Loma  Baumbach

Loma Baumbach

1598051940

Pessimistic concurrency control vs Optimistic concurrency control

n this video, I discuss the different concurrency control at database transactions, specifically the pessimistic vs optimistic concurrency control. and the pros and cons of each.

0:00 Intro
3:00 concurrency Control
5:30 Pessimistic concurrency Control
9:20 Optimistic concurrency Control

#database

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Pessimistic concurrency control vs Optimistic concurrency control
Autumn  Blick

Autumn Blick

1598839687

How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

PWA vs Native App: Which Is Better Option In 2021?

Every year, the world is expanding with the launch of new smartphones and other gadgets available in the market. According to Statista, more than 50% of the population will be using smartphones by the end of 2021.

Hence, businesses worldwide have understood the importance of smartphones and are joining the mobile industry by launching native apps.

Apart from native apps, progressive web apps is another technology that is gaining a lot of attention among businesses. Moreover, various leading companies worldwide have openly accepted PWA and built progressive web apps.

Now, the question arises, how is PWA different from the native apps? Read More

#pwa vs native #pwa vs native app #progressive web app vs native #progressive web app vs native app #pwa vs native app performance

Loma  Baumbach

Loma Baumbach

1598051940

Pessimistic concurrency control vs Optimistic concurrency control

n this video, I discuss the different concurrency control at database transactions, specifically the pessimistic vs optimistic concurrency control. and the pros and cons of each.

0:00 Intro
3:00 concurrency Control
5:30 Pessimistic concurrency Control
9:20 Optimistic concurrency Control

#database

Tamia  Walter

Tamia Walter

1601396400

Bulk Updates with Optimistic Concurrency Control

In this blog we are going to focus on a scenario where you want to do many updates to vertices in a graph stored in Azure Cosmos DB using the Gremlin API, where each update needs to account for other updates that might occur at the same time.

A great feature about the Core (SQL) API in Azure Cosmos DB is that it is fully interoperable with the Gremlin API with respect to CRUD operations, which means you can use all of the powerful features in Core (SQL) API and it’s SDKs to manipulate vertices and edges in a graph.

A feature that has been added to the .NET SDK in Azure Cosmos DB since version 3 is bulk support, which we will also explore here. The bulk support feature in the SDK is a replacement for the older bulk executor library, and now fully supports all CRUD operations (insert, update, read, delete).

The full code sample for the below can be found here.

Bulk Scenario

Imagine you have a graph which models devices across a fleet of cars. Suppose you want to run a bulk operation to increase a temperature setting on each device by a certain amount for all devices in a particular fleet, but you are aware that independent operations could also be setting the temperature setting at the same time, and you want to make sure that this temperature state is not overwritten in your bulk update. In other words, you want to ensure all devices have their temperature setting increased by the same amount, relative to the value that was present in the database at the time of bulk update, without missing any interim updates. First, lets model the vertices in the graph as classes:

    public class VertexDevice
    {
        [JsonProperty("id")]
        internal string Id { get; set; }

        [JsonProperty("pk")]
        internal string pk { get; set; }

        [JsonProperty("label")]
        internal string label { get; set; }

        [JsonProperty("model")]
        public List<VertexProperty> model { get; set; }

        [JsonProperty("temp")]
        public List<VertexPropertyNumber> temp { get; set; }

        [JsonProperty("status")]
        public List<VertexProperty> status { get; set; }

        [JsonProperty("_rid")]
        internal string _rid { get; set; }

        [JsonProperty("_self")]
        internal string _self { get; set; }

        [JsonProperty("_etag")]
        internal string _etag { get; set; }

        [JsonProperty("_attachments")]
        internal string _attachments { get; set; }

        [JsonProperty("_ts")]
        internal string _ts { get; set; }
    }

    public class VertexProperty
    {
        [JsonProperty("id")]
        public string Id { get; set; }

        [JsonProperty("_value")]
        public string _value { get; set; }
    }

    public class VertexPropertyNumber
    {
        [JsonProperty("id")]
        public string Id { get; set; }

        [JsonProperty("_value")]
        public int _value { get; set; }
    }

#core (sql) api #gremlin api #tips and tricks #.net sdk #bulk delete #bulk insert #bulk reads #bulk support #bulk updates #etag #gremlin #optimistic concurrency #sql api

Madelyn  Frami

Madelyn Frami

1598438700

10 Open Source/Commercial Control Panels For Virtual Machines (VM's) Management

Automatic creation and management of virtual machines is a topical issue for any company that provides VPS services. If you manage a large number of machines, a command line is definitely not the only tool you may need to perform various operations including client tasks, because such operations may be time-consuming.

In order to simplify routine tasks of server administrators and users, various companies develop control panels for virtual machines management, including interface-based solutions.

Don’t Miss20 Open Source/Commercial Control Panels to Manage Linux Servers

A control panel empowers you to perform any operation with a mouse click, whereas it would take you a good deal of time to complete the same task in the console. With a control panel, you will save your time and effort. However, it’s not all that simple.

Nowadays, VMmanager is the most popular software product for small and medium-sized businesses. VMware, in its turn, is a leading solution for large organizations. Both software products are commercial and rather expensive.

They deliver a large number of functions, however, some companies, especially, startups may need them. Besides, many of them cannot afford such an expensive product. For example, startups and companies in times of crisis may experience financial difficulties. Moreover, one can find interesting, outstanding solutions integrated with billing systems including tools for VM management.

How not to get lost among a great number of offers? We decided to help our users and wrote the following article, in which they will find answers to this question.

In this article, we will describe control panels for virtual machines management, both commercial and open-source, and help you choose the right solution to meet your personal needs.

1. VMmanager

VMmanager is one of the most popular commercial server virtualizations platforms based on QEMU/KVM technology. The solution has a reach feature set, that can suit both IT infrastructure owners and VPS services providers’ needs.

Virtual servers can be created within 2 minutes. Many routine tasks are performed automatically: including migration, cloning, reinstalling the OS, backups, adding and deleting interfaces, virtual server image creation, monitoring, statistics collection, server provisioning, etc.

The main advantages of VMmanager are:

  • Centralized management of various clusters.
  • Fault tolerance due to a microservice architecture.
  • Overselling, which helps to improve VPS provider’s equipment efficiency.
  • Complete control of the infrastructure thanks to a robust system of metrics collection.
  • A modern and intuitive interface.

VMmanager - Virtualization Management Platform

VMmanager – Virtualization Management Platform

2. VMware vSphere

VMware vSphere is the world’s leading server virtualization platform for building cloud infrastructure. With tons of its different powerful features, vSphere is a truely state-of-the-art software virtual machines management software. It is an ideal solution for large VPS providers with appropriate budgets and professional staff.

VMWare vSphere - Server Virtualization Platform

#control panels #virtualization #hosting control panel #linux control panels #virtual mahine control panels #linux