In-Memory Computing Planet® Blogs and Events

IMC Planet presents in-memory computing blogs and events from around the world. Read the latest in-memory computing news here. Submit your RSS feed or post your upcoming events and help the in-memory computing community stay up to date on the latest developments.

Nov
05
2014
Posted by The In-Memory Revolution


Ever wonder how subscribing to feeds from a news channel brings you the latest and relevant information as soon as it is published on their website? Or, how users can join a chat room, over Skype or Google Hangouts, for example, and exchange messages between multiple users? It is the Publish/Subscribe (pub-sub) messaging model – a distributed computing abstraction where publishers and subscribers are connected together by a common topic.  


 
Oct
21
2014
Posted by The In-Memory Revolution


Getting real-time notifications to users is a popular feature in social media these days. For example, notifications in Facebook that notifies users of any new likes or comments they receive on their posts or pictures. Or a leaderboard in an online game, that refreshes as a new leader emerges with a greater score. 


While data changes can be constructed by continuously pulling data from the source (DB or In-Memory cache), an alternative way is to directly push these updates from the source. In other words…
 
Oct
10
2014
Posted by The In-Memory Revolution


Failing-over web session caching is problematic when you run multiple application servers. It is not uncommon for web applications to run in a cluster to distribute the load of high volume of web requests. But what if one of the application servers crashes? The load balancer will just route the web request to another available application server, but all of user’s session data is lost. In simple words, you may be filling your shopping cart with your favorite items, but if the application server serving your request crashes, you will end up with an empty cart.


 
Dec
14
2012
Posted by Tech by Sample
Summary:  Gridgain is advanced software middleware that combines compute and data grid capabilities to provide a framework for processing large data sets.    Gridgain implements a well known parallel design pattern developed by Google, called MapReduce.   It’s zero deployment feature allows it to be used for building high performance cloud applications.   In honor of the presidential

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Sep
30
2012
Posted by Tech by Sample
Summary: Unit testing involves testing business logic in isolation.  In many situations,  Java classes  will have a natural dependency on other classes.  These dependent classes can be replaced with mock objects.   Mock objects are instances of test provided classes. For example, let’s say you would like to unit test an algorithm that calculates a company’s

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Aug
25
2012
Posted by Tech by Sample
Summary: In this post, we will implement RESTful style web services using Jersey. Jersey is an open source, production grade, JAX-RS (JSR 311) Reference Implementation for building RESTful web services.  RESTful style web services was first introduced in Roy Fielding’s research paper,  “Architectural Styles and the Design of Network-based Software Architectures” in 2000.  As a result of its simplicity,

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Jun
20
2012
Posted by Tech by Sample
Summary: In this post, we use JGAP (pronounced “jay-gap”), an open source Genetic Algorithm (GA) framework, to select an optimal set of movies based on our interests. A Genetic algorithm (GA) is a type of search algorithm that simulates the process of natural evolution. This type of algorithm is used to select an optimal solution

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May
22
2012
Posted by Tech by Sample
Summary: In this post we utilize Esper, a Complex Event Processing  (CEP) engine, to monitor a fictitious data stream of gas prices to determine when and where to buy gas.  Event processing with Esper involves ‘real time’ tracking, analyzing, and responding to streams of information.    These data streams could be sales orders, Twitter feeds, stock market feeds,

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May
09
2012
Posted by Tech by Sample
Summary: This article highlights the steps involved in creating as well as processing custom annotations in Java.    Annotations are typically used to provide  additional information about the software.   This valuable information can be utilized at compile time, run time, or during the deployment phase. Prerequisites: If you would like to obtain this article’s complete sample,

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May
04
2012
Posted by Tech by Sample
Summary: This article highlights Spring 3.1’s new Cache Abstraction.    In many enterprise applications, there are data access methods that return the same result for the same input parameters.   For these types of use cases, Spring 3.1’s Cache abstraction can reduce method invocations and improve overall application responsiveness. Prerequisites: If you would like to obtain this

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Apr
22
2012
Posted by Tech by Sample
Summary: JUnit is the standard unit testing framework for Java.  JUnit 4.x further reduces the complexity for unit testing by utilizing annotations.  As a result, software developers are ‘freed’  from inheriting from specific classes as well as applying specific naming conventions to methods. This post will describe how to make use of some of the

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Dec
20
2011
Posted by In-Memory Computing Blog
Business operations have very diverse access patterns. They include read-mostly queries of analytical applications and write-intensive transactions of daily business. Further, all variants of data selects are present including point selects (e.g., details of a specific product) and range selects, retrieving sets of data (e.g., from a specified period like sales overview per region of a specific product for the last month).

Column and row-oriented storage in HANA provides the foundation to store data according to its frequent usage patterns in column or in row-oriented manner to achieve optimal performance. Through the usage of SQL…
 
Dec
19
2011
Posted by In-Memory Computing Blog
Analytics on historical data
All enterprise data has a lifespan: depending on the application, a datum might be expected to be changed or updated in the future in many cases, in few cases, or never. In financial accounting, for example, all data that is not from the current year plus all open items from the previous year can be considered 'historic data', since they may no longer be changed.

In HANA, historical data is instantly available for analytical processing from solid state disk (SSD) drives. Only active data is required to reside in-memory permanently.…
 
Nov
25
2011
Posted by In-Memory Computing Blog
By default, all data is stored in-memory to achieve high speed data access. However, not all data is expected to be read or updated frequently and needs to reside in-memory, as this increases the required amount of main memory unnecessarily. This so-called historic or passive data can be stored in a specific passive data storage based on less expensive storage media, such as SSDs or hard disks, still providing sufficient performance for possible accesses at lower cost. The dynamic transition from active to passive data is supported by the database, based on custom rules defined as per…
 
Nov
22
2011
Posted by In-Memory Computing Blog
Insert-only or append-only describes how data is managed when inserting new data. The principle idea of insert-only is that changes to existing data are handled by appending new tuples to the data storage. In other words, the database does not allow applications to perform updates or deletions on physically stored tuples of data.

This design approach allows the introduction of a specific write-optimized data store for fast writing and a read-optimized data store for fast reading.Traditional database systems support four operations for data manipulations, i.e. inserting new data, selecting data,…