Go by the word. Test Plan means we are planning for particular scope. We have to test on given environment withing given time frame defined in Test Plan. While the strategies will be common at organization level which is high level description about testing, what kind of testing and where etc.

I can only think of one possible reason: your "server" doesn't have direct Internet connection and it's using a proxy server for accessing hosts outside of its intranet.

JMeter by default considers that it has direct connection to the application under test, if this is not the case you can specify an upstream proxy for JMeter to use, it can be done in 2 ways:

By passing the upstream proxy server details via command-line arguments like:

jmeter -H your_proxy host -P your_proxy port ....
By passing the upstream proxy server details via system.properties file (lives in "bin" folder of your JMeter installation:

http.proxyHost=your_proxy_host
http.proxyPort=your_proxy_port
https.proxyHost=your_proxy_host
https.proxyPort=your_proxy_port

So I have the first tab; the main tab. I want to open multiple tabs using selenium and once their task is done, to close them until we're back to the original first tab

url = "https://www.google.com/"
i=4
for each in reversed(range(i, 0, -1)):
    print(each)
    driver.execute_script(f"window.open('{url}');")
    driver.switch_to.window(driver.window_handles[each])
    #do stuff
    driver.close()
    driver.switch_to.window(driver.window_handles[each-1])

I get the following error:

selenium.common.exceptions.NoSuchWindowException: Message: no such window: target window already closed from unknown error: web view not found

I know its something to do with the index values of each tab, where 0 would be the inital tab, correct me if I'm wrong, but I can't get it to work.# properly.

The best I could do is to get it to close each tab randomly until left with 2, then suddenly it closes both of them (no tabs left, exits browser) when reach the value of 1

Go by the word. Test Plan means we are planning for particular scope. We have to test on given environment withing given time frame defined in Test Plan. While the strategies will be common at organization level which is high level description about testing, what kind of testing and where etc.

At some point in their lives, projects begin to require support and testing. To do this, in most cases, they come to the distribution of assemblies on dev - stage - prod, where each element is a polygon with its own version of the code.

dev: developer's unstable polygon, for development. Errors, temporary offline, manual edits and so on are allowed.
stage: pre-prod polygon, for testing and error detection. Errors allowed, offline not allowed, fully automated roll-out using CI.
prod: "battle" polygon. Users come here. Its fall and found bugs are the reason for the decrease in bonuses for programmers / testers / devops.
Accordingly, each polygon has its own database, its own environment, and so on. Typically, this is a collection of separate virtual machines. There can be several polygons of each type, depending on the goals, it is allowed to raise a sub-dev-polygon using containerization directly on the developer's machine.

Also, for each polygon in the repository, its own branch is created, the commit to which should initialize the automatic deployment of the fresh release to the polygon. With prod, as a rule, they do not do anything, but I think this is purely for personal reasons.

It means that you test having only partial access, for example, to the structure of databases or parameters sets that web services receive but you do not have access to the source code

I carry out load testing of my API by YandexTank.

Load: 100RPS for 60 seconds POST request with a small body
I don’t understand what’s going on: for about the first 1600-1900 requests I get a successful response with a code 200. The rest of the requests are error 111 Connection refused.
If you run the test again immediately after the first run, 111 Connection refused errors will fly from the first request, and if you wait 10 minutes after launch, the situation will be as in the beginning: 1600-1900 successful and then only 111 Connection refused.

If the load is reduced to 30RPS and the test is extended to 100 seconds. Then the Situation will repeat itself, everything will break again after 1600-1900 requests.
The feeling that somewhere there is some kind of limit on the quantity and lifetime of "something". I would be glad to have any suggestions on how to fix this! What parameters to tweak or where to look?

Played with different parameters: worker_processes, worker_rlimit_nofile, worker_connections, keepalive_timeout. The last remaining configuration is shown below. Nothing has helped yet.

ulimit -n 200000
Enviroment: Ubuntu 18.04.1, DigitalOcean: RAM 2Gb + 2CPU

Nginx config:

user  www-data;
worker_processes  4;

error_log  logs/error.log;
error_log  logs/error.log debug;

worker_rlimit_nofile 33000;

events {
    worker_connections  4000;
    use epoll;
    multi_accept on;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    reset_timedout_connection on;
    sendfile        on;
    keepalive_timeout 15;

    include '/etc/nginx/sites-enabled/*';
}

File (server + location)

...
    location ~ ^/api {
        content_by_lua '
            ngx.say("OK")
            return ngx.exit(200)
        ';
    }
...

YandexTank Ammo

[Host: myserver.com]
[Content-Type: application/x-www-form-urlencoded]
80 /api
xxxxxx=777777777&yyyyyyy=666666666&zzzzzzzz=ce96c7c3-87e5-4b90-b1e5-9664697aa5b6

In the test assignment for the Junior QA position, among other things, they were given the task to write test cases for an already finished product. Please tell me how to act more correctly. Look for errors, or can you not find existing bugs, but invent them yourself? After all, as far as I understand the meaning of this is not to find an error, but to see my understanding?