vdi performance issues

Go from: http://blog.devdlh.com/blog/2013/03/18/performance-problerm-caused-by-shadowpath/drawing Shadow raised IOS drawing performance Issues SummaryMAR 18TH, 2013 | COMMENTSIn IOS development, you can easily add a shadow effect to UIView by setting the Shadowcolor, Shadowopacity, Shadowoffset, and Shadowradius properties of the layer. However, the previous time

cache it, so that the next time the user loads, it is directly out of the cache, the efficiency is fast.For a Web site, CSS, JavaScript, logos, icons, these static resources file updates are relatively low frequency, and these files are almost every time the HTTP request is required, if you cache these files in the browser, can improve performance very well. By setting the properties of Cache-control and expires in the HTTP header, you can set the br

Java Design Polling thread performance issues with while loopThe polling thread is widely used in the development process, where I simulate a scenario that has a queue and polling thread, the main thread queues messages into the queue, and the polling thread loops through the queue to read the message and print the message content. A bit like handler in Android sends messages. First define a message class.p

About performance issues with the for each statement in Java7Today I did a full-array algorithm on leetcode , and I had the right results in my eclipse, but when I submitted it to Leetcode, I reported the result of "time Limit exceeded" .The permutation problem on LeetcodeI began to wonder, in the Leetcode search for a lot of similar problems encountered, but did not find the same as the problems they encou

IE is not as stupid as we think. It knows that the total number of cycles is still 10 million. Therefore, we need to separate these one hundred cycles. Although Javascript is single-threaded, you can use setTimeout or setInterval to simulate multithreading. Suppose we want to generate 10 million random numbers. The general practice is as follows: var numbers = []; for (var i = 0; i However, when executing this code in IE, a window is displayed prompting you whether to stop the script. In this

Overreleased object that detects the complete memory of the zombie. Note that this memory history is the only part of the allocation instrument in the use of meaningful zombie tracking templates. discover Zombies in your code Open the zombie template. Select your app to select a target from the pop-up menu. Click the Record button and run your app. When a zombie gives a dialog box, click the Message Text dialog box to the right of the attention button. Open the Extended

1.cell has too many sub-views, which adds to the burden of the cell2. When loading the picture, choose asynchronous load, loads the cable in the sub-line3. Avoid cell re-layout. cell layout fills are time-consuming and generally well laid out when created. 4. Do not use Clearcolor, no background color, and do not set the opacity to 05.layoutSubviews This method will be called in the cell, scrolling table, and so on, and the call is very frequent, so this method try not to write time-consuming op

=NewBackgroundtasks01{Console.WriteLine ("Blogname:{0},blogid:{1}", blog. Blogname, blog. BLOGID);});inti =0; while(I++ -) {bg. ADD (NewBlog () {BlogId = i, Blogname ="Default" });} Console.ReadLine (); BG. ADD (NewBlog () {BlogId = +, Blogname ="Zhang San"}); bg. ADD (NewBlog () {BlogId =1001, Blogname ="John Doe"});View CodeThis design solves both asynchronous execution and resource-occupying problems.But there is no perfect thing in the world, the code is the same, because the task in the q

interfaceRegisterfun_getinstance (EXT)Return Ext,ext.supperEnd---Inheriting object instances[Email protected] #table Ext instance of current object[email protected] An instance #table base base classfunction Inheritance (ext,base)--Assert (False, "call this function can only be accessed through supper, if how much inheritance, only the last inheritance will take effect")return Inheritancea (ext or {},base, "__supper")End---inherit from model file[Email protected] #table Ext instance of current

Deadlock Example program: ThreadTest, which is a classic example of a deadlock that occurs with synchronous nesting; Public classThreadTest { Public StaticObject Lock1 =NewObject (); Public StaticObject Lock2 =NewObject (); Public Static voidmethod1 () {Trace ("Inside method1"); synchronized(lock1) {Trace ("Method1 got Lock1"); DoSomething (); synchronized(Lock2) {Trace ("Method1 got Lock2, sleeping"); DoSomething (); Trace ("Method1 Returning"); } } } P

Scene:Simulate a day's data, each 10 seconds, traverse 1000 devices, each device simulates a real-time data, the total amount of data is: 24*60*60/10*1000 = 8.64 million records.--------------------------------------------------------------------------------------------------------------- ------Strategy: For time-phased, splicing SQL statement query.1, to a device, the average day per hour, the time spent 3 minutes.2, the Domainid+devicecode+eventtime index, the time cost 10 seconds.------------

; Method 2--8.8877 100000 times: Method 1--15.3749; Method 2--65.5758 Or is method 1 less time-consuming? If you don't accept it, I can't help it. I believe it. So why is this result? Cause description View the source code of the sum method of LINQ. The Code is as follows: public static int Sum(this IEnumerable Obviously, every time you call the Evaluate Method of LINQ, the set is traversed. Therefore, method 2 traverses the set five times, and method 1 only needs to traverse the set once,

Review compatibility issues from the JavaScript array, and performance optimization (from yuber blog), javascript yuberReason JavaScript array deduplication is often used in front-end pen questions, such: There are arrays var arr = ['A', 'B', 'C', '1', 0, 'C', 1, '', 1, 0], use JavaScript to implement the unqiue function so that unique (arr) Returns ['A', 'B', 'C', '1', 0, 1, ''] As a pen exam, there are

these tables in steps.Other circumstances. You should control the use of temporal tables and table variables.Note the collation.About temporal table generation use SELECT into and create TABLE + INSERT into options.6. Avoid using cursorsFor some line-by-row processing, consider putting the clientConsider using an associated subquery instead of a cursorThe following issues must be noted when using cursors:Use an efficient cursor type (such as forward-

This article was reproduced from: http://blog.csdn.net/yuanyuanispeak/article/details/527561671 PrefaceThe database large concurrency operation takes into account the deadlock and lock performance issues. See online most vague (especially update lock), so here is a concise explanation, for the following description of the convenient, here with T1 for a database execution request, T2 represents another reque

Locating performance issues, especially when CPU usage is high, often requires finding threads with higher CPU consumption and then looking at their stacks to get into code positioning issues.In this scenario, Jstack+top is a very classic way.jstack+top: 1, top-h view CPU-intensive threads, log a decimal thread id2, Jstack dump thread information into a file, and find the thread's stack based on the thread

production environment can not use full async, because in addition to some times, our server down may lose some important log information, there may be the following blog described the problem78939031Of course, in addition to this problem, there is a hole that others have stepped on here to sharehttps://juejin.im/post/5b7d5b34518825430810be8eFinally, there are some usage methods and configuration information for LOG4J2A detailed explanation of the configuration of the Log4j2Https://www.cnblogs.

A few days ago an old system encountered a performance problem, an upload, there are more than 1000 lines of verification. A piece of data, upload quickly, when uploading two hundred or three hundred, the moment is slow change, it takes 1 hours to feedback results.After troubleshooting, the original is Sqlreader.read () read data after completion, have not done sqlreader.close () shutdown sqlreader, resulting in a large number of database connections

attributes attribute of the element, access the Special collection: Document.fo Rm/document.images. The list of elements that access the DOCUMENT is expensive and should minimize access to the element list.// var imageList = document.getElementsByTagName ("img"); // imagelist:nodelist // Good Example for (var i = 0, len = imagelist.length; i // use Len to save imagelist.length instead of accessing imagelist.length every time. 　　　　　　　　　　　　　　　　var image = Imagelist[i]; // use image to keep t

performance issues with spring's jdbctemplate batch update These two days accidentally found a jdbctemplate batch update performance problem, the problem is such a one-time bulk Delete and insert 3,000 records, incredibly used 400s I was also frightened. I also looked at the code is really using the JdbcTemplate batchupdate method, the usage is not wrong, the no