radia perlman

James Gosling, father of Java, posted a picture on his blog, which should represent the mood of many technical people: By the way, he also wrote a sentence: So long, old friend... Goodbye, Sun! This was a great company that once created many gods. This hero is a great company. This is a great company that has proposed many years ago that the network is a grand vision of computer. [Outstanding scientists and engineers who work at Sun Company] Bill Joy (father of BSD and VI) Ivan Suthe

automatically selects routes without loading route tables or setting parameters. STP (Spanning Tree Protocol) is a data link layer (Layer 2) communication protocol based on the OSI network model, used to ensure a non-circular local network environment. Based on the algorithm prescribed by Radia Perlman during Dec operations, STP allows a network to be designed to contain standby (duplicate) connections s

"Copyright notice: Original translation articles, translation level is limited, errors are unavoidable, The Translator is not responsible for the consequences of errors or omissions in the article, please be careful to reprint them. Reproduced please retain this statement and source: blog.csdn.net/shallnet, download the English version of the book "The author of the book thanked Radia Perlman for his time i

Learning the Spanning Tree Protocol, you can try to avoid the failure of the entire LAN due to a switch.The Spanning Tree Protocol was invented by Dr Radia Perlman, a well-known engineer at Sun Microsystems. The bridge, invented by Dr. Polman, can achieve the ideal realm of layer-2 routing: redundancy and loop-free operation. You can imagine the Spanning Tree Protocol as a tree structure in which each bridg

Ethernet and FDDI is 10 (1000/100). Thismethod of computing has been used until the 1983 when Radia Perlman started the protocol, with the rise of Gigabit Ethernet and OC-48 ATM (2.4 Gbps), the problem of the path overhead cannot be expressed using decimals, such as oc_48 The cost of the ATM is calculated as 1000mbps/2400mbps=0.41667, but this is an invalid path cost value. One solution to this problem is

to eat characters, hyphens, slow, but rich features, so instead of a wide range of today's major regular expression engine, such as Perl, Ruby, Python's re module, The Regex libraries for Java and. NET are all NFA.2. Only NFA supports features such as lazy and backreference;3. NFA is eager to desire please, so the most Zokozheng-style priority matches the success, so occasionally miss the best match results, the DFA is "the longest Zokozheng-type priority match success".4. The NFA defaults to t

NFA.2. Only NFA supports features such as lazy and backreference;3. NFA is eager to offer rewards. Therefore, the leftmost subregularizedregular expression is matched first, so the best matching result is occasionally missed. DFA is "the longest left subregularizedregular expression is matched first ".4. NFA uses greedy quantifiers by default (see item 4 );5. NFA may fall into the trap of recursive calling and has poor performance. Here is an example to illustrate the 3rd impacts. For example,

/, and./, the modules in/perl/lib will be first found and used. Use lib usage can play the same effect as BEGIN {unshift @ INC, $ dir}-see "perlman: lib": http://www.perlmonks.org /? Node = perlman % 3 Alib % 3 Alib. * use Foo: What does Bar mean? * use Foo: Bar does not mean to find a file named Foo: Bar in the @ INC directory. pm module File. It means to find a "sub-directory" named 'foo' in the @ INC dir

instructs Perl to search for the module name in the @ INC array. @ INC usually includes: /Perl/lib/perl/site/lib. "." Indicates the current working directory. The core module is installed in the PERL/lib directory, and the non-core module is installed in the PERL/site/lib directory. You can add a custom directory to @ INC. As shown below: Begin {push @ INC, '/My/dir'} # orbegin {unshift @ INC,'/My/dir'} # oruse lib '/My/dir '; We need to use the begin block to add val

Image source: HDFS-1623 design Document Picture Author: Sanjay Radia, Suresh Srinivas In this diagram, we can see the general structure of Ha, whose design considerations include: Use shared storage to synchronize edits information between two nn. The previous HDFS is share nothing but nn, now NN and share storage, this is actually transferred the location of a single point of failure, but in high-end storage devices have a variety of raid and

sequential, sequence of integers.Value is the data used to train, usually a bunch of real numbers.#=======================================================Second, thesvm_train () function. The best document is Help (Svm_train):Help on function Svm_train in module Svmutil:svm_train (arg1, Arg2=none, Arg3=none) svm_train (y, x [, Options]) mo del | ACC | MSE Svm_train (prob [, Options])-model | ACC | MSE svm_train (prob, param)-model | acc| MSE Train an SVM model from data (y, x) or a svm_probl

from:http://blog.csdn.net/zhuqiuhui/article/details/531803951. Find the azimuth of two latitude and longitude points, P0 (LatA, Lona), P1 (LATB, lonb) (many blogs do not write very well, summarize here) def getdegree (LatA, Lona, LATB, lonb): "" " Args: Point P1 (LatA, Lona) point P2 (LATB, lonb) Returns : bearing between the "GPS points, default:the basis of heading direction is" "" radlata =

. The reasons for this contrast, I think it is the emotional bar, the former will be the feelings of their parents to all the elderly, made a very natural seat move, and the reason why the spectators appreciate the beauty, it is because of the feeling of this emotion, rather than just see someone do a moral thing. In the same way, when we admire an art work, we unconsciously take our own experience or match it through association, thus trying to resonate with the work. For example, when I first

nonprinting characters, such as tab, space, end of line, and so on. If the tab cannot be displayed, make sure the. vimrc file is set with the set lcs=tab:>-command, and make sure that your file has a tab, and if Expendtab is turned on, tab will be expanded to a space.Vim TutorialsOn UNIX Systems$ vimtutorOn a Windows system: Help Tutor: syntax lists syntax items that have already been defined: syntax clear clears the defined grammar rules: syntax case match casing sensitive, int and int will be

not visible it'll always return No wifi or cellular because your C Ode reads the text in the Status bar thats all.The best-of-the-solve your problem, just make the not hidden then the Status bar application would get the text about th E Network type.Determine the network typeGPRS 2G (2.5) General Packet Radia Service 114kbpsEDGE 2G (2.75G) Enhanced Data rate for GSM Evolution 384kbpsThe UMTS 3G WCDMA 3G Universal Mobile telecommunication System compl

High Availability for the HDFS namenode Sanjay Radia, Suresh Srinivas Yahoo! INC (This article is a translation of namdnoe ha design documents) 1. Problem Description There are many ways to improve the availability of HDFS namednoe (NN), including reducing the startup time and updating the configuration without restarting the cluster, reduce the upgrade time and provide a manual or automatic NN failover. This article focuses on NN failover to solve th

========================================================== ======================Read browser history Simulate the return key function 1. java. lang. Runtime Runtime runtime = Runtime.getRuntime();runtime.exec("input keyevent " + KeyEvent.KEYCODE_BACK);2. android. app. Instrumentation Instrumentation inst = new Instrumentation();inst.sendKeyDownUpSync(KeyEvent.KEYCODE_BACK);Listen to boot Broadcast public class BootReceiver extends BroadcastReceiver { @Override public void onReceive(Contex

(0, 100%, 27%) 4%, HSL (0, 100%, 18%) 8%, Hsla (0, 100%, 20%, 0) 10%) 50px 50px, Radial-gradient (Hsla (0, 100%, 30%, 0.8) 20%, Hsla (0, 100%, 20%, 0)) 50px 0, Radia L-gradient (Hsla (0, 100%, 30%, 0.8) 20%, Hsla (0, 100%, 20%, 0)) 0 50px, radial-gradient (Hsla (0, 100%, 20%, 1 ) 35%, Hsla (0, 100%, 20%, 0) 60%) 50px 0, Radial-gradient (Hsla (0, 100%, 20%, 1) 35%, Hsla (0, 100%, 20%, 0) 60%) 100px 50px, Radial-gradient (Hsla (0, 100%, 15%, 0.7), Hsla

Call method: imagesrcchart. phpchart. php is the file name of this article? * Convert the angle to the radian * functionradians ($ degrees) {return ($ degrees * (pi () 180.0);} *** to obtain (0, 0) at the center of the curve) * functioncircle_point ($ degrees, $ diameter) {$ xcos (radia // call method: // Chart. php is the file name of this article /* Converts degrees to radians. */ Function radians ($ degrees) { Return ($ degrees * (pi ()/180.0 )

= HEIGHT/2; Mcamera = new Camera (); } @Override protected void applytransformation (float interpolatedtime, transformation t) {final double Radia NS = Math.PI * INTERPOLATEDTIME; float degrees = (float) (180.0 * radians/math.pi); if (interpolatedtime >= 0.5f) {degrees-= 180.F; Mfromview.setvisibility (View.gone); Mtoview.setvisibility (view.visible); } if (Mforward) {degrees =-degrees; } fi