Installing NVIDIA Driver on Ubuntu 16.04

I am not sure if there were NVIDIA drivers when I installed Ubuntu 16.01 on a machine with Intel processor and GTX 1060 graphic card, but at least I saw this in the terminal (it is not clear what actually FAILED):

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Installing Google Play Services on a Windows 10 with MS VS2015

If Android support is enabled in MS VS2015, it installs Android SDK without Google Play Services and I did not find an option in SDK Manager that installs them. When I started “C:\Program Files (x86)\Android\android-sdk\SDK Manager.exe” with admin privileges, it automatically offered to install some 9 packages:

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GeForce GTX 1060 does not trigger the boost state (Solved)

MSI GeForce GTX 1060 3GB graphic card does not trigger its boost state when its GPU is loaded at 99-100% with NiceHash miner. Compare the values in the green rectangles:

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How I fixed 504 Gateway Timeout error on Nginx + PHP-FPM

Today I got 504 Gateway Timeout error while updating my Joomla website and solved this issue by adding “fastcgi_read_timeout 300” into Nginx virtual host:

location ~ \.php$ {
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass unix:/run/php/www-shar.sock;
    fastcgi_index index.php;
    include fastcgi.conf;
    fastcgi_read_timeout 300;
}

I already had request_terminate_timeout option set to 300s in the pool configuration file:

; The timeout for serving a single request after which the worker process will
; be killed. This option should be used when the 'max_execution_time' ini option
; does not stop script execution for some reason. A value of '0' means 'off'.
; Available units: s(econds)(default), m(inutes), h(ours), or d(ays)
; Default Value: 0
request_terminate_timeout = 300s

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How to remove ID from URL in Joomla 3.8 and higher

In Joomla 3.8.2 (and probably 3.8) or later to remove ID from URL you go to System->Global Configuration->Articles->Integration page, select Modern URL Routing and then select Remove IDs from URLs:

How to remove ID from URL in Joomla 3.8

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Configuring Postfix with Yandex.ru relay in Ubuntu 16.04

Today I read that Postfix can be better than sendmail and found a great Russian article on how to configure Postfix to work with Yandex.ru relay (Yandex.ru is some kind of Russian Google). The only notice I would give is that in a Docker container I need also install rsyslog, otherwise /var/log/mail.log file is not created:

apt install rsyslog

After doing all the steps described in this Russian manual I was able to send email to Yandex.ru and GMail accounts, but GMail landed all the emails to its spam folder. My first idea was that it is because I did not configure ‘from address’ correctly, so I had the following in /var/log/mail.log, and also there was a message ‘Cannot assign requested address‘:

Oct 27 11:36:19 0675c97b78aa postfix/pickup[1210]: 8C7ECE5B72: uid=0 from=<root>
Oct 27 11:36:19 0675c97b78aa postfix/cleanup[10786]: 8C7ECE5B72: message-id=<20171027113619.8C7ECE5B72@0675c97b78aa.localdomain>
Oct 27 11:36:19 0675c97b78aa postfix/qmgr[1211]: 8C7ECE5B72: from=<root@0675c97b78aa.localdomain>, size=405, nrcpt=2 (queue active)
Oct 27 11:36:19 0675c97b78aa postfix/smtp[10788]: connect to gmail-smtp-in.l.google.com[2a00:1450:400c:c09::1b]:25: Cannot assign requested address
...

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Configuring sendmail with GMail relay on Ubuntu 16.04

Previously I published post How I configured sendmail for PHP on Ubuntu Server 12.04 describing how to configure sendmail to use custom SMTP server. But after switching to Ubuntu 16.04 VPS my first idea was that I can use sendmail in its default configuration, but this idea was wrong, because while sendmail worked well with yandex.ru (some Russian mail server), for example, it did not work with GMail, because GMail did not accept the mail reporting ‘DSN: Service unavailable.‘┬áin /var/log/mail.log, see my post on Ubuntu Forum for more information. Now my second idea is that using GMail as sendmail relay will prevent GMail from rejecting my mail. Below I provided a short instruction on how to realize this successful idea.

Install the packages

apt-get install sendmail mailutils

mailutils allows to run mail command.

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Fun with Bitcoin mining on a home Windows machine.

I have heard many times that there are a lot of Russian guys who build mining farms and earn money with cryptocurrencies. Who knows, probably cryptocurrencies are still only at the starting point of their growth, or probably it is too late to start mining, or as another alternative Russian government will forbid them, but anyway it was interesting for me, how much Bitcoins my home Windows computer with relatively old graphic card can mine.

I overclocked my GeForce GTX 750 graphics card a bit:

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Exponential growth policy of std::vector

Once std::vector is filled (size() equals to capacity()), a subsequent push_back(…) results in an exponential expansion of the vector capacity. The following table shows that the expansion happens when the index reaches a power of two:

index: 0, capacity: 1, address: 0x1fa6c20
index: 1, capacity: 2, address: 0x1fa6c40
index: 2, capacity: 4, address: 0x1fa6c20
index: 4, capacity: 8, address: 0x1fa6c60
index: 8, capacity: 16, address: 0x1fa6c90
index: 16, capacity: 32, address: 0x1fa6ce0
index: 32, capacity: 64, address: 0x1fa6d70
index: 64, capacity: 128, address: 0x1fa6e80
index: 128, capacity: 256, address: 0x1fa7090
index: 256, capacity: 512, address: 0x1fa74a0
index: 512, capacity: 1024, address: 0x1fa7cb0
index: 1024, capacity: 2048, address: 0x1fa8cc0
index: 2048, capacity: 4096, address: 0x1faacd0
index: 4096, capacity: 8192, address: 0x1faece0
index: 8192, capacity: 16384, address: 0x1fb6cf0
index: 16384, capacity: 32768, address: 0x1fc6d00
index: 32768, capacity: 65536, address: 0x1fe6d10
index: 65536, capacity: 131072, address: 0x2026d20
index: 131072, capacity: 262144, address: 0x20a6d30
index: 262144, capacity: 524288, address: 0x21a6d40
index: 524288, capacity: 1048576, address: 0x23a6d50
index: 1048576, capacity: 2097152, address: 0x27a6d60
index: 2097152, capacity: 4194304, address: 0x2fa6d70
index: 4194304, capacity: 8388608, address: 0x7f8e9225f010
index: 8388608, capacity: 16777216, address: 0x7f8e8e25e010
index: 16777216, capacity: 33554432, address: 0x7f8e8625d010
index: 33554432, capacity: 67108864, address: 0x7f8e7625c010
index: 67108864, capacity: 134217728, address: 0x7f8e5625b010
index: 134217728, capacity: 268435456, address: 0x7f8e1625a010
index: 268435456, capacity: 536870912, address: 0x7f8d96259010
index: 536870912, capacity: 1073741824, address: 0x7f8c96258010

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How to erase an element with a reverse iterator from C++ container

The following C++ code demonstrates how to erase an element a reverse iterator points to:

#include <iostream>
#include <set>
#include <vector>
#include <assert.h>

int main()
{
	std::set<int> set;

	set.insert(15);

	std::cout << set.size() << " ";

	auto ri = set.rbegin();

	auto i1 = --ri.base();

	auto i2 = --set.end();

	assert(i1 == i2);

	set.erase(i1);

	std::cout << set.size() << std::endl;
}

The output is ‘0 1’. The key point here is that the reverse iterator is an adaptor for reverse-order traversal that can be created from forward iterator with std::make_reverse_iterator.