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  • How Lead-Acid Batteries Work [Video]

    - by Jason Fitzpatrick
    Every morning when you go out and start your car, you’re pulling power from a lead-acid battery. But how exactly do they work? In this informative video we see how lead plates and sulfuric acid provide the power your car craves. Courtesy of Engineer Guy Video: Bill explains the essential principles of a lead-acid battery. He shows the inside of motorcycle lead-acid battery, removes the lead and lead-oxide plates and shows how they generate a 2 volt potential difference when placed in sulfuric acid. He explains how the build up of lead sulfate between the plates will make the battery unusable if it discharged completely, which leads him to a description of how to make a deep cycle battery used for collecting solar energy. [via Make] How to Use an Xbox 360 Controller On Your Windows PC Download the Official How-To Geek Trivia App for Windows 8 How to Banish Duplicate Photos with VisiPic

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  • IE9 Acid 3 test?

    - by yuval
    Does anybody know if Microsoft is planning on having IE9 pass with 100/100 on acid 3? The current version of IE9 gets a 68/100 on the test (can be viewed here, main site here). What did IE8 pass with? What about IE7? How does it compare to other modern browsers such as Safari, Firefox, and Chrome? Please submit useful answers, not opinions on how bad IE is, I don't like it either. Thanks a bunch!

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  • SQL SERVER – Core Concepts – Elasticity, Scalability and ACID Properties – Exploring NuoDB an Elastically Scalable Database System

    - by pinaldave
    I have been recently exploring Elasticity and Scalability attributes of databases. You can see that in my earlier blog posts about NuoDB where I wanted to look at Elasticity and Scalability concepts. The concepts are very interesting, and intriguing as well. I have discussed these concepts with my friend Joyti M and together we have come up with this interesting read. The goal of this article is to answer following simple questions What is Elasticity? What is Scalability? How ACID properties vary from NOSQL Concepts? What are the prevailing problems in the current database system architectures? Why is NuoDB  an innovative and welcome change in database paradigm? Elasticity This word’s original form is used in many different ways and honestly it does do a decent job in holding things together over the years as a person grows and contracts. Within the tech world, and specifically related to software systems (database, application servers), it has come to mean a few things - allow stretching of resources without reaching the breaking point (on demand). What are resources in this context? Resources are the usual suspects – RAM/CPU/IO/Bandwidth in the form of a container (a process or bunch of processes combined as modules). When it is about increasing resources the simplest idea which comes to mind is the addition of another container. Another container means adding a brand new physical node. When it is about adding a new node there are two questions which comes to mind. 1) Can we add another node to our software system? 2) If yes, does adding new node cause downtime for the system? Let us assume we have added new node, let us see what the new needs of the system are when a new node is added. Balancing incoming requests to multiple nodes Synchronization of a shared state across multiple nodes Identification of “downstate” and resolution action to bring it to “upstate” Well, adding a new node has its advantages as well. Here are few of the positive points Throughput can increase nearly horizontally across the node throughout the system Response times of application will increase as in-between layer interactions will be improved Now, Let us put the above concepts in the perspective of a Database. When we mention the term “running out of resources” or “application is bound to resources” the resources can be CPU, Memory or Bandwidth. The regular approach to “gain scalability” in the database is to look around for bottlenecks and increase the bottlenecked resource. When we have memory as a bottleneck we look at the data buffers, locks, query plans or indexes. After a point even this is not enough as there needs to be an efficient way of managing such large workload on a “single machine” across memory and CPU bound (right kind of scheduling)  workload. We next move on to either read/write separation of the workload or functionality-based sharing so that we still have control of the individual. But this requires lots of planning and change in client systems in terms of knowing where to go/update/read and for reporting applications to “aggregate the data” in an intelligent way. What we ideally need is an intelligent layer which allows us to do these things without us getting into managing, monitoring and distributing the workload. Scalability In the context of database/applications, scalability means three main things Ability to handle normal loads without pressure E.g. X users at the Y utilization of resources (CPU, Memory, Bandwidth) on the Z kind of hardware (4 processor, 32 GB machine with 15000 RPM SATA drives and 1 GHz Network switch) with T throughput Ability to scale up to expected peak load which is greater than normal load with acceptable response times Ability to provide acceptable response times across the system E.g. Response time in S milliseconds (or agreed upon unit of measure) – 90% of the time The Issue – Need of Scale In normal cases one can plan for the load testing to test out normal, peak, and stress scenarios to ensure specific hardware meets the needs. With help from Hardware and Software partners and best practices, bottlenecks can be identified and requisite resources added to the system. Unfortunately this vertical scale is expensive and difficult to achieve and most of the operational people need the ability to scale horizontally. This helps in getting better throughput as there are physical limits in terms of adding resources (Memory, CPU, Bandwidth and Storage) indefinitely. Today we have different options to achieve scalability: Read & Write Separation The idea here is to do actual writes to one store and configure slaves receiving the latest data with acceptable delays. Slaves can be used for balancing out reads. We can also explore functional separation or sharing as well. We can separate data operations by a specific identifier (e.g. region, year, month) and consolidate it for reporting purposes. For functional separation the major disadvantage is when schema changes or workload pattern changes. As the requirement grows one still needs to deal with scale need in manual ways by providing an abstraction in the middle tier code. Using NOSQL solutions The idea is to flatten out the structures in general to keep all values which are retrieved together at the same store and provide flexible schema. The issue with the stores is that they are compromising on mostly consistency (no ACID guarantees) and one has to use NON-SQL dialect to work with the store. The other major issue is about education with NOSQL solutions. Would one really want to make these compromises on the ability to connect and retrieve in simple SQL manner and learn other skill sets? Or for that matter give up on ACID guarantee and start dealing with consistency issues? Hybrid Deployment – Mac, Linux, Cloud, and Windows One of the challenges today that we see across On-premise vs Cloud infrastructure is a difference in abilities. Take for example SQL Azure – it is wonderful in its concepts of throttling (as it is shared deployment) of resources and ability to scale using federation. However, the same abilities are not available on premise. This is not a mistake, mind you – but a compromise of the sweet spot of workloads, customer requirements and operational SLAs which can be supported by the team. In today’s world it is imperative that databases are available across operating systems – which are a commodity and used by developers of all hues. An Ideal Database Ability List A system which allows a linear scale of the system (increase in throughput with reasonable response time) with the addition of resources A system which does not compromise on the ACID guarantees and require developers to learn new paradigms A system which does not force fit a new way interacting with database by learning Non-SQL dialect A system which does not force fit its mechanisms for providing availability across its various modules. Well NuoDB is the first database which has all of the above abilities and much more. In future articles I will cover my hands-on experience with it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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  • SQL SERVER – Weekend Project – Experimenting with ACID Transactions, SQL Compliant, Elastically Scalable Database

    - by pinaldave
    Database technology is huge and big world. I like to explore always beyond what I know and share the learning. Weekend is the best time when I sit around download random software on my machine which I like to call as a lab machine (it is a pretty old laptop, hardly a quality as lab machine) and experiment it. There are so many free betas available for download that it’s hard to keep track and even harder to find the time to play with very many of them.  This blog is about one you shouldn’t miss if you are interested in the learning various relational databases. NuoDB just released their Beta 7.  I had already downloaded their Beta 6 and yesterday did the same for 7.   My impression is that they are onto something very very interesting.  In fact, it might be something really promising in terms of database elasticity, scale and operational cost reduction. The folks at NuoDB say they are working on the world’s first “emergent” database which they tout as a brand new transitional database that is intended to dramatically change what’s possible with OLTP.  It is SQL compliant, guarantees ACID transactions, yet scales elastically on heterogeneous and decentralized cloud-based resources. Interesting note for sure, making me explore more. Based on what I’ve seen so far, they are solving the architectural challenge that exists between elastic, cloud-based compute infrastructures designed to scale out in response to workload requirements versus the traditional relational database management system’s architecture of central control. Here’s my experience with the NuoDB Beta 6 so far: First they pretty much threw away all the features you’d associate with existing RDBMS architectures except the SQL and ACID transactions which they were smart to keep.  It looks like they have incorporated a number of the big ideas from various algorithms, systems and techniques to achieve maximum DB scalability. From a user’s perspective, the NuoDB Beta software behaves like any other traditional SQL database and seems to offer all the benefits users have come to expect from standards-based SQL solutions. One of the interesting feature is that one can run a transactional node and a storage node on my Windows laptop as well on other platforms – indeed interesting for sure. It’s quite amazing to see a database elastically scale across machine boundaries. So, one of the basic NuoDB concepts is that as you need to scale out, you can easily use more inexpensive hardware when/where you need it.  This is unlike what we have traditionally done to scale a database for an application – we replace the hardware with something more powerful (faster CPU and Disks). This is where I started to feel like NuoDB is on to something that has the potential to elastically scale on commodity hardware while reducing operational expense for a big OLTP database to a degree we’ve never seen before. NuoDB is able to fully leverage the cloud in an asynchronous and highly decentralized manner – while providing both SQL compliance and ACID transactions. Basically what NuoDB is doing is so new that it is all hard to believe until you’ve experienced it in action.  I will keep you up to date as I test the NuoDB Beta 7 but if you are developing a web-scale application or have an on-premise app you are thinking of moving to the cloud, testing this beta is worth your time. If you do try it, let me know what you think.  Before I say anything more, I am going to do more experiments and more test on this product and compare it with other existing similar products. For me it was a weekend worth spent on learning something new. I encourage you to download Beta 7 version and share your opinions here. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Guaranteeing ACID properties for InnoDB databases.

    - by plinehan
    What steps must one take to ensure that an otherwise defaultly-configured InnoDB server is truly ACID compliant? The InnoDB configuration page mentions that the hardware itself must be configured to honor fsync calls, i.e. disable any write-back caches. This page mentions some other concerns, but may be conflating the binary log and the InnoDB log, and may be a bit out of date regarding default settings for MySQL 5.x. Upon reading the binary log document page it would seem that the "sync_binlog=1" setting is not required for ACID properties in general, only for ACID properties vis a vis point-in-time recovery and replication. So, is disabling write-back disk caching sufficient, or are there other settings that must be tweaked?

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  • SQL – What ACID stands in the Database? – Contest to Win 24 Amazon Gift Cards and Joes 2 Pros 2012 Kit

    - by Pinal Dave
    We love puzzles. One of the brain’s main task is to solve puzzles. Sometime puzzles are very complicated (e.g Solving Rubik Cube or Sodoku)  and sometimes the puzzles are very simple (multiplying 4 by 8 or finding the shortest route while driving). It is always to solve puzzle and it creates an experience which humans are not able to forget easily. The best puzzles are the one where one has to do multiple things to reach to the final goal. Let us do something similar today. We will have a contest where you can participate and win something interesting. Contest This contest have two parts. Question 1: What ACID stands in the Database? This question seems very easy but here is the twist. Your answer should explain minimum one of the properties of the ACID in detail. If you wish you can explain all the four properties of the ACID but to qualify you need to explain minimum of the one properties. Question 2: What is the size of the installation file of NuoDB for any specific platform. You can answer this question following format – NuoDB installation file is of size __ MB for ___ Platform. Click on the Download the Link and download your installation file for NuoDB. You can post figure out the file size from the properties of the file. We have exciting content prizes for the winners. Prizes 1) 24 Amazon Gift Cards of USD 10 for next 24 hours. One card at every hour. (Open anywhere in the world) 2) One grand winner will get Joes 2 Pros SQL Server 2012 Training Kit worth USD 249. (Open where Amazon ship books). Amazon | 1 | 2 | 3 | 4 | 5  Rules The contest will be open till July 21, 2013. All the valid comments will be hidden till the result is announced. The winners will be announced on July 24, 2013. Hint: Download NuoDB  Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • MySQL se tourne encore plus vers InnoDB, qui sera utilisé pour les tables systèmes pour bénéficier des propriétés ACID

    MySQL se tourne encore plus vers InnoDB qui sera utilisé pour les tables systèmes pour bénéficier des propriétés ACID Depuis le rachat de MySQL par Oracle, le célèbre SGBD a entamé une lente transition de son moteur de base de données, passant du moteur d'origine MyISAM qui est basé sur la méthode ISAM (Indexed Sequential Access Methode) à InnoDB. Cette transition s'est d'ailleurs achevée partiellement par l'intronisation d'InnoDB comme moteur par défaut pour les versions de MySQL 5.5 et plus.Partiellement,...

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  • Transaction Isolation on select, insert, delete

    - by Bradford
    What could possibly go wrong with the following transaction if executed by concurrent users in the default isolation level of READ COMMITTED? BEGIN TRANSACTION SELECT * FROM t WHERE pid = 10 and r between 40 and 60 -- ... this returns tid = 1, 3, 5 -- ... process returned data ... DELETE FROM t WHERE tid in (1, 3, 5) INSERT INTO t (tid, pid, r) VALUES (77, 10, 35) INSERT INTO t (tid, pid, r) VALUES (78, 10, 37) INSERT INTO t (tid, pid, r) VALUES (79, 11, 39) COMMIT

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  • Transactional NTFS (TxF) on Process.Start()

    - by Ian
    Consider the following code: try { using(TransactionScope) { Process.Start("SQLInstaller.EXE"); throw new Exception(); Commit(); } } catch(Exception ex) { //Do something here } Will the changes made by SQLInstaller.exe be rollback in this scenario? More specifically, will the changes made by an external process launched through Process.Start() be handled by TxF? Thanks!

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  • value of type 'string' cannot be converted to 'Devart.data.postgresql.PgSqlParameter'

    - by hector
    The following is my PostgreSQL table structure and the vb.net code to insert into the tables.Using Devart's Component For PostgreSQL Connect table gtab83 CREATE TABLE gtab83 ( orderid integer NOT NULL DEFAULT nextval('seq_gtab83_id'::regclass), acid integer, slno integer, orderdte date ) table gtab84 CREATE TABLE gtab84 ( orderdetid integer DEFAULT nextval('seq_gtab84_id'::regclass), productid integer, qty integer, orderid integer ) Code to insert into the above tables is below '1.)INSERT INTO gtab83(orderid,acid, slno, orderdte) VALUES (?, ?, ?); '2.)INSERT INTO gtab84(orderdetid,productid, qty, orderid) VALUES (?, ?, ?); Try Dim cmd As PgSqlCommand = New PgSqlCommand("", Myconnstr) cmd.CommandText = _ "INSERT INTO GTAB83(ACID,SLNO,ORDERDTE)" & _ "VALUES " & _ "(@acid,@slno,@orderdte);" Dim paramAcid As PgSqlParameter = New PgSqlParameter("@acid", PgSqlType.Int, 0) Dim paramSlno As PgSqlParameter = New PgSqlParameter("@slno", PgSqlType.Int, 0) Dim paramOrderdte As PgSqlParameter = New PgSqlParameter("@orderdte", PgSqlType.Date, 0) paramAcid = cboCust.SelectedValue paramSlno = txtOrderNO.Text #ERROR# paramOrderdte = (txtDate.Text, "yyyy-MM-dd") #ERROR# Catch ex As Exception End Try ERROR : value of type 'string' cannot be converted to 'Devart.data.postgresql.PgSqlParameter'

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  • What is a simple way to get ACID transactions with persistence on the local file system (in Java)?

    - by T.R.
    I'm working on a small (java) project where a website needs to maintain a (preferably comma-separated) list of registered e-mail addresses, nothing else, and be able to check if an address is in the list. I have no control over the hosting or the server's lack of database support. Prevayler seemed a good solution, but the website is a ghost town, with example code missing from just about everywhere it's supposed to be, so I'm a little wary. What other options are recommended for such a task?

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  • SQLAuthority News – Weekend Experiment with NuoDB – Points to Pondor and Whitepaper

    - by pinaldave
    This weekend I have downloaded the latest beta version of NuoDB. I found it much improved and better UI. I was very much impressed as the installation was very smooth and I was up and running in less than 5 minutes with the product. The tools which are related to the Administration of the NuoDB seems to get makeover during this beta release. As per the claim they support now Solaris platform and have improved the native MacOS installation. I neither have Mac nor Solaris – I wish I would have experimented with the same. I will appreciate if anyone out there can confirm how the installations goes on these platforms. I have previously blogged about my experiment with NuoDB here: SQL SERVER – Weekend Project – Experimenting with ACID Transactions, SQL Compliant, Elastically Scalable Database SQL SERVER – Beginning NuoDB – Who will Benefit and How to Start SQL SERVER – Follow up on Beginning NuoDB – Who will Benefit and How to Start – Part 2 I am very impressed with the product so far and I have decided to understand the product further deep. Here are few of the questions which I am going to try to find answers with regards to NuoDB. Just so it is clear – NuoDB is not NOSQL, matter of the fact, it is following all the ACID properties of the database. If ACID properties are crucial why many NoSQL products are not adhering to it? (There are few out there do follow ACID but not all). I do understand the scalability of the database however does elasticity is crucial for the database and if yes how? (Elasticity is where the workload on the database is heavily fluctuating and the need of more than a single database server is coming up). How NuoDB has built scalable, elastic and 100% ACID compliance database which supports multiple platforms? How is NOSQL compared to NuoDB’s new architecture? In the next coming weeks, I am going to explore above concepts and dive deeper into the understanding of the same. Meanwhile I have read following white paper written by Experts at University of California at Santa Barbara. Very interesting read and great starter on the subject Database Scalability, Elasticity, and Autonomy in the Cloud. Additionally, my questions are also talking about NoSQL, this weekend I have started to learn about NoSQL from Pluralsight‘s online learning library. I will share my experience very soon. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, T SQL, Technology Tagged: NuoDB

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  • Move Data into the grid for scalable, predictable response times

    - by JuergenKress
    CloudTran is pleased to introduce the availability of the CloudTran Transaction and Persistence Manager for creating scalable, reliable data services on the Oracle Coherence In-Memory Data Grid (IMDG). Use of IMDG architectures has been key to handling today’s web-scale loads because it eliminates database latency by storing important and frequently access data in memory instead of on disk. The CloudTran product lets developers easily use an IMDG for full ACID-compliant transactions without having to be concerned about the location or spread of data. The system has its own implementation of fast, scalable distributed transactions that does NOT depend on XA protocols but still guarantees all ACID properties. Plus, CloudTran asynchronously replicates data going into the IMDG to back-end datastores and back-up data centers, again ensuring ACID properties. CloudTran can be accessed through Java Persistence API (JPA via TopLink Grid) and now, through a new Low-Level API, or LLAPI. This is ideal for use in SOA applications that need data reliability, high availability, performance, and scalability. It is still in its limited beta release, the LLAPI gives developers the ability to use standard put/remove logic available in Coherence and then wrap logic with simple Spring annotations or XML+AspectJ to start transactions. An important feature of LLAPI is the ability to join transactions. This is a common outcome for SOA applications that need to reduce network traffic by aggregating data into single cache entries and then doing SOA service processing in the node holding the data. This results in the need to orchestrate transaction processing across multiple service calls. CloudTran has the capability to handle these “multi-client” transactions at speed with no loss in ACID properties. Developing software around an IMDG like Oracle Coherence is an important choice for today’s web-scale applications and services. But this introduces new architectural considerations to maintain scalability in light of increased network loads and data movement. Without using CloudTran, developers are faced with an incredibly difficult task to ensure data reliability, availability, performance, and scalability when working with an IMDG. Working with highly distributed data that is entirely volatile while stored in memory presents numerous edge cases where failures can result in data loss. The CloudTran product takes care of all of this, leaving developers with the confidence and peace of mind that all data is processed correctly. For those interested in evaluating the CloudTran product and IMDGs, take a look at this link for more information: http://www.CloudTran.com/downloadAPI.ph , or send your questions to [email protected]. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit  www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Technorati Tags: CloudTran,data grid,M,SOA Community,Oracle SOA,Oracle BPM,BPM,Community,OPN,Jürgen Kress

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  • Move Data into the Grid for Scalable, Predictable Response Times

    - by JuergenKress
    CloudTran is pleased to introduce the availability of the CloudTran Transaction and Persistence Manager for creating scalable, reliable data services on the Oracle Coherence In-Memory Data Grid (IMDG). Use of IMDG architectures has been key to handling today’s web-scale loads because it eliminates database latency by storing important and frequently access data in memory instead of on disk. The CloudTran product lets developers easily use an IMDG for full ACID-compliant transactions without having to be concerned about the location or spread of data. The system has its own implementation of fast, scalable distributed transactions that does NOT depend on XA protocols but still guarantees all ACID properties. Plus, CloudTran asynchronously replicates data going into the IMDG to back-end datastores and back-up data centers, again ensuring ACID properties. CloudTran can be accessed through Java Persistence API (JPA via TopLink Grid) and now, through a new Low-Level API, or LLAPI. This is ideal for use in SOA applications that need data reliability, high availability, performance, and scalability. Still in limited beta release, the LLAPI gives developers the ability to use standard put/remove logic available in Coherence and then wrap logic with simple Spring annotations or XML+AspectJ to start transactions. An important feature of LLAPI is the ability to join transactions. This is a common outcome for SOA applications that need to reduce network traffic by aggregating data into single cache entries and then doing SOA service processing in the node holding the data. This results in the need to orchestrate transaction processing across multiple service calls. CloudTran has the capability to handle these “multi-client” transactions at speed with no loss in ACID properties. Developing software around an IMDG like Oracle Coherence is an important choice for today’s web-scale applications and services. But this introduces new architectural considerations to maintain scalability in light of increased network loads and data movement. Without using CloudTran, developers are faced with an incredibly difficult task to ensure data reliability, availability, performance, and scalability when working with an IMDG. Working with highly distributed data that is entirely volatile while stored in memory presents numerous edge cases where failures can result in data loss. The CloudTran product takes care of all of this, leaving developers with the confidence and peace of mind that all data is processed correctly. For those interested in evaluating the CloudTran product and IMDGs, take a look at this link for more information: http://www.CloudTran.com/downloadAPI.php, or, send your questions to [email protected]. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. BlogTwitterLinkedInMixForumWiki Technorati Tags: Coherence,cloudtran,cache,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • What's a good open source java project for students to hack on?

    - by Evan Grim
    I'm working with a professor to develop a course teaching practical software development tools and methodology. We're looking for a sample code base that we can use for hands-on experience in each of the topics and as the basis for a semester-long project where students will work in a team to implement a feature or fix bugs. Here are some basic guidelines for the project that we'd like to come close to meeting: java based, ~50K SLOC, uses ant, depends upon some external library, has a test suite (preferably jUnit), friendly for development within eclipse, actively developed with a substantial history available within a version control system (such as subversion), the more "coolness" factor the better (to motivate the students), and preferably with some kind of user interface (e.g.: not just a library).

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  • Big Data – Buzz Words: Importance of Relational Database in Big Data World – Day 9 of 21

    - by Pinal Dave
    In yesterday’s blog post we learned what is HDFS. In this article we will take a quick look at the importance of the Relational Database in Big Data world. A Big Question? Here are a few questions I often received since the beginning of the Big Data Series - Does the relational database have no space in the story of the Big Data? Does relational database is no longer relevant as Big Data is evolving? Is relational database not capable to handle Big Data? Is it true that one no longer has to learn about relational data if Big Data is the final destination? Well, every single time when I hear that one person wants to learn about Big Data and is no longer interested in learning about relational database, I find it as a bit far stretched. I am not here to give ambiguous answers of It Depends. I am personally very clear that one who is aspiring to become Big Data Scientist or Big Data Expert they should learn about relational database. NoSQL Movement The reason for the NoSQL Movement in recent time was because of the two important advantages of the NoSQL databases. Performance Flexible Schema In personal experience I have found that when I use NoSQL I have found both of the above listed advantages when I use NoSQL database. There are instances when I found relational database too much restrictive when my data is unstructured as well as they have in the datatype which my Relational Database does not support. It is the same case when I have found that NoSQL solution performing much better than relational databases. I must say that I am a big fan of NoSQL solutions in the recent times but I have also seen occasions and situations where relational database is still perfect fit even though the database is growing increasingly as well have all the symptoms of the big data. Situations in Relational Database Outperforms Adhoc reporting is the one of the most common scenarios where NoSQL is does not have optimal solution. For example reporting queries often needs to aggregate based on the columns which are not indexed as well are built while the report is running, in this kind of scenario NoSQL databases (document database stores, distributed key value stores) database often does not perform well. In the case of the ad-hoc reporting I have often found it is much easier to work with relational databases. SQL is the most popular computer language of all the time. I have been using it for almost over 10 years and I feel that I will be using it for a long time in future. There are plenty of the tools, connectors and awareness of the SQL language in the industry. Pretty much every programming language has a written drivers for the SQL language and most of the developers have learned this language during their school/college time. In many cases, writing query based on SQL is much easier than writing queries in NoSQL supported languages. I believe this is the current situation but in the future this situation can reverse when No SQL query languages are equally popular. ACID (Atomicity Consistency Isolation Durability) – Not all the NoSQL solutions offers ACID compliant language. There are always situations (for example banking transactions, eCommerce shopping carts etc.) where if there is no ACID the operations can be invalid as well database integrity can be at risk. Even though the data volume indeed qualify as a Big Data there are always operations in the application which absolutely needs ACID compliance matured language. The Mixed Bag I have often heard argument that all the big social media sites now a days have moved away from Relational Database. Actually this is not entirely true. While researching about Big Data and Relational Database, I have found that many of the popular social media sites uses Big Data solutions along with Relational Database. Many are using relational databases to deliver the results to end user on the run time and many still uses a relational database as their major backbone. Here are a few examples: Facebook uses MySQL to display the timeline. (Reference Link) Twitter uses MySQL. (Reference Link) Tumblr uses Sharded MySQL (Reference Link) Wikipedia uses MySQL for data storage. (Reference Link) There are many for prominent organizations which are running large scale applications uses relational database along with various Big Data frameworks to satisfy their various business needs. Summary I believe that RDBMS is like a vanilla ice cream. Everybody loves it and everybody has it. NoSQL and other solutions are like chocolate ice cream or custom ice cream – there is a huge base which loves them and wants them but not every ice cream maker can make it just right  for everyone’s taste. No matter how fancy an ice cream store is there is always plain vanilla ice cream available there. Just like the same, there are always cases and situations in the Big Data’s story where traditional relational database is the part of the whole story. In the real world scenarios there will be always the case when there will be need of the relational database concepts and its ideology. It is extremely important to accept relational database as one of the key components of the Big Data instead of treating it as a substandard technology. Ray of Hope – NewSQL In this module we discussed that there are places where we need ACID compliance from our Big Data application and NoSQL will not support that out of box. There is a new termed coined for the application/tool which supports most of the properties of the traditional RDBMS and supports Big Data infrastructure – NewSQL. Tomorrow In tomorrow’s blog post we will discuss about NewSQL. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • Unable to install PEM/pkcs12 created by gnutls to Cisco ASA

    - by ACiD GRiM
    I've been pulling some hair out trying to figure out why cisco devices don't like my certificates. My primary need is to get a trustpoint set up with CA,cert,key on the ASA for VPN systems, however I'm having the same issues on my IOS devices. I created a pkcs12 with openssl a few months ago that imported with no issues, but now that I'm getting ready to move this lab to production I'm using gnutls certtool as I found it adds alt_dns and ip_address fields properly to the certificate, (which cost me a few more hairs trying to get to work with openssl's ca tool) I'm including the current test certs below, don't worry I'm not using these in production ;) The maddening thing is that after I thought gnutls was generating certs incorrectly, I tried making a pkcs12 for a printserver and it imported with no issues. Here's my command flow for creating these certs: certtool --generate-privkey --disable-quick-random --outfile nn-ca.key certtool --generate-self-signed --load-privkey nn-ca.key --outfile nn-ca.crt certtool --generate-privkey --disable-quick-random --outfile nn-g0.key certtool --generate-certificate --load-privkey nn-g0.key --outfile nn-g0.crt --load-ca-privkey nn-ca.key --load-ca-certificate nn-ca.crt openssl pkcs12 -export -certfile nn-ca.crt -in nn-g0.crt -inkey nn-g0.key -out nn-g0.p12 openssl enc -base64 -in nn-g0.p12 -out nn-g0.base64.p12 The password for the attatched pkcs12 is "ciscohelp" without quotes. Thanks for any help TestCerts

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  • How to set up linux watchdog daemon with Intel 6300esb

    - by ACiD GRiM
    I've been searching for this on Google for sometime now and I have yet to find proper documentation on how to connect the kernel driver for my 6300esb watchdog timer to /dev/watchdog and ensure that watchdog daemon is keeping it alive. I am using RHEL compatible Scientific Linux 6.3 in a KVM virtual machine by the way Below is everything I've tried so far: dmesg|grep 6300 i6300ESB timer: Intel 6300ESB WatchDog Timer Driver v0.04 i6300ESB timer: initialized (0xffffc900008b8000). heartbeat=30 sec (nowayout=0) | ll /dev/watchdog crw-rw----. 1 root root 10, 130 Sep 22 22:25 /dev/watchdog | /etc/watchdog.conf #ping = 172.31.14.1 #ping = 172.26.1.255 #interface = eth0 file = /var/log/messages #change = 1407 # Uncomment to enable test. Setting one of these values to '0' disables it. # These values will hopefully never reboot your machine during normal use # (if your machine is really hung, the loadavg will go much higher than 25) max-load-1 = 24 max-load-5 = 18 max-load-15 = 12 # Note that this is the number of pages! # To get the real size, check how large the pagesize is on your machine. #min-memory = 1 #repair-binary = /usr/sbin/repair #test-binary = #test-timeout = watchdog-device = /dev/watchdog # Defaults compiled into the binary #temperature-device = #max-temperature = 120 # Defaults compiled into the binary #admin = root interval = 10 #logtick = 1 # This greatly decreases the chance that watchdog won't be scheduled before # your machine is really loaded realtime = yes priority = 1 # Check if syslogd is still running by enabling the following line #pidfile = /var/run/syslogd.pid Now maybe I'm not testing it correctly, but I would expecting that stopping the watchdog service would cause the /dev/watchdog to time out after 30 seconds and I should see the host reboot, however this does not happen. Also, here is my config for the KVM vm <!-- WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE OVERWRITTEN AND LOST. Changes to this xml configuration should be made using: virsh edit sl6template or other application using the libvirt API. --> <domain type='kvm'> <name>sl6template</name> <uuid>960d0ac2-2e6a-5efa-87a3-6bb779e15b6a</uuid> <memory unit='KiB'>262144</memory> <currentMemory unit='KiB'>262144</currentMemory> <vcpu placement='static'>1</vcpu> <os> <type arch='x86_64' machine='rhel6.3.0'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <cpu mode='custom' match='exact'> <model fallback='allow'>Westmere</model> <vendor>Intel</vendor> <feature policy='require' name='tm2'/> <feature policy='require' name='est'/> <feature policy='require' name='vmx'/> <feature policy='require' name='ds'/> <feature policy='require' name='smx'/> <feature policy='require' name='ss'/> <feature policy='require' name='vme'/> <feature policy='require' name='dtes64'/> <feature policy='require' name='rdtscp'/> <feature policy='require' name='ht'/> <feature policy='require' name='dca'/> <feature policy='require' name='pbe'/> <feature policy='require' name='tm'/> <feature policy='require' name='pdcm'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='ds_cpl'/> <feature policy='require' name='pclmuldq'/> <feature policy='require' name='xtpr'/> <feature policy='require' name='acpi'/> <feature policy='require' name='monitor'/> <feature policy='require' name='aes'/> </cpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/libexec/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/mnt/data/vms/sl6template.img'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </disk> <controller type='usb' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> </controller> <interface type='bridge'> <mac address='52:54:00:44:57:f6'/> <source bridge='br0.2'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <interface type='bridge'> <mac address='52:54:00:88:0f:42'/> <source bridge='br1'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> <watchdog model='i6300esb' action='reset'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </watchdog> <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </memballoon> </devices> </domain> Any help is appreciated as the most I've found are patches to kvm and general softdog documentation or IPMI watchdog answers.

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  • Relying on AppDomain.IsDefaultAppDomain()

    - by lysergic-acid
    I have a component which should be initialized in a certain way ONLY on the main AppDomain. On other AppDomains, it is initialized as a proxy to the object that lives in the main appdomain. The component uses AppDomain.Current.IsDefaultAppDomain() to determine whether it is on the main appdomain or not. My problem is that when running unit tests (NUnit), this method returns false, as the test runner initializes my test classes in a different app domain, causing the tests to not behave right. How can this be resolved?

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