Search Results

Search found 6031 results on 242 pages for 'imaginary numbers'.

Page 215/242 | < Previous Page | 211 212 213 214 215 216 217 218 219 220 221 222  | Next Page >

• Populate an Object Model from a data dataTable(C#3.0)

  - by Newbie

  I have a situation I am getting data from some external sources and is populating into the datatable. The data looks like this DATE WEEK FACTOR 3/26/2010 1 RM_GLOBAL_EQUITY 3/26/2010 1 RM_GLOBAL_GROWTH 3/26/2010 2 RM_GLOBAL_VALUE 3/26/2010 2 RM_GLOBAL_SIZE 3/26/2010 2 RM_GLOBAL_MOMENTUM 3/26/2010 3 RM_GLOBAL_HIST_BETA I have a object model like this public class FactorReturn { public int WeekNo { get; set; } public DateTime WeekDate { get; set; } public Dictionary<string, decimal> FactorCollection { get; set; } } As can be seen that the Date field is always constant. And a single(means unique) week can have multiple FACTORS. i.e. For a date(3/26/2010), for Week No. 1, there are two FACTORS(RM_GLOBAL_EQUITY and RM_GLOBAL_GROWTH). Similarly, For a date(3/26/2010), for Week No. 2, there are three FACTORS(RM_GLOBAL_VALUE , RM_GLOBAL_SIZE and RM_GLOBAL_MOMENTUM ). Now we need to populate this data into our object model. The final output will be WeekDate: 3/26/2010 WeekNo : 1 FactorCollection : RM_GLOBAL_EQUITY FactorCollection : RM_GLOBAL_GROWTH WeekNo : 2 FactorCollection : RM_GLOBAL_VALUE FactorCollection : RM_GLOBAL_SIZE FactorCollection : RM_GLOBAL_MOMENTUM WeekNo : 3 FactorCollection : RM_GLOBAL_HIST_BETA That is, overall only 1 single collection, where the Factor type will vary depending on week numbers. I have tried but of useless. Nothing works. Could you please help me?. I feel it is very tough I am using C# 3.0 Thanks

  Read the article

• Best way to store data in database when you don't know the type

  - by stiank81

  I have a table in my database that represents datafields in a custom form. The DataField gives some representation of what kind of control it should be represented with, and what value type it should take. Simplified you can say that I have 2 entities in this table - Textbox taking any string and Textbox only taking numbers. Now I have the different values stored in a separate table, referencing the datafield definition. What is the best way to store the data value here, when the type differs? One possible solution is to have the FieldValue table hold one field per possible value type. Now this would certainly be redundant, but at least I would get the value stored in its correct form - simplifying queries later. FieldValue ---------- Id DataFieldId IntValue DoubleValue BoolValue DataValue .. Another possibility is just storing everything as String, and casting this in the queries. I am using .Net with NHibernate, and I see that at least here there is a Projections.Cast that can be used to cast e.g. string to int in the query. Either way in these two solutions I need to know which type to use when doing the query, but I will know that from the DataField, so that won't be a problem. Anyway; I don't think any of these solutions sounds good. Are they? Or is there a better way?

  Read the article

• Why doesn't my processor have built-in BigInt support?

  - by ol

  As far as I understood it, BigInts are usually implemented in most programming languages as strings containing numbers, where, eg.: when adding two of them, each digit is added one after another like we know it from school, e.g.: 246 816 * * ---- 1062 Where * marks that there was an overflow. I learned it this way at school and all BigInt adding functions I've implemented work similar to the example above. So we all know that our processors can only natively manage ints from 0 to 2^32 / 2^64. That means that most scripting languages in order to be high-level and offer arithmetics with big integers, have to implement/use BigInt libraries that work with integers as strings like above. But of course this means that they'll be far slower than the processor. So what I've asked myself is: Why doesn't my processor have a built-in BigInt function? It would work like any other BigInt library, only (a lot) faster and at a lower level: Processor fetches one digit from the cache/RAM, adds it, and writes the result back again. Seems like a fine idea to me, so why isn't there something like that?

  Read the article

• Help with java threads or executors: Executing several MySQL selects, inserts and updates simmultane

  - by Martin

  Hi. I'm writing an application to analyse a MySQL database, and I need to execute several DMLs simmultaneously; for example: // In ResultSet rsA: Select * from A; rsA.beforeFirst(); while (rsA.next()) { id = rsA.getInt("id"); // Retrieve data from table B: Select * from B where B.Id=" + id; // Crunch some numbers using the data from B // Close resultset B } I'm declaring an array of data objects, each with its own Connection to the database, which in turn calls several methods for the data analysis. The problem is all threads use the same connection, thus all tasks throw exceptios: "Lock wait timeout exceeded; try restarting transaction" I believe there is a way to write the code in such a way that any given object has its own connection and executes the required tasks independent from any other object. For example: DataObject dataObject[0] = new DataObject(id[0]); DataObject dataObject[1] = new DataObject(id[1]); DataObject dataObject[2] = new DataObject(id[2]); ... DataObject dataObject[N] = new DataObject(id[N]); // The 'DataObject' class has its own connection to the database, // so each instance of the object should use its own connection. // It also has a "run" method, which contains all the tasks required. Executor ex = Executors.newFixedThreadPool(10); for(i=0;i<=N;i++) { ex.execute(dataObject[i]); } // Here where the problem is: Each instance creates a new connection, // but every DML from any of the objects is cluttered in just one connection // (in MySQL command line, "SHOW PROCESSLIST;" throws every connection, and all but // one are idle). Can you point me in the right direction? Thanks

  Read the article

• excluding previously randomized integer, and randomize again without it

  - by Rob

  <?php if (isset($_POST['Roll!'])) { $sides = $_POST['sides']; $rolled = rand(1,$sides); echo "$rolled was rolled by the dice, it is now out!"; } ?> This is the code I currently have. After rolling that number, however, I want it to roll again, but without the previously rolled number, until it has rolled all number except one, which would be the winning number. I have no idea how to go about doing that. Any ideas? EDIT: I'm sorry, I should have been more clear, thank you all for the help so far, but I also need to echo each number rolled, such as echo "$rolledArray[0] was rolled, it lost.\n"; echo "$rolledArray[1] was rolled, it lost.\n"; echo "$rolledArray[2] was rolled, it lost.\n"; echo "$rolledArray[3] was rolled, it lost.\n"; echo "$rolledArray[x] was rolled, it lost.\n"; echo "$rolledArray[x] was rolled, it lost.\n"; echo "$rolledArray[50?] was rolled, it lost."; EDIT AGAIN: Also I only want them to have to click Roll! once, not multiple times until they've rolled all the numbers, meaning no need for session, I think, though I could be wrong, most of you are clearly more experienced than me. Sorry, I should have mentioned that before as well.

  Read the article

• Need Multiple Sudoku Solutions

  - by user1567909

  I'm trying to output multiple sudoku solutions in my program. For example, when You enter this as input: 8..6..9.5.............2.31...7318.6.24.....73...........279.1..5...8..36..3...... .'s denote blank spaces. Numbers represent already-filled spaces. The output should be a sudoku solution like so: 814637925325149687796825314957318462241956873638274591462793158579481236183562749 However, I want to output multiple solutions. This would be all the solutions that should be printed: 814637925325149687796825314957318462241956873638274591462793158579481236183562749 814637925325941687796825314957318462241569873638472591462793158579184236183256749 834671925125839647796425318957318462241956873368247591682793154579184236413562789 834671925125839647796524318957318462241956873368247591682793154519482736473165289 834671925125839647796524318957318462241965873368247591682793154519482736473156289 But my program only prints out one solution. Below is my recursive solution to solving a sudoku solution bool sodoku::testTheNumber(sodoku *arr[9][9], int row, int column) { if(column == 9) { column = 0; row++; if(row == 9) return true; } if(arr[row][column]->number != 0) { return testTheNumber(arr, row, column+1); } for(int k = 1; k < 10; k++) { if(k == 10) { arr[row][column]->number = 0; return false; } if(rowIsValid(arr, k, row) && columnIsValid(arr, k, column) && boxIsValid(arr, k, row, column)) { arr[row][column]->number = k; if(testTheNumber(arr, row, column+1)==true) { return true; } arr[row][column]->number = 0; } } return false; } Could anyone help me come up with a way to print out multiple solutions? Thanks.

  Read the article

• Managing modes in Windows application working directly with SQL Server 2008

  - by hgulyan

  Hi, I have a MS Access 97 application (but the question is general) working directly with SQL Server 2008 (without application server or anything). Numbers of users can be up to 1000. Windows Authentication is used. The question is: How to handle modes, so some users will be allowed to work in read-only mode some users won't have access to db for some time My versions: Using a table with a mode id for every group of users, that will work the same way. On Form Load application will query that table for mode id. Using trigger on the tables, that must work according to that mode. The trigger will query mode value and doesn't work if access is closed or it's in read-only mode I know it's not these are not the best solutions, that's why I'm asking for your advice. There's one more point. If the mode is changed to "access-is-closed" for a group of users, that group must not be able to query to DB starting that moment. With first solution I wrote it won't work, because user can be in application at that moment and no form load event will work. How can I do this? Is there any optimal solution? Thank you. Any help would be appreciated.

  Read the article

• huge C file debugging problem

  - by valdo

  Hello all. I have a source file in my project, which has more than 65,536 code lines (112,444 to be exact). I'm using an "sqlite amalgamation", which comes in a single huge source file. I'm using MSVC 2005. The problems arrives during debugging. Everything compiles and links ok. But then when I'm trying to step into a function with the debugger - it shows an incorrect code line. What's interesting is that the difference between the correct line number and the one the debugger shows is exactly 65536. This makes me suspect (almost be sure in) some unsigned short overflow. I also suspect that it's not a bug in the MSVC itself. Perhaps it's the limitation of the debug information format. That is, the debug information format used by MSVC stores the line numbers as 2-byte shorts. Is there anything can be done about this (apart from cutting the huge file into several smaller ones) ?

  Read the article

• MySql: Is it reasonable to use 'view' or I would better denormalize my DB?

  - by Budda

  There is 'team_sector' table with following fields: Id, team_id, sect_id, size, level It contains few records for each 'team' entity (referenced with 'team_id' field). Each record represent sector of team's stadium (totally 8 sectors). Now it is necessary to implement few searches: by overall stadium size (SUM(size)); the best quality (SUM(level)/COUNT(*)). I could create query something like this: SELECT TS.team_id, SUM(TS.size) as OverallSize, SUM(TS.Level)/COUNT(TS.Id) AS QualityLevel FROM team_sector GROUP BY team_id ORDER BY OverallSize DESC / ORDER BY QualityLevel DESC But my concern here is that calculation for each team will be done each time on query performed. It is not too big overhead (at least now), but I would like to avoid performance issues later. I see 2 options here. The 1st one is to create 2 additional fields in 'team' table (for example) and store there OverallSize and QualityLevel fields. If information if 'sector' table is changed - update those table too (probably would be good to do that with triggers, as sector table doesn't change too often). The 2nd option is to create a view that will provide required data. The 2nd option seems much easier for me, but I don't have a lot of experience/knowledge of work with views. Q1: What is the best option from your perspective here and why? Probably you could suggest other options? Q2: Can I create view in such way that it will do calculations rarely (at least once per day)? If yes - how? Q3: Is it reasonable to use triggers for such purpose (1st option). P.S. MySql 5.1 is used, overall number of teams is around 1-2 thousand, overall number of records in sector table - overall 6-8 thousand. I understand, those numbers are pretty small, but I would like to implement the best practice here.

  Read the article

• Incorrect usage of UPDATE and ORDER BY

  - by nico55555

  I have written some code to update certain rows of a table with a decreasing sequence of numbers. To select the correct rows I have to JOIN two tables. The last row in the table needs to have a value of 0, the second last -1 and so on. To achieve this I use ORDER BY DESC. Unfortunately my code brings up the following error: Incorrect usage of UPDATE and ORDER BY My reading suggests that I can't use UPDATE, JOIN and ORDER BY together. I've read that maybe subqueries might help? I don't really have any idea how to change my code to do this. Perhaps someone could post a modified version that will work? while($row = mysql_fetch_array( $result )) { $products_id = $row['products_id']; $products_stock_attributes = $row['products_stock_attributes']; mysql_query("SET @i = 0"); $result2 = mysql_query("UPDATE orders_products op, orders ord SET op.stock_when_purchased = (@i:=(@i - op.products_quantity)) WHERE op.orders_id = ord.orders_id AND op.products_id = '$products_id' AND op.products_stock_attributes = '$products_stock_attributes' AND op.stock_when_purchased < 0 AND ord.orders_status = 2 ORDER BY orders_products_id DESC") or die(mysql_error()); }

  Read the article

• Why does this sql statement keep saying it is a boolean and not a parameter? (php/Mysql)

  - by ggfan

  In this statement, I am trying to see if there if the latest posting in the database that has the exact same title, price, city, state, detail. If there is, then it would say to the user that the exact post has been already made; if not then insert the posting into the dbc. (This is one type of check so that users can't accidentally post twice. This may not be the best check, but this statement error is annoying me, so I want it to work :)) Why won't this sql work? I think it's not letting the title=$title and not getting the value in the $title... ERROR: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in postad.php on line 365 //there is a form that users fill out that has title, price, city, etc <form> blah blah </form> //if users click submit, then does all the checks and if all okay, insert to dbc if (isset($_POST['submit'])) { // Grab the pposting data from the POST and gets rid of any funny stuff $title = mysqli_real_escape_string($dbc, trim($_POST['title'])); $price = mysqli_real_escape_string($dbc, trim($_POST['price'])); $city = mysqli_real_escape_string($dbc, trim($_POST['city'])); $state = mysqli_real_escape_string($dbc, trim($_POST['state'])); $detail = mysqli_real_escape_string($dbc, trim($_POST['detail'])); if (!is_numeric($price) && !empty($price)) { echo "<p class='error'>The price can only be numbers. No special characters, etc</p>"; } //Error problem...won't let me set title=$title, detail=$detail, etc. //this statement after all the checks so that none of the variables are empty $query="Select * FROM posting WHERE user_id={$_SESSION['user_id']} AND title=$title AND price=$price AND city=$city AND state=$state AND detail=$detail"; $data = mysqli_query($dbc, $query); if(mysqli_num_rows($data)==1) { echo "You already posted this ad. Most likely caused by refreshing too many times."; } }

  Read the article

• Is my approach for persistent login secure ?

  - by Jay

  I'm very much stuck with the reasonable secure approach to implement 'Remember me' feature in a login system. Here's my approach so far, Please advice me if it makes sense and is reasonably secure: Logging: User provides email and password to login (both are valid).. Get the user_id from DB Table Users by comparing provided email Generate 2 random numbers hashed strings: key1, key2 and store in cookies. In DB Table COOKIES, store key1, key2 along with user_id. To Check login: If key1 and key2 both cookies exist, validate both keys in DB Table COOKIES (if a row with key1, and key2 exists, user is logged). if cookie is valid, regenrate key2 and update it in cookie and also database. Why re-genrating key: Because if someone steals cookie and login with that cookie, it will be working only until the real user login. When the real user will login, the stolen cookie will become invalid. Right? Why do I need 2 keys: Because if i store user_id and single key in cookie and database, and the user want to remember the password on another browser, or computer, then the new key will be updated in database, so the user's cookie in earlier browser/PC will become invalid. User wont be able to remember password on more than one place. Thanks for your opinions.

  Read the article

• In Perl, how to match several prefixes

  - by xorsyst

  I have 2 input files. One is a list of prefix and lengths, like this: 101xxx 102xxx 30xx 31xx (where x is any number) And another is a list of numbers. I want to iterate through the second file, matching each number against any of the prefix/lengths. This is fairly easy. I build a list of regexps: my @regexps = ('101...', '102...', '30..', '31..'); Then: foreach my $regexp (@regexps) { if (/$regexp/) { # do something But, as you can guess, this is slow for a long list. I could convert this to a single regexp: my $super_regexp = '101...|102...|30..|31..'; ...but, what I need is to know which regexp matched the item, and what the ..s matched. I tried this: my $catching_regexp = '(101)(...)|(102)(...)|(30)(..)|(31)(..)'; but then I don't know whether to look in $1, $3, %5 or $7. Any ideas? How can I match against any of these prefix/lengths and know which prefix, and what the remaining digits where?

  Read the article

• Can reducing index length in Javascript associative array save memory

  - by d777

  I am trying to build a large Associative Array in JavaScript (22,000 elements). Do I need to worry about the length of the indices with regards to memory usage? In other words, which of the following options saves memory? or are they the same in memory consumption? Option 1: var student = new Array(); for (i=0; i<22000; i++) student[i] = { "studentName": token[0], "studentMarks": token[1], "studentDOB": token[2] }; Option 2: var student = new Array(); for (i=0; i<22000; i++) student[i] = { "n": token[0], "m": token[1], "d": token[2] }; I tried to test this on Google Chrome DevTools, but the numbers are inconsistent to make a decision. My best guess is that because the Array indices repeat, the browser can optimize memory usage by not repeating them for each student[i], but that is just a guess. Thanks.

  Read the article

• C# return and display syntax issue

  - by thatdude

  I am having trouble passing the return value from TheMethod() to Main and displaying the word if the if statement is passed as true. I have thought of two ways of doing this, neither has worked but I think I am missing synatx. Using a return ?; non void method and then displaying the returned value. Using a void method and actually writing out(example below) So yes I am new at this, however I have made so many iterations everything is blending together and I have forgot what I have tried. Any help on the syntax be great for either of these ways. Basically I need it to iterate numbers 1,2,3,4 and depending on if the current iteration matches an expression in the if statements it will display a word. Example: if (3 = i) { Console.WriteLine("Word"); } Code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Proj5 { class Program { int i = 0; static void Main(int i) { for (i = 0; i < 101; i++) { Console.WriteLine("test"); } } string TheMethod(int i) { string f = "Word1"; string b = "Word2"; if (i == 3) { return f; } if (i == 5) { return b; } if (0 == (i % 3)) { return f; } if (0 == i % 5) { return b; } else { return b; } } } }

  Read the article

• C non-trivial constants

  - by user525869

  I want to make several constants in C with #define to speed up computation. Two of them are not simply trivial numbers, where one is a right shift, the other is a power. math.h in C gives the function pow() for doubles, whereas I need powers for integers, so I wrote my own function, ipow, so I wouldn't need to be casting everytime. My question is this: One of the #define constants I want to make is a power, say ipow(M, T), where M and T were also #define constants. ipow is a function in the actual code, so this actually seems to slows things down when I run the code (is it running ipow everytime the constant is mentioned?). However, when I ues the built in pow function and just do (int)pow(M,T), the code is sped up. I'm confused as to why this is, since the ipow and pow functions are just as fast. On a more general note, can I define constants using #define using functions inside the actual code? The above example has me confused on whether this speeds things up or actually slows things down.

  Read the article

• Finding k elements of length-n list that sum to less than t in O(nlogk) time

  - by tresbot

  This is from Programming Pearls ed. 2, Column 2, Problem 8: Given a set of n real numbers, a real number t, and an integer k, how quickly can you determine whether there exists a k-element subset of the set that sums to at most t? One easy solution is to sort and sum the first k elements, which is our best hope to find such a sum. However, in the solutions section Bentley alludes to a solution that takes nlog(k) time, though he gives no hints for how to find it. I've been struggling with this; one thought I had was to go through the list and add all the elements less than t/k (in O(n) time); say there are m1 < k such elements, and they sum to s1 < t. Then we are left needing k - m1 elements, so we can scan through the list again in O(n) time looking for all elements less than (t - s1)/(k - m1). Add in again, to get s2 and m2, then again if m2 < k, look for all elements less than (t - s2)/(k - m2). So: def kSubsetSumUnderT(inList, k, t): outList = [] s = 0 m = 0 while len(outList) < k: toJoin = [i for i in inList where i < (t - s)/(k - m)] if len(toJoin): if len(toJoin) >= k - m: toJoin.sort() if(s0 + sum(toJoin[0:(k - m - 1)]) < t: return True return False outList = outList + toJoin s += sum(toJoin) m += len(toJoin) else: return False My intuition is that this might be the O(nlog(k)) algorithm, but I am having a hard time proving it to myself. Thoughts?

  Read the article

• How to split up input from System.in

  - by zzaw

  Alright so I'm working on something where I take input from System.in; the first line is an int (n) representing the size of a matrix. The next n lines are the matrix itself like so: 10 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 The problem is there may be multiple matrix's in a single input, so the next line would have another int and the corresponding matrix underneath until it hits a line with a single 0. I then have to pass each matrix along with the size at the top as a BufferedReader to a method which adds the numbers to a 2D array. I'm just a little unsure on how to split the input up and send it to the method. Would making a new BufferedReader using skip() and specifying a size each time work? The biggest problem I seem to be running into is reading the size but then the size being excluded as it has already been read. Cheers

  Read the article

• JVM process resident set size "equals" max heap size, not current heap size

  - by Volune

  After a few reading about jvm memory (here, here, here, others I forgot...), I am expecting the resident set size of my java process to be roughly equal to the current heap space capacity. That's not what the numbers are saying, it seems to be roughly equal to the max heap space capacity: Resident set size: # echo 0 $(cat /proc/1/smaps | grep Rss | awk '{print $2}' | sed 's#^#+#') | bc 11507912 # ps -C java -O rss | gawk '{ count ++; sum += $2 }; END {count --; print "Number of processes =",count; print "Memory usage per process =",sum/1024/count, "MB"; print "Total memory usage =", sum/1024, "MB" ;};' Number of processes = 1 Memory usage per process = 11237.8 MB Total memory usage = 11237.8 MB Java heap # jmap -heap 1 Attaching to process ID 1, please wait... Debugger attached successfully. Server compiler detected. JVM version is 24.55-b03 using thread-local object allocation. Garbage-First (G1) GC with 18 thread(s) Heap Configuration: MinHeapFreeRatio = 10 MaxHeapFreeRatio = 20 MaxHeapSize = 10737418240 (10240.0MB) NewSize = 1363144 (1.2999954223632812MB) MaxNewSize = 17592186044415 MB OldSize = 5452592 (5.1999969482421875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 20971520 (20.0MB) MaxPermSize = 85983232 (82.0MB) G1HeapRegionSize = 2097152 (2.0MB) Heap Usage: G1 Heap: regions = 2560 capacity = 5368709120 (5120.0MB) used = 1672045416 (1594.586769104004MB) free = 3696663704 (3525.413230895996MB) 31.144272834062576% used G1 Young Generation: Eden Space: regions = 627 capacity = 3279945728 (3128.0MB) used = 1314914304 (1254.0MB) free = 1965031424 (1874.0MB) 40.089514066496164% used Survivor Space: regions = 49 capacity = 102760448 (98.0MB) used = 102760448 (98.0MB) free = 0 (0.0MB) 100.0% used G1 Old Generation: regions = 147 capacity = 1986002944 (1894.0MB) used = 252273512 (240.5867691040039MB) free = 1733729432 (1653.413230895996MB) 12.702574926293766% used Perm Generation: capacity = 39845888 (38.0MB) used = 38884120 (37.082786560058594MB) free = 961768 (0.9172134399414062MB) 97.58628042120682% used 14654 interned Strings occupying 2188928 bytes. Are my expectations wrong? What should I expect? I need the heap space to be able to grow during spikes (to avoid very slow Full GC), but I would like to have the resident set size as low as possible the rest of the time, to benefit the other processes running on the server. Is there a better way to achieve that? Linux 3.13.0-32-generic x86_64 java version "1.7.0_55" Running in Docker version 1.1.2 Java is running elasticsearch 1.2.0: /usr/bin/java -Xms5g -Xmx10g -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -Xss256k -Djava.awt.headless=true -XX:+UseG1GC -XX:MaxGCPauseMillis=350 -XX:InitiatingHeapOccupancyPercent=45 -XX:+AggressiveOpts -XX:+UseCompressedOops -XX:-OmitStackTraceInFastThrow -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintClassHistogram -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCApplicationConcurrentTime -Xloggc:/opt/elasticsearch/logs/gc.log -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/opt elasticsearch/logs/heapdump.hprof -XX:ErrorFile=/opt/elasticsearch/logs/hs_err.log -Des.logger.port=99999 -Des.logger.host=999.999.999.999 -Delasticsearch -Des.foreground=yes -Des.path.home=/opt/elasticsearch -cp :/opt/elasticsearch/lib/elasticsearch-1.2.0.jar:/opt/elasticsearch/lib/*:/opt/elasticsearch/lib/sigar/* org.elasticsearch.bootstrap.Elasticsearch There actually are 5 elasticsearch nodes, each in a different docker container. All have about the same memory usage. Some stats about the index: size: 9.71Gi (19.4Gi) docs: 3,925,398 (4,052,694)

  Read the article

• Unix sort keys cause performance problems

  - by KenFar

  My data: It's a 71 MB file with 1.5 million rows. It has 6 fields All six fields combine to form a unique key - so that's what I need to sort on. Sort statement: sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 -k6,6 -o output.csv input.csv The problem: If I sort without keys, it takes 30 seconds. If I sort with keys, it takes 660 seconds. I need to sort with keys to keep this generic and useful for other files that have non-key fields as well. The 30 second timing is fine, but the 660 is a killer. More details using unix time: sort input.csv -o output.csv = 28 seconds sort -t ',' -k1 input.csv -o output.csv = 28 seconds sort -t ',' -k1,1 input.csv -o output.csv = 64 seconds sort -t ',' -k1,1 -k2,2 input.csv -o output.csv = 194 seconds sort -t ',' -k1,1 -k2,2 -k3,3 input.csv -o output.csv = 328 seconds sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 input.csv -o output.csv = 483 seconds sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 input.csv -o output.csv = 561 seconds sort -t ',' -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 -k6,6 input.csv -o output.csv = 660 seconds I could theoretically move the temp directory to SSD, and/or split the file into 4 parts, sort them separately (in parallel) then merge the results, etc. But I'm hoping for something simpler since looks like sort is just picking a bad algorithm. Any suggestions? Testing Improvements using buffer-size: With 2 keys I got a 5% improvement with 8, 20, 24 MB and best performance of 8% improvement with 16MB, but 6% worse with 128MB With 6 keys I got a 5% improvement with 8, 20, 24 MB and best performance of 9% improvement with 16MB. Testing improvements using dictionary order (just 1 run each): sort -d --buffer-size=8M -t ',' -k1,1 -k2,2 input.csv -o output.csv = 235 seconds (21% worse) sort -d --buffer-size=8M -t ',' -k1,1 -k2,2 input.csv -o ouput.csv = 232 seconds (21% worse) conclusion: it makes sense that this would slow the process down, not useful Testing with different file system on SSD - I can't do this on this server now. Testing with code to consolidate adjacent keys: def consolidate_keys(key_fields, key_types): """ Inputs: - key_fields - a list of numbers in quotes: ['1','2','3'] - key_types - a list of types of the key_fields: ['integer','string','integer'] Outputs: - key_fields - a consolidated list: ['1,2','3'] - key_types - a list of types of the consolidated list: ['string','integer'] """ assert(len(key_fields) == len(key_types)) def get_min(val): vals = val.split(',') assert(len(vals) <= 2) return vals[0] def get_max(val): vals = val.split(',') assert(len(vals) <= 2) return vals[len(vals)-1] i = 0 while True: try: if ( (int(get_max(key_fields[i])) + 1) == int(key_fields[i+1]) and key_types[i] == key_types[i+1]): key_fields[i] = '%s,%s' % (get_min(key_fields[i]), key_fields[i+1]) key_types[i] = key_types[i] key_fields.pop(i+1) key_types.pop(i+1) continue i = i+1 except IndexError: break # last entry return key_fields, key_types While this code is just a work-around that'll only apply to cases in which I've got a contiguous set of keys - it speeds up the code by 95% in my worst case scenario.

  Read the article

• How to calculate CPU % based on raw CPU ticks in SNMP

  - by bjeanes

  According to http://net-snmp.sourceforge.net/docs/mibs/ucdavis.html#scalar_notcurrent ssCpuUser, ssCpuSystem, ssCpuIdle, etc are deprecated in favor of the raw variants (ssCpuRawUser, etc). The former values (which don't cover things like nice, wait, kernel, interrupt, etc) returned a percentage value: The percentage of CPU time spent processing user-level code, calculated over the last minute. This object has been deprecated in favour of 'ssCpuRawUser(50)', which can be used to calculate the same metric, but over any desired time period. The raw values return the "raw" number of ticks the CPU spent: The number of 'ticks' (typically 1/100s) spent processing user-level code. On a multi-processor system, the 'ssCpuRaw*' counters are cumulative over all CPUs, so their sum will typically be N*100 (for N processors). My question is: how do you turn the number of ticks into percentage? That is, how do you know how many ticks per second (it's typically — which implies not always — 1/100s, which either means 1 every 100 seconds or that a tick represents 1/100th of a second). I imagine you also need to know how many CPUs there are or you need to fetch all the CPU values to add them all together. I can't seem to find a MIB that gives you an integer value for # of CPUs which makes the former route awkward. The latter route seems unreliable because some of the numbers overlap (sometimes). For example, ssCpuRawWait has the following warning: This object will not be implemented on hosts where the underlying operating system does not measure this particular CPU metric. This time may also be included within the 'ssCpuRawSystem(52)' counter. Some help would be appreciated. Everywhere seems to just say that % is deprecated because it can be derived, but I haven't found anywhere that shows the official standard way to perform this derivation. The second component is that these "ticks" seem to be cumulative instead of over some time period. How do I sample values over some time period? The ultimate information I want is: % of user, system, idle, nice (and ideally steal, though there doesn't seem to be a standard MIB for this) "currently" (over the last 1-60s would probably be sufficient, with a preference for smaller time spans).

  Read the article

• Bad motherboard / controller / HDs?

  - by quidpro

  On a leased server, I am running into some timing issues with an application that requires precise timing. Server is a Dual Xeon E5410 running on a Supermicro X7DVL-3 motherboard under CentOs 5.5 x64. The application I am running is timer sensitive and keeps sensing drift whether under load or at idle, but especially under load. I did some investigating with atop and dd and found some mind-blowing numbers. Mind you, I am no Linux guru but something sure seems out of whack. I ran: dd bs=4096 if=/dev/zero of=/bigtestfile to generate disk activity. Regardless whether I wrote it to sda or sdb my DSK value in atop would go over 100%, at one time peaking at 1700%. Again it does not matter if I am writing to sda or sdb. DSK | sdb | busy 675% | read 0 | write 110 | avio 78 ms | Here are the smartctl outputs: # smartctl -A /dev/sda smartctl version 5.38 [x86_64-redhat-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF READ SMART DATA SECTION === SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000b 200 200 051 Pre-fail Always - 0 3 Spin_Up_Time 0x0007 165 165 021 Pre-fail Always - 2750 4 Start_Stop_Count 0x0032 100 100 040 Old_age Always - 21 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x000a 200 200 051 Old_age Always - 0 9 Power_On_Hours 0x0032 065 065 000 Old_age Always - 25831 10 Spin_Retry_Count 0x0012 100 253 051 Old_age Always - 0 11 Calibration_Retry_Count 0x0012 100 253 051 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 21 194 Temperature_Celsius 0x0022 116 093 000 Old_age Always - 27 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0012 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0012 200 200 000 Old_age Always - 0 199 UDMA_CRC_Error_Count 0x000a 200 253 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 200 200 051 Old_age Offline - 0 # smartctl -A /dev/sdb smartctl version 5.38 [x86_64-redhat-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF READ SMART DATA SECTION === SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 200 200 051 Pre-fail Always - 0 3 Spin_Up_Time 0x0003 180 180 021 Pre-fail Always - 3958 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 22 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x000f 200 200 051 Pre-fail Always - 0 9 Power_On_Hours 0x0032 068 068 000 Old_age Always - 24087 10 Spin_Retry_Count 0x0013 100 253 051 Pre-fail Always - 0 11 Calibration_Retry_Count 0x0013 100 253 051 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 21 194 Temperature_Celsius 0x0022 122 096 000 Old_age Always - 25 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0012 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 200 200 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0009 200 200 051 Pre-fail Offline - 0 Any idea what's wrong here? Bad motherboard? It would seem rare that both drives are going bad (smartctl says they PASS_, so it leaves the mobo as the culprit in my eyes.

  Read the article

• Disk performance below expectations

  - by paulH

  this is a follow-up to a previous question that I asked (Two servers with inconsistent disk speed). I have a PowerEdge R510 server with a PERC H700 integrated RAID controller (call this Server B) that was built using eight disks with 3Gb/s bandwidth that I was comparing with an almost identical server (call this Server A) that was built using four disks with 6Gb/s bandwidth. Server A had much better I/O rates than Server B. Once I discovered the difference with the disks, I had Server A rebuilt with faster 6Gbps disks. Unfortunately this resulted in no increase in the performance of the disks. Expecting that there must be some other configuration difference between the servers, we took the 6Gbps disks out of Server A and put them in Server B. This also resulted in no increase in the performance of the disks. We now have two identical servers built, with the exception that one is built with six 6Gbps disks and the other with eight 3Gbps disks, and the I/O rates of the disks is pretty much identical. This suggests that there is some bottleneck other than the disks, but I cannot understand how Server B originally had better I/O that has subsequently been 'lost'. Comparative I/O information below, as measured by SQLIO. The same parameters were used for each test. It's not the actual numbers that are significant but rather the variations between systems. In each case D: is a 2 disk RAID 1 volume, and E: is a 4 disk RAID 10 volume (apart from the original Server A, where E: was a 2 disk RAID 0 volume). Server A (original setup with 6Gpbs disks) D: Read (MB/s) 63 MB/s D: Write (MB/s) 170 MB/s E: Read (MB/s) 68 MB/s E: Write (MB/s) 320 MB/s Server B (original setup with 3Gpbs disks) D: Read (MB/s) 52 MB/s D: Write (MB/s) 88 MB/s E: Read (MB/s) 112 MB/s E: Write (MB/s) 130 MB/s Server A (new setup with 3Gpbs disks) D: Read (MB/s) 55 MB/s D: Write (MB/s) 85 MB/s E: Read (MB/s) 67 MB/s E: Write (MB/s) 180 MB/s Server B (new setup with 6Gpbs disks) D: Read (MB/s) 61 MB/s D: Write (MB/s) 95 MB/s E: Read (MB/s) 69 MB/s E: Write (MB/s) 180 MB/s Can anybody suggest any ideas what is going on here? The drives in use are as follows: Dell Seagate F617N ST3300657SS 300GB 15K RPM SAS Dell Hitachi HUS156030VLS600 300GB 3.5 inch 15000rpm 6GB SAS Hitachi Hus153030vls300 300GB Server SAS Dell ST3146855SS Seagate 3.5 inch 146GB 15K SAS

  Read the article

• Benchmarking hosting providers IO with Bonnie

  - by Derek Organ

  Ok, because of a bunch of projects I'm working on I've access to dedicated Servers on a 3 hosting providers. As an experiment and for educational purposes I decided to see if I could benchmark how good the IO is with each. Bit of research lead me to Bonnie++ So I installed it on the server and ran this simple command /usr/sbin/bonnie -d /tmp/foo The 3 machines in different hosting providers are all dedicated machines, one is a VPS, other two are on some cloud platform e.g. VMWare / Xen using some kind of clustered SAN for storage This might be a naive thing to do but here are the results I found. HOST A Version 1.03c ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP xxxxxxxxxxxxxxxx 1G 45081 88 56244 14 19167 4 20965 40 67110 6 67.2 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 15264 28 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ xxxxxxxx,1G,45081,88,56244,14,19167,4,20965,40,67110,6,67.2,0,16,15264,28,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++ HOST B Version 1.03d ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP xxxxxxxxxxxx 4G 43070 91 64510 15 19092 0 29276 47 39169 0 448.2 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 24799 52 +++++ +++ +++++ +++ 25443 54 +++++ +++ +++++ +++ xxxxxxx,4G,43070,91,64510,15,19092,0,29276,47,39169,0,448.2,0,16,24799,52,+++++,+++,+++++,+++,25443,54,+++++,+++,+++++,+++ HOST C Version 1.03c ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP xxxxxxxxxxxxx 1536M 15598 22 85698 13 258969 20 16194 22 723655 21 +++++ +++ ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 14142 22 +++++ +++ 18621 22 13544 22 +++++ +++ 17363 21 xxxxxxxx,1536M,15598,22,85698,13,258969,20,16194,22,723655,21,+++++,+++,16,14142,22,+++++,+++,18621,22,13544,22,+++++,+++,17363,21 Ok, so first off what is the best way to read the figures and are there any issues with really comparing these numbers? Is this in any way a true representation of IO Speed? If not is there any way for me to test that? Note: these 3 machines are using either Ubuntu or Debian (I presume that doesn't really matter)

  Read the article

• OSX 10.6.6 SSH md5 break-in check

  - by Alex

  Information Recently one of the linux servers that I access was compromised to steal passwords and ssh keys using a modified ssh binary. This lead me to question if the attacker had compromised my OSX Laptop which had ssh access turned on. A sophos virus scan turned up nothing, and I did not have rkhunter installed before the attack, so I could not compare hashes of the system binaries to be sure. However because OSX is relatively standard for each of their major releases, I asked fiends for md5 hashes md5 /usr/bin/ssh and md5 /usr/sbin/sshd as a basic first check to see if there was anything different about my machine. A few emails later I have found the following data: Version (Arch) [N] MD5 (/usr/bin/ssh) MD5 (/usr/sbin/sshd) OSX 10.5.8 (PPC) [3] 1e9fd483eef23464ec61c815f7984d61 9d32a36294565368728c18de466e69f1 OSX 10.5.8 (intel) [5] 1e9fd483eef23464ec61c815f7984d61 9d32a36294565368728c18de466e69f1 OSX 10.6.x (intel) [7] 591fbe723011c17b6ce41c537353b059 e781fad4fc86cf652f6df22106e0bf0e OSX 10.6.x (intel) [4] 58be068ad5e575c303ec348a1c71d48b 33dafd419194b04a558c8404b484f650 Mine 10.6.6 (intel) df344cc00a294c91230c65e8b7332a79 b5094ccf4cd074aaf573d4f5df75906a where N is the number of machines with with that MD5, and the last row is my laptop. The sample is relatively heterogeneous spaning a few years of different makes and models of Apples, and different versions of 10.6.x. The different hash for my system made me worried that these binaries might have been compromised. So I made sure that my backup for the week was good, and dived into formatting my system and reinstalling OSX. After reinstalling OSX from the manufacturer DVD, I found that the MD5 hash did not change for either ssh, or sshd. Goal Make sure that my system is does not have any malicious software. Should I be worried that this base install of OSX (with no other software installed) has been compromised? I have also updated my system to 10.6.6 and found no change as well. Other Information I am not sure if this is helpful information, but my laptop is a i7 15 inch MacBook Pro bought in Nov 2010, and here is some output from system_profiler: System Software Overview: System Version: Mac OS X 10.6.6 (10J567) Kernel Version: Darwin 10.6.0 64-bit Kernel and Extensions: No Time since boot: 1:37 Hardware: Hardware Overview: Model Name: MacBook Model Identifier: MacBook6,2 Processor Name: Intel Core i7 Processor Speed: 2.66 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache (per core): 256 KB L3 Cache: 4 MB Memory: 4 GB Processor Interconnect Speed: 4.8 GT/s Boot ROM Version: MBP61.0057.B0C SMC Version (system): 1.58f16 Sudden Motion Sensor: State: Enabled On the laptop, I find: $ codesign -vvv /usr/bin/ssh /usr/bin/ssh: valid on disk /usr/bin/ssh: satisfies its Designated Requirement $ codesign -vvv /usr/sbin/sshd /usr/sbin/sshd: valid on disk /usr/sbin/sshd: satisfies its Designated Requirement $ ls -la /usr/bin/ssh -rwxr-xr-x 1 root wheel 1001520 Feb 11 2010 /usr/bin/ssh $ ls -la /usr/sbin/sshd -rwxr-xr-x 1 root wheel 1304800 Feb 11 2010 /usr/sbin/sshd $ ls -la /sbin/md5 -r-xr-xr-x 1 root wheel 65232 May 18 2009 /sbin/md5 Update So far I have not gotten an answer about this question, but if you could help by increasing the number of hashes that I can compare against, that would be great. To get hashes, and version numbers, run the following on osx: md5 /usr/bin/ssh md5 /usr/sbin/sshd ssh -V sw_vers

  Read the article

< Previous Page | 211 212 213 214 215 216 217 218 219 220 221 222  | Next Page >