Search Results

Search found 501 results on 21 pages for 'reliability'.

Page 17/21 | < Previous Page | 13 14 15 16 17 18 19 20 21  | Next Page >

• What are the essential Java libraries and utilities for a returning dynamic language user?

  - by jbwiv

  Guys, Long time Java developer here, but I've spent more time working with Ruby over the past 3 years or so as far as web applications go. I really have enjoyed it, but there are concerns I've uncovered that I won't cover here. Now that I've found the Play! framework, I'm thrilled about the prospect of having a Rails-like experience with Java's speed and reliability. Aside from what Play! provides out of the box, I'm looking for recommendations on "can't miss" libraries and tools for the Java developer used to pragmatic, dynamic experiences. I've found Project Lombok, which looks like a very intriguing way to eliminate a lot of the boiler plate, unnecessary Java noise. What else should I know about? I know Google has released quite a few libraries over the past three years that I've heard mentioned on the Java Posse, but I can't recall exactly what they are. I'm sure I've missed others in my absence. So, what makes up your essential Java toolbox these days? Thanks for your answers!

  Read the article

• How to make write operation idempotent?

  - by Morgan Cheng

  I'm reading article about recently release Gizzard sharding framework by twitter(http://engineering.twitter.com/2010/04/introducing-gizzard-framework-for.html). It mentions that all write operations must be idempotent to make sure high reliability. According to wikipedia, "Idempotent operations are operations that can be applied multiple times without changing the result." But, IMHO, in Gazzard case, idempotent write operation should be operations that sequence doesn't matter. Now, my question is: How to make write operation idempotent? The only thing I can image is to have a version number attached to each write. For example, in blog system. Each blog must have a $blog_id and $content. In application level, we always write a blog content like this write($blog_id, $content, $version). The $version is determined to be unique in application level. So, if application first try to set one blog to "Hello world" and second want it to be "Goodbye", the write is idempotent. We have such two write operations: write($blog_id, "Hello world", 1); write($blog_id, "Goodbye", 2); These two operations are supposed to changed two different records in DB. So, no matter how many times and what sequence these two operations executed, the results are same. This is just my understanding. Please correct me if I'm wrong.

  Read the article

• Need opinions on LaTeX and ever upgrading

  - by yCalleecharan

  Hi, I've been using LaTeX since 2005 with the TeXLive distribution and I've been upgrading as each new TeXLive distribution comes out. In the recent years I noticed an increase in new packages, updated packages and in one instance a new package bearing a different name replacing an old one by the same package author. A LaTeX document which relies heavily on packages and which has been produced a few years back may start to get some warnings and error messages on present-day LaTeX compilation. The primary reason I switched to LaTeX is because of its reliability and robustness to create big documents easily, not to mention the adorable typographic quality. With LaTeX one doesn't have to worry about how to open a docx in an old program supporting only doc for instance. Now, when there are so much continual changes in the packages in a LaTeX distribution, I tend to wonder when will this madness end. Not that having enhanced and new features are bad in packages, but not all updated packages are backward compatible. Eventually one would like to be able to compile a LaTeX file in 10 years time that he/she is working on at present and not get any compilation warnings/error messages due to some unpredictable behavior of updated packages or due to a package that has been cast-off from a LaTeX distribution. If I understand correctly CTAN do keep a database with all packages from different versions. I would like to know how you LaTeX users handle this issue. Thanks a lot...

  Read the article

• Export large amount of data from Oracle 10G to SQL Server 2005

  - by uniball

  Dear all, I need to export 100 million data rows (avg row length ~ 100 bytes) from Oracle 10G database table into SQL server (over WAN/VLAN with 6MBits/sec capacity) on a regular basis. So far, these are the options that I have tried and a quick summary. Has anyone tried this before? Are there other better options? Which option would be the best in terms of performance and reliability? The time taken has been calculated using tests on smaller amounts of data and then extrapolating it to estimate the time required. Using data import wizard on the SQL server or SSIS packages to import the data. It will take around 150 hours to complete the task. Using Oracle batch job to spool data into a comma-delimited flat-file. Then using SSIS package to FTP this file to the SQL server and then load directly from the flat-file. The issue here is the size of the flat-file which is expected to run in GBs. Although this option is drastically different, I am even considering the option of using Linked Server to query the Oracle data directly at run-time to avoid bringing in data. Performance is a big problem and I have limited control over the Oracle database in terms of creating table indexes. Regards, Uniball

  Read the article

• Disabling browser print options (headers, footers, margins) from page?

  - by Anthony

  I have seen this question asked in a couple of different ways on SO and several other websites, but most of them are either too specific or out-of-date. I'm hoping someone can provide a definitive answer here without pandering to speculation. Is there a way, either with CSS or javascript, to change the default printer settings when someone prints within their browser? And of course by "prints from their browser" I mean some form of HTML, not PDF or some other plug-in reliant mime-type. Please note: If some browsers offer this and others don't (or if you only know how to do it for some browsers) I welcome browser-specific solutions. Similarly, if you know of a mainstream browser that has specific restrictions against EVER doing this, that is also helpful, but some fairly up-to-date documentation would be appreciated. (simply saying "that goes against XYZ's security policy" isn't very convincing when XYZ has made significant changes in said policy in the last three years). Finally, when I say "change default print settings" I don't mean forever, just for my page, and I am referring specifically to print margins, headers, and footers. I am very aware that CSS offers the option of changing the page orientation as well as the page margins. One of the many struggles is with Firefox. If I set the page margins to 1 inch, it ADDS this to the half inch it already puts into place. I very much want to reduce the usage of PDFs on my client's site, but the infringement on presentation (as well as the lack of reliability) are their main concern.

  Read the article

• Enterprise Platform in Python, Design Advice

  - by Jason Miesionczek

  I am starting the design of a somewhat large enterprise platform in Python, and was wondering if you guys can give me some advice as to how to organize the various components and which packages would help achieve the goals of scalability, maintainability, and reliability. The system is basically a service that collects data from various outside sources, with each outside source having its own separate application. These applications would poll a central database and get any requests that have been submitted to perform on the external source. There will be a main website and REST/SOAP API that should also have access to the central data service. My initial thought was to use Django for the web site, web service and data access layer (using its built-in ORM), and then the outside source applications can use the web service(s) to get the information they need to process the request and save the results. Using this method would allow me to have multiple instances of the service applications running on the same or different machines to balance out the load. Are there more elegant means of accomplishing this? i've heard of messaging systems such as MQ, would something like that be beneficial in this scenario? My other thought was to use a completely separate data service not based on Django, and use some kind of remoting or remote objects (in they exist in Python) to interact with the data model. The downside here would be with the website which would become much slower if it had to push all of its data requests through a second layer. I would love to hear what other developers have come up with to achieve these goals in the most flexible way possible.

  Read the article

• Listening UDP or switch to TCP in a MFC application

  - by Alexander.S

  I'm editing a legacy MFC application, and I have to add some basic network functionalities. The operating side has to receive a simple instruction (numbers 1,2,3,4...) and do something based on that. The clients wants the latency to be as fast as possible, so naturally I decided to use datagrams (UDP). But reading all sorts of resources left me bugged. I cannot listen to UDP sockets (CAsyncSocket) in MFC, it's only possible to call Receive which blocks and waits. Blocking the UI isn't really a smart. So I guess I could use some threading technique, but since I'm not all that experienced with MFC how should that be implemented? The other part of the question is should I do this, or revert to TCP, considering reliability and implementation issues. I know that UDP is unreliable, but just how unreliable is it really? I read that it is up to 50% faster, which is a lot for me. References I used: http://msdn.microsoft.com/en-us/library/09dd1ycd(v=vs.80).aspx

  Read the article

• JMS message. Model to include data or pointers to data?

  - by John

  I am trying to resolve a design difference of opinion where neither of us has experience with JMS. We want to use JMS to communicate between a j2ee application and the stand-alone application when a new event occurs. We would be using a single point-to-point queue. Both sides are Java-based. The question is whether to send the event data itself in the JMS message body or to send a pointer to the data so that the stand-alone program can retrieve it. Details below. I have a j2ee application that supports data entry of new and updated persons and related events. The person records and associated events are written to an Oracle database. There are also stand-alone, separate programs that contribute new person and event records to the database. When a new event occurs through any of 5-10 different application functions, I need to notify remote systems through an outbound interface using an industry-specific standard messaging protocol. The outbound interface has been designed as a stand-alone application to support scalability through asynchronous operation and by moving it to a separate server. The j2ee application currently has most of the data in memory at the time the event is entered. The data would consist of approximately 6 different objects; a person object and some with multiple instances for an average size in the range of 3000 to 20,000 bytes. Some special cases could be many times this amount. From a performance and reliability perspective, should I model the JMS message to pass all the data needed to create the interface message, or model the JMS message to contain record keys for the data and have the stand-alone Java application retrieve the data to create the interface message?

  Read the article

• innerText/textContent vs. retrieving each text node

  - by J-P

  I've heard that using el.innerText||el.textContent can yield unreliable results, and that's why I've always insisted on using the following function in the past: function getText(node) { if (node.nodeType === 3) { return node.data; } var txt = ''; if (node = node.firstChild) do { txt += getText(node); } while (node = node.nextSibling); return txt; } This function goes through all nodes within an element and gathers the text of all text nodes, and text within descendants: E.g. <div id="x">foo <em>foo...</em> foo</div> Result: getText(document.getElementById('x')); // => "foo foo... foo" I'm quite sure there are issues with using innerText and textContent, but I've not been able to find a definitive list anywhere and I am starting to wonder if it's just hearsay. Can anyone offer any information about the possibly lacking reliability of textContent/innerText? EDIT: Found this great answer by Kangax -- http://stackoverflow.com/questions/1359469/innertext-works-in-ie-but-not-in-firefox/1359822#1359822

  Read the article

• T-SQL Improvements And Data Types in ms sql 2008

  - by Aamir Hasan

   Microsoft SQL Server 2008 is a new version released in the first half of 2008 introducing new properties and capabilities to SQL Server product family. All these new and enhanced capabilities can be defined as the classic words like secure, reliable, scalable and manageable. SQL Server 2008 is secure. It is reliable. SQL2008 is scalable and is more manageable when compared to previous releases. Now we will have a look at the features that are making MS SQL Server 2008 more secure, more reliable, more scalable, etc. in details.Microsoft SQL Server 2008 provides T-SQL enhancements that improve performance and reliability. Itzik discusses composable DML, the ability to declare and initialize variables in the same statement, compound assignment operators, and more reliable object dependency information. Table-Valued ParametersInserts into structures with 1-N cardinality problematicOne order -> N order line items"N" is variable and can be largeDon't want to force a new order for every 20 line itemsOne database round-trip / line item slows things downNo ARRAY data type in SQL ServerXML composition/decomposition used as an alternativeTable-valued parameters solve this problemTable-Valued ParametersSQL Server has table variablesDECLARE @t TABLE (id int);SQL Server 2008 adds strongly typed table variablesCREATE TYPE mytab AS TABLE (id int);DECLARE @t mytab;Parameters must use strongly typed table variables Table Variables are Input OnlyDeclare and initialize TABLE variable  DECLARE @t mytab;  INSERT @t VALUES (1), (2), (3);  EXEC myproc @t;Procedure must declare variable READONLY  CREATE PROCEDURE usetable (    @t mytab READONLY ...)  AS    INSERT INTO lineitems SELECT * FROM @t;    UPDATE @t SET... -- no!T-SQL Syntax EnhancementsSingle statement declare and initialize  DECLARE @iint = 4;Compound Assignment Operators  SET @i += 1;Row constructors  DECLARE @t TABLE (id int, name varchar(20));  INSERT INTO @t VALUES    (1, 'Fred'), (2, 'Jim'), (3, 'Sue');Grouping SetsGrouping Sets allow multiple GROUP BY clauses in a single SQL statementMultiple, arbitrary, sets of subtotalsSingle read pass for performanceNested subtotals provide ever better performanceGrouping Sets are an ANSI-standardCOMPUTE BY is deprecatedGROUPING SETS, ROLLUP, CUBESQL Server 2008 - ANSI-syntax ROLLUP and CUBEPre-2008 non-ANSI syntax is deprecatedWITH ROLLUP produces n+1 different groupings of datawhere n is the number of columns in GROUP BYWITH CUBE produces 2^n different groupingswhere n is the number of columns in GROUP BYGROUPING SETS provide a "halfway measure"Just the number of different groupings you needGrouping Sets are visible in query planGROUPING_ID and GROUPINGGrouping Sets can produce non-homogeneous setsGrouping set includes NULL values for group membersNeed to distinguish by grouping and NULL valuesGROUPING (column expression) returns 0 or 1Is this a group based on column expr. or NULL value?GROUPING_ID (a,b,c) is a bitmaskGROUPING_ID bits are set based on column expressions a, b, and cMERGE StatementMultiple set operations in a single SQL statementUses multiple sets as inputMERGE target USING source ON ...Operations can be INSERT, UPDATE, DELETEOperations based onWHEN MATCHEDWHEN NOT MATCHED [BY TARGET] WHEN NOT MATCHED [BY SOURCE]More on MERGEMERGE statement can reference a $action columnUsed when MERGE used with OUTPUT clauseMultiple WHEN clauses possible For MATCHED and NOT MATCHED BY SOURCEOnly one WHEN clause for NOT MATCHED BY TARGETMERGE can be used with any table sourceA MERGE statement causes triggers to be fired onceRows affected includes total rows affected by all clausesMERGE PerformanceMERGE statement is transactionalNo explicit transaction requiredOne Pass Through TablesAt most a full outer joinMatching rows = when matchedLeft-outer join rows = when not matched by targetRight-outer join rows = when not matched by sourceMERGE and DeterminismUPDATE using a JOIN is non-deterministicIf more than one row in source matches ON clause, either/any row can be used for the UPDATEMERGE is deterministicIf more than one row in source matches ON clause, its an errorKeeping Track of DependenciesNew dependency views replace sp_dependsViews are kept in sync as changes occursys.dm_sql_referenced_entitiesLists all named entities that an object referencesExample: which objects does this stored procedure use?sys.dm_sql_referencing_entities 

  Read the article

• USB software protection dongle for Java with an SDK which is cross-platform “for real”. Does it exist?

  - by Unai Vivi

  What I'd like to ask is if anybody knows about an hardware USB-dongle for software protection which offers a very complete out-of-the-box API support for cross-platform Java deployments. Its SDK should provide a jar (only one, not one different library per OS & bitness) ready to be added to one's project as a library. The jar should contain all the native stuff for the various OSes and bitnesses From the application's point of view, one should continue to write (api calls) once and run everywhere, without having to care where the end-user will run the software The provided jar should itself deal with loading the appropriate native library Does such a thing exist? With what I've tried so far, you have different APIs and compiled libraries for win32, linux32, win64, linux64, etc (or you even have to compile stuff yourself on the target machine), but hey, we're doing Java here, we don't know (and don't care) where the program will run! And we can't expect the end-user to be a software engineer, tweak (and break!) its linux server, link libraries, mess with gcc, litter the filesystem, etc... In general, Java support (in a transparent cross-platform fashion) is quite bad with the dongle SDKs I've evaluated so far (e.g. KeyLok and SecuTech's UniKey). I even purchased (no free evaluation kit available) SecureMetric SDKs&dongles (they should've been "soooo" straighforward to integrate -- according to marketing material :\ ) and they were the worst ever: SecureDongle X has no 64bit support and SecureDongle SD is not cross-platform at all. So, has anyone out there been through this and found the ultimate Java security usb dongle for cross-platform deployments? Note: software is low-volume, high-value; application is off-line (intranet with no internet access), so no online-activation alternatives and the like. -- EDIT Tried out HASP dongles (used to be called "Aladdin"), and added them to the no-no list: here, too, there is no out-of-the-box (out-of-the-jar) support: e.g. end-linux-user has to manually put the .so library (the specific file for the appropriate bitness) in the right place on his filesystem, and export an env. variable accordingly. -- EDIT 2 I really don't understand all the negativity and all the downvoting: is this a taboo topic? Is it so hard to understand that a freelance developer has to put food on the table everyday to feed its family and pay the bills at the end of the month? Please don't talk about "adding value" as a supplier, because that'd be off-topic. Furthermore I'm not in direct contact with end-customers, but there's an intermediate reselling entity: it's this entity I want to prevent selling copies of the software without sharing the revenue. -- EDIT 3 I'd like to emphasize the fact that the question is looking for a technical answer, not one about opinions concerning business models, philosophical lucubrations on the concept of value, resellers' reliability, etc. I cannot change resellers, because this isn't a "general purpose" kind of sw, but a very vertical one and (for some reasons it's not worth explaining here) I must go through them. I just need to prevent the "we sold 2 copies, here's your share [bwahaha we sold 10]" scenario.

  Read the article

• New Communications Industry Data Model with "Factory Installed" Predictive Analytics using Oracle Da

  - by charlie.berger

  Oracle Introduces Oracle Communications Data Model to Provide Actionable Insight for Communications Service Providers   We've integrated pre-installed analytical methodologies with the new Oracle Communications Data Model to deliver automated, simple, yet powerful predictive analytics solutions for customers.  Churn, sentiment analysis, identifying customer segments - all things that can be anticipated and hence, preconcieved and implemented inside an applications.  Read on for more information! TM Forum Management World, Nice, France - 18 May 2010 News Facts To help communications service providers (CSPs) manage and analyze rapidly growing data volumes cost effectively, Oracle today introduced the Oracle Communications Data Model. With the Oracle Communications Data Model, CSPs can achieve rapid time to value by quickly implementing a standards-based enterprise data warehouse that features communications industry-specific reporting, analytics and data mining. The combination of the Oracle Communications Data Model, Oracle Exadata and the Oracle Business Intelligence (BI) Foundation represents the most comprehensive data warehouse and BI solution for the communications industry. Also announced today, Hong Kong Broadband Network enhanced their data warehouse system, going live on Oracle Communications Data Model in three months. The leading provider increased its subscriber base by 37 percent in six months and reduced customer churn to less than one percent. Product Details Oracle Communications Data Model provides industry-specific schema and embedded analytics that address key areas such as customer management, marketing segmentation, product development and network health. CSPs can efficiently capture and monitor critical data and transform it into actionable information to support development and delivery of next-generation services using: More than 1,300 industry-specific measurements and key performance indicators (KPIs) such as network reliability statistics, provisioning metrics and customer churn propensity. Embedded OLAP cubes for extremely fast dimensional analysis of business information. Embedded data mining models for sophisticated trending and predictive analysis. Support for multiple lines of business, such as cable, mobile, wireline and Internet, which can be easily extended to support future requirements. With Oracle Communications Data Model, CSPs can jump start the implementation of a communications data warehouse in line with communications-industry standards including the TM Forum Information Framework (SID), formerly known as the Shared Information Model. Oracle Communications Data Model is optimized for any Oracle Database 11g platform, including Oracle Exadata, which can improve call data record query performance by 10x or more. Supporting Quotes "Oracle Communications Data Model covers a wide range of business areas that are relevant to modern communications service providers and is a comprehensive solution - with its data model and pre-packaged templates including BI dashboards, KPIs, OLAP cubes and mining models. It helps us save a great deal of time in building and implementing a customized data warehouse and enables us to leverage the advanced analytics quickly and more effectively," said Yasuki Hayashi, executive manager, NTT Comware Corporation. "Data volumes will only continue to grow as communications service providers expand next-generation networks, deploy new services and adopt new business models. They will increasingly need efficient, reliable data warehouses to capture key insights on data such as customer value, network value and churn probability. With the Oracle Communications Data Model, Oracle has demonstrated its commitment to meeting these needs by delivering data warehouse tools designed to fill communications industry-specific needs," said Elisabeth Rainge, program director, Network Software, IDC. "The TM Forum Conformance Mark provides reassurance to customers seeking standards-based, and therefore, cost-effective and flexible solutions. TM Forum is extremely pleased to work with Oracle to certify its Oracle Communications Data Model solution. Upon successful completion, this certification will represent the broadest and most complete implementation of the TM Forum Information Framework to date, with more than 130 aggregate business entities," said Keith Willetts, chairman and chief executive officer, TM Forum. Supporting Resources Oracle Communications Oracle Communications Data Model Data Sheet Oracle Communications Data Model Podcast Oracle Data Warehousing Oracle Communications on YouTube Oracle Communications on Delicious Oracle Communications on Facebook Oracle Communications on Twitter Oracle Communications on LinkedIn Oracle Database on Twitter The Data Warehouse Insider Blog

  Read the article

• MongoDB usage best practices

  - by andresv

  The project I'm working on uses MongoDB for some stuff so I'm creating some documents to help developers speedup the learning curve and also avoid mistakes and help them write clean & reliable code. This is my first version of it, so I'm pretty sure I will be adding more stuff to it, so stay tuned! C# Official driver notes The 10gen official MongoDB driver should always be referenced in projects by using NUGET. Do not manually download and reference assemblies in any project. C# driver quickstart guide: http://www.mongodb.org/display/DOCS/CSharp+Driver+Quickstart Reference links C# Language Center: http://www.mongodb.org/display/DOCS/CSharp+Language+Center MongoDB Server Documentation: http://www.mongodb.org/display/DOCS/Home MongoDB Server Downloads: http://www.mongodb.org/downloads MongoDB client drivers download: http://www.mongodb.org/display/DOCS/Drivers MongoDB Community content: http://www.mongodb.org/display/DOCS/CSharp+Community+Projects Tutorials Tutorial MongoDB con ASP.NET MVC - Ejemplo Práctico (Spanish):http://geeks.ms/blogs/gperez/archive/2011/12/02/tutorial-mongodb-con-asp-net-mvc-ejemplo-pr-225-ctico.aspx MongoDB and C#:http://www.codeproject.com/Articles/87757/MongoDB-and-C C# driver LINQ tutorial:http://www.mongodb.org/display/DOCS/CSharp+Driver+LINQ+Tutorial C# driver reference: http://www.mongodb.org/display/DOCS/CSharp+Driver+Tutorial Safe Mode Connection The C# driver supports two connection modes: safe and unsafe. Safe connection mode (only applies to methods that modify data in a database like Inserts, Deletes and Updates. While the current driver defaults to unsafe mode (safeMode == false) it's recommended to always enable safe mode, and force unsafe mode on specific things we know aren't critical. When safe mode is enabled, the driver internal code calls the MongoDB "getLastError" function to ensure the last operation is completed before returning control the the caller. For more information on using safe mode and their implicancies on performance and data reliability see: http://www.mongodb.org/display/DOCS/getLastError+Command If safe mode is not enabled, all data modification calls to the database are executed asynchronously (fire & forget) without waiting for the result of the operation. This mode could be useful for creating / updating non-critical data like performance counters, usage logging and so on. It's important to know that not using safe mode implies that data loss can occur without any notification to the caller. As with any wait operation, enabling safe mode also implies dealing with timeouts. For more information about C# driver safe mode configuration see: http://www.mongodb.org/display/DOCS/CSharp+getLastError+and+SafeMode The safe mode configuration can be specified at different levels: Connection string: mongodb://hostname/?safe=true Database: when obtaining a database instance using the server.GetDatabase(name, safeMode) method Collection: when obtaining a collection instance using the database.GetCollection(name, safeMode) method Operation: for example, when executing the collection.Insert(document, safeMode) method Some useful SafeMode article: http://stackoverflow.com/questions/4604868/mongodb-c-sharp-safemode-official-driver Exception Handling The driver ensures that an exception will be thrown in case of something going wrong, in case of using safe mode (as said above, when not using safe mode no exception will be thrown no matter what the outcome of the operation is). As explained here https://groups.google.com/forum/?fromgroups#!topic/mongodb-user/mS6jIq5FUiM there is no need to check for any returned value from a driver method inserting data. With updates the situation is similar to any other relational database: if an update command doesn't affect any records, the call will suceed anyway (no exception thrown) and you manually have to check for something like "records affected". For MongoDB, an Update operation will return an instance of the "SafeModeResult" class, and you can verify the "DocumentsAffected" property to ensure the intended document was indeed updated. Note: Please remember that an Update method might return a null instance instead of an "SafeModeResult" instance when safe mode is not enabled. Useful Community Articles Comments about how MongoDB works and how that might affect your application: http://ethangunderson.com/blog/two-reasons-to-not-use-mongodb/ FourSquare using MongoDB had serious scalability problems: http://mashable.com/2010/10/07/mongodb-foursquare/ Is MongoDB a replacement for Memcached? http://www.quora.com/Is-MongoDB-a-good-replacement-for-Memcached/answer/Rick-Branson MongoDB Introduction, shell, when not to use, maintenance, upgrade, backups, memory, sharding, etc: http://www.markus-gattol.name/ws/mongodb.html MongoDB Collection level locking support: https://jira.mongodb.org/browse/SERVER-1240 MongoDB performance tips: http://www.quora.com/MongoDB/What-are-some-best-practices-for-optimal-performance-of-MongoDB-particularly-for-queries-that-involve-multiple-documents Lessons learned migrating from SQL Server to MongoDB: http://www.wireclub.com/development/TqnkQwQ8CxUYTVT90/read MongoDB replication performance: http://benshepheard.blogspot.com.ar/2011/01/mongodb-replication-performance.html

  Read the article

• Oracle’s New Memory-Optimized x86 Servers: Getting the Most Out of Oracle Database In-Memory

  - by Josh Rosen, x86 Product Manager-Oracle

  With the launch of Oracle Database In-Memory, it is now possible to perform real-time analytics operations on your business data as it exists at that moment – in the DRAM of the server – and immediately return completely current and consistent data. The Oracle Database In-Memory option dramatically accelerates the performance of analytics queries by storing data in a highly optimized columnar in-memory format.  This is a truly exciting advance in database technology.As Larry Ellison mentioned in his recent webcast about Oracle Database In-Memory, queries run 100 times faster simply by throwing a switch.  But in order to get the most from the Oracle Database In-Memory option, the underlying server must also be memory-optimized. This week Oracle announced new 4-socket and 8-socket x86 servers, the Sun Server X4-4 and Sun Server X4-8, both of which have been designed specifically for Oracle Database In-Memory.  These new servers use the fastest Intel® Xeon® E7 v2 processors and each subsystem has been designed to be the best for Oracle Database, from the memory, I/O and flash technologies right down to the system firmware.Amongst these subsystems, one of the most important aspects we have optimized with the Sun Server X4-4 and Sun Server X4-8 are their memory subsystems.  The new In-Memory option makes it possible to select which parts of the database should be memory optimized.  You can choose to put a single column or table in memory or, if you can, put the whole database in memory.  The more, the better.  With 3 TB and 6 TB total memory capacity on the Sun Server X4-4 and Sun Server X4-8, respectively, you can memory-optimize more, if not your entire database.   Sun Server X4-8 CMOD with 24 DIMM slots per socket (up to 192 DIMM slots per server) But memory capacity is not the only important factor in selecting the best server platform for Oracle Database In-Memory.  As you put more of your database in memory, a critical performance metric known as memory bandwidth comes into play.  The total memory bandwidth for the server will dictate the rate in which data can be stored and retrieved from memory.  In order to achieve real-time analysis of your data using Oracle Database In-Memory, even under heavy load, the server must be able to handle extreme memory workloads.  With that in mind, the Sun Server X4-8 was designed with the maximum possible memory bandwidth, providing over a terabyte per second of total memory bandwidth.  Likewise, the Sun Server X4-4 also provides extreme memory bandwidth in an even more compact form factor with over half a terabyte per second, providing customers with scalability and choice depending on the size of the database.Beyond the memory subsystem, Oracle’s Sun Server X4-4 and Sun Server X4-8 systems provide other key technologies that enable Oracle Database to run at its best.  The Sun Server X4-4 allows for up 4.8 TB of internal, write-optimized PCIe flash while the Sun Server X4-8 allows for up to 6.4 TB of PCIe flash.  This enables dramatic acceleration of data inserts and updates to Oracle Database.  And with the new elastic computing capability of Oracle’s new x86 servers, server performance can be adapted to your specific Oracle Database workload to ensure that every last bit of processing power is utilized.Because Oracle designs and tests its x86 servers specifically for Oracle workloads, we provide the highest possible performance and reliability when running Oracle Database.  To learn more about Sun Server X4-4 and Sun Server X4-8, you can find more details including data sheets and white papers here. Josh Rosen is a Principal Product Manager for Oracle’s x86 servers, focusing on Oracle’s operating systems and software.  He previously spent more than a decade as a developer and architect of system management software. Josh has worked on system management for many of Oracle's hardware products ranging from the earliest blade systems to the latest Oracle x86 servers. 

  Read the article

• OSI Model

  - by kaleidoscope

  The Open System Interconnection Reference Model (OSI Reference Model or OSI Model) is an abstract description for layered communications and computer network protocol design. In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer Model. A layer is a collection of conceptually similar functions that provide services to the layer above it and receives service from the layer below it. Description of OSI layers: Layer 1: Physical Layer ·         Defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. ·         Establishment and termination of a connection to a communications medium. ·         Participation in the process whereby the communication resources are effectively shared among multiple users. ·         Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel. Layer 2: Data Link Layer ·         Provides the functional and procedural means to transfer data between network entities. ·         Detect and possibly correct errors that may occur in the Physical Layer. The error check is performed using Frame Check Sequence (FCS). ·         Addresses is then sought to see if it needs to process the rest of the frame itself or whether to pass it on to another host. ·         The Layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. ·         MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. ·         LLC layer controls frame synchronization, flow control and error checking.   Layer 3: Network Layer ·         Provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks. ·         Performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. ·         Network Layer Routers operate at this layer—sending data throughout the extended network and making the Internet possible.   Layer 4: Transport Layer ·         Provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers. ·         Controls the reliability of a given link through flow control, segmentation/de-segmentation, and error control. ·         Transport Layer can keep track of the segments and retransmit those that fail. Layer 5: Session Layer ·         Controls the dialogues (connections) between computers. ·         Establishes, manages and terminates the connections between the local and remote application. ·         Provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. ·         Implemented explicitly in application environments that use remote procedure calls. Layer 6: Presentation Layer ·         Establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the presentation service understands both and the mapping between them. The presentation service data units are then encapsulated into Session Protocol data units, and moved down the stack. ·         Provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer. Layer 7: Application Layer ·         This layer interacts with software applications that implement a communicating component. ·         Identifies communication partners, determines resource availability, and synchronizes communication. o       When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. o       When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists. o       In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer. Technorati Tags: Kunal,OSI,Networking

  Read the article

• Listen to Online Radio with Antenna

  - by Asian Angel

  Are you looking for some fresh new music to listen to at home or at work? With Antenna you can listen to online radio stations from all over the world. Note: Requires Adobe AIR (download link at bottom of article). Antenna in Action Once you have completed the installation and started Antenna up this is the window that you will see. The left side will have a “browsing pane” where you can search for the stations that you would like to listen to using the various categories. Based on the stations that you choose the background map will change location to match the stations locations. Here is a closer look at the “Categories Bar”. For our first example we used the “Country Category” to find our first station to listen to. When you choose a country you will be presented with a list of the stations available for that country. To start listening to a particular station just double click on the appropriate entry line. A closer look at the “browser pane” with our first station playing. Notice the “Reliability Indicator” that will be available for each listing…some may be better than others and you can use this to choose the best streaming stations from the list. In the upper left corner you will notice three icons…each will open a small pop-up window with a specific purpose. The first icon will open up the “About Window”. If you need to contact Antenna’s creator or would like to place a request for a station to be added to the app then this is the best way to do it. The second icon will open up a Antenna specific chat window. The third icon will allow you to set a default location and make adjustments to some of the app’s settings. Recording Audio The “Recording Function” is the only area where we experienced some “quirkiness” with the app. To start recording press the “Round White Button”… Note: Based on feedback on the app creator’s webpage some people have experienced the same problem as we did during our tests with the app failing to complete the recordings. Hopefully this bug will be fixed with the next release. Once recording has started the button will turn red. Click on the button again to stop recording. Once you have stopped recording you will see the following message window appear and the main window will be shaded over with a whitish color until you click “OK”. Conclusion Regardless of the slight quirkiness in recording online music Antenna more than makes up for it with the terrific selection of online stations and streaming capability. New fresh music for you to listen to is only a click or two away… Links Download Antenna (Antenna Homepage) Download Antenna at Softpedia Download Adobe AIR Similar Articles Productive Geek Tips Listen to Local FM Radio in Windows 7 Media CenterListen to Over 100,000 Radio Stations in Windows Media CenterListen To XM Radio with Windows Media Center in Windows 7Listen and Record Over 12,000 Online Radio Stations with RadioSureWeekend Fun: Watch Television on Your PC with AnyTV TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Will it Blend? iPad Edition Penolo Lets You Share Sketches On Twitter Visit Woolyss.com for Old School Games, Music and Videos Add a Custom Title in IE using Spybot or Spyware Blaster When You Need to Hail a Taxi in NYC Live Map of Marine Traffic

  Read the article

• Monitor System Resources from the Windows 7 Taskbar

  - by Asian Angel

  The problem with most system monitoring apps is that they get covered up with all of your open windows, but you can solve that problem by adding monitoring apps to the Taskbar. Setting Up & Using SuperbarMonitor All of the individual monitors and the .dll files necessary to run them come in a single zip file for your convenience. Simply unzip the contents, add them to an appropriate “Program Files Folder”, and create shortcuts for the monitors that you would like to use on your system. For our example we created shortcuts for all five monitors and set the shortcuts up in their own “Start Menu Folder”. You can see what the five monitors (Battery, CPU, Disk, Memory, & Volume) look like when running…they are visual in appearance without text to clutter up the looks. The monitors use colors (red, green, & yellow) to indicate the amount of resources being used for a particular category. Note: Our system is desktop-based but the “Battery Monitor” was shown for the purposes of demonstration…thus the red color seen here. Hovering the mouse over the “Battery, CPU, Disk, & Memory Monitors” on our system displayed a small blank thumbnail. Note: The “Battery Monitor” may or may not display more when used on your laptop. Going one step further and hovering the mouse over the thumbnails displayed a small blank window. There really is nothing that you will need to worry with outside of watching the color for each individual monitor. Nice and simple! The one monitor with extra features on the thumbnail was the “Volume Monitor”. You can turn the volume down, up, on, or off from here…definitely useful if you have been wanting to hide the “Volume Icon” in the “System Tray”. You can also pin the monitors to your “Taskbar” if desired. Keep in mind that if you do close any of the monitors they will “temporarily” disappear from the “Taskbar” until the next time they are started. Note: If you want the monitors to start with your system each time you will need to add the appropriate shortcuts to the “Startup Sub-menu” in your “Start Menu”. Conclusion If you have been wanting a nice visual way to monitor your system’s resources then SuperbarMonitor is definitely worth trying out. Links Download SuperbarMonitor Similar Articles Productive Geek Tips Monitor CPU, Memory, and Disk IO In Windows 7 with Taskbar MetersUse Windows Vista Reliability Monitor to Troubleshoot CrashesTaskbar Eliminator Does What the Name Implies: Hides Your Windows TaskbarBring Misplaced Off-Screen Windows Back to Your Desktop (Keyboard Trick)How To Fix System Tray Tooltips Not Displaying in Windows XP TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites

  Read the article

• Oracle WebLogic Server and Oracle Database: A Robust Infrastructure for your Applications

  - by Ruma Sanyal

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 It has been said that a chain is as strong as its weakest link. Well, this is also true for your application infrastructure. Not only are the various components that constitute your infrastructure, like database and application server critical, the integration between these things [whether coming out of the box from your vendor or done in-house] is paramount. Imagine your database being down and your application server not knowing about it and as a result your application waiting indefinitely for a database response – not a great situation if high availability is critical to your application. Or one of your database nodes is very busy, but your application server doesn’t have the intelligence to decipher that – it keeps pinging the busy node when it can in fact get a response from another idle node much faster. This is what Oracle WebLogic and Database integration provides: Intelligent integration out of the box. Tight integration between Oracle WebLogic and Database makes your infrastructure robust enough that not only does each of your infrastructure component provide you with improved RASP [reliability availability, scalability, and performance] but these components work together to offer improved performance & availability, better resource sharing, inherent scalability, ease of configuration and automated management for your entire infrastructure. Oracle WebLogic Server is the only application server with this degree of integration to Oracle Database. With Oracle WebLogic Server 11g, we introduced Active GridLink for Real Application Clusters (RAC). In conjunction with Oracle Database, this powerful software technology simplifies management, increases availability, and ensures fast connection failover with runtime connection, load balancing and affinity capabilities. With the release of Oracle Database 12c this summer, even tighter integration between Oracle WebLogic Server 12c (12.1.2) and Oracle Database 12c has been achieved and this further optimizes the integration for a global cloud environment. Read about these capabilities in detail in the Oracle WebLogic-Database Integration Whitepaper. Get in depth ‘how-to’ details from this YouTube video on the topic from our resident expert, Monica Roccelli. /* 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;}

  Read the article

• Functional/nonfunctional requirements VS design ideas

  - by Nicholas Chow

  Problem domain Functional requirements defines what a system does. Non-Functional requirements defines quality attributes of what the system does as a whole.(performance, security, reliability, volume, useability, etc.) Constraints limits the design space, they restrict designers to certain types of solutions. Solution domain Design ideas , defines how the system does it. For example a stakeholder need might be we want to increase our sales, therefore we must improve the usability of our webshop so more customers will purchase, a requirement can be written for this. (problem domain) Design takes this further into the solution domain by saying "therefore we want to offer credit card payments in addition to the current prepayment option". My problem is that the transition phase from requirement to design seems really vague, therefore when writing requirements I am often confused whether or not I incorporated design ideas in my requirements, that would make my requirement wrong. Another problem is that I often write functional requirements as what a system does, and then I also specify in what timeframe it must be done. But is this correct? Is it then a still a functional requirement or a non functional one? Is it better to seperate it into two distinct requirements? Here are a few requirements I wrote: FR1 Registration of Organizer FR1 describes the registration of an Organizer on CrowdFundum FR1.1 The system shall display a registration form on the website. FR1.2 The system shall require a Name, Username, Document number passport/ID card, Address, Zip code, City, Email address, Telephone number, Bank account, Captcha code on the registration form when a user registers. FR1.4 The system shall display an error message containing: “Registration could not be completed” to the subscriber within 1 seconds after the system check of the registration form was unsuccessful. FR1.5 The system shall send a verification email containing a verification link to the subscriber within 30 seconds after the system check of the registration form was successful. FR1.6 The system shall add the newly registered Organizer to the user base within 5 seconds after the verification link was accessed. FR2 Organizer submits a Project FR2 describes the submission of a Project by an Organizer on CrowdFundum - FR2 The system shall display a submit Project form to the Organizer accounts on the website.< - FR2.3 The system shall check for completeness the Name of the Project, 1-3 Photo’s, Keywords of the Project, Punch line, Minimum and maximum amount of people, Funding threshold, One or more reward tiers, Schedule of when what will be organized, Budget plan, 300-800 Words of additional information about the Project, Contact details within 1 secondin after an Organizer submits the submit Project form. - FR2.8 The system shall add to the homepage in the new Projects category the Project link within 30 seconds after the system made a Project webpage - FR2.9 The system shall include in the Project link for the homepage : Name of the Project, 1 Photo, Punch line within 30 seconds after the system made a Project webpage. Questions: FR 1.1 : Have I incorporated a design idea here, would " the system shall have a registration form" be a better functional requirement? F1.2 ,2.3 : Is this not singular? Would the conditions be better written for each its own separate requirement FR 1.4: Is this a design idea? Is this a correct functional requirement or have I incorporated non functional(performance) in it? Would it be better if I written it like this: FR1 The system shall display an error message when check is unsuccessful. NFR: The system will respond to unsuccesful registration form checks within 1 seconds. Same question with FR 2.8 and 2.9. FR2.3: The system shall check for "completeness", is completeness here used ambigiously? Should I rephrase it? FR1.2: I added that the system shall require a "Captcha code" is this a functional requirement or does it belong to the "security aspect" of a non functional requirement. I am eagerly waiting for your response. Thanks!

  Read the article

• CacheAdapter 2.4 – Bug fixes and minor functional update

  - by Glav

  Note: If you are unfamiliar with the CacheAdapter library and what it does, you can read all about its awesome ability to utilise memory, Asp.Net Web, Windows Azure AppFabric and memcached caching implementations via a single unified, simple to use API from here and here.. The CacheAdapter library is receiving an update to version 2.4 and is currently available on Nuget here. Update: The CacheAdapter has actualy just had a minor revision to 2.4.1. This significantly increases the performance and reliability in memcached scenario under more extreme loads. General to moderate usage wont see any noticeable difference though. Bugs This latest version fixes a big that is only present in the memcached implementation and is only seen in rare, intermittent times (making i particularly hard to find). The bug is where a cache node would be removed from the farm when errors in deserialization of cached objects would occur due to serialised data not being read from the stream in entirety. The code also contains enhancements to better surface serialization exceptions to aid in the debugging process. This is also specifically targeted at the memcached implementation. This is important when moving from something like memory or Asp.Web caching mechanisms to memcached where the serialization rules are not as lenient. There are a few other minor bug fixes, code cleanup and a little refactoring. Minor feature addition In addition to this bug fix, many people have asked for a single setting to either enable or disable the cache.In this version, you can disable the cache by setting the IsCacheEnabled flag to false in the application configuration file. Something like the example below: <Glav.CacheAdapter.MainConfig> <setting name="CacheToUse" serializeAs="String"> <value>memcached</value> </setting> <setting name="DistributedCacheServers" serializeAs="String"> <value>localhost:11211</value> </setting> <setting name="IsCacheEnabled" serializeAs="String"> <value>False</value> </setting> </Glav.CacheAdapter.MainConfig> Your reasons to use this feature may vary (perhaps some performance testing or problem diagnosis). At any rate, disabling the cache will cause every attempt to retrieve data from the cache, resulting in a cache miss and returning null. If you are using the ICacheProvider with the delegate/Func<T> syntax to populate the cache, this delegate method will get executed every single time. For example, when the cache is disabled, the following delegate/Func<T> code will be executed every time: var data1 = cacheProvider.Get<SomeData>("cache-key", DateTime.Now.AddHours(1), () => { // With the cache disabled, this data access code is executed every attempt to // get this data via the CacheProvider. var someData = new SomeData() { SomeText = "cache example1", SomeNumber = 1 }; return someData; }); One final note: If you access the cache directly via the ICache instance, instead of the higher level ICacheProvider API, you bypass this setting and still access the underlying cache implementation. Only the ICacheProvider instance observes the IsCacheEnabled setting. Thanks to those individuals who have used this library and provided feedback. Ifyou have any suggestions or ideas, please submit them to the issue register on bitbucket (which is where you can grab all the source code from too)

  Read the article

• 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.

  Read the article

• The Latest Major Release of AutoVue is Now Available!

  - by Pam Petropoulos

  Click here to read the full press release. To learn more about AutoVue 20.2, check out the What's New in AutoVue 20.2 Datasheet AutoVue 20.2 continues to set the standard for enterprise level visualization with Augmented Business Visualization, a new paradigm which reconciles information and business data from multiple sources into a single view, providing rich and actionable visual decision-making environments. The release also includes; capabilities that enhance end-to-end approval workflow; solutions to visually enable the mobile workforce; and support for the latest manufacturing and high tech formats.     New capabilities in release 20.2 include: ·         Enhancements to the Augmented Business Visualization framework o    Creation of 2D hotspots has been extended in 2D drawings, PDF and image files and can now be defined as regional boxes, rather than just text strings o    New 3D Hotspot links in models and drawings. Parts or components of 3D models can be selected to create hotspot links. ·         Enhanced end-to-end approval workflows with digital stamping and batch stamping improvements ·         Solutions that visually enable the mobile workforce and extend enterprise visualization to mobile devices, including iPads through OVDI (Oracle Virtual Desktop Infrastructure) ·         Enhancements to AutoVue enterprise readiness: reliability and performance improvements, as well as security enhancements which adhere to Oracle’s Software Security Assurance standards ·         Timely support for new MCAD, ECAD, and Office formats ·         New 20.2 versions of AutoVue Document Print Services and Integration SDK (iSDK) ·         New Dutch language availability   The press release also contains terrific supporting quotes from AutoVue customers and partners.        “AutoVue’s stamping enhancements will greatly benefit our building permit management processes,” said Ties Kremer, Information Manager, Noordenveld Municipality, Netherlands. “The ability to batch stamp documents will speed up our approval processes, enable us to save time and money, and help us meet our regulatory compliance obligations.”          “AutoVue provides our non-technical teams in marketing and sales with access to customer order requirements and supporting CAD documents and drawings,” said James Lim, Regional Technical Systems Manager at Molex Incorporated. “AutoVue 20.2 has enabled us to refine our quotation process, and reduce order errors.”         “We are excited about our use of AutoVue’s Augmented Business Visualization framework, which will offer Meridian users enhanced access to related technical documentation,” said Edwin van Dijk, Director of Product Management, BlueCielo.  “By including AutoVue’s new regional hotspot capabilities within BlueCielo Meridian Enterprise, the context of engineering information is carried over into the visual representation of complex assets, thereby helping us to improve productivity and operational excellence.”    

  Read the article

• Learn Many Languages

  - by Jeff Foster

  My previous blog, Deliberate Practice, discussed the need for developers to “sharpen their pencil” continually, by setting aside time to learn how to tackle problems in different ways. However, the Sapir-Whorf hypothesis, a contested and somewhat-controversial concept from language theory, seems to hold reasonably true when applied to programming languages. It states that: “The structure of a language affects the ways in which its speakers conceptualize their world.” If you’re constrained by a single programming language, the one that dominates your day job, then you only have the tools of that language at your disposal to think about and solve a problem. For example, if you’ve only ever worked with Java, you would never think of passing a function to a method. A good developer needs to learn many languages. You may never deploy them in production, you may never ship code with them, but by learning a new language, you’ll have new ideas that will transfer to your current “day-job” language. With the abundant choices in programming languages, how does one choose which to learn? Alan Perlis sums it up best. “A language that doesn‘t affect the way you think about programming is not worth knowing“ With that in mind, here’s a selection of languages that I think are worth learning and that have certainly changed the way I think about tackling programming problems. Clojure Clojure is a Lisp-based language running on the Java Virtual Machine. The unique property of Lisp is homoiconicity, which means that a Lisp program is a Lisp data structure, and vice-versa. Since we can treat Lisp programs as Lisp data structures, we can write our code generation in the same style as our code. This gives Lisp a uniquely powerful macro system, and makes it ideal for implementing domain specific languages. Clojure also makes software transactional memory a first-class citizen, giving us a new approach to concurrency and dealing with the problems of shared state. Haskell Haskell is a strongly typed, functional programming language. Haskell’s type system is far richer than C# or Java, and allows us to push more of our application logic to compile-time safety. If it compiles, it usually works! Haskell is also a lazy language – we can work with infinite data structures. For example, in a board game we can generate the complete game tree, even if there are billions of possibilities, because the values are computed only as they are needed. Erlang Erlang is a functional language with a strong emphasis on reliability. Erlang’s approach to concurrency uses message passing instead of shared variables, with strong support from both the language itself and the virtual machine. Processes are extremely lightweight, and garbage collection doesn’t require all processes to be paused at the same time, making it feasible for a single program to use millions of processes at once, all without the mental overhead of managing shared state. The Benefits of Multilingualism By studying new languages, even if you won’t ever get the chance to use them in production, you will find yourself open to new ideas and ways of coding in your main language. For example, studying Haskell has taught me that you can do so much more with types and has changed my programming style in C#. A type represents some state a program should have, and a type should not be able to represent an invalid state. I often find myself refactoring methods like this… void SomeMethod(bool doThis, bool doThat) { if (!(doThis ^ doThat)) throw new ArgumentException(“At least one arg should be true”); if (doThis) DoThis(); if (doThat) DoThat(); } …into a type-based solution, like this: enum Action { DoThis, DoThat, Both }; void SomeMethod(Action action) { if (action == Action.DoThis || action == Action.Both) DoThis(); if (action == Action.DoThat || action == Action.Both) DoThat(); } At this point, I’ve removed the runtime exception in favor of a compile-time check. This is a trivial example, but is just one of many ideas that I’ve taken from one language and implemented in another.

  Read the article

• Subversion vision and roadmap

  - by gbjbaanb

  Recently C Michael Pilato of the core subversion team posted a mail to the subversion dev mailing list suggesting a vision and roadmap for the future of Subversion. Naturally, he wanted as much feedback and response as possible which is why I'm posting this here - to elicit some suggestions and contributions from you, the administrators of Subversion. Any comments are welcome, and I shall feedback a synopsis with a link to this question to the dev mailing list. Similarly, I've created a post on StackOverflow to get feedback from the programmer/user side of things too. So, without further ado: Vision The first thing on his "vision statement" is: Subversion has no future as a DVCS tool. Let's just get that out there. At least two very successful such tools exist already, and to squeeze another horse into that race would be a poor investment of energy and talent. There's no need to suggest distributed features for subversion. If you want a DVCS, there should be no ill-feeling if you migrate to Git, Mercurial or Bazaar. As he says, its pointless trying to make SVN like them when they already exist, especially when there are different usage patterns that SVN should be targetting. The vision for Subversion is: Subversion exists to be universally recognized and adopted as an open-source, centralized version control system characterized by its reliability as a safe haven for valuable data; the simplicity of its model and usage; and its ability to support the needs of a wide variety of users and projects, from individuals to large-scale enterprise operations. Roadmap Several ideas were suggested as being "very nice to have" and are offered as the starting point of a future roadmap. These are: Obliterate Shelve/Checkpoint Repository-dictated Configuration Rename Tracking Improved Merging Improved Tree Conflict Handling Enterprise Authentication Mechanisms Forward History Searching Log Message Templates Repository-dictated Configuration If anyone has suggestions to add, or comments on these, the subversion community would welcome all of them. Community And lastly, there was a call for more people to become involved with Subversion development. As with most OSS projects it can be daunting to join, but there is now a push for more to be done to help. If you feel like you can contribute, please do so.

  Read the article

• Critique My Backup and Storage Plan

  - by MetaHyperBolic

  My current storage (RAID-1 off of a hardware RAID card) and backup (a spare drive) solutions for my home network are inadequate. I have too much data scattered on various one-off drives. It is time to evolve. Backups seem simple enough, at least: lots of big drives. However, I am bewildered by the number of choices for small home storage. The Drobo S looks appealing. So does the ReadyNAS. I am not looking for bunches of shiny features, I'm mostly interested in reliability. I am not interested in building Yet Another PC to create a file server or doing something in the cloud, or whatever. I'm stupid, so I am keeping it simple. Requirements for Main Volume: Starting working space roughly 2TB, with options for growth up to 5TB RAID or something RAID-like with at least one parity drive eSATA II for speed during backups Ability to shut down gracefully when alerted of low power by a UPS Optional but Desirable: Will take 2TB drives now with options for the larger 3TB drives coming in 2010-2011 Optional but Desirable: : RAID-6 or something similar, with two parity drives Optional but Desirable: : Hot spare Ethernet connection not required, as the volume will be shared via the same machines which runs my home print server Backups: Backup performed via ROBOCOPY in mirror mode to an external hard drive via a eSATA II connection. Start with rotating between two external 2TB hard drives, will go up to six external 2TB drives. Start with a weekly backup, move to a bi-weekly backup as more drives are added. Move to 3TB drives as the size of my main volume increases. Backup drives will be stored on an off-site location. Hard drives: I plan on buying all of the same model, but different batches from different vendors. I found a "burn-in" utility with which I can pound away on the drives for a couple of weeks before adding them to the backup pool or the main volume. I estimate that I am looking at roughly $1,500 to start, once I start throwing in two TB drives for backup and four for storage. So, are there any obvious flaws in my plan? What have I overlooked? Any suggestions for the storage device for my main volume that fits my requirements? Or do I just keep it simple, 2 drives in RAID-1, then perform due diligence with my backups, accepting that I will have to buy a whole new unit when my data grows past 2TB?

  Read the article

< Previous Page | 13 14 15 16 17 18 19 20 21  | Next Page >