Introducing some important low latency applications

In this section, we will explore some common low latency applications in different business areas in order to familiarize ourselves with different kinds of latency-sensitive applications and how latency plays an important part in their performance. Additionally, discussing these applications will reveal some similarities in the nature and design of these applications.

Lower-level low latency applications

First, we will start with applications that would be considered extremely low-level, meaning very close to the hardware. Note that all low latency applications have at least some portion of the application that is low-level since, by definition, that is how low latency performance is achieved. These applications, however, have large portions of the entire application dealing with mostly low-level details; let us discuss those next.

Telecommunications

We already discussed that C++ is one of the fastest programming languages out there. It is used a lot in building telephone switches, routers, internet, space probes, and various other parts of telecommunications infrastructure. These applications are required to handle a large number of simultaneous connections and facilitate communication between them. These applications need to perform these tasks with speed and efficiency, making them a good example of low latency applications.

Embedded systems

Since C++ is closer to the hardware compared to other high-level programming languages, it is used in latency-sensitive embedded systems. Some examples of these would be machines used in the field of medicine, surgical tools, smart watches, and so on. C++ is usually the language of choice for medical applications such as MRI machines, lab testing systems, and systems to manage patient information. Additionally, there are use cases to model medical data, run simulations for research, and so on.

Compilers

Interestingly, compilers for various programming languages use C and C++ to build the compilers for those languages. The reason for this is, again, that C and C++ are low-level languages closer to the hardware and can build these compilers efficiently. The compiler applications themselves are able to optimize the code for the programming language to a very large degree and produce low latency machine code.

Operating systems

From Microsoft Windows to macOS to Linux itself, all the major OSes are built in C++ – yet again, another example of a low latency application where the fact that C++ is a low-level language makes it an ideal fit. OSes are extremely large and extremely complex. In addition to that, they have to have low latency and be highly performant to be a competitive modern OS.

For instance, Linux is typically the OS of choice for many high-load servers as well as servers designed for low latency applications, so the OS itself needs to have very high performance. In addition to traditional OSes, C and C++ are also heavily used to build mobile OSes such as iOS, Android, and Windows phone kernels. In summary, OSes need to be extremely fast and efficient at managing all the system and hardware resources. C++ developers building OSes can leverage the language’s abilities to build super-low-latency OSes.

Cloud/distributed systems

Organizations that develop and use cloud and distributed storage and processing systems have very low latency requirements. For this reason, they rely heavily on a programming language such as C++. Distributed storage systems have to support very fast and very efficient filesystem operations, so need to be close to the hardware. Additionally, distributed processing generally means high levels of concurrency, reliance on low latency multithreading libraries, as well as high load tolerance and scalability optimization requirements.

Databases

Databases are another good example of applications that need low latencies and high levels of concurrency and parallelism. Databases are also critical components in many different applications in many different business areas. Postgres, MySQL, and MongoDB (which are by far the most popular database systems right now) are written in C and C++ – yet another example of why C++ is the preferred language for low latency applications. C++ is also ideal for designing and structuring databases to optimize storage efficiency.

Flight software and traffic control

Flight software for commercial airplanes and military aircraft is a class of latency-critical applications. Here, not only is it important that the code follow very strict guidelines, be extremely robust, and be very well tested but the applications also need to respond and react to events predictably and within strict latency thresholds.

Traffic control software depends on many sensors, which need to monitor the speed, location, and volume of vehicles and transmit them to the central software. The software then uses the information to control traffic signs, maps, and traffic lights. Obviously, for such real-time applications, there is a requirement for it to be low latency and easily able to handle the large volume of data quickly and efficiently.

Higher-level low latency applications

In this subsection, we will discuss what many might consider slightly higher-level low latency applications. These are the applications people typically think of when trying to solve business problems; however, one thing to keep in mind is that these applications still have to implement and use lower-level optimization techniques to provide the performance that is required of them.

Graphics and video game applications

Graphics applications require super-fast rendering performance and serve as another example of a low latency application. Graphics software employs techniques from computer vision, image processing, and so on, which typically involves a lot of very fast and very efficient matrix operations on numerous large matrices. When it comes to graphics rendering in video games, there are even more stringent requirements for low latency performance since these are interactive applications, and speed and responsiveness are critical to the user experience. Nowadays, video games are typically made available on multiple platforms to reach a larger target audience. What this means is that these applications, or slightly stripped-down versions of these applications, need to run on low-end devices, which might not have a lot of computation and memory resources available. Video games overall have a lot of resource-intensive operations – rendering graphics, handling multiple players simultaneously, fast responsiveness to user inputs, and so on. C++ is a very good fit for all these applications and has been used to create a lot of well-known games such as Counter-Strike, Starcraft, and Warcraft, and game engines such as Unreal Engine. C++ is also a good fit for different gaming platforms – Windows PCs, Nintendo Switch, Xbox, and PlayStation.

Augmented reality and virtual reality applications

Augmented reality (AR) and virtual reality (VR) are both technologies that augment and enhance a real-life environment or create a whole new virtual environment. While AR just augments the environment by adding digital elements to our live view, VR creates a completely new simulated environment. So, these applications take graphics rendering and video game applications to a whole new level.

AR and VR technology has found a lot of different business use cases, such as design and construction, maintenance and repairs, training and education, healthcare, retail and marketing, and even in the field of technology itself. AR and VR applications have similar requirements as video game applications and need to handle large amounts of data from various sources in real time, as well as handle user interactions seamlessly and smoothly. The technical challenges for these applications are handling limited processing capability and available memory, possibly limited mobile bandwidth, and maintaining low latency and real-time performance to not hurt the user experience.

Browsers

Web browsers are often more complicated than they might appear. There are rendering engines in a web browser that require low latencies and efficient processing. Additionally, there are often interactions with databases and interactive rendering code so that users do not have to wait a long time for the content to update or for interactive content to respond. Due to the low latency requirements of web browsers, it is no surprise that C++ is often the preferred language for this application as well. In fact, some of the most popular web browsers (Google Chrome, Mozilla Firefox, Safari, Opera, etc.) heavily employ C++.

Search engines

Search engines are another use case that requires low latency and highly efficient data structures, algorithms, and code bases. Modern search engines such as Google use techniques such as internet crawling technology, indexing infrastructures, page rank algorithms, and other complex algorithms including machine learning. Google’s search engine relies on C++ to implement all these requirements in a highly low latency and efficient fashion.

Libraries

Many high-level libraries often have stringent performance requirements and can be regarded as low latency applications themselves but usually, they are key components in larger low latency applications and businesses. These libraries cover different areas – network programming, data structures, faster algorithms, databases, multithreading, mathematical libraries (for example, machine learning), and many more. Such libraries require very low latency and high-performance processing such as computations that involve many matrix operations on a large number of matrices, a lot of which can also be very large in size.

It should be clear here that performance is critical in such applications – another area where C++ is often used quite heavily. Even though a lot of these libraries such as TensorFlow are available in Python, under the hood, the core machine learning mathematical operations are actually implemented in C++ to power these machine learning methods on huge datasets.

Banking and financial applications

Banking applications are another class of low latency applications that need to process millions of transactions every day and require low latency, high concurrency, and robustness. Large banks have millions of clients and hundreds of millions of transactions that all need to be executed correctly and quickly and be able to scale up to handle the client load and thus database and server loads. C++ is automatically the choice here for a lot of these banking applications for the reasons we have discussed before.

When it comes to applications such as financial modeling, electronic trading systems, and trading strategies, low latency is more critical than in any other field. The speed and deterministic performance of C++ make it ideal for processing billions of market updates. sending millions of orders, and transacting at the exchange, especially when it comes to HFT. Since markets update very quickly, trading applications need the right data very quickly to execute trades extremely quickly. Large latencies in this system can cause losses that destroy a significant amount of trading profits, or worse. On the research and development side of things, simulations over many trading instruments across multiple exchanges also need large-scale low latency distributed processing to be done quickly and efficiently. The quantitative development and research and risk analysis libraries are also written in C++ because they need to process massive amounts of data as quickly as possible. One of the best examples of this would be the pricing and risk libraries that calculate fair trading prices for options products and run many simulations to assess options risk, as the search space is enormous.

Mobile phone applications

Modern mobile phone applications are quite feature-rich. Additionally, they have to run on platforms with very limited hardware resources. This makes it even more important that the implementation of these applications be very low latency and highly efficient in how they use the limited resources they have. However, these applications still need to be extremely quick to respond to user interactions, possibly handle backend connectivity, and render high-quality graphics on mobile devices. Mobile platforms such as Android and the Windows OS, browsers such as Google Chrome and Firefox, and apps such as YouTube have a lot of C++ involvement.

Internet of Things and machine-to-machine applications

Internet of Things (IoT) and machine-to-machine (M2M) applications are based on connecting devices to collect, store and exchange data with each other automatically. Overall, while IoT and M2M are similar in nature, there are some differences around aspects such as networks, scalability, interoperability, and human interactions.

IoT is a broad term that refers to connecting different physical devices together. IoT devices are generally actuators and sensors that are embedded inside other larger devices such as smart thermostats, refrigerators, doorbells, cars, smart watches, TVs, and medical devices. These devices operate on platforms with limited computing resources, power requirements, and minimal available memory resources.

M2M is a communication method where multiple machines interact with each other using wired or wireless connections without any human oversight or interaction. The point here is that internet connectivity is not necessary for M2M. So IoT is a subset of M2M, but M2M is a broader universe of M2M communication-based systems. M2M technology is used in different applications such as security, tracking and tracing, automation, manufacturing, and facility management.

We have already discussed these applications before, but to summarize again here, IoT and M2M technology are used in applications such as telecommunications, medical and healthcare, pharmaceuticals, automotive and aerospace industries, retail and logistics and supply chain management, manufacturing, and military satellite data analysis systems.

This section was all about different business areas and use cases where low latency applications thrive and, in some cases, are a necessity for the business. Our hope is that you understand that low latency applications are used in many different areas, even though it might not be immediately obvious. The other objective here was to establish similarities that these applications share, even though they are designed to solve different business problems.