designs, and inter-system traffic flows, need to be reconsidered and quite likely re-architected to take advantage of new features like virtual NICs and switches, bandwidth control, load balancing, and traffic isolation. For example, traditional multi-tier Web services (Web server, App server, DB server) that share net traffic over Ethernet wires can now be virtualized and hosted on shared-resource systems that communicate within a larger server at system bus speeds, increasing performance and reducing wired network traffic. And virtualized traffic flows can be monitored and adjusted as needed to optimize network performance for dynamically changing cloud workloads. Additionally, as VEs come and go and move around in the cloud, static network configuration methods cannot easily accommodate the routing and addressing flexibility that VE mobility implies; virtualizing the network itself is a requirement. Oracle Solaris 11 [5] includes key network virtualization technologies needed to implement cloud computing infrastructures. It includes features for the creation and management of virtual NICs and switches, and for the allocation and control of the traffic flows among VEs [6]. Additionally it allows for both sharing and dedication of hardware components to network tasks, such as allocating specific CPUs and vNICs to VEs, and even protocol-specific management of traffic. So, have a look at your current network topology and management practices in view of evolving cloud computing technologies. And don't simply duplicate the physical architecture of servers and connections in a virtualized environment…rethink the traffic flows among VEs and how they can be optimized using Oracle Solaris 11 and other Oracle products and services. [1] I use the term "virtual environment" or VE here instead of the more commonly used "virtual machine" or VM, because not all virtualized operating system environments are full OS kernels under the control of a hypervisor…in other words, not all VEs are VMs. In particular, VEs include Oracle Solaris zones, as well as SPARC VMs (previously called LDoms), and x86-based Solaris and Linux VMs running under hypervisors such as OEL, Xen, KVM, or VMware. [2] Oracle follows VMware into network virtualization space with Xsigo purchase; http://www.mercurynews.com/business/ci_21191001/oracle-follows-vmware-into-network-virtualization-space-xsigo [3] Oracle Buys Xsigo; http://www.oracle.com/us/corporate/press/1721421 [4] Oracle Solaris 11 Networking Virtualization Technology, http://www.oracle.com/technetwork/server-storage/solaris11/technologies/networkvirtualization-312278.html [5] Oracle Solaris 11; http://www.oracle.com/us/products/servers-storage/solaris/solaris11/overview/index.html [6] For example, the Solaris 11 'dladm' command can be used to limit the bandwidth of a virtual NIC, as follows: dladm create-vnic -l net0 -p maxbw=100M vnic0

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• MVC Communication Pattern

  - by Kedu

  This is kind of a follow up question to this http://stackoverflow.com/questions/23743285/model-view-controller-and-callbacks, but I wanted to post it separately, because its kind of a different topic. I'm working on a multiplayer cardgame for the Android platform. I split the project into MVC which fits the needs pretty good, but I'm currently stuck because I can't figure out a good way to communicate between the different parts. I have everything setup and working with the controller being a big state machine, which is called over and over from the gameloop, and calls getter methods from the GUI and the android/network part to get the input. The input itself in the GUI and network is set by inputlisteners that set a local variable which I read in the getter method. So far so good, this is working. But my problem is, the controller has to check every input separately,so if I want to add an input I have to check in which states its valid and call the getter method from all these states. This is not good, and lets the code look pretty ugly, makes additions uncomfortable and adds redundance. So what I've got from the question I mentioned above is that some kind of command or event pattern will fit my needs. What I want to do is to create a shared and threadsafe queue in the controller and instead of calling all these getter methods, I just check the queue for new input and proceed it. On the other side, the GUI and network don't have all these getters, but instead create an event or command and send it to the controller through, for example, observer/observable. Now my problem: I can't figure out a way, for these commands/events to fit a common interface (which the queue can store) and still transport different kind of data (button clicks, cards that are played, the player id the command comes from, synchronization data etc.). If I design the communication as command pattern, I have to stick all the information that is needed to execute the command into it when its created, that's impossible because the GUI or network has no knowledge of all the things the controller needs to execute stuff that needs to be done when for example a card is played. I thought about getting this stuff into the command when executing it. But over all the different commands I have, I would need all the information the controller has, and thus give the command a reference to the controller which would make everything in it public, which is real bad design I guess. So, I could try some kind of event pattern. I have to transport data in the event. So, like the command, I would have an interface, which all events have in common, and can be stored in the shared queue. I could create a big enum with all the different events that a are possible, save one of these enums in the actual event, and build a big switch case for the events, to proceed different stuff for different events. The problem here: I have different data for all the events. But I need a common interface, to store the events in a queue. How do I get the specific data, if I can only access the event through the interface? Even if that wouldn't be a problem, I'm creating another big switch case, which looks ugly, and when i want to add a new event, I have to create the event itself, the case, the enum, and the method that's called with the data. I could of course check the event with the enum and cast it to its type, so I can call event type specific methods that give me the data I need, but that looks like bad design too.

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• Faster Memory Allocation Using vmtasks

  - by Steve Sistare

  You may have noticed a new system process called "vmtasks" on Solaris 11 systems: % pgrep vmtasks 8 % prstat -p 8 PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP 8 root 0K 0K sleep 99 -20 9:10:59 0.0% vmtasks/32 What is vmtasks, and why should you care? In a nutshell, vmtasks accelerates creation, locking, and destruction of pages in shared memory segments. This is particularly helpful for locked memory, as creating a page of physical memory is much more expensive than creating a page of virtual memory. For example, an ISM segment (shmflag & SHM_SHARE_MMU) is locked in memory on the first shmat() call, and a DISM segment (shmflg & SHM_PAGEABLE) is locked using mlock() or memcntl(). Segment operations such as creation and locking are typically single threaded, performed by the thread making the system call. In many applications, the size of a shared memory segment is a large fraction of total physical memory, and the single-threaded initialization is a scalability bottleneck which increases application startup time. To break the bottleneck, we apply parallel processing, harnessing the power of the additional CPUs that are always present on modern platforms. For sufficiently large segments, as many of 16 threads of vmtasks are employed to assist an application thread during creation, locking, and destruction operations. The segment is implicitly divided at page boundaries, and each thread is given a chunk of pages to process. The per-page processing time can vary, so for dynamic load balancing, the number of chunks is greater than the number of threads, and threads grab chunks dynamically as they finish their work. Because the threads modify a single application address space in compressed time interval, contention on locks protecting VM data structures locks was a problem, and we had to re-scale a number of VM locks to get good parallel efficiency. The vmtasks process has 1 thread per CPU and may accelerate multiple segment operations simultaneously, but each operation gets at most 16 helper threads to avoid monopolizing CPU resources. We may reconsider this limit in the future. Acceleration using vmtasks is enabled out of the box, with no tuning required, and works for all Solaris platform architectures (SPARC sun4u, SPARC sun4v, x86). The following tables show the time to create + lock + destroy a large segment, normalized as milliseconds per gigabyte, before and after the introduction of vmtasks: ISM system ncpu before after speedup ------ ---- ------ ----- ------- x4600 32 1386 245 6X X7560 64 1016 153 7X M9000 512 1196 206 6X T5240 128 2506 234 11X T4-2 128 1197 107 11x DISM system ncpu before after speedup ------ ---- ------ ----- ------- x4600 32 1582 265 6X X7560 64 1116 158 7X M9000 512 1165 152 8X T5240 128 2796 198 14X (I am missing the data for T4 DISM, for no good reason; it works fine). The following table separates the creation and destruction times: ISM, T4-2 before after ------ ----- create 702 64 destroy 495 43 To put this in perspective, consider creating a 512 GB ISM segment on T4-2. Creating the segment would take 6 minutes with the old code, and only 33 seconds with the new. If this is your Oracle SGA, you save over 5 minutes when starting the database, and you also save when shutting it down prior to a restart. Those minutes go directly to your bottom line for service availability.

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• Using WPF and SlimDx (DirectX 10/11)

  - by slurmomatic

  I am using SlimDX with WinForms for a while now, but want to make the switch to WPF now. However, I can't figure out how to get DX10/11 working with WPF. The February release of SlimDX provides a WPF example, which only works with DX 9 though. I found the following solution: http://jmorrill.hjtcentral.com/Home/tabid/428/EntryId/437/Direct3D-10-11-Direct2D-in-WPF.aspx but can't get it to work with SlimDX. My main problem is the shared resource handle as I don't know how to retrieve the shared handle from a SlimDX texture. I can't find any information to this topic. In C++ the code looks like this: HRESULT D3DImageEx::GetSharedHandle(IUnknown *pUnknown, HANDLE * pHandle) { HRESULT hr = S_OK; *pHandle = NULL; IDXGIResource* pSurface; if (FAILED(hr = pUnknown->QueryInterface(__uuidof(IDXGIResource), (void**)&pSurface))) return hr; hr = pSurface->GetSharedHandle(pHandle); pSurface->Release(); return hr; } Basically, what I want to do (because I think that this is the solution), is to share a texture between a Direct3d9DeviceEx (for rendering the WPF D3DImage) and a Direct3d10Device (a texture render target for my scene). Any pointers in the right direction are greatly appreciated.

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• Linq The specified type 'string' is not a valid provider type.

  - by Joe Pitz

  Using Linq to call a stored procedure that passes a single string, The stored procedure returns a data set row that contains a string and an int. Code: PESQLDataContext pe = new PESQLDataContext(strConnStr); pe.ObjectTrackingEnabled = false; gvUnitsPassed.DataSource = pe.PassedInspection(Line); gvUnitsPassed.DataBind(); pe.dispose(); When the code runs an exception gets called below: The exception is thrown at the IExecuteResult result = statement: Enclosed is my result class in the designer.cs file. [Function(Name = "dbo.PassedInspection")] public ISingleResult<PassedInspectionResult> PassedInspection([Parameter(Name = "Model", DbType = "VarChar(4)")] string model) { IExecuteResult result = this.ExecuteMethodCall(this, ((MethodInfo)(MethodInfo.GetCurrentMethod())), model); return ((ISingleResult<PassedInspectionResult>)(result.ReturnValue)); } public partial class PassedInspectionResult { private string _Date; private int _Passed; public PassedInspectionResult() { } [Column(Storage = "_Date", DbType = "string NULL")] public string Date { get { return this._Date; } set { if ((this._Date != value)) { this._Date = value; } } } [Column(Storage = "_Passed", DbType = "Int NULL")] public int Passed { get { return this._Passed; } set { if ((this._Passed != value)) { this._Passed = value; } } } } } I have other stored procedures with similar arguments that run just fine. Thanks

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• Calling WCF service with parameter using jQuery

  - by Remi Despres-Smyth

  I'm trying to call a WCF web service hosted by IIS using jQuery. I can call it fine without any parameters, and I can also call it fine with a GET request that includes my parameter, but as soon as I try to send in the request via POST, the call is failing. The web service is currently nothing but: [OperationContract, WebInvoke] public ValidationResultSummary TestValidateOn( object day) { return null; } I've set the parameter to object, to make sure the issue isn't something with type coercion. With a breakpoint in the web service, I know the call without parameters as well as the GET call with param succeeds; in the latter the expected value is sent up. Calling code looks like: $.ajax({ // type: "GET", // url: "../Shared/Services/DomainServices.svc/TestValidateOn?day='12/Jan/2010'", type: "POST", url: "../Shared/Services/DomainServices.svc/TestValidateOn", // data: "{ }", --This works if object type param, calls with null data: "{'day': " + selectedDate + "}", // This fails miserably // data: "{'day': '" + selectedDate + "'}", --This also fails miserably contentType: "application/json; charset=utf-8", dataType: "json", success: function(data) { displayResults(data.d); }, error: function(xmlHttpReq, status, errThrown) { displayError(xmlHttpReq, status, errThrown); } }); The POST call never reaches my breakpoint, and on the client, error 500 - "Internal Server Error" - is returned. Any help would be appreciated.

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• Managing Dependency Hell with WiX and C#

  - by Tom the Junglist

  We are on the eve of product launch, and at the last minute I am being bombarded with crash reports that appear to be related to our installer, which is a WiX3 project with separate outputs for x86 and x64 builds. These have been an ongoing problem that I always thought were fixed, only to find out that they were still lurking. The product itself is a collection of binaries that communicate with each other via .Net remoting, including a Windows Service and a small COM component that is loaded as an addon in another app. The service runs as SYSTEM, the COM piece runs in a low-rights context, while the other pieces run in normal user contexts. Other pieces include an third-party COM object library DLL and a shared DLL with the .net Remoting interfaces. I've observed flat-out weird behavior with MSI, particularly on version upgrades. Between MS' anal strong-name implementation (specifically, the exact version check before loading a given assembly), a documented WiX/MSI bug that sees critical files erased on upgrades (essentially, if a file in the upgrade MSI has the same version number as the existing install, that file is deleted), and having to work around Wow64 virtualization (x86 MSI can only write to registry/HD locations via Wow64, yet x64 MSIs cannot run on x86 computers...), I am about ready to trash the whole thing and port it over to a different install system. What I am looking for on tips + tricks, techniques, or suggestions on how to properly do things so that I am not fighting with Windows Installer's twisted sense of logic. I am tired of fighting with WiX/MSI/Windows Installer. All it needs to do is place files and registry keys where I tell it to, upgrade them when appropriate, and don't delete anything until the user uninstalls. Instead, dependencies are deleted willy-nilly, bringing up a whole bunch of uncatchable exceptions (can't wrap a try{} block around function declarations) and GPF'ing the whole app. I am particularly interested in 'best practices' and examples regarding shared and dependency DLLs, and any tips on making sure if a file needs to go to GAC, that it actually goes to the GAC and stays there until it is appropriate to remove it. Thanks! Tom

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• pylucene: install error

  - by Pradeep

  I am trying to install Pylucene (pylucene-3.3-3-src.tar.gz) on my ubuntu linux 11.10. I have python 2.7.2. I was able to compile JCC (I think) because I didnt see any error when I installed it. When I tried to install Pylucene I get the following error. Can someone help? Thanks. ICU not installed /usr/bin/python -m jcc --shared --jar lucene-java-3.3/lucene/build/lucene-core-3.3.jar --jar lucene-java-3.3/lucene/build/contrib/analyzers/common/lucene-analyzers-3.3.jar --jar lucene-java-3.3/lucene/build/contrib/memory/lucene-memory-3.3.jar --jar lucene-java-3.3/lucene/build/contrib/highlighter/lucene-highlighter-3.3.jar --jar build/jar/extensions.jar --jar lucene-java-3.3/lucene/build/contrib/queries/lucene-queries-3.3.jar --jar lucene-java-3.3/lucene/build/contrib/grouping/lucene-grouping-3.3.jar --package java.lang java.lang.System java.lang.Runtime --package java.util java.util.Arrays java.util.HashMap java.util.HashSet java.text.SimpleDateFormat java.text.DecimalFormat java.text.Collator --package java.util.regex --package java.io java.io.StringReader java.io.InputStreamReader java.io.FileInputStream --exclude org.apache.lucene.queryParser.Token --exclude org.apache.lucene.queryParser.TokenMgrError --exclude org.apache.lucene.queryParser.QueryParserTokenManager --exclude org.apache.lucene.queryParser.ParseException --exclude org.apache.lucene.search.regex.JakartaRegexpCapabilities --exclude org.apache.regexp.RegexpTunnel --exclude org.apache.lucene.analysis.cn.smart.AnalyzerProfile --python lucene --mapping org.apache.lucene.document.Document 'get:(Ljava/lang/String;)Ljava/lang/String;' --mapping java.util.Properties 'getProperty:(Ljava/lang/String;)Ljava/lang/String;' --sequence java.util.AbstractList 'size:()I' 'get:(I)Ljava/lang/Object;' --rename org.apache.lucene.search.highlight.SpanScorer=HighlighterSpanScorer --version 3.3 --module python/collections.py --module python/ICUNormalizer2Filter.py --module python/ICUFoldingFilter.py --module python/ICUTransformFilter.py --files 3 --build /usr/bin/python: No module named jcc make: *** [compile] Error 1 Here is my Makefile configuration which I uncommented PREFIX_PYTHON=/usr ANT=ant PYTHON=$(PREFIX_PYTHON)/bin/python JCC=$(PYTHON) -m jcc --shared NUM_FILES=3

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• What is wrong with this solution? (Perm-Missing-Elem codility test)

  - by user2956907

  I have started playing with codility and came across this problem: A zero-indexed array A consisting of N different integers is given. The array contains integers in the range [1..(N + 1)], which means that exactly one element is missing. Your goal is to find that missing element. Write a function: int solution(int A[], int N); that, given a zero-indexed array A, returns the value of the missing element. For example, given array A such that: A[0] = 2 A[1] = 3 A[2] = 1 A[3] = 5 the function should return 4, as it is the missing element. Assume that: N is an integer within the range [0..100,000]; the elements of A are all distinct; each element of array A is an integer within the range [1..(N + 1)]. Complexity: expected worst-case time complexity is O(N); expected worst-case space complexity is O(1), beyond input storage (not counting the storage required for input arguments). I have submitted the following solution (in PHP): function solution($A) { $nr = count($A); $totalSum = (($nr+1)*($nr+2))/2; $arrSum = array_sum($A); return ($totalSum-$arrSum); } which gave me a score of 66 of 100, because it was failing the test involving large arrays: "large_range range sequence, length = ~100,000" with the result: RUNTIME ERROR tested program terminated unexpectedly stdout: Invalid result type, int expected. I tested locally with an array of 100.000 elements, and it worked without any problems. So, what seems to be the problem with my code and what kind of test cases did codility use to return "Invalid result type, int expected"?

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• Reading excel files with xlrd

  - by snurre

  I'm having problems reading .xls files written by a Perl script which I have no control over. The files contain some formatting and line breaks within cells. filename = '/home/shared/testfile.xls' book = xlrd.open_workbook(filename) sheet = book.sheet_by_index(0) for rowIndex in xrange(1, sheet.nrows): row = sheet.row(rowIndex) This is throwing the following error: _locate_stream(Workbook): seen 0 5 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 20 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 172480= 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 172500 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 3 2 172520 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 173840= 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 173860 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 173880 1 1 1 1 1 1 1 1 Traceback (most recent call last): File "/home/shared/xlrdtest.py", line 5, in <module> book = xlrd.open_workbook(filename) File "/usr/local/lib/python2.7/site-packages/xlrd/__init__.py", line 443, in open_workbook ragged_rows=ragged_rows, File "/usr/local/lib/python2.7/site-packages/xlrd/book.py", line 84, in open_workbook_xls ragged_rows=ragged_rows, File "/usr/local/lib/python2.7/site-packages/xlrd/book.py", line 616, in biff2_8_load self.mem, self.base, self.stream_len = cd.locate_named_stream(qname) File "/usr/local/lib/python2.7/site-packages/xlrd/compdoc.py", line 393, in locate_named_stream d.tot_size, qname, d.DID+6) File "/usr/local/lib/python2.7/site-packages/xlrd/compdoc.py", line 421, in _locate_stream raise CompDocError("%s corruption: seen[%d] == %d" % (qname, s, self.seen[s])) xlrd.compdoc.CompDocError: Workbook corruption: seen[2] == 4 I'm not able to find any info about CompDocError or Workbook corruption, even less the seen[2] == 4 part.

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