Customized Base64 algorithme
What is numeric promotion?
I'm setting up an Nginx web server and and want to perform load balancing using the round robin method.  This is what I have found thus far:  upstream backend  {    server backend1.example.com;    server backend2.example.com;    server backend3.example.com; }   According to the page they says i need to add the above lines to my nginx.conf file and upload it to server to load balance.  I do not understand what it means by server backend3.example.com;.  How do I setup a backend instance? Can a decision in a node of a decision tree be based on comparison between 2 columns of the dataset? Assume the features in the dataframe are columns - A,B,C and my target is Y  Can my decision tree have a decision node which looks for say, if A&gt;B then true else false? How do I generate the upper triangular indices from a list? Is there a noun that doesn't have a plural in any of its forms? While attempting to answer  @ProgramFox has been trying to come up with an example of a noun with no plural.   The best I've come up with is egotism and Judaism.  ()  Some of the contenders I've already shot down are air, water, and money.  (Airs, waters, and monies are all legitimate plurals.)  My question is, a) Do my two examples have actual plurals?  b) Are there any other non-ism nouns that don't have a plural? Keeping an updated balance (Accounting) I have been struggling trying to find a way to properly and reliably maintain a balance for accounts in an order/payment system.  Currently, the process consists of three tables. Below example is very simplified but gets the point across.  Table one contains the account ID, name, total paid, total orders, balance etc.  Table two contains payments, date, the account ID (FK) and amount.  Table three contains orders, date, the account ID (FK) and amount.  Calculating the balance is of course as easy as  SELECT SUM(payments.AMOUNT) FROM payments WHERE ID = [account] SELECT SUM(orders.AMOUNT) FROM orders WHERE ID = [account]   Followed by some simple addition/subtraction math:  UPDATE accounts SET BALANCE = [balance] WHERE ID = [account]   All good - the problem is - how do I maintain this over let's assume years of activity and many, many transactions?  Currently the accounts table is updated every single time a transaction is made, meaning the above three statements run every time. There is of course an index on the ID column in all three tables, and everything is fast and neat for now, but I work with less than 100,000 transactions, meaning everything fits into the RAM and basically all I throw at the database gets executed immediately. Over time this will change, of course - so how do I handle this?  Is it better to mark the accounts as "dirty" and process balancing in a batch job later, or can I keep updating the balance real-time even when I reach the point where the orders and payments tables will not fit into the RAM?  Do I need to segment the orders and payments and "lock" everything before a given time, such as before last calculation? (I would rather not). I ask because then I could do a SUM WHERE DATE > [last lock timestamp] and update with UPDATE BALANCE = [balance] + [value for last lock] and prevent the problem from outgrowing resources.  I don't need a running balance for each transaction. That's all I can find results for when I try to research this problem. I just care about the total amount paid, the total amount ordered and the balance of accounts.  Why don't I calculate on the fly when I need the balance, you ask? Because one must be able to query the system and ask "Which of my (let's say) 50.000 accounts have a balance below 0?" - something we cannot do easily if we do not store the balance with every account. timestamp, modification time, and created time of a file How to download all required Ubuntu drivers Is there a package of Ubuntu drivers as driver pack solution? I tried to search for it, but I did not find it. If there is, how can I easily get it? Travelling through the Schengen area with a Refugee Travel Document issued by the USA I just want to double check to make sure I won't run into any issues at the border of entry.  I'm a permanent resident of the USA with a green card and I have a travel document issued by the USA (I-571). Will I have any issues traveling around in the Schegen countries?  Do I need a visa? Do I have to pay any fees? public static IQueryable&lt;TResult&gt; ApplySortFilter&lt;T, TResult&gt;(this IQueryable&lt;T&gt; query, string columnName)   where T : EntityObject {   var param = Expression.Parameter(typeof(T), "o");   var body = Expression.PropertyOrField(param,columnName);    var sortExpression = Expression.Lambda(body, param);   return query.OrderBy(sortExpression); }   Because the type for OrderBy is not inferred from sortExpression I need to specify it something like this at run time:  var sortExpression = Expression.Lambda&lt;T, TSortColumn&gt;(body, param);   Or  return query.OrderBy&lt;T, TSortColumn&gt;(sortExpression);   I don't think this is possible however as TSortColumn can only be determined during runtime.  Is there a way around this? How to use `ybar interval` without skipping the last value I have the following code  \documentclass[tikz]{standalone} \usepackage{pgfplots} \usepackage{pgfplotstable} \usepackage{filecontents}  \begin{filecontents}{testdata.dat}   -3.316988309367815e-07 0.07000000000000001   -1.948815911147526e-08 0.13   7.15864175355987e-08 0   1.799432483450127e-07 0   0.0002850606647384129 0   0.0009429559686380238 0.08999999999999997   0.00157188462064142 0   0.005259918700865051 0   0.01739392641273605 0.18   0.06208364670743995 0.55   68.69485148165926 6.970000000000001   31.217611224923 79.12   0 12.89 \end{filecontents}  \pgfplotsset{compat=newest} \pgfplotstableread{testdata.dat}\datatable  \begin{document} \begin{tikzpicture} \begin{axis}[   ybar interval,   width=10cm,   height=5cm,   enlargelimits=false,    xtick=data,   ymin=0, ymax=100,   xticklabels={0 -- 0.063,0.063 -- 0.125,0.125 -- 0.25,0.25 -- 0.5,0.5 -- 1,                1 -- 2,2 -- 4,4 -- 5.6,5.6 -- 8,                8 -- 11.2,11.2 -- 16,16 -- 22.4,22.4 -- 31.5},   x tick label style={rotate=60,anchor=east}   ]   \addplot table[x expr=\coordindex,y=0]{\datatable};   \addplot table[x expr=\coordindex,y=1]{\datatable};  \end{axis} \end{tikzpicture} \end{document}   and the output looks like this:    But the command ybar interval does skip the last value. It should look like:    I prefer to have the last value to show up in the interval 22.4 -- 31.5. How do I achieve this without inserting a row of zeros to my table? How to get back sudo on Ubuntu? Is there a way to find out if I need a transit visa for Canada? What is the difference between therapy and treatment? Can we let users with privileges on one site have them on another? I have almost 4k reputation on Arqade. On Stack Overflow, I have to suggest edits and can't hit the close button. But I want to help with the close queue, which is at 62k at the time of this writing.  While I realize that people may be inexperienced with the system, I think I am experienced enough. If I want to edit something, I have to let it sit in the queue and get robo-reviewed. Yes, I know more about gaming than about coding. But I think I would know if this question is a duplicate of that, and if this question is off topic.  So, my request is that we should have the same privledges on every site, based on the site that we have the most reputation in. I am not asking that all the reputation be merged. I'd like to add an invisible watermark to each PDF document that I produce so that in case it leaks, I know where it leaked from. Anyone knows what would a good way for an invisible watermark be in a PDF document and how to add one? How can I convert a string to boolean in JavaScript? Can I convert a string representing a boolean value (e.g., 'true', 'false') into a intrinsic type in JavaScript?  I have a hidden form in HTML that is updated based upon a user's selection within a list. This form contains some fields which represent boolean values and are dynamically populated with an intrinsic boolean value. However, once this value is placed into the hidden input field it becomes a string.  The only way I could find to determine the field's boolean value, once it was converted into a string, was to depend upon the literal value of its string representation.  var myValue = document.myForm.IS_TRUE.value; var isTrueSet = myValue == 'true';   Is there a better way to accomplish this? Ideally, I'd like to write a unit test to help me "dummy check" for unexpected effects of the upcoming guest user sharing setting changes.  We'd had some controller/trigger code "gracefully handling" data it couldn't see thanks to the new sharing restrictions ... which resulted in simply "not doing" some work that it was supposed to do, which from a business process perspective isn't "graceful" at all (it was an important automation for downstream processes).  I'd like to write up a unit test with some system.assert statements validating that "data still goes where it's supposed to" when the "submit" button a public-facing Visualforce page of a community is clicked.  Unfortunately, I can't seem to make the "submit" button on a Controller for a public-facing Visualforce page work in the context of a unit test because the record whose creation it results in doesn't get its corresponding "sharing setting" record created in time for the execution context to pick it up.  I did a little proof of concept here ...  @isTest public class TestClass {      private static Id guestProfileId = Util.getProfileIdByName('Public Facing Portal Profile');     private static User guestUser;     private static Id portalGroupId = [SELECT Id FROM Group WHERE Name = 'Public_Portal' LIMIT 1][0].Id;      private static Custom_Object__c co;       private static testMethod void runTest() {         createCO();         Test.startTest();         // Note that putting createCO() inside the test and doesGuestSharingRuleExistForCO() doesn't help.         // That's what I was afraid of.         try {             doesGuestSharingRuleExistForCO(co.Id);         }         catch (Util.DeveloperException e) {             System.assert(FALSE, e.getMessage());         }         Test.stopTest();     }       private static void cacheUsers() {         guestUser = [SELECT Id FROM User WHERE profileid = :guestProfileId AND IsActive = TRUE LIMIT 1][0];     }      private static void createCO() {         co = new Custom_Object__c();         INSERT co;     }      private static void doesGuestSharingRuleExistForCO(Id coId) {         List&lt;SObject&gt; existingSharingRulesOnCO = [             SELECT Id FROM Custom_Object__share             WHERE RowCause = 'GuestRule' AND AccessLevel = 'Read' AND ParentId = :coId AND UserOrGroupId = :portalGroupId LIMIT 1         ];         if ( existingSharingRulesOnCO.isEmpty() ) { throw new Util.DeveloperException('Guest User sharing is not on for this custom object ID'); }     }      private static Boolean isCOSharingFlippedOnAtAll(){         String lookingFor = 'Custom_Object__Share';         for (Schema.SObjectType sObjectType : Schema.getGlobalDescribe().values() ) {             String sobjName = String.valueOf(sObjectType);             if (sobjName.contains(lookingFor) ) { return TRUE; }         }         return FALSE;     }  }   Am I just out of luck?  Is there no way to properly unit-test the effects (to automations relying upon "guest user" sharing settings when running as "guest user") of simulating the insertion of records into my database from a Visualforce page, due to not being able to separate out "execution context" enough and "wait" for the sharing rule record for the new record to come into existence? Is there a way to call process builder from Apex? How can I reset my menus? Exception messages in English?