GAE Standard: In what cases would I actually require a single instance to run permanently vs. spinning up only when there’s user activity?

I’m looking to create a website on GAE utilizing the Node.js Standard environment. The website will be a two-sided marketplace (similar to Fiverr, Uber, Airbnb, etc.) where I’d be performing back-end logic and CRUD updates with the Cloud Firestore database. I’m also looking to leverage Firebase Authentication, Cloud Storage, Cloud Functions, and Cloud Messaging.

Given my use case above, am I okay with just using the F1 instance class with the auto_scaling option that only creates an instance with actual user activity on my website (assuming low user activity)? If not, why?

What limitations should I keep in mind that may cause me problems right off the bat or in the near future? Roughly how much user activity would make this impractical? Why?

Thanks in advance.

Is the language { | p and n are natural numbers and there’s no prime number in [p,p+n]} belongs to NP class?

I was wondering if the following language belongs to NP class and if its complimentary belongs to NP class:

\begin{align} C=\left\{\langle p,n\rangle\mid\right.&\ \left. p \text{ and $ n$ are natural numbers}\right.\ &\left.\text{ and there’s no prime number in the range}\left[p,p+n\right]\right\} \end{align}

I am not sure, but here’s what I think: for each word $ \langle p,n\rangle \in C$ we know that the word belongs to C because there exists a primal certificate – an nontrivial divisor to any of the numbers between $ [p,p+n]$ , though I am not really sure it is in NP.

regarding the complement: I think it is in NP because the compliment compositeness can be decided by guessing a factor nondeterministically. But again I am not so sure about it and I don’t know how to correctly prove and show it.

Would really appreciate your input on that as I am quite unsure and also checked textbooks and internet (and this site) about it.

Accidentally sent BCH to BTC address… I tried to use the private keys in a BCH wallet to recover, and there’s no coins showing

I’ve read many other threads like this and it seems to be the common consensus that to recover BCH sent to a BTC address, just use the private key inside a BCH compatible wallet. Well, I did that, and there are no coins showing, nor the address that I originally sent the BCH to (which has 100+ confirmations already).

Not really sure what to do in this case. The wallet which I originally sent the BCH to was a Bitcoin wallet in the Copay app.

Managing QA testing when there’s pressure to merge things at the earliest possible

I’m working in a team of 12 where we have around 8 developers and a QA. We do not follow a git flow model but we do have feature branches where individual feature developments take place and then these are merged to master and then released. As there are many developers and only one QA, the QA person always creates a bottleneck as testing has to be done on feature branches before merging to master.

But this blocks the developers as merge conflicts occur due to the time taken during the testing phase. Therefore the QA person has to be asked to merge things at the earliest possible and then testing everything together in master.

Is there anything that could be done to refine this process? Will following a git flow help? Though it adds an additional layer of development branch which could cause more maintenance worries?

POP DELE(xxx) FAILED — ERR: There’s no message xxx

Since about 2 weeks I have this problem on all my catchall accounts. 
First I thought it was because I have overlap – use the same catchall with different projects, then I thought it was because there were too many emails etc. But after some work, hand-cleaning all emails, running only one project and resetting data (parsed email cache) I believe the problem must be somewhere outside my control.

Here’s what happens when I verify (or verify email only): 
Checking E-mail catchall@myserver.com for links (243 verifications waiting)…
Parsing 1705 E-Mails…
Parsing of …. 0% … 100% ) with a lot of Data found, 
Deleting messages of catchalll@myserver.com done by 0%
POP3 DELE(1626) failed – ERR There’s no message 1626.
— at this point the project stalls. Seems to stop doing anything, thread count is 1.
When I finally hit STOP a host of more verification messages come.
example:
Found 722 URL(s) (720 verify, 0 login) for WordPress Article – https://www.flexiform.co.uk in E-Mails

Very strange. Sometimes it seems to delete a few (17% for instance) and then hit that DELE error.
Note that when I hand-login into these accounts the number of emails is smaller than the DELE err number (sometimes by 2-5, sometimes by over 200). When I login before the number is higher. So it seems GSA is deleting messages successfully, but then tries to delete one of them again?

PS Does reset data – parsed email cache really do something? It always exits very quickly without any notice, and when I run it a few times with a quick Active (VE) in between, the verification always starts from the next email server, as if it would remember what it just had done…(might of course also be a question of randomization)

TimeMachine’s `tmutil compare` shows lots of files as changed even though there’s been no updates

For example, if I run tmutil compare I see lots of entry like:

+ 42B                           /Applications/Books.app/Contents/Frameworks/BKLibrary.framework/Versions/A/Resources/vi.lproj/InfoPlist.strings + 291B                          /Applications/Books.app/Contents/Frameworks/BKLibrary.framework/Versions/A/Resources/vi.lproj/Localizable.strings + 42B                           /Applications/Books.app/Contents/Frameworks/BKLibrary.framework/Versions/A/Resources/zh_CN.lproj/InfoPlist.strings + 193B                          /Applications/Books.app/Contents/Frameworks/BKLibrary.framework/Versions/A/Resources/zh_CN.lproj/Localizable.strings 

Finder says Books.app was last updated two weeks ago. I have TimeMachine backing up to two drives connected to a Mac Mini, and I connect from my MBP over the house Wifi. Both volumes had a successful backup complete today.

If I force a new backup, it’s reporting 1.4GB has changed despite doing a full back up just a few hours ago, and me only browsing with Chrome and Safari since then.

Why is tmutil listing all these files as changed? and how do I fix it?