magento2 – Magento 2 : Does redis make any difference on low traffic store

I’ve recently come across redis being installed and configured on single server low traffic stores.

Generally the default response for anyone when reporting their Magento 2 store (which is everyone) is for the web hosts to install and configure redis (among other things). However so far it is my personal opinion that having redis adds an additional barrier when trying to load new content and I see very little performance gain.

Knowing a bit about the technology and how it works it is my understanding is that with a webserver using ssd’s with low traffic the benefit is minimal. I’m wondering if anyone in the community has some benchmarks on low traffic stores with a before and after to confirm my theory.

I do however understand how redis has a positive impact on high traffic stores.

I’m keen to hear other’s experiences. I see questions on configuring redis but I don’t seen that anyone has asked this question on magento 2.

What’s the difference between an executable signed with a Windows Digital Signature and one signed with PGP?

I’m trying to figure out how to establish trust in Windows executables that I download from the internet.

Some software that I download, such as KeepassXC, has a Windows Digital Signature, but they also provide a PGP signature that I can manually verify using a certificate that I get from their code repository.

Other software that I download, such as my tax software, is also signed with a Windows signature but they don’t provide a PGP signature that I can verify.

  • Does a Windows Digital Signature and a PGP signature perform the same function?
  • Is one or the other enough to trust that the executable hasn’t been tampered with by a third-party? If so, why does some software provide the additional PGP signature and tell me that I need to validate it, if that software is already signed?

data structures – What is the difference between a state machine and a database

State machines and databases are quite different entities, and their usage (or functionality) is very different.
In this answer, I’ll just try to separate them with respect to the similarity you mention. This is by no means a comprehensive description of neither state machines nor databases.

The states of a state machine can indeed be thought of as representing data (although this is not always obvious, and sometimes state machines do not reveal what data they store in their states). However, the crucial element of a state machine is the transitions between the states, which represent the behaviour of the machine.

That is, a state machine does something. It computes. During its run (or runs, in nondeterministic models), it moves from state to state according to some predetermined set of rules, and possibly according to a given input, and this process is called a computation. At the end of the computation (if it’s finite), you might receive an output, from which you can derive some information.

For example, a Turing machine receives an input and if it halts, tells you whether the input is accepted or rejected, from which you can formalize a decision problem.
Similarly, an automaton does the same, but without external memory.

In contrast, a database merely stores data. How this storage is done, which operations are allowed on the data, and what their respective complexity is, are all interesting questions, and their answers depend on the type of database you use.
However, databases do not compute anything by themselves, they just store the data, possibly efficiently.

dhcp – What is the difference between a ‘host’ entry and a ‘lease’ entry in dhcpd.leases?

In the managed file dhcpd.leases, our lifecycle management application adds a host h1.example.com { ... } entry when building a virtual-machine from the application. However, already built machines that were migrated into the application and required a lease renewal have the entry lease X.X.X.X { ... client-hostname "h2"; } (note: the lack of domain in the lease entry).

A clearer example of what I’m talking about:

host h1.example.com {
  dynamic;
  hardware ethernet 00:11:22:AA:BB:CC;
  fixed-address 192.168.1.10;
        supersede server.filename = "pxelinux.0";
        supersede server.next-server = AA:BB:CC:DD;
        supersede host-name = "h1.example.com";
}

lease 192.168.2.20 {
  starts 4 2021/01/01 00:00:00;
  ends 6 2021/04/01 00:00:00;
  cltt 4 2021/02/25 00:00:00;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 00:11:22:AA:BB:DD;
  client-hostname "h2"; 
}

For some additional information: our lifecycle management application also manages DNS. We noticed an entry for in dhcpd.lease for the host h2 had a lease entry and IP that didn’t match its DNS record. The lease entry was automatically populated when the host requested a new IP. It seems no host record is created upon lease renewal and only appears when the lifecycle management app builds a new host.

What are the differences between the two entries host {...} and lease {...} in dhcpd.leases and what other functions do they affect?

sync – What is the difference between a “Phone” calendar and a “Local” calendar in Android?

I’ve been helping a friend with their Android phone. They have 3 different types of calendars, according to their “Business Calendar 2” app:

  1. Calendars synced to a Google account
  2. “Phone” calendar (it has 1, and no more can be added)
  3. “Local” calendars (it has 1, but more can be added)

What is the difference between a “Phone” calendar and a “Local” calendar, and how can one remove all the data in the “Phone” calendar?

Is MySQL more scalable than PostgreSQL due to the difference in how they handle connections?

I’m trying to decide if either MySQL or PostgreSQL would be more suitable for an application that will get hit by potentially thousands of simultaneous requests at a time.

During research, one fact that stands out is that PostgreSQL forks a new process for each connection, whereas MySQL creates a new thread to handle each connection.

  • Does this mean that MySQL is more efficient than PostgreSQL at handling many concurrent connections?

  • How much of an impact does this difference have on how well both systems scale? Is it something that I should worry about to begin with?

algebra precalculus – How to find the time for a treatment when counting the difference of pills taken?

The problem is as follows:

Louis took three and a half type $A$ pills every twelve hours and a
half type $B$ pills every $6$ hours. He did this until the difference
in the number of pills taken was $25$. If he starts taking both types
of pills together, how long does the treatment last and how many pills
had he taken in total?.

The alternatives given in my book are as follows:

$begin{array}{ll}
1.&textrm{4.75 days and 44 pills}\
2.&textrm{4.75 days and 45 pills}\
3.&textrm{3.75 days and 43 pills}\
4.&textrm{4.5 days and 45 pills}\
end{array}$

How exactly should I solve this problem?.

What I’ve attempted so far was to use this formula which is based on the fact that the number of pills taken can be found by computing the division of the total time with that of the interval between each dose plus $1$ which guarantees to account all together and without falling in the off by one error.

Thus the labels are as follows:

$t_{1}$: total elapsed time

$t_{2}$: interval time between dose

$textrm{total of A pills: a}$

$textrm{total of B pills: b}$

$left(3+frac{1}{2}right)left(frac{t_1}{t_2}+1right)=a$

$left(frac{1}{2}right)left(frac{t_1}{t_2}+1right)=b$

$a-b=8$

Replacing with the given information:

$left(3+frac{1}{2}right)left(frac{t_1}{12}+1right)=a$

$left(frac{1}{2}right)left(frac{t_1}{6}+1right)=b$

$left(3+frac{1}{2}right)left(frac{t_1}{12}+1right)-left(frac{1}{2}right)left(frac{t_1}{6}+1right)=25$

Then solving this yields:

$t=frac{528}{5}$

But this number is not an integer and it doesn’t seem to help me to get the requested time. Thus I need help in the right approach for this question. Can someone help me here? It would help me a lot a wordy answer so I can understand what is going on.