Enabling HTTP/2 in Ubuntu 18.04 I've just upgraded to 18.04 from 16.04 and am having a problem enabling HTTP/2 on my websites. First of all, my websites all use HTTPS.  I have done the following:  sudo a2enmod http2   added the following text to /etc/apache2/apache2.conf  Protocols h2 h2c http/1.1   and finished off with:  sudo systemctl restart apache2   As far as I am aware, that is all I need to do but none of my sites are working with HTTP/2 after doing the above operations. Can anyone lend a hand as to what I might be doing wrong, please?  Edit: I figured out what the problem was. I was using mod_php and mpm-prefork but in order to support HTTP/2 I needed to be using mpm_event and php7.2-fpm. I did this and got the sites working with HTTP/2 but now I have another problem. php7.2-fpm is timing out when I tried to start up upon reboot resulting in a 503 server error and I have no idea why it is timing out at all.
Getting HTTP/2 Working on Apache 2.4.29 on Debian 8 I am trying to update my apache2 (Apache/2.4.29 (Debian 8)) server to support http2 but after enabling http2   with following code, it does not work because of mpm_prefork does not support http2  &lt;IfModule http2_module&gt;     ProtocolsHonorOrder On     Protocols h2 h2c http/1.1 &lt;/IfModule&gt;    since mpm_prefork apache (2.4.29)  does not work with http2, I tried using  mpm_event/mpm_worker but it does not work, so I enable mpm_prefork  sudo a2dismod mpm_event  sudo a2dismod mpm_worker  sudo a2enmod mpm_prefork   Since I am still running php5 what should I do to have http2 support on Debian8?  Will I have to update php5 to php7?  Is there any workaround to use mpm_worker/mpm_event with php5 with http2 support?  apache error log  [http2:warn] [pid 11992] AH10034: The mpm module (prefork.c) is not supported by mod_http2. The mpm determines how things are processed in your server. HTTP/2 has more demands in this regard and the currently selected mpm will just not do. This is an advisory warning. Your server will continue to work, but the HTTP/2 protocol will be inactive. [mpm_prefork:notice] [pid 11992] AH00163: Apache/2.4.29 (Debian) OpenSSL/1.1.0g configured -- resuming normal operations [core:notice] [pid 11992] AH00094: Command line: '/usr/sbin/apache2'
Why can't Python's raw string literals end with a single backslash? I'm robotic engineer. I'm using OpenSCAD to model robotic components (gears, pulleys, parts, etc). But I need application to model physics and interaction of the components (for i.e. how will robot move if I will rotate current gear).  So, is it possible to import OpenSCAD models into Blender and model interactions in it?  I have models in STL format (for i.e. gears). I need to make reductor from it and see how it moves (if possible - measure rotation speed and torque). I'm trying to solve a question where I need to write $\frac {1}{1+z^2} $ as a power series centered at $z_0=1$  I'm not allowed to use taylor expansion. So my first thought was to rewrite the function in a form where I can apply the basic identity:  $$ \frac{1}{1-x} = \sum_{n=0}^\infty x^n $$  So let's rewrite the original function $f(z) = \frac {1}{1+z^2} $ and use above identity:  $$\frac {1}{1+z^2} = \frac {1}{1-(-z^2)} $$ But observe that I need to center it at $z_0=1$ so I rewrote it to:  $$\frac {1}{1-(-z^2)}=\frac {1}{2z-(-(z-1)^2)} $$  I can factor out $\frac {1}{2z}$ and use the basic identity to get : $$\frac {1}{2z}\frac {1}{1-\frac{(z-1)^2}{2z}} = \frac {1}{2z}\sum_{n=0}^\infty \left(\frac{-(z-1)^2}{2z}\right)^n =\frac {1}{2z}\sum_{n=0}^\infty \frac{(-1)^n(z-1)^{2n}}{(2z)^n} = \sum_{n=0}^\infty \frac{(-1)^n(z-1)^{2n}}{(2z)^{n+1}}$$  The problem is if I ask wolfram alpha: power series$ \frac{1}{1+z^2} $centered at z = 1 it will give me a different answer that doesn't match the sum I found.  Can anyone help me figure this one out? What am I doing wrong? "NG NS" on ticket after airport security I went through security at the Sacramento Airport with a friend. He got something written on his boarding pass "NG NS". I didn't have that. We both went through the same metal detector, neither beeped nor had random checks. Flying to Edmonton through Seattle connection. Early for flight.  I have tried searching for "what is tsa ng ns" on Google but nothing useful came up. Any ideas? Is this defined by the language? Is there a defined maximum? Is it different in different browsers? How to show the parent and child taxonomy term? Forest tree not symmetric How to use JACK and Pulseaudio/ALSA at the same time on the same audio device? Whenever I launch hydrogen it breaks my audio in all other applications which use Pulse, for example, I can no longer play videos in Chrome after having launched Hydrogen once, until I restart my PC or do sudo alsa force-reload. I have found people with similar issues, but no actual guide to fix this, often there are links to  (which has moved to  ) I am using Ubuntu Studio 14.04 64bit.  ALTERNATIVELY if this is truly impossible to achieve, can someone tell me how to use Jack on one soundcard and Pulse on another? This way I could plug in a USB sound card only when I need JACK.  Please don't make me use windows. How to shift EXIF date/time created by time in days, hours, minutes? I'll preface this by saying I'm very new to Blender - I'm trying to put a bevel on an edge, looks something like this:    As you can see, the vertical side is much longer than the horizontal side.  When I apply to bevel to the edge there, the bevel stretches proportionally - so there's 'more' bevel on the longer side.  I want to bevel without any 'ratio' like that - just a 45-degree bevel, if that makes any sense.  Do I have to put in a loop cut to make the side lengths equal?  I tried using a sub-surf modifier, but it applies on a bunch of nearby edges, when I just want to round this one corner. Rigor in quantum field theory Programmatically download (seamless) NED tiles? I used to download 1/3 arcsecond elevation geotiffs from extract.cr.usgs.gov using web services.  But a few days ago, that stopped working, probably because USGS reorganized their site.  I tried emailing USGS and haven't heard back yet.    I could, of course, manually download states or degree tiles using the seamless server, but I want to do it programmatically so that users of my trip planner can get elevation data for their region without human intervention.  And SRTM isn't high enough resolution for bicycle/wheelchair trip planning.  Any ideas? How can I read input from the console using the Scanner class in Java? Windows does not mount USB NTFS superfloppy I have a Transcend Storejet external USB hard disk. This is not an SSD, but a mechanical disk with rotating plates. I have formatted the whole disk, without partitioning, as NTFS. I have used mkntfs tool under Linux.  When plugged into a Linux machine, the system sees a drive with two partitions (/dev/sdc /dev/sdc1 /dev/sdc2). However, as I know it is a partitionless disk, I can mount the whole device (mount -t ntfs /dev/sdc /mnt) and it works without any problems.  When plugged into a MS Windows XP machine, the systems sees a disk with two unformatted partitions, and it does not assign a drive letter to either the whole disk, nor to any of the partitions.  Would anyone know how to get MS Windows to mount my disk as a NTFS superfloppy?  I have already tried removing old USB mounting points and residual devices using 'DriveCleanup'. It did not help.  By the way, I also have an external Kingston USB SSD, also formatted as NTFS superfloppy, without partitioning. However, this one is recognized and mounted normally by MS Windows. Why would Mystique's DNA allow for Sentinels that can duplicate mutant powers? How do I install Adobe Flash player? I have had significant problems with watching flash video in 64-bit Ubuntu.  Does anyone know of a good way to get flash running on the platform? Position of a relative clause before/after a verb I'm not sure about the sentence structure below:  All kinds of problems arise that smaller animals or plants do not have to cope with.  It looks like that works as a relative pronoun for all kinds of problems, but I couldn't find such usage in my dictionary or online. This sentence could be divided into  There are all kinds of problems. Smaller animals or plants do not have to cope with all kinds of problems.  But, I can't figure out where 'arise' fits. If you have any thoughts, please share them. Does Linux have the capability to use "junctioned" symbolic links? I'm not sure if this is an actual term or not, so let me explain the concept.  I have a git repository containing all my configuration dot files in ~/dotfiles. I use symbolic links into this directory in order to "activate" them. For example, by executing ln -s ~/dotfiles/bash/bash_profile ~/.bash_profile to produce the link:  ~/.bash_profile -&gt; ~/dotfiles/bash/bash_profile   However, I find myself in a situation where I want to combine the contents of multiple files. For example, I want the ~/.bash_profile symbolic link to point to two separate files, one for each project. E.g.:  ~/.bash_profile (1) -&gt; ~/dotfiles/bash/bash_profile (2) -&gt; ~/dotfiles/proj/bash_profile   I know I can simply concatenate the two files (e.g., cat ~/dotfiles/{bash,proj}/bash_profile &gt; ~/.bash_profile), but if I can do the same thing with symbolic links, I would prefer to.  I imagine that if such a feature exists (Nix is pretty huge), then under the hood it would have to map the two different files together, hiding all sorts of complexities under the hood (mapping file offsets of all non-first "mapped" files, locking all files when writing to the junctioned symbolic link, etc, etc).  If such a feature doesn't exist, are there are plans to implement it? Recording claimable expenses in GnuCash Proving $\frac{1}{n+1} + \frac{1}{n+2}+\cdots+\frac{1}{2n} &gt; \frac{13}{24}$ for $n&gt;1,n\in\Bbb N$  To solve it I used induction but it is leading me nowhere my attempt was as follows:  Lets assume the inequality is true for $n = k$ then we need to prove that it is true for $k+1$  so we need to prove $\frac1{k+2} + \frac1{k+3}+\cdots+\frac1{2(k+1)} &gt; 13/24$  I don't know where to go from here please help.