Android – How do I configure flutter offline?

I want to use flutter for Android development. I already downloaded and placed floodlight sdk in the path, I already have android sdk and added it to the environment variable, I even downloaded gradle. The problem is that I don't know how to tell Flutter to use the Gradle I downloaded and I have it locally on my PC. Would anyone know how to solve this problem? Thank you

Powershell – Install optional Windows features in offline mode

How can optional Windows functions be installed on a server without internet access?

Enable-WindowsOptionalFeature -Online -FeatureName "IIS-IPSecurity" -All

This works well with most features as I assume they are packed (but not enabled) with Windows Server 2016 (default). In particular, two functions cannot be installed because the server is not connected to the Internet:

Enable-WindowsOptionalFeature : The source files could not be found. 
Use the "Source" option to specify the location of the files that are 
required to restore the feature. For more information on specifying a source 
location, see 
http://go.microsoft.com/fwlink/?LinkId=243077.
At line:1 char:1
+ Enable-WindowsOptionalFeature -Online -FeatureName "IIS-NetFxExtensib ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) (Enable-WindowsOptionalFeature), COMException
+ FullyQualifiedErrorId : Microsoft.Dism.Commands.EnableWindowsOptionalFeatureCommand

The error mentions that the -Source option is used to possibly indicate a local source. In the linked documentation, however, I can find no indication of how these source files are obtained individually for the installation.

Are these files available? Or do I have to create an image to use it with DISM?

SQL Server – If I manually failover my AlwaysOn AG primary replica to the secondary replica and take the primary database offline, will the automatic synchronization take place when I am online again?

I have an AlwaysOn AG setup between database A (primary replica) on server 1 and database B (secondary replica) on server 2. When I force manual failover from my primary replica on server 1 to the secondary replica on server 2 and then Will database A (on server 1) be automatically synchronized offline from database B (on server 2) when I bring it back online?

Do I have to wait for the synchronization to complete before manually switching back from database B to database A?

Can I track the progress of the synchronization in the AG dashboard?

Applications – Offline Mesh Instant Messaging

TLDR: Is there an Android app that enables reliable instant messaging in areas without internet?

I'm looking for a free Android app that allows multiple users to communicate with each other over short distances, even if they may not have an internet connection. I tried a number of apps that claimed exactly this function and work via Bluetooth and ad hoc WiFi, but none of them worked reliably. These include:

  • FireChat: I know that it worked in the past, but not in the current version
  • Bridgefy: Seems to only support text messages in the current version and is unreliable, but it's still the best thing I could find
  • Briar: didn't work well
  • Signal: did not work well
  • goTenna: probably works well but very expensive

I only tested it between two devices each time. In practice, does one of these methods work better with more users than should theoretically be the case in mesh networks? Is there an app that could help me if I haven't tried it yet? Or is there a reason to try old versions of FireChat hoping to find one that works? If so, could I trust him (both the APK from a mirror and the app related to data security)?

Blitz Network – I read about "Loop-In" and it seems like it's a one-way offline channel. Is that correct?

I would not recommend introducing a one-way offline channel. In the past, one-way channels could be built for a long time by offering new signatures for the delivery of a 2-2 wallet to the second party, with more and more BTC being given to the second party of the used input. The second party naturally has an incentive to publish the latest information.

Loop is more like a submarine swap. With loop in You request a credit on your side on a payment channel.

Let's say you have a payment channel with a capacity of 0.1 BTC, but all the money is with your partners. However, you want to add some money to your page without rebalancing your channels or opening a new channel.

To do this, you can create an invoice with a payment hash. A person may be willing to pay this bill in a flash if you refund that person on the chain. The question that solves this loop is to make this process trustworthy.

You send the person in question a Btc code, but you charge a second issue, which is returned to you with a timeout. The expenditure that can be requested by this person can only be requested if the model of your payment hash is presented. This works right before the timeout expires.

Now there are two cases. Either the person pays your bill and receives a preview picture and can be sure that it will be refunded. Or if the person does not pay the bill, you can reclaim your BTC after the timeout. Nobody has to trust the other side.

What I don't know is whether Trezor allows you to sign such a deferred / special transaction and how the Trezor API works. However, I see no reason why it would not support signing such a transaction.

backup – Bitcoin Core offline reinstallation

If you have a tar.gz file, extract it as follows:

  • tar xzf bitcoin-0.14.2-x86_64-linux-gnu.tar.gz

install it

  • sudo install -m 0755 -o root -g root -t /usr/local/bin bitcoin-0.14.2/bin/*

Finally run it

if you mean "you copied all files" that you copied .bitcoin Directory so do that after the previous step:

Move and run the files that you have copied to this directory