Developers Club geek daily blog

Hunting for rodents under Linux

1 year, 3 months ago
There is a mass of monitors of an operating system, but the special sense is made by a task to catch the moment of emergence of a problem and to catch the reason of high loading or a source of problems with performance. I call it hunting for "rodents" of resources.

For this purpose I composed for myself a simple script of ratskill.sh which you will be able to modify under the systems and tasks.

The principle of work simple — a script is started with the set frequency, checks the Load Average level (you can use other control parameters) and in case of exceeding of the set value the script executes the set set of diagnostic commands with creation of the report which is sent on the postal address specified by you.

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New Year's voice habrachat (2016)

1 year, 3 months ago
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New year already not far off, and it can mean only one — time for warm, lamp communication in a voice habrachatik (there is also a normal chat).

Let's communicate in TeamSpeak 3.
It is possible to download it here.

For connection to the server it is enough to enter IP — speakserver.cloudapp.net and your nickname.

With coming, friends!

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Process priority, or attempt to optimize is a little more server

1 year, 3 months ago


In a case when a startup the project young and perspective, but the budget is strongly limited — it is necessary to squeeze out a maximum possible from the available resources.
Well if money under an equipment upgrade is budgeted (in mythical good time), but now it is necessary to receive performance maximum from the available resources.

On open spaces of the Internet there are many articles on a subject as to implement it — failure from LAMP for benefit of nginx+php-fpm or uWSGI (out of need), their thin setup (we do not forget to cache a statics), the PHP installation of an accelerator, tuning of DBMS (if it is used), and other useful things.

But even at installation and competent execution of all points it is possible to optimize work of services a little more.

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Free practical course on Bash and other good news

1 year, 3 months ago


Hi, Habr!

Long ago did not write about updates in our educational project of Hekslet, and here just New year — is a high time to share good news. We made free a popular course "by Bash: Bases of the command line"! It is a unique course because exercises in it (as well as everywhere in Heksleta) are executed in the conditions which are brought closer to fighting: the personal container with root-access in which Bash cover is among other things started is available to you.

The course affects navigation, work with file system, pagers, the redirections and flows, history, aliases and other aspects of work with Bash which any programmer respecting himself has to own.

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We join tox-community or installation of a note in 5 minutes

1 year, 4 months ago
I welcome you, about the greedy reader, the pedant and the fighter for justice on the Internet! In our weapon replenishment, is called it tox. Now I will show you, % %username, its assembly dismantling.

debian_tox_dht

There is such remarkable system which is called TOX. There is their official site, and here a profile on github.

Already wrote a set of times about tox, but I will list the main buns: There is no DHT — dependence on the central server, there is enough at least one note, enciphering on the client — Vasya writes Masha, the Pasha will read nothing telegram.

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Quickly lifted it is not considered fallen. We increase fault tolerance of the built-in systems

1 year, 4 months ago
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A year ago performed quite interesting work on development of the built-in computer for one enterprise which is engaged in electronics. The computer represented nothing essentially interesting: the Cortex A-8 processor working at subgigahertz frequencies, 512Mb as DDR3, 1Gb NAND, lightweight assembly of Linux. However the device which the computer was built in, so and to him should work in quite severe conditions. Broad temperature range (from-40 to +85 Celsius degrees), moisture resistance, resistance to electro-magnetic radiations, kilovoltage impulses on power supply, protection against a statics in 4 kV and a lot of things interesting that is well described in different state standard specifications on special equipment, – all this about it. One of the main requirements of the customer – development term on failure not less than 10 years. At the same time the vendor provides warranty repair of a product within five years therefore a question not rhetorical, but monetary and serious. In a product the corresponding element base was mortgaged. The device with honor passed tests and received required certificates, but conversation not about that. Problems began when the installation lot was produced, and devices dispersed on departments and CB for creation of application software. Returns with the formulation went: "Something is not loaded".

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The VNC installation of the server, and setup of its work over SSH

1 year, 4 months ago

Yes, for some reason not all clients want to work in such convenient and black terminal, the panel completely does not satisfy their esthetic requirements, and in general — "where my such darling and convenient VNC?".
question of a habit and taste

In this article an example of installation and the VNC server setup and a graphic cover (GUI) on the example of OC Debian 8 jessie will be reviewed.

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Myths about / dev/urandom

1 year, 4 months ago
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For certain many of you repeatedly faced myths about / dev/urandom and / dev/random. Perhaps, you even trust in some of them. In this post we will break covers from all these myths and we will sort the presents strong and weaknesses of these random number generators.

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How I week vduplyal in Bareos

1 year, 4 months ago
The task to organize backup with GUI and that it is direct as at big uncles got to me. Earlier there was rsnapshot and everything worked wonderfully so far amounts did not increase up to hundreds of gigabytes, the websites and databases, hundreds of test platforms. The park of servers increased and it became difficult to manage all this affair. From all available solutions we selected opensors and stopped on bareos as on the most often used if something happens fast to google.

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"Transparent" Squid with filtering of HTTPS of resources without substitution of certificates (h86, h64 — the universal instruction)

1 year, 4 months ago
Hi everyone! Last article about transparent proxying of HTTPS by means of Squid'a was quite successful. The set of responses about successful installation of this system came by mail. But also also letters with requests for the help arrived. Problems were quite solvable. But not so long ago one colleague about the help in installation of this system on h64 to architecture (Debian) appealed to me. Here we were puzzled. First, it turned out that last article is unsuitable for this purpose because of lack of the necessary source codes in Debian repository (there now 3.5.10). It was not succeeded to find the necessary source codes in the first article Debian'ovskiye, and checkinstall gave strange error messages. Secondly, there was a wish for more universal solution which without problems would work both on h64, and on h86, and (whenever possible) at other distribution kits. The solution was found. Small addition to the previous article + some amendments turned out. This instruction allows to compile both h86, and h64 Squid'a versions and to create the corresponding packets. The instruction will be broken into several points and subparagraphs. If it is interesting, we go under kat:

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