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Linux Mastering Development Ubuntu

package corruption?

i have an ubuntu 18.04.4 server installed on a vmware esxi 6.5 server as a vm… the server was recently suffered from multiple power outages that caused one of the ssd drives in it to act up, causing the ubuntu server boot drive vmdk on it to be wierd. i later managed to fix it […]

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Development Game Creation

Fishbowl effect correction in raycasting engine suggestions (pseudo 3d projection)

I’m writing a simple raycaster in golang and I have some problems understanding perspective correction. The code is simple, the main rendering loop is this: curVector := playerVector.NewRotated(-curFov / 2) rotateStep := curFov / float64(screen.Width()) // Angles per screen row // Traverse each row of our screen, cast a ray and render it to screen […]

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Mastering Development System & Network

Running a production, self-hosted GitLab CE/EE in a Docker container: how mature and/or popular? [NOT Docker for GitLab Runner]

How many users/communities run GitLab CE/EE for production in a Docker image/container? In other words, how popular is GitLabCE/EE running on/in Docker? My team is trying to gauge the maturity of the GitLabCE/CE-in-Docker use case based upon its popularity. (This is a VERY DIFFERENT point/question than asking about GitLab runners in Docker for CI/CD purposes. […]

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Mastering Development System & Network

How to tell how many Aurora cluster replicas had been running at a particular time in a past?

I tried searching for various available metrics in an Aurora cluster in AWS. There seem to be no metric that tells you how many nodes in a cluster a given time? There is such a metrics per ELB, Target Group or ASG.

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Mastering Development System & Network

Cannot ping own interface over ipv6

I have a raspberry pi with two network interfaces; one connected to a traditional managed-mode AP (wlan0), and one that hosts an ad-hoc (IBSS) network (wlan1). Recently, I started from scratch from a clean raspbian build, and I seem to have something messed up in my ipv6 configuration, because simply pinging my own interface is […]

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Mastering Development System & Network

what should the ACL value be when limiting S3 object access to CloudFront only?

I followed https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/private-content-restricting-access-to-s3.html But I cannot figure out what should the ACL on AWS.S3.PutObjectRequest be when I upload to s3 bucket. Possible values: “private”|”public-read”|”public-read-write”|”authenticated-read”|”aws-exec-read”|”bucket-owner-read”|”bucket-owner-full-control” Using JavaSript SDK Currently I have “public-read”, I know I should change this, but I am not sure which is the best for this case. My initial thought is to “private”.

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Ask Mathematics

The closed form for $\sum_{n=1}^\infty \frac{H_{n/2}}{n^2}x^n$

Is there a closed form for $$\sum_{n=1}^\infty \frac{H_{n/2}}{n^2}x^n\ ?$$ Where $H_{n/2}=\int_0^1\frac{1-x^{n/2}}{1-x}\ dx$ is the harmonic number. I managed to find the closed form but had hard time finding the constant. My trial I was able to prove $$\sum_{n=1}^\infty \frac{H_{n/2}}{n}x^n=\operatorname{Li}_2\left(\frac{1}{1-x}\right)+\operatorname{Li}_2\left(\frac{1}{1+x}\right)-\operatorname{Li}_2\left(\frac{1-x}{1+x}\right)$$ $$+\ln(1-x)\ln(1+x)+\ln^2(1-x)-2\ln(x)\ln(1-x)-i\pi\ln(1-x)-\zeta(2)=f(x)$$ If we divide both sides by $x$ then integrate we get $$\sum_{n=1}^\infty \frac{H_{n/2}}{n^2}x^n=\int\frac{f(x)}{x}\ dx$$ Wolfram […]

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Ask Mathematics

If $u\in C_{0}^{\infty}(\mathbb{C})$ and $\frac{\partial u}{\partial\overline{z}}$ is a real valued nonnegative function, then $u\equiv 0$.

The problem: If $u\in C_{0}^{\infty}(\mathbb{C})$ and $\frac{\partial u}{\partial\overline{z}}$ is a real valued nonnegative function, then $u\equiv 0$. Thoughts: I believe this is done in the following fashion: First, I am supposed to prove that if $u\in C_{0}^{\infty}(\mathbb{C})$ and $n\geq 0$ is an integer, then $\iint_{\mathbb{C}}\frac{\partial u}{\partial \overline{z}}\cdot z^n dz\wedge d \overline{z}=0$. Second, I am suppose […]

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Ask Mathematics

$\lim_{n \to \infty} \frac{1}{n} \sum_{r=1}^{\infty} e^{-\frac{r^2}{2n^2}}$

Let $a_n = \frac{1}{n} \sum_{r=1}^{\infty} e^{-\frac{r^2}{2n^2}}$. The sequence is well-defined by considering the ratio test. What then is $\lim_{n \to \infty} a_n$? I suspect it is $\sqrt{\pi/2}$, by converting the “riemann sum” into a gaussian integral, but there were some slight details that I’m unable to justify. I’ve tried using another sequence, $b_{L,n} = \frac{1}{n} […]

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Linux Mastering Development

Xming sometimes works, sometimes does not work. How to fix this issue?

My OS is Windows 10. The OS in host server is CentOS 7. Sometime, I can display figures in Xming, but sometimes not. If I reboot my laptop, I may use Xming again. Any suggestion would be highly appreciated.