I don't do server stuffs on regular basis, I was just wondering how to check SSH login logs and found that it can be checked using sudo cat /var/log/auth.log and checked on my server and there were lots of Failed password for root from [IP] This is a newly installed remote server there's no way I could have logged so many times.  Then I read it carefully it says Failed password for root from [IP] I was like what? Its for root? I have created my separate user account and except the first time when I had to create a new user account I have never touch root user. It seems to me someone is trying his luck by bruteforcing for credentials. Still, I wanted to be sure so asking here.
I just checked my server's /var/log/auth.log and found that I'm getting over 500 failed password/break-in attempt notifications per day! My site is small, and its URL is obscure. Is this normal? Should I be taking any measures?
Is there a sorted collection type in .NET? I'm looking for a container that keeps all its items in order.  I looked at SortedList, but that requires a separate key, and does not allow duplicate keys.  I could also just use an unsorted container and explicitly sort it after each insert.  Usage:   Occasional insert Frequent traversal in order Ideally not working with keys separate from the actual object, using a compare function to sort. Stable sorting for equivalent objects is desired, but not required.  Random access is not required.   I realize I can just build myself a balanced tree structure, I was just wondering if the framework already contains such a beast. How to get new answers to old/popular questions read/voted on? If a question has more than one page of answers then a new answer is not likely to get much attention.  I think the stackoverflow engine should give some more weight to newer answers to old questions but I'm not sure how.  Maybe a tweaked UI to get access to newer answers.  NB. In the related questions this  popped up, I hadnt realised either that these tools existed. Does $\mathbb R^2$ remain connected when countably many points are removed? Does it remain path connected?  This is not homework but is in response to working several problems where countable or uncountable many points are removed and the pattern always holds.  Thank you. Properties vs Methods Quick question: When do you decide to use properties (in C#) and when do you decide to use methods?  We are busy having this debate and have found some areas where it is debatable whether we should use a property or a method. One example is this:  public void SetLabel(string text) {     Label.Text = text; }   In the example, Label is a control on a ASPX page. Is there a principle that can govern the decision (in this case) whether to make this a method or a property.  I'll accept the answer that is most general and comprehensive, but that also touches on the example that I have given. Break a previous commit into multiple commits How to validate an email address in JavaScript Is there a regular expression to validate an email address in JavaScript? Trying to remember the name of a grade-school book about an alien in a cereal box When I was a kid (Grade school, Elementary, can't remember the exact grade, but it was between 1992 and 1999) I read a book about a kid who found an alien in his cereal.  This alien informed him that he was there to defeat an evil threat to Earth, that took the form of the school's most popular student.  The alien came with a gun that did nothing, and the alien in the popular kid disguise had the power to make the kid's fingernails bleed by damaging his nerve endings.  In the end, it was revealed that the evil alien had a huge craving for, and vulnerability towards, pizza flakes, and was defeated by gorging himself on them and then exploding. Which arena do free and crown chests use when determining the cards you will get? If I am in arena X when I collect my tenth crown for the crown chest, or a free chest becomes unlocked, then proceed to climb to arena X+1 before opening the chests, which arena will be used to determine the cards I get? Will it use the arena I was in when I unlocked the chests in, or the arena I opened them in? Is a URL with a query string better or worse for SEO then one without one? I want to know, is there a huge difference in terms of SEO between these URLs:  example.com/ontario/toronto/listings   or  example.com/listings.php?p=ontario&amp;c=toronto   Will one URL rank higher than the other? Is there a huge difference here? VT-x is not available, but is enabled in BIOS Recently I started having an issue with VT-x on my Windows 10 running on HP EliteBook. I was using Oracle VirtualBox to run some VMs on it before and VT-x was enabled in BIOS and was working fine.  I started getting VT-x is not available error every time I was trying to start any of my VMs. That started happening after I installed Docker on my machine, so I tried uninstalling it and rebooting. Didn't help.  I checked BIOS settings and it says VT-x is enabled but checking with Intel(R) Processor Identification Utility shows that VT-x is not supported and Oracle VirtualBox also doesn't see it.  There were no hardware changes and the only software change was installing/uninstalling Docker.  How can this issue be fixed? How can I make Safari cmd+number shortcut switch tabs instead of opening the bookmark associated with that number? I'm used to switching tabs with cmd+x where x is a number and takes me to tab x in firefox and pretty much every other browser I've ever used. I like safari's speed and would like to try it a bit, but the cmd+x shortcut is burned in my brain and every time I use safari I end up screwing up. I'd like to know if its possible to change this behavior, because this simple thing is a stopper for me. Determining ethnicity according to ancestry? My sister, cousins, and other relatives speculate that my mom's grandmother was Jewish (for various reasons). I've heard people say at times things like, for example, "I'm 50% German" or "I'm 25% Swedish." This has to do with their ancestry. But, how exactly is this calculated? Say for example that my mother's paternal grandmother was indeed 100% Jewish, what would that make me and my siblings, and how is it calculated? Setting git default flags on commands How to parse a query string into a NameValueCollection in .NET I would like to parse a string such as p1=6&amp;p2=7&amp;p3=8 into a NameValueCollection.  What is the most elegant way of doing this when you don't have access to the Page.Request object? Primefaces growl is not working in all the pages I was trying to run chmod -R 777 ./ but ended up typing chmod -R 777 / and set 777 on my entire machine. What can go wrong? How can I fix it? Change desktop background to a solid color (e.g. pitch black) in GNOME 3 I just installed Ubuntu 16.04 with GNOME and I would like to set the background color to black. If I right click in the background I can select a wallpaper or a photo or a color. But there are only a few colors available. How can I open a palette and select the #000000 color ? Updated title of arxiv not recognised by Google Scholar? I submitted a paper to a journal and one of the referees suggested to slightly change the title of the paper. The paper was already posted on arxiv. I have updated the paper on arxiv after the revision, but this update is not recognised by Google Scholar. The main problem with this is that Google Scholar is not detecting the new citations to the arxiv paper since the new citations use the new title.  Any suggestions on how to solve this issue?  Update: I updated the arxiv version 2 months ago but Google Scholar does not detect it. It detects new papers that cite my manuscript, but not the updated arxiv.  Disclaimer. I am aware of the following questions, but they are related to different issues. Family name pluralization PHP: Static and non Static functions and Objects