Author: ultroni1

What are cloud models? The cloud models define the deployment type of cloud resources. The three main cloud models are: private, public, and hybrid.

Private cloud

Let’s start with a private cloud. A private cloud is, in some ways, the natural evolution from a corporate datacenter. It’s a cloud (delivering IT services over the internet) that’s used by a single entity. Private cloud provides much greater control for the company and its IT department. However, it also comes with greater cost and fewer of the benefits of a public cloud deployment. Finally, a private cloud may be hosted from your on site datacenter. It may also be hosted in a dedicated datacenter offsite, potentially even by a third party that has dedicated that datacenter to your company.

Public cloud

A public cloud is built, controlled, and maintained by a third-party cloud provider. With a public cloud, anyone that wants to purchase cloud services can access and use resources. The general public availability is a key difference between public and private clouds.

Hybrid cloud

A hybrid cloud is a computing environment that uses both public and private clouds in an inter-connected environment. A hybrid cloud environment can be used to allow a private cloud to surge for increased, temporary demand by deploying public cloud resources. Hybrid cloud can be used to provide an extra layer of security. For example, users can flexibly choose which services to keep in public cloud and which to deploy to their private cloud infrastructure.

virtualization training courses malaysia

You may have heard of the shared responsibility model, but you may not understand what it means or how it impacts cloud computing.

Start with a traditional corporate datacenter. The company is responsible for maintaining the physical space, ensuring security, and maintaining or replacing the servers if anything happens. The IT department is responsible for maintaining all the infrastructure and software needed to keep the datacenter up and running. They’re also likely to be responsible for keeping all systems patched and on the correct version.

With the shared responsibility model, these responsibilities get shared between the cloud provider and the consumer. Physical security, power, cooling, and network connectivity are the responsibility of the cloud provider. The consumer isn’t collocated with the datacenter, so it wouldn’t make sense for the consumer to have any of those responsibilities.

At the same time, the consumer is responsible for the data and information stored in the cloud. (You wouldn’t want the cloud provider to be able to read your information.) The consumer is also responsible for access security, meaning you only give access to those who need it.

Then, for some things, the responsibility depends on the situation. If you’re using a cloud SQL database, the cloud provider would be responsible for maintaining the actual database. However, you’re still responsible for the data that gets ingested into the database. If you deployed a virtual machine and installed an SQL database on it, you’d be responsible for database patches and updates, as well as maintaining the data and information stored in the database.

With an on-premises datacenter, you’re responsible for everything. With cloud computing, those responsibilities shift. The shared responsibility model is heavily tied into the cloud service types (covered later in this learning path): infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS). IaaS places the most responsibility on the consumer, with the cloud provider being responsible for the basics of physical security, power, and connectivity. On the other end of the spectrum, SaaS places most of the responsibility with the cloud provider. PaaS, being a middle ground between IaaS and SaaS, rests somewhere in the middle and evenly distributes responsibility between the cloud provider and the consumer.

aws certification malaysia

Cloud computing is the delivery of computing services over the internet. Computing services include common IT infrastructure such as virtual machines, storage, databases, and networking. Cloud services also expand the traditional IT offerings to include things like Internet of Things (IoT), machine learning (ML), and artificial intelligence (AI).

Because cloud computing uses the internet to deliver these services, it doesn’t have to be constrained by physical infrastructure the same way that a traditional datacenter is. That means if you need to increase your IT infrastructure rapidly, you don’t have to wait to build a new datacenter—you can use the cloud to rapidly expand your IT footprint.

oracle certification malaysia

In this module, you’ll be introduced to general cloud concepts. You’ll start with an introduction to the cloud in general. Then you’ll dive into concepts like shared responsibility, different cloud models, and explore the unique pricing method for the cloud.

If you’re already familiar with cloud computing, this module may be largely review for you.

Learning objectives

After completing this module, you’ll be able to:

• Define cloud computing.
• Describe the shared responsibility model.
• Define cloud models, including public, private, and hybrid.
• Identify appropriate use cases for each cloud model.
• Describe the consumption-based model.
• Compare cloud pricing models.

red hat certification malaysia

Microsoft Azure is a cloud computing platform with an ever-expanding set of services to help you build solutions to meet your business goals. Azure services support everything from simple to complex. Azure has simple web services for hosting your business presence in the cloud. Azure also supports running fully virtualized computers managing your custom software solutions. Azure provides a wealth of cloud-based services like remote storage, database hosting, and centralized account management. Azure also offers new capabilities like artificial intelligence (AI) and Internet of Things (IoT) focused services.

In this series, you’ll cover cloud computing basics, be introduced to some of the core services provided by Microsoft Azure, and will learn more about the governance and compliance services that you can use.

What is Azure Fundamentals?

Azure Fundamentals is a series of three learning paths that familiarize you with Azure and its many services and features.

Whether you’re interested in compute, networking, or storage services; learning about cloud security best practices; or exploring governance and management options, think of Azure Fundamentals as your curated guide to Azure.

Azure Fundamentals includes interactive exercises that give you hands-on experience with Azure. Many exercises provide a temporary Azure portal environment called the sandbox, which allows you to practice creating cloud resources for free at your own pace.

Technical IT experience isn’t required; however, having general IT knowledge will help you get the most from your learning experience.

veeam certification malaysia

Software as a service (SaaS) is the most complete cloud service model from a product perspective. With SaaS, you’re essentially renting or using a fully developed application. Email, financial software, messaging applications, and connectivity software are all common examples of a SaaS implementation.

While the SaaS model may be the least flexible, it’s also the easiest to get up and running. It requires the least amount of technical knowledge or expertise to fully employ.

Shared responsibility model

The shared responsibility model applies to all the cloud service types. SaaS is the model that places the most responsibility with the cloud provider and the least responsibility with the user. In a SaaS environment you’re responsible for the data that you put into the system, the devices that you allow to connect to the system, and the users that have access. Nearly everything else falls to the cloud provider. The cloud provider is responsible for physical security of the datacenters, power, network connectivity, and application development and patching.

lpi linux administration certification training courses malaysia

Platform as a service (PaaS) is a middle ground between renting space in a datacenter (infrastructure as a service) and paying for a complete and deployed solution (software as a service). In a PaaS environment, the cloud provider maintains the physical infrastructure, physical security, and connection to the internet. They also maintain the operating systems, middleware, development tools, and business intelligence services that make up a cloud solution. In a PaaS scenario, you don’t have to worry about the licensing or patching for operating systems and databases.

PaaS is well suited to provide a complete development environment without the headache of maintaining all the development infrastructure.

Shared responsibility model

The shared responsibility model applies to all the cloud service types. PaaS splits the responsibility between you and the cloud provider. The cloud provider is responsible for maintaining the physical infrastructure and its access to the internet, just like in IaaS. In the PaaS model, the cloud provider will also maintain the operating systems, databases, and development tools. Think of PaaS like using a domain joined machine: IT maintains the device with regular updates, patches, and refreshes.

Depending on the configuration, you or the cloud provider may be responsible for networking settings and connectivity within your cloud environment, network and application security, and the directory infrastructure.

nodejs training courses malaysia

Infrastructure as a service (IaaS) is the most flexible category of cloud services, as it provides you the maximum amount of control for your cloud resources. In an IaaS model, the cloud provider is responsible for maintaining the hardware, network connectivity (to the internet), and physical security. You’re responsible for everything else: operating system installation, configuration, and maintenance; network configuration; database and storage configuration; and so on. With IaaS, you’re essentially renting the hardware in a cloud datacenter, but what you do with that hardware is up to you.

Shared responsibility model

The shared responsibility model applies to all the cloud service types. IaaS places the largest share of responsibility with you. The cloud provider is responsible for maintaining the physical infrastructure and its access to the internet. You’re responsible for installation and configuration, patching and updates, and security.

vmware vsphere certification training courses malaysia

PostgreSQL uses memory that can be classified as:

• Local memory – allocated to each process
• Shared memory – used by all processes

Local memory

Each process in PostgreSQL requires memory for query processing. The following server parameters allow you to define memory usage:

work_mem defines memory required for sorting tuples for ORDER BY and DISTINCT operations. This parameter determines the amount of memory available for internal sort operations and hash tables. If you have large amount of available memory and your workload has queries with complex sorting, increasing this parameter value could improve performance by allowing larger scans in-memory before spilling to disk.

However, one complex query could have many sort and hash operations running concurrently. Each operation uses as much memory as this value allows before it starts writing to disk based temporary files. On a busy system, therefore, total memory usage is many times that of an individual work_mem parameter.

To tune this value, use Total RAM * 0.25 / max_connections as initial value.

maintenance_work_mem is memory required by vacuum and reindex. This parameter determines the amount of memory available for internal sort operations and hash tables. The default value is 64 KB but increasing this value improves performance for vacuuming.

autovacuum_work_mem sets the maximum memory to be used by each autovacuum process.

temp_buffers defines memory for storing temporary tables. This parameter sets the maximum number of temporary buffers used by each database session.

effective_cache_size defines the amount of available memory for disk caching by the operating system and within the database. The PostgreSQL query planner determines whether this memory is fixed in RAM. Index scans are most likely to be used against higher values; otherwise, sequential scans are used if the value is low.

Set effective_cache_size to 50% of the machine’s total RAM.

Shared memory

Shared memory is allocated at startup. Shared memory is used for:

shared_buffers defines the shared memory buffers used by the server. PostgreSQL loads pages of tables and indexes from persistent storage to a shared buffer pool, and then works on them in memory. This shared buffer pool is the major component of the shared memory used by the server. The default value is 128 MB (depending on the compute tier). If you decide to allocate more memory, you need to restart the server.

wal_buffers defines the number of disk page buffers in shared memory for write ahead logging (WAL) before writing it to persistent storage.

In summary, the important server parameters relating to memory that you could want tune are:

• shared_buffers
• work_mem
• effective_cache_size

web development

PostgreSQL is a client/server relational database management system (RDMS). PostgreSQL also supports a wide range of extensions, such as the Citus extension in the Azure Cosmos DB for PostgreSQL option. After an extension is loaded into the database, it functions like any built-in feature.

PostgreSQL also has its own query language called pgsql. In addition, PostgreSQL supports procedural languages such as Ruby on Rails.

Client/server architecture

PostgreSQL is based on a client/server architecture. The server stores, manages, and returns data to client programs. Client programs request data using pgSQL, or one of the procedural languages that PostgreSQL supports, such as PL/pgSQL.

A PostgreSQL session consists of three parts:

• The postmaster
• The client application
• The server

Postmaster

The Postmaster is the supervisory daemon process that manages a PostgreSQL server. The postmaster daemon manages communication among the various server processes including initializing the server, shutting down the server, handling connection requests, and performing other background processes. In Azure Database for PostgreSQL, you don’t have access to the file system, or to the Postmaster process.

testing