Spring & Hibernate developer Innovation
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Wikipedia
Spring (previously known as Spring Source) was the company created by the founders of the Spring Framework (a programming model for enterprise Java applications) to support and develop Spring and related projects. Originally incorporated as Interface 21, it was renamed Spring Source in 2008 to better reflect its main business. Over time most of the Spring developers were employed full-time by the company which offered training and consulting services to finance its activities (Spring itself is open source and is freely available to all). The company was then renamed as Spring. Recognizing that the platform of choice for most Spring applications was Apache Tomcat, Spring merged with Covalent on January 29, 2008. Like Spring, Covalent was the financial vehicle supporting some of the developers of Tomcat.
Several other acquisitions followed: G2 One (the company behind Groovy and Grails), Hyperic (who developed a tool for monitoring Java applications and their environment) and Cloud Foundry (a Platform as a Service provider). As a result, Spring Source employed some of the lead developers and committers of the Apache Tomcat, Apache HTTP Server, Hyperic, Apache Groovy and Grails open source communities. Spring Source was also a participant in the Java Community Process.
Using these acquisitions, the company’s business expanded beyond support for its application frameworks, Spring and Grails. It could now offer a suite of software products across all three stages of the enterprise Java application life cycle: build (develop), run (deploy), and manage. Spring Source created two commercial, server products specifically aimed at Spring developers. TC Server is a commercial version of Tomcat integrated with Hyperic for deployment and management. DM Server was an OSGi based server which never was commercially viable. After spending millions on development with no result, it was subsequently donated to the Eclipse Foundation as the Virgo project. Both servers came with a number of customer support options.
Educational services expanded to offer training for the Spring framework, Apache Tomcat, tc Server and Groovy/Grails through its educational services unit, the Spring Source University and also a number of partner training providers.
Spring Source was purchased for $420m by VM ware in August 2009, where it was maintained for some time as a separate division within VMware. The commercial products were rebadged as the vFabric Application Suite. Acquisitions continued including RabbitMQ (an open-source AMQP message broker), Redis (an open source, noSQL key-value store) and Gemstone (developer of several data-management products). These products (except redis) also became part of the vFabric product set.
In April 2013, VMware, and its parent company EMC Corporation, formally created a joint venture (with GE) called Pivotal Software. All of VMware’s application-oriented products, including Spring were transferred to this organization. VMWare reaquired Pivotal in 2019 and folded it into the Tansu application suite.
VMware sold the Gemstone object database products to Gem Talk Systems in May 2013. Pivotal ended their sponsorship of Groovy/Grails in March 2015.
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal hetero thermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most commonly occurs during winter months.
Although traditionally reserved for “deep” hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and utilise similar mechanisms. The equivalent during the summer months is aestivation.
Hibernation functions to conserve energy when sufficient food is not available. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months—depending on the species, ambient temperature, time of year, and the individual’s body-condition. Before entering hibernation, animals need to store enough energy to last through the duration of their dormant period, possibly as long as an entire winter. Larger species become hyper phagic, eating a large amount of food and storing the energy in fat deposits. In many small species, food caching replaces eating and becoming fat.
Some species of mammals hibernate while gestating young, which are born either while the mother hibernates or shortly afterwards. For example, female black bears go into hibernation during the winter months in order to give birth to their offspring. The pregnant mothers significantly increase their body mass prior to hibernation, and this increase is further reflected in the weight of the offspring. The fat accumulation enables them to provide a sufficiently warm and nurturing environment for their newborns. During hibernation, they subsequently lose 15–27% of their pre-hibernation weight by using their stored fats for energy.
Ectothermic animals also undergo periods of metabolic suppression and dormancy, which in many invertebrates is referred to as diapause. Some researchers and members of the public use the term brumate to describe winter dormancy of reptiles, but the more general term hibernation is believed adequate to refer to any winter dormancy. Many insects, such as the wasp Polistes exclamans, exhibit periods of dormancy which have often been referred to as hibernation, despite their ectothermy. Botanists may use the term “seed hibernation” to refer to a form of seed dormancy.
There is a variety of definitions for terms that describe hibernation in mammals, and different mammal clades hibernate differently. The following subsections discuss the terms obligate and facultative hibernation. The last two sections point out in particular primates, none of whom were thought to hibernate until recently, and bears, whose winter torpor had been contested as not being “true hibernation” during the late 20th century, since it is dissimilar from hibernation seen in rodents.
Obligate hibernators are animals that spontaneously, and annually, enter hibernation regardless of ambient temperature and access to food. Obligate hibernators include many species of ground squirrels, other rodents, mouse lemurs, European hedgehogs and other insectivores, mono tremes, and marsupials. These species undergo what has been traditionally called “hibernation”: a physiological state wherein the body temperature drops to near ambient temperature, and heart and respiration rates slow drastically.
The typical winter season for obligate hibernators is characterized by periods of torpor interrupted by periodic, euthermic arousals, during which body temperatures and heart rates are restored to more typical levels. The cause and purpose of these arousals is still not clear; the question of why hibernators may return periodically to normal body temperatures has plagued researchers for decades, and while there is still no clear-cut explanation, there are multiple hypotheses on the topic. One favored hypothesis is that hibernators build a “sleep debt” during hibernation, and so must occasionally warm up to sleep. This has been supported by evidence in the Arctic ground squirrel. Other theories postulate that brief periods of high body temperature during hibernation allow the animal to restore its available energy sources or to initiate an immune response.
Hibernating Arctic ground squirrels may exhibit abdominal temperatures as low as −2.9 °C (26.8 °F), maintaining sub-zero abdominal temperatures for more than three weeks at a time, although the temperatures at the head and neck remain at 0 °C (32 °F) or above.