LYME and LYCE are

software stack In computing, a solution stack or software stack is a set of software subsystems or components needed to create a complete platform such that no additional software is needed to support applications. Applications are said to "run on" or "run on t ...

s composed entirely of

free and open-source software Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

to build high-availability heavy duty

dynamic web page A server-side dynamic web page is a web page whose construction is controlled by an application server processing server-side scripts. In server-side scripting, parameters determine how the assembly of every new web page proceeds, and inclu ...

s. The stacks are composed of: * Linux, the

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

; * Yaws, the

web server A web server is computer software and underlying hardware that accepts requests via HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, commonly a web browser or web crawler, initi ...

; * Mnesia or CouchDB, the

database In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spa ...

; * Erlang, the

functional programming language In computer science, functional programming is a programming paradigm where programs are constructed by applying and composing functions. It is a declarative programming paradigm in which function definitions are trees of expressions that ...

. The LYME and LYCE bundles can be and are combined with many other free and open-source software packages such as e.g.

netsniff-ng netsniff-ng is a free Linux network analyzer and networking toolkit originally written by Daniel Borkmann. Its gain of performance is reached by zero-copy mechanisms for network packets (RX_RING, TX_RING), so that the Linux kernel does not need ...

for security testing and hardening, Snort, an

intrusion detection An intrusion detection system (IDS; also intrusion prevention system or IPS) is a device or software application that monitors a network or systems for malicious activity or policy violations. Any intrusion activity or violation is typically rep ...

(IDS) and

intrusion prevention system An intrusion detection system (IDS; also intrusion prevention system or IPS) is a device or software application that monitors a network or systems for malicious activity or policy violations. Any intrusion activity or violation is typically rep ...

(IPS),

RRDtool RRDtool (''round-robin database tool'') aims to handle time series data such as network bandwidth, temperatures or CPU load. The data is stored in a circular buffer based database, thus the system storage footprint remains constant over time. ...

for diagrams, or

Nagios Nagios Core , formerly known as Nagios, is a free and open-source computer-software application that monitors systems, networks and infrastructure. Nagios offers monitoring and alerting services for servers, switches, applications and servic ...

, Collectd, or

Cacti A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gree ...

, for monitoring.

Details

Both databases

Mnesia Mnesia is a distributed computing, distributed, real-time computing, soft real-time database management system written in the Erlang (programming language), Erlang programming language. It is distributed as part of the Open Telecom Platform. De ...

and

CouchDB Apache CouchDB is an open-source document-oriented NoSQL database, implemented in Erlang. CouchDB uses multiple formats and protocols to store, transfer, and process its data. It uses JSON to store data, JavaScript as its query language using ...

as well as Yaws (and also Mochiweb, Misultin, and Cowboy) are written in Erlang, so web applications developed for LYME/LYCE may be run entirely in one Erlang

virtual machine In computing, a virtual machine (VM) is the virtualization/ emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized har ...

. This is in contrast to LAMP where the web server ( Apache) and the application (written in

PHP PHP is a General-purpose programming language, general-purpose scripting language geared toward web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementati ...

Perl Perl is a family of two High-level programming language, high-level, General-purpose programming language, general-purpose, Interpreter (computing), interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it ...

or Python) might be in the same

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management *Business process, activities that produce a specific se ...

, but the database is always a separate process. As a result of using Erlang, LYME and LYCE applications perform well under high load and if distribution and fault tolerance is needed. The query and

data manipulation language A data manipulation language (DML) is a computer programming language used for adding (inserting), deleting, and modifying (updating) data in a database. A DML is often a sublanguage of a broader database language such as SQL, with the DML com ...

of Mnesia is also Erlang (rather than SQL), therefore a web-application for LYME is developed using only a single programming language. Interest in LYME as a stack had begun by August 2005, as was soon cited as a high-performance web application platform that used a single development language throughout. Favorable comparisons to other popular stacks such as

Ruby on Rails Ruby on Rails (simplified as Rails) is a server-side web application framework written in Ruby under the MIT License. Rails is a model–view–controller (MVC) framework, providing default structures for a database, a web service, and web ...

were soon forthcoming. Comparisons to LAMP have also been favourable, although some have highlighted the difficulties of porting "SQL thinking" to the very different context of Mnesia.

Adoption

A successful user of LYME is the Swedish internet payment-processing company

Klarna Klarna Bank AB, commonly referred to as Klarna, is a Swedish fintech company that provides online financial services such as payments for online storefronts and direct payments along with post-purchase payments. The company has more than 4,00 ...

, who have built their whole architecture on LYME. This is seen as a successful project that demonstrates virtues of both LYME and

functional programming In computer science, functional programming is a programming paradigm where programs are constructed by applying and composing functions. It is a declarative programming paradigm in which function definitions are trees of expressions that ...

in general. LYME was also covered in the Erlang session at the Software Practice Advancement (SPA) 2008. Besides Yaws, there are several other web servers written in Erlang, e.g. Mochiweb, Misultin, and Cowboy. Besides Mnesia and CouchDB, there are a couple of other databases written in Erlang, e.g., Cloudant, Couchbase Server (born as Membase), database management system optimized for storing data behind interactive web applications,

Riak Riak (pronounced "ree-ack" ) is a distributed NoSQL key-value data store based on Amazon's Dynamo paper, including its "tunable AP" approach, that is tunable consistency, to the tradeoffs imposed by the CAP Theorem. Riak offers high availability, ...

, and

SimpleDB Amazon SimpleDB is a distributed database written in Erlang by Amazon.com. It is used as a web service in concert with Amazon Elastic Compute Cloud (EC2) and Amazon S3 and is part of Amazon Web Services. It was announced on December 13, 20 ...

(part of

Amazon Web Services Amazon Web Services, Inc. (AWS) is a subsidiary of Amazon.com, Amazon that provides Software as a service, on-demand cloud computing computing platform, platforms and Application programming interface, APIs to individuals, companies, and gover ...

What You Need To Know About Amazon SimpleDB
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References

{{Linux Erlang (programming language) Free web software Web frameworks Web development software Internet software for Linux

Details

Adoption

See also

References