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TL;DR: Don't ever interrupt me while taking a shit.
>be me taking a shit comfortably in the bathroom, not bothering anyone
>hear my cousin outside calling his gf
>nofsgiven.jpg
>suddenly stuff comes flying through the window and hear her gf laughing in his phone speaker
>stupid asshat was trying to make his gf laugh by bothering me while in the debug room
>scream from the top of my lungs for him to stop interrupting my defecation process
>stuff keeps coming from the window
>my brown creation comes back inside like a scared turtle
>pull up pantaloons
>get out of thinking room
>open up laptop, start ubuntu
>sudo apt-get install aircrack-ng
>enable monitor mode, get phone, ap mac addresses
>vim shittyvengeance.sh
>write small script that deauths his phone and then waits some seconds and then starts over again so he doesn't think it's me
>:wq and make script executable
>sleep 180; cowsay ding dong ur vengeance has arrived; sudo ./shittyvengeance.sh
>tuck into bed and close laptop before sleep time ends
>his call suddenly drops
>"Matt are you messing up with my WiFi again?"
>"Nah man. Not working for me either. Must be localcompany's problem."
>mfw he can't talk with his gf for more than 15 seconds before losing connection
>omgitworks.jpg
>figure that it was the most useful thing I had made in a pc in these two years at uni
>be proud of me for making a stupid script
>think about going back to my pearl white throne
>no longer wanting to drop my supplies
>go to sleep
>mfw forgot to wipe ass
My first story in devRant! Was lurking for quite a while and finally felt like sharing something 🙃24 -
The website for our biggest client went down and the server went haywire. Though for this client we don’t provide any infrastructure, so we called their it partner to start figuring this out.
They started blaming us, asking is if we had upgraded the website or changed any PHP settings, which all were a firm no from us. So they told us they had competent people working on the matter.
TL;DR their people isn’t competent and I ended up fixing the issue.
Hours go by, nothing happens, client calls us and we call the it partner, nothing, they don’t understand anything. Told us they can’t find any logs etc.
So we setup a conference call with our CXO, me, another dev and a few people from the it partner.
At this point I’m just asking them if they’ve looked at this and this, no good answer, I fetch a long ethernet cable from my desk, pull it to the CXO’s office and hook up my laptop to start looking into things myself.
IT partner still can’t find anything wrong. I tail the httpd error log and see thousands upon thousands of warning messages about mysql being loaded twice, but that’s not the issue here.
Check top and see there’s 257 instances of httpd, whereas 256 is spawned by httpd, mysql is using 600% cpu and whenever I try to connect to mysql through cli it throws me a too many connections error.
I heard the IT partner talking about a ddos attack, so I asked them to pull it off the public network and only give us access through our vpn. They do that, reboot server, same problems.
Finally we get the it partner to rollback the vm to earlier last night. Everything works great, 30 min later, it crashes again. At this point I’m getting tired and frustrated, this isn’t my job, I thought they had competent people working on this.
I noticed that the db had a few corrupted tables, and ask the it partner to get a dba to look at it. No prevail.
5’o’clock is here, we decide to give the vm rollback another try, but first we go home, get some dinner and resume at 6pm. I had told them I wanted to be in on this call, and said let me try this time.
They spend ages doing the rollback, and then for some reason they have to reconfigure the network and shit. Once it booted, I told their tech to stop mysqld and httpd immediately and prevent it from start at boot.
I can now look at the logs that is leading to this issue. I noticed our debug flag was on and had generated a 30gb log file. Tail it and see it’s what I’d expect, warmings and warnings, And all other logs for mysql and apache is huge, so the drive is full. Just gotta delete it.
I quietly start apache and mysql, see the website is working fine, shut it down and just take a copy of the var/lib/mysql directory and etc directory just go have backups.
Starting to connect a few dots, but I wasn’t exactly sure if it was right. Had the full drive caused mysql to corrupt itself? Only one way to find out. Start apache and mysql back up, and just wait and see. Meanwhile I fixed that mysql being loaded twice. Some genius had put load mysql.so at the top and bottom of php ini.
While waiting on the server to crash again, I’m talking to the it support guy, who told me they haven’t updated anything on the server except security patches now and then, and they didn’t have anyone familiar with this setup. No shit, it’s running php 5.3 -.-
Website up and running 1.5 later, mission accomplished.6 -
Two big moments today:
1. Holy hell, how did I ever get on without a proper debugger? Was debugging some old code by eye (following along and keeping track mentally, of what the variables should be and what each step did). That didn't work because the code isn't intuitive. Tried the print() method, old reliable as it were. Kinda worked but didn't give me enough fine-grain control.
Bit the bullet and installed Wing IDE for python. And bam, it hit me. How did I ever live without step-through, and breakpoints before now?
2. Remember that non-sieve prime generator I wrote a while back? (well maybe some of you do). The one that generated quasi lucas carmichael (QLC) numbers? Well thats what I managed to debug. I figured out why it wasn't working. Last time I released it, I included two core methods, genprimes() and nextPrime(). The first generates a list of primes accurately, up to some n, and only needs a small handful of QLC numbers filtered out after the fact (because the set of primes generated and the set of QLC numbers overlap. Well I think they call it an embedding, as in QLC is included in the series generated by genprimes, but not the converse, but I digress).
nextPrime() was supposed to take any arbitrary n above zero, and accurately return the nearest prime number above the argument. But for some reason when it started, it would return 2,3,5,6...but genprimes() would work fine for some reason.
So genprimes loops over an index, i, and tests it for primality. It begins by entering the loop, and doing "result = gffi(i)".
This calls into something a function that runs four tests on the argument passed to it. I won't go into detail here about what those are because I don't even remember how I came up with them (I'll make a separate post when the code is fully fixed).
If the number fails any of these tests then gffi would just return the value of i that was passed to it, unaltered. Otherwise, if it did pass all of them, it would return i+1.
And once back in genPrimes() we would check if the variable 'result' was greater than the loop index. And if it was, then it was either prime (comparatively plentiful) or a QLC number (comparatively rare)--these two types and no others.
nextPrime() was only taking n, and didn't have this index to compare to, so the prior steps in genprimes were acting as a filter that nextPrime() didn't have, while internally gffi() was returning not only primes, and QLCs, but also plenty of composite numbers.
Now *why* that last step in genPrimes() was filtering out all the composites, idk.
But now that I understand whats going on I can fix it and hypothetically it should be possible to enter a positive n of any size, and without additional primality checks (such as is done with sieves, where you have to check off multiples of n), get the nearest prime numbers. Of course I'm not familiar enough with prime number generation to know if thats an achievement or worthwhile mentioning, so if anyone *is* familiar, and how something like that holds up compared to other linear generators (O(n)?), I'd be interested to hear about it.
I also am working on filtering out the intersection of the sets (QLC numbers), which I'm pretty sure I figured out how to incorporate into the prime generator itself.
I also think it may be possible to generator primes even faster, using the carmichael numbers or related set--or even derive a function that maps one set of upper-and-lower bounds around a semiprime, and map those same bounds to carmichael numbers that act as the upper and lower bound numbers on the factors of a semiprime.
Meanwhile I'm also looking into testing the prime generator on a larger set of numbers (to make sure it doesn't fail at large values of n) and so I'm looking for more computing power if anyone has it on hand, or is willing to test it at sufficiently large bit lengths (512, 1024, etc).
Lastly, the earlier work I posted (linked below), I realized could be applied with ECM to greatly reduce the smallest factor of a large number.
If ECM, being one of the best methods available, only handles 50-60 digit numbers, & your factors are 70+ digits, then being able to transform your semiprime product into another product tree thats non-semiprime, with factors that ARE in range of ECM, and which *does* contain either of the original factors, means products that *were not* formally factorable by ECM, *could* be now.
That wouldn't have been possible though withput enormous help from many others such as hitko who took the time to explain the solution was a form of modular exponentiation, Fast-Nop who contributed on other threads, Voxera who did as well, and support from Scor in particular, and many others.
Thank you all. And more to come.
Links mentioned (because DR wouldn't accept them as they were):
https://pastebin.com/MWechZj912 -
!rant
I'm developing an OS. I tried running it on the laptop that's on the ground. Everything works fine except text mode. There is no output when running it in text mode(not the high resolution one shown on image). Since the OS sends all data that is printed to the first serial port I might as well read the output from the serial ports. Since the laptop I use for development doesn't have any serial ports I had to use the older Windows 98 PC. For unknown reasons I could not get any output from the serial ports so I gave up.
tl;dr I wasted some time trying to debug my OS.
Image of my debugging setup(taken with the latest potato).
13 -
There should be a dev superhero. Like DevFace or Dr. Debug! And his special ability would be sth. like RealWorldInjection.
time.stop ()
car.engine.speed += 500
food.make ('Cheeseburger')
So many possibilities 😆😃 I would buy a ticket for the movie!2 -
Visual Studio - Release: Oh looks like this works.
Visual Studio - Debug: It seems you have an error:
"MVP = P*V*M;"
Quickly checks release... wait..
"
MVP=P*V;
MVP=MVP*M;
"
Compiles Debug version... Hey it works!!! Closes application window.... Error _free_dbg(block...
WTF...
Tries again, closes the cmd window, rather than win32 window. No errors.
TL;DR Screw windows for debugging C/C++
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