Developers Club geek daily blog

Tarantool as application server

1 year, 11 months ago
Hi, %khabrayuzer of %. The command of the Tarantula continues to share insayta and examination for effective work with data in the high-loaded projects. Today we will try to understand why Tarantool is "two in one": not only database, but also application server. Probably, some heard about the Tarantula as about superfast persistent in-memory storage with support of replication and hranimok on Lua. Provide that we take Redis pieces, we add the frozen Node.js, on top we fill Go then we cook, slowly mixing, within five minutes after boiling. It would seem at what here Application Server?


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We build services based on Nginx and Tarantool

1 year, 11 months ago
Such architecture is familiar to you? A round dance of the demons dancing between cache and storage.



What minuses of such architecture can be noted? Solving problems within such architecture, we face a heap of questions: what language (and?) to take what I/O framework to select how to synchronize cache and storage? Heap of infrastructure questions. And why to resolve infrastructure issues when it is necessary to solve a problem? Certainly, one may say, that we like certain X and Y technologies and to transfer these minuses to a framework of ideological. But it is impossible to deny the fact that data are had on somebody distance from a code (the picture higher) that adds latency that can reduce RPS.

The purpose of this article — to tell about alternative which is constructed based on Nginx as web server, balancer and Tarantool as App Server, Cache, Storage.

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Asterisk + LUA: fast start

1 year, 11 months ago
For the last year on Habré there were several articles about use of a dialplan of lua in asterisk (time, two, three, four). It is rather interesting method of writing of flexible and powerful dialplan. But to try such method of writing of dialplan it is necessary to spend time quantity: to set the necessary libraries, to rebuild with necessary for options an asterisk.

In addition many users have asterisk'the different level of preparation: someone is closer to system administration or even to traditional telephony, than to programming. Plus specifics of telephony — are better not to load with unfamiliar experiments the working systems once again, and to carry out tests and experiments on the notebook — it is necessary to litter system. Generally, there are many reasons "to postpone for later".

I want to show in this article to everyone and working with an asterisk as, using docker, it is possible to feel taste of the flexible scenarios lua quickly. And then to these it is worth deciding to use further in practice or not. (To whom it is uninteresting to read, and it is interesting to watch and listen — at the end of the text to 6-minute video with highlights and result.)


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Management of things of the real world from the virtual world of Minecraft (transfer)

1 year, 12 months ago
Recently I started over again playing Minecraft. Vanilla Minecraft is a little boring as on me, and I always look for modpak (packets of additions). In search of new modpak I came across FTB Horizons: Daybreaker. From the list of the spendthrifts who are contained in it drew my attention OpenComputers modes.

As it is possible to assume from the name, the OpenComputers module adds computers to Minecraft. These computers! At the same time they too modular. You can add the periphery: from monitors to keyboards and expansion cards which add features such as graphics and a network. And these computers can be programmed in the Lua language, directly in game. Also there is such type of cards as the Internet card which you can imagine, can be connected to the Internet of the real world. Not bad.
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So, what we can make approximately at one o'clock free time?

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Nginx + Lua + Redis. Effectively we process session and we give data

2 years ago
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Let's assume, you have data which you want to cache and give, without using difficult languages as php, at the same time checking that the user is authenticated and has the right to data access. Today I will tell how, using a linking of nginx lua redis to carry out this task, to unload the server and to increase the speed of return of information the server in tens of times.

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"Stored procedures" in Redis

2 years ago
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Many know about an opportunity to store procedures in sql databases, about it many chubby manuals and articles are written. However very few people know that similar opportunities are available also in Redis, starting with version 2.6.0. But as Redis is not a relational DB, and the principles of the description of stored procedures rather strongly differ. Stored procedures in Redis — almost full-fledged Lua scripts (at the time of writing of article as the interpreter Lua 5.1 is used).

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Lua 5.3 Reference guide

2 years ago

Translated into Russian "Lua 5.3 the Reference guide". Its chm-version can be taken on a file hosting service.

Actually, translated for itself therefore in the text of the original manual placed a set of notes, both in pop-up windows, and in the form of text inserts (with spoilers and without them) a small gray font on a yellowish background.

I am not a programmer, I have no basic knowledge so everywhere where "stumbled" on terms, tried to facilitate thus to itself understanding.

Besides, for those who, perhaps, will want to change something enclosed Lua5.3.hhp file in archive — that any could sort/collect the chm-file by the HTML Help Workshop program.

Well and at last, I do not know English, translated generally on-line translation programs (by means of the QTranslate program).

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Use of Remote API in V-REP robosimulator

2 years, 1 month ago


V-REP represents the environment for simulating (sandbox) of different types of robots, thus the user does not have need to have physical access to the real machine that saves money and time. The V-REP environment provides the convenient interface for visualization of operations of the robot in three-dimensional virtual space much earlier, than the real prototype of the robot will be created. By means of this manual you are convinced that to work in this environment, the programmer does not need to have wide technical experience in the field of robotics.

Absence (for that time) knowledge of the Lua language in which all scripts of control of the robot, and its smaller popularity are by default written became the reason of creation of this manual. The purpose of this manual to show as to use remote (Remote) of API of this environment on the example of the Python language.

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Asterisk Manager Interface in the dialplena

2 years, 3 months ago
As well as all ASTERISK'ERY I faced problem of more than once that on PBX there are some trunks which are used for outgoing communication. And as at many, at my customers too the part of these trunks is the main, and the others play role reserve, on falling/employment case / chego-libo still the first.

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We do game with Gideros

2 years, 3 months ago
Very long ago there was article about Gideros (development of games on LUA), but I have not found continuation. Therefore has made small article how to develop games on Gideros Studio. Source codes and apkshnik of the project at the end of article. Continuation under cat.


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