Which is the best provider this time? Price is not an issue, clean IP storage is

Which is currently the BEST dedicated server provider?

Price is not the main issue as we are currently one of the most expensive providers (IBM because it is a soft layer), but there must be immaculately clean IP storage. The deliverability of emails is the most important problem for my customer.

Central USA, but can also be in other US areas
Linux / Cpanel

Clean up a list of values ​​without missing data

I'm trying to clean up a list of missing items by inserting the middle feature variable into the missing data

list = {{"age", "height", "weight"}, {32, 176, 75}, {27, "", 82}, {24,180, ""}, {"", 183, 89}};
list // TableForm
copylist = list
copylist[[All ;; 5, 1 ;; 3]] // TableForm;
goodsamples = Table[Cases[copylist[[All, i]], _?NumericQ], {i, 3}] // N;
goodSamplesMean = Table[Mean[goodsamples[[i]]], {i, 3}] // N
cleanlist = copylist[[All ;; 5, 1 ;; 3]] /. "" Table[goodSamplesMean[[i]], {i, 3}];

I get the error message when I run the code

ReplaceAll :: reps: {27.6667, 179.667, 82.} is neither a list of replacement rules nor a valid shipping table and therefore cannot be used for replacement.

What I'm aiming for is to replace the middle feature variables from


So that


appears as follows

cleanlist={{"age", "height", "weight"}, {32, 176, 75}, {27, 179.667, 82}, {24,180, 82.}, {27.6667, 183, 89}};

Linux – I use & # 39; sudo apt-get clean & # 39; too often these days. How can I avoid using it again?

I have a LAMP server hosted by Digital Ocean that has been running for more than 3 years. I use the server to run an ERP site where users have to log in to do what they have to do.

Until recently, people could easily get into ERP and do what they had to do. However, it has often happened that when trying to log in to ERP, the user is presented with the login page without any error messages.

I tried to investigate by logging in to the server with Putty and determining where the problem was, and I received a message that there was no more memory.

I read that online sudo apt-get clean fixes the problem so I tried it and it fixed it … for a few days until I had to do it again for the same reason. I have been doing this repeatedly for weeks and I want to see if there is a way to avoid this.

What do I have to do so that the server has enough memory? I tried archiving old files and removing them from the server to see if that could help, but as far as I can see it only made a small dent.

Can you help me please? Thanks a lot!

Edit, someone asked me to run df -h and df -i on PuTTy. Here are the results:

df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            992M     0  992M   0% /dev
tmpfs           201M   21M  180M  11% /run
/dev/vda1        49G   49G   65M 100% /
tmpfs          1001M     0 1001M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs          1001M     0 1001M   0% /sys/fs/cgroup
/dev/vda15      105M  3.4M  102M   4% /boot/efi
tmpfs           201M     0  201M   0% /run/user/0

df -i
Filesystem      Inodes   IUsed   IFree IUse% Mounted on
udev            253701     378  253323    1% /dev
tmpfs           256014     529  255485    1% /run
/dev/vda1      6451200 1033830 5417370   17% /
tmpfs           256014       1  256013    1% /dev/shm
tmpfs           256014       6  256008    1% /run/lock
tmpfs           256014      16  255998    1% /sys/fs/cgroup
/dev/vda15           0       0       0     - /boot/efi

Local version of "White Balance" in GIMP to clean up the photo of the document

I have a photo of a document with black text on a white background.

The photo has a few problems:

  • The text is a bit blurry.
  • Overall, there is noise even in the white areas.
  • The background is not really white, but somewhat yellowish.
  • Most importantly: Some areas of the image, including the areas that are supposed to be white, are darker than others.

I want to clean up this picture. I am on Linux.

The "Colors> Auto> White Balance" filter in GIMP delivers promising results. However, the background in different areas of the image is not balanced.

However, if I only select a portion of the image, the "White Balance" filter actually works better in that area.

Therefore I imagine that the gradual application of the "white balance" would work very well in local areas of the image.

I imagine that the "White Balance" filter is implemented as follows:

  1. Collect color statistics of the entire image.
  2. Create a color conversion matrix and apply it globally.

So what do I want instead:

  1. Collect local color statistics for each area from e.g. 100 * 100 px.
  2. Create local color conversion matrices.
  3. Create a continuous function of the conversion matrices per pixel.
  4. Apply locally per pixel.

Do you know something that works either in GIMP or as standalone software, e.g. for the linux command line?

Clean up – Bitcoin Core v0.19.0.1 will be cleaned up automatically. I keep losing the blockchain. How can I stop it?

Bitcoin Core v0.19.0.1 is automatically truncated. I keep losing the blockchain. How can I stop it?

I went into the settings and deselected the cut. I also added the line prune = 0 to bitcoin.conf. And yet when I booted up my computer after a power failure, Bitcoin Core Desktop cut my copy of the blockchain. When I booted up my Mac, Bitcoin Core initially showed me a screen asking for the Bitcoin file system location. I had to mount the external USB hard drive and enter the encryption password. Once I confirmed the location of the file, it was time to crop it. This problem is not limited to power outages. If I upgrade to the next version of the software, it will be removed. How can I end this?

Authentication – Good / clean practice for creating the authentication part of an application

I am starting with a greenfield project and have not carried out or archived the registration / registration and authorization part of the backend for a long time. Therefore my knowledge of the good practices of today is very limited. I basically only performed basic local login / logon functions.

The app refers to social networks, so thousands of users are expected in the near future. So of course I want to start with the cleanest possible architecture. But also try to "look into the future" and anticipate costs.

I now need registration / registration options for the project with:

  • Mobile phone number.
  • E-mail
  • Apple Account
  • Facebook Account

I deal with managed services like Auth0, AWS Cognito (particularly interested in this) etc.

However, I'm not sure if I know how to set up process and user account management. If I use a relational database, I still have to create the user account models in my application and then:

  • When a user signs in via email, my app does all the authentication, including signing in, and generating and processing access and update tokens.
  • When a user logs on through another third party, I use the managed authentication service and link the user record on the service to a user record in my database. Then use the managed token generation and handling service.

Or do I delegate all user management (including user account models and data) to the managed authentication service? The only functionality related to managing authentication and user accounts in my application are calls to the managed authentication service …?

How can I achieve a bright, clean look that is normally found in portrait photography?

In my opinion we have 2 steps here.

The second step: post-processing

I start with the second one. The post-processing. It's not that difficult at all.

I'm not using Lightroom in this example, but it's the same for different applications. Play with the levels.

1) I hinted the gamma (which is a very special kind of curve) at 2-2.3. (it's probably a bit exaggerated in my example)

Adjust the black level accordingly.

2) Cut the white point. This creates additional brightness, but it also saturates your photo.

3) You can saturate your photo a bit more. (I didn't saturate them in these cases because I show the difference on the histogram when I use steps 1 and 2.)

And the first step

Get a good picture from the start!

In this example, the first photo has a nice diffuse light, and in the second you can see that they used a hard flash that projects some bad shadows. The bright look can be achieved, but a pleasant diffuse light makes the difference.

Some tips for taking pictures

  • If possible, use the available ambient light. Particularly large windows.

  • Bounce your flashes on the white cells or walls. Note that I mentioned lightning. For a studio photo (or one on-site), you usually need multiple shots, depending on the type of photo, close-ups, or wide-angle shots.

  • Illuminate your motifs, but also your backgrounds. Depending on the situation, this can be difficult, as hot spots can sometimes be seen everywhere on a wide background. For this reason, you must use the ambient light as much as possible.

  • Use a large aperture lens. These photos usually have a shallow DOF because of the nice bokeh, but also because … they use nice ambient light. If you use flashes, this helps because you can place the flashes further away and create a more even light.

Levels – Uncle Bob's clean architecture – Dealing with anemic interactors, tiering and front-end MVVM


In Uncle Bob's Clean Architecture, use case interactors are responsible for orchestrating business objects to achieve some user goals.
As a simple example, an e-commerce application could have a use case to buy items in a shopping cart: the interactor receives a request (DTO) to make a purchase, and then the interactor could query various output ports (gateways), for example Check inventory / availability, check if payment can be made, and if so, maintain a change in inventory service that ends with a response (another DTO) indicating the success / failure of the interaction (then the levels of the user interface) presents this information to the user).

When trying to apply the principles of clean architecture to my applications, I kept asking whether the use case interactor and gateways should be implemented on a front end, back end, or both. Consider the scenario for a cell phone app that communicates with a web app. In a scenario like this, I found that implementing use case interactors in the front end leads to severe anemia. This means that they only forward requests from the user interface (usually a function call that is executed in a view model) to an output port (gateway interface). The gateway is good as it offers some level of abstraction about how the back-end communicates (HTTP, sockets, IPC, RPC, etc.), a detail Uncle Bob wants to keep open for as long as possible. However, I question the value of a use case interactor that only forwards requirements. Why shouldn't a view model depend directly on the output port? This is particularly the case if the critical business rules must be protected by execution on an external device (e.g. web server, hardware, etc.) to prevent incorrect or unauthorized requests.

My typical attempt usually ends as follows. The output port provides a separation from the specific mechanism for sending a request. The only problem is that, as mentioned, the use case interactor is very anemic because it only forwards a request to the gateway because the interesting business logic occurs on the external device or the web app.
Enter image description here

I therefore wonder whether I should choose the following approach instead, but I am not sure which advantages and disadvantages of removing the use case – interactor entails an abstraction).

Enter image description here

In these circumstances, I don't care how external servers, hardware or web applications are implemented as long as I comply with the API contract.
Suppose I was responsible for the implementation of the external application. Is the use case interactor useful here because there are now important business rules and user flows that require orchestration?

My current conclusion is that it appears that in a front-end / back-end system, the front-end is only interested in use-case interactors, provided that the interesting business rules are only within this level (ie the front- End) occur). If there are interesting business rules that the front end may not be able to fully execute due to security / authorization requirements, we have to move this use case interactor to the back end layer instead and can simply have a view model hanging directly from the output port, as in the second diagram.


Does anyone have an expert opinion on tiering, MVVM and clean architecture that can show me where I get lost? I hope to understand:

  1. Is it useful (possibly for maintainability reasons) if use case interactors are only forwarded to one gateway (since the sophisticated business logic occurs at a different level)?
  2. What harm does it do to switch directly from a view model (an entry point adapter) to an exit point adapter via an output port interface?

Javascript – How and Should We Use Clean Architecture in the Front End?

I use Vuejs with TypScript and use Composition API with a folder structure that is inherited and mixed from https://github.com/chrisvfritz/vue-enterprise-boilerplate and https://github.com/NarHakobyan/. Awesome-Vue boilerplate for an enterprise-level application.

but I think it may not be as good as the standard, or maybe as good as a well-known architecture that could be shared in the mind of any developer, like "clean architecture" (https://blog.cleancoder.com/ uncle-bob /2012/08/13/the-clean-architecture.html).
Enter image description here
How do you develop a best practice in Vuejs? (Is there a suite and an article or tut about clean architecture and use in frontend and Vuejs?)
(I have already found a vuejs github that used CA https://github.com/andoshin11/clean-architecture-example-vue but did not contain an article about it in the en version.)

Thanks in advance for the instructions.