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• NullPointerException when setting adapter

  - by Sorin Grecu

  I'm trying to get the filenames in a folder inside a listview(that listview is inside a layout of a ViewPager) but i'm getting a NullPointerException and i can't figure what's wrong. public void citire() { ListView lv1 = (ListView) findViewById(R.id.lv1); myList = new ArrayList<String>(); File directory = Environment.getExternalStorageDirectory(); file = new File(directory + "/InterSRL"); File list[] = file.listFiles(); for (int i = 0; i < list.length; i++) { myList.add(list[i].getName()); } ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, android.R.id.text1, myList); lv1.setAdapter(adapter); } I'm getting the error at lv1.setAdapter(adapter); 06-28 13:10:57.987: E/AndroidRuntime(30450): Caused by: java.lang.NullPointerException 06-28 13:10:57.987: E/AndroidRuntime(30450): at com.example.testlayout.Gestionare.citire(Gestionare.java:169) 06-28 13:10:57.987: E/AndroidRuntime(30450): at com.example.testlayout.Gestionare.onCreate(Gestionare.java:33) 06-28 13:10:57.987: E/AndroidRuntime(30450): at android.app.Activity.performCreate(Activity.java:5104) 06-28 13:10:57.987: E/AndroidRuntime(30450): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 06-28 13:10:57.987: E/AndroidRuntime(30450): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)

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• parse string with regular exression

  - by llamerr

  I trying to parse this string: $right = '34601)S(1,6)[2] - 34601)(11)[2] + 34601)(3)[2,4]'; with following regexp: const word = '(\d{3}\d{2}\)S{0,1}\([^\)]*\)S{0,1}\[[^\]]*\])'; preg_match('/'.word.'{1}(?:\s{1}([+-]{1})\s{1}'.word.'){0,}/', $right, $matches); print_r($matches); i want to return array like this: Array ( [0] => 34601)S(1,6)[2] - 34601)(11)[2] + 34601)(3)[2,4] [1] => 34601)S(1,6)[2] [2] => - [3] => 34601)(11)[2] [4] => + [5] => 34601)(3)[2,4] ) but i return only following: Array ( [0] => 34601)S(1,6)[2] - 34601)(11)[2] + 34601)(3)[2,4] [1] => 34601)S(1,6)[2] [2] => + [3] => 34601)(3)[2,4] ) i think, its becouse of [^)]* or [^]]* in the word, but how i should correct regexp for matching this in another way? i tryied to specify it: \d+(?:[,#]\d+){0,} so word become const word = '(\d{3}\d{2}\)S{0,1}\(\d+(?:[,#]\d+){0,}\)S{0,1}\[\d+(?:[,#]\d+){0,}\])'; but it gives nothing

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• Strange results while measuring delta time on Linux

  - by pachanga

  Folks, could you please explain why I'm getting very strange results from time to time using the the following code: #include <unistd.h> #include <sys/time.h> #include <time.h> #include <stdio.h> int main() { struct timeval start, end; long mtime, seconds, useconds; while(1) { gettimeofday(&start, NULL); usleep(2000); gettimeofday(&end, NULL); seconds = end.tv_sec - start.tv_sec; useconds = end.tv_usec - start.tv_usec; mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5; if(mtime > 10) printf("WTF: %ld\n", mtime); } return 0; } (You can compile and run it with: gcc test.c -o out -lrt && ./out) What I'm experiencing is sporadic big values of mtime variable almost every second or even more often, e.g: $ gcc test.c -o out -lrt && ./out WTF: 14 WTF: 11 WTF: 11 WTF: 11 WTF: 14 WTF: 13 WTF: 13 WTF: 11 WTF: 16 How can this be possible? Is it OS to blame? Does it do too much context switching? But my box is idle( load average: 0.02, 0.02, 0.3). Here is my Linux kernel version: $ uname -a Linux kurluka 2.6.31-21-generic #59-Ubuntu SMP Wed Mar 24 07:28:56 UTC 2010 i686 GNU/Linux

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• Getting $n number of maximum values

  - by KPL

  Hello all, Straight to the question - If $n = 3, and input is - Array ( [04] => 3 [07] => 4 [01] => 5 [06] => 5 [05] => 5 [03] => 6 [08] => 6 [02] => 7 [09] => 8 [12] => 9 [10] => 10 [15] => 10 [19] => 11 [20] => 11 [13] => 12 [21] => 12 [16] => 13 [14] => 14 [22] => 14 [23] => 15 [11] => 15 [00] => 15 [17] => 17 [18] => 17 ) Output should be - Array ( [14] => 14 [22] => 14 [23] => 15 [11] => 15 [00] => 15 [17] => 17 [18] => 17 ) Thank you, all, for help.

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• Stored procedure for generic MERGE

  - by GilliVilla

  I have a set of 10 tables in a database (DB1). And there are 10 tables in another database (DB2) with exact same schema on the same SQL Server 2008 R2 database server machine. The 10 tables in DB1 are frequently updated with data. I intend to write a stored procedure that would run once every day for synchronizing the 10 tables in DB1 with DB2. The stored procedure would make use of the MERGE statement. Now, my aim is to make this as generic and parametrized as possible. That is, accommodate for more tables down the line... and accommodate different source and target DB names. Definitely no hard coding is intended. This is my algorithm so far: Have the database names as parameters Have the first query within the stored procedure... result in giving the names of the 10 tables from a lookup table (this can be 10, 20 or whatever) Have a generic MERGE statement that does the sync for each of the above set of tables (based on primary key?) This is where I need more inputs on. What is the best way to achieve this stored procedure? SQL syntax would be helpful.

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• Can't store UTF-8 in RDS despite setting up new Parameter Group using Rails on Heroku

  - by Lail

  I'm setting up a new instance of a Rails(2.3.5) app on Heroku using Amazon RDS as the database. I'd like to use UTF-8 for everything. Since RDS isn't UTF-8 by default, I set up a new Parameter Group and switched the database to use that one, basically per this. Seems to have worked: SHOW VARIABLES LIKE '%character%'; character_set_client utf8 character_set_connection utf8 character_set_database utf8 character_set_filesystem binary character_set_results utf8 character_set_server utf8 character_set_system utf8 character_sets_dir /rdsdbbin/mysql-5.1.50.R3/share/mysql/charsets/ Furthermore, I've successfully setup Heroku to use the RDS database. After rake db:migrate, everything looks good: CREATE TABLE `comments` ( `id` int(11) NOT NULL AUTO_INCREMENT, `commentable_id` int(11) DEFAULT NULL, `parent_id` int(11) DEFAULT NULL, `content` text COLLATE utf8_unicode_ci, `child_count` int(11) DEFAULT '0', `created_at` datetime DEFAULT NULL, `updated_at` datetime DEFAULT NULL, PRIMARY KEY (`id`), KEY `commentable_id` (`commentable_id`), KEY `index_comments_on_community_id` (`community_id`), KEY `parent_id` (`parent_id`) ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; In the markup, I've included: <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> Also, I've set: production: encoding: utf8 collation: utf8_general_ci ...in the database.yml, though I'm not very confident that anything is being done to honor any of those settings in this case, as Heroku seems to be doing its own config when connecting to RDS. Now, I enter a comment through the form in the app: "Úbe® ƒåiL", but in the database I've got "Úbe® Æ’Ã¥iL" It looks fine when Rails loads it back out of the database and it is rendered to the page, so whatever it is doing one way, it's undoing the other way. If I look at the RDS database in Sequel Pro, it looks fine if I set the encoding to "UTF-8 Unicode via Latin 1". So it seems Latin-1 is sneaking in there somewhere. Somebody must have done this before, right? What am I missing?

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• Delete on a very deep tree

  - by Kathoz

  I am building a suffix trie (unfortunately, no time to properly implement a suffix tree) for a 10 character set. The strings I wish to parse are going to be rather long (up to 1M characters). The tree is constructed without any problems, however, I run into some when I try to free the memory after being done with it. In particularly, if I set up my constructor and destructor to be as such (where CNode.child is a pointer to an array of 10 pointers to other CNodes, and count is a simple unsigned int): CNode::CNode(){ count = 0; child = new CNode* [10]; memset(child, 0, sizeof(CNode*) * 10); } CNode::~CNode(){ for (int i=0; i<10; i++) delete child[i]; } I get a stack overflow when trying to delete the root node. I might be wrong, but I am fairly certain that this is due to too many destructor calls (each destructor calls up to 10 other destructors). I know this is suboptimal both space, and time-wise, however, this is supposed to be a quick-and-dirty solution to a the repeated substring problem. tl;dr: how would one go about freeing the memory occupied by a very deep tree? Thank you for your time.

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• I just learned about C++ functions, can i use if statements onto functions?

  - by Sagistic

  What I am confused on is about the isNumPalindrome() function. It returns a boolean value of either true or false. How am I suppose to use that so I can display if its a palindrome or not. For ex. If (isNumPalindrome = true) cout "Your number is a palindrome" else "your number is not a palindrome." #include "stdafx.h" int _tmain(int argc, _TCHAR* argv[]) { return 0; } #include <iostream> #include <cmath> using namespace std; int askNumber(); bool isNumPalindrome(); int num, pwr; int main() { askNumber(); isNumPalindrome(); return 0; } bool isNumPalindrome() { int pwr = 0; if (num < 10) return true; else { while (num / static_cast<int>(pow(10.0, pwr)) >=10) pwr++; while (num >=10) { int tenTopwr = static_cast<int>(pow(10.0, pwr)); if ((num / tenTopwr) != (num% 10)) return false; else { num = num % tenTopwr; num = num / 10; pwr = pwr-2; } } return true; } } int askNumber() { cout << "Enter an integer in order to determine if it is a palindrome: " ; cin >> num; cout << endl; return num; }

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• Remove array elements that are less than X

  - by GGio

  I have arrays: $arr1 = array(5, 3, 9, 11, 6, 15); $arr2 = array(11, 20, 1, 3, 8); Now I need to loop through $arr1 and find the largest number that is less than X: foreach($arr1 as $x) { //need element that is MAX in $arr2 but is less than $x } so for example for the first run when $x = 5, maximum in $arr2 is 3 that is less than 5. Is it possible to do this without having nested loop? I do not want to loop through $arr2. I tried using array_filter but didnt really work. Maybe I used it wrong. This is what I tried with array_filter: $results = array(); foreach($arr1 as $x) { $max = max(array_filter($arr2, function ($x) { return $x < $y; })); $results[$x] = $max; } The result should be this: 5 => 3, 3 => 1, 9 => 8, 11 => 8, 6 => 3, 15 => 11

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• sprintf bug with php & apache in windows?

  - by potatoe

  I've run into a strange problem on a WAMP server setup (PHP version 5.3.0, Apache 2.2.11). When using sprintf to output a number, I occasionally get erroneous characters in the output string. Example: (not trimmed from anything, this is the only code in the script) $dt1 = new DateTime('now'); $dt2 = new DateTime('now - 10 min'); $interval = $dt1->diff($dt2); $number = 10.0; $string = sprintf("%.1f", $number); echo "number: $number, string: $string\n"; If I run this at the command prompt with PHP CLI, I get the expected output: number: 10, string: 10.0 However, if I serve it using Apache, in the browser I get number: 10, string: :.0 with a colon where '10' should be. (Note that ':' is the next ascii character in sequence after '9', if $number is 0-9, everything works. Numbers greater than 10 appear to use ascii equivalents - so 11 is ';', 12 is '<', etc.) The strangest part is that the first four lines in the above code sample seem to affect the results. Logically, those statements should have no impact, but if I comment them out or remove them the problem goes away. Any ideas? Anyone else able to replicate this?

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• Finding the closest match

  - by doublescorpio

  I Have an object with a set of parameters like: var obj = new {Param1 = 100; Param2 = 212; Param3 = 311; param4 = 11; Param5 = 290;} On the other side i have a list of object: var obj1 = new {Param1 = 1221; Param2 = 212; Param3 = 311; param4 = 11; Param5 = 290;} var obj3 = new {Param1 = 35; Param2 = 11; Param3 = 319; param4 = 211; Param5 = 790;} var obj4 = new {Param1 = 126; Param2 = 218; Param3 = 2; param4 = 6; Param5 = 190;} var obj5 = new {Param1 = 213; Param2 = 121; Param3 = 61; param4 = 11; Param5 = 29;} var obj7 = new {Param1 = 161; Param2 = 21; Param3 = 71; param4 = 51; Param5 = 232;} var obj9 = new {Param1 = 891; Param2 = 58; Param3 = 311; param4 = 21; Param5 = 590;} var obj11 = new {Param1 = 61; Param2 = 212; Param3 = 843; param4 = 89; Param5 = 210;} What is the best (easiest) algorithm to find the closest match for the first obj in the listed objects?

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• Using data.table to aggregate

  - by dayne

  After multiple suggestions from SO users, I am finally trying to convert my code over to using data.tables. library(data.table) DT <- data.table(plate = paste0("plate",rep(1:2,each=5)), id = rep(c("CTRL","CTRL","ID1","ID2","ID3"),2), val = 1:10) > DT plate id val 1: plate1 CTRL 1 2: plate1 CTRL 2 3: plate1 ID1 3 4: plate1 ID2 4 5: plate1 ID3 5 6: plate2 CTRL 6 7: plate2 CTRL 7 8: plate2 ID1 8 9: plate2 ID2 9 10: plate2 ID3 10 What I would like to do is take the average of DT[,val] by plate when the id is "CTRL". I would normally aggregate the data frame, then use match to map the values back to a new column, 'ctrl'. Using the data.table package I can get: DT[id=="CTRL",ctrl:=mean(val),by=plate] > DT plate id val ctrl 1: plate1 CTRL 1 1.5 2: plate1 CTRL 2 1.5 3: plate1 ID1 3 NA 4: plate1 ID2 4 NA 5: plate1 ID3 5 NA 6: plate2 CTRL 6 6.5 7: plate2 CTRL 7 6.5 8: plate2 ID1 8 NA 9: plate2 ID2 9 NA 10: plate2 ID3 10 NA What I need is really: DT <- data.table(plate = paste0("plate",rep(1:2,each=5)), id = rep(c("CTRL","CTRL","ID1","ID2","ID3"),2), val = 1:10, ctrl = rep(c(1.5,6.5),each=5)) > DT plate id val ctrl 1: plate1 CTRL 1 1.5 2: plate1 CTRL 2 1.5 3: plate1 ID1 3 1.5 4: plate1 ID2 4 1.5 5: plate1 ID3 5 1.5 6: plate2 CTRL 6 6.5 7: plate2 CTRL 7 6.5 8: plate2 ID1 8 6.5 9: plate2 ID2 9 6.5 10: plate2 ID3 10 6.5 Eventually I would like to use much more complicated selections of the values, but I do not know how to select specific values, run some function, then map those values back to the appropriate row using data frames.

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• array and point problem

  - by bezetek

  Here, I have a bad program. Its outputs confusing me, anyone can tell me why ? #include <stdio.h> #include <stdlib.h> int main() { int i = 0; char *a_result[10]; char *b_result[10]; for (i = 0; i < 10; i++) { char a_array[10]; char *b_array = malloc(10*sizeof(char)); int j = 0; for (j = 0; j < 9; j++) { a_array[j] = 'a' + i; b_array[j] = 'a' + i; } a_array[j] = '\0'; b_array[j] = '\0'; a_result[i] = a_array; b_result[i] = b_array; } for (i = 0; i < 10; i++) printf("a_result: %s b_result: %s\n",a_result[i],b_result[i]); return 0; } I think the a_result and b_result should be the same, but it is not. Here is the output on my computer. a_result: jjjjjjjjj b_result: aaaaaaaaa a_result: jjjjjjjjj b_result: bbbbbbbbb a_result: jjjjjjjjj b_result: ccccccccc a_result: jjjjjjjjj b_result: ddddddddd a_result: jjjjjjjjj b_result: eeeeeeeee a_result: jjjjjjjjj b_result: fffffffff a_result: jjjjjjjjj b_result: ggggggggg a_result: jjjjjjjjj b_result: hhhhhhhhh a_result: jjjjjjjjj b_result: iiiiiiiii a_result: jjjjjjjjj b_result: jjjjjjjjj any explanation about this is appreciate!

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• Class Inside Structure

  - by Knvn

  Could some one please explain, What happens when a reference type is defined inside the value type. I write the following code: namespace ClassInsideStruct { class ClassInsideStruct { static void Main(string[] args) { ValueType ObjVal = new ValueType(10); ObjVal.Display(); ValueType.ReferenceType ObjValRef = new ValueType.ReferenceType(10); ObjValRef.Display(); Test(ObjVal, ObjValRef); ObjVal.Display(); ObjValRef.Display(); Console.ReadKey(); } private static void Test(ValueType v, ValueType.ReferenceType r) { v.SValue = 50; r.RValue = 50; } } struct ValueType { int StructNum; ReferenceType ObjRef; public ValueType(int i) { StructNum = i; ObjRef = new ReferenceType(i); } public int SValue { get { return StructNum; } set { StructNum = value; ObjRef.RValue = value; } } public void Display() { Console.WriteLine("ValueType: " + StructNum); Console.Write("ReferenceType Inside ValueType Instance: "); ObjRef.Display(); } public class ReferenceType { int ClassNum; public ReferenceType(int i) { ClassNum = i; } public void Display() { Console.WriteLine("Reference Type: " + ClassNum); } public int RValue { get { return ClassNum; } set { ClassNum = value; } } } } } Which outputs: ValueType: 10 ReferenceType Inside ValueType Instance: Reference Type: 10 Reference Type: 10 ValueType: 10 ReferenceType Inside ValueType Instance: Reference Type: 50 Reference Type: 50 I'm curious to know, after calling the method Test(ObjVal, ObjValRef), how the values of ReferenceType is changed to 50 which resides inside the ValueType who's value is not changed?

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• trying to switch beginning of an array with another

  - by user1874574

  I have a problem where i am trying to swap two arrays so that they switch beginnings. example: array 1 = (1,2,3,4,5,6,7,8) and array 2 = (11,12,13,14,15,16,17,18) i want to end up with the first array being (11,12,13,14,5,6,7,8) and i want the second array to be (1,2,3,4,15,16,17,18) but for some reason i end up with 1=(11,12,13,14,5,6,7,8) and 2=(11,12,13,14,15,16,17,18) my code is provided below, what am i doing wrong? public static void Mutate(Genetic lowest, Genetic secondLowest) { int halfway = (lowest.getPopulation().length)/2; int[] one = lowest.getPopulation(); int[] two = secondLowest.getPopulation(); int[] temp = secondLowest.getPopulation(); int[] temp2 = lowest.getPopulation(); for(int i = 0; i < halfway; i++){ temp[i] = one[i]; } lowest.setPopulation(temp); for(int i = 0; i < lowest.getPopulation().length; i++){ System.out.print(temp[i]); } System.out.println(); for(int i = 0; i < halfway; i++){ temp2[i] = two[i]; } for(int i = 0; i < lowest.getPopulation().length; i++){ System.out.print(temp2[i]); } }

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• Why do apache2 upgrades remove and not re-install libapache2-mod-php5?

  - by nutznboltz

  We repeatedly see that when an apache2 update arrives and is installed it causes the libapache2-mod-php5 package to be removed and does not subsequently re-install it automatically. We must subsequently re-install the libapache2-mod-php5 manually in order to restore functionality to our web server. Please see the following github gist, it is a contiguous section of our server's dpkg.log showing the November 14, 2011 update to apache2: https://gist.github.com/1368361 it includes 2011-11-14 11:22:18 remove libapache2-mod-php5 5.3.2-1ubuntu4.10 5.3.2-1ubuntu4.10 Is this a known issue? Do other people see this too? I could not find any launchpad bug reports about it. Platform details: $ lsb_release -ds Ubuntu 10.04.3 LTS $ uname -srvm Linux 2.6.38-12-virtual #51~lucid1-Ubuntu SMP Thu Sep 29 20:27:50 UTC 2011 x86_64 $ dpkg -l | awk '/ii.*apache/ {print $2 " " $3 }' apache2 2.2.14-5ubuntu8.7 apache2-mpm-prefork 2.2.14-5ubuntu8.7 apache2-utils 2.2.14-5ubuntu8.7 apache2.2-bin 2.2.14-5ubuntu8.7 apache2.2-common 2.2.14-5ubuntu8.7 libapache2-mod-authnz-external 3.2.4-2+squeeze1build0.10.04.1 libapache2-mod-php5 5.3.2-1ubuntu4.10 Thanks At a high-level the update process looks like: package package_name do action :upgrade case node[:platform] when 'centos', 'redhat', 'scientific' options '--disableplugin=fastestmirror' when 'ubuntu' options '-o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"' end end But at a lower level def install_package(name, version) run_command_with_systems_locale( :command = "apt-get -q -y#{expand_options(@new_resource.options)} install #{name}=#{version}", :environment = { "DEBIAN_FRONTEND" = "noninteractive" } ) end def upgrade_package(name, version) install_package(name, version) end So Chef is using "install" to do "update". This sort of moves the question around to "how does apt-get safe-upgrade" remember to re-install libapache-mod-php5? The exact sequence of packages that triggered this was: apache2 apache2-mpm-prefork apache2-mpm-worker apache2-utils apache2.2-bin apache2.2-common But the code is attempting to run checks to make sure the packages in that list are installed already before attempting to "upgrade" them. case node[:platform] when 'debian', 'centos', 'fedora', 'redhat', 'scientific', 'ubuntu' # first primitive way is to define the updates in the recipe # data bags will be used later %w/ apache2 apache2-mpm-prefork apache2-mpm-worker apache2-utils apache2.2-bin apache2.2-common /.each{ |package_name| Chef::Log.debug("is #{package_name} among local packages available for changes?") next unless node[:packages][:changes].keys.include?(package_name) Chef::Log.debug("is #{package_name} available for upgrade?") next unless node[:packages][:changes][package_name][:action] == 'upgrade' package package_name do action :upgrade case node[:platform] when 'centos', 'redhat', 'scientific' options '--disableplugin=fastestmirror' when 'ubuntu' options '-o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"' end end tag('upgraded') } # after upgrading everything, run yum cache updater if tagged?('upgraded') # Remove old orphaned dependencies and kernel images and kernel headers etc. # Remove cached deb files. case node[:platform] when 'ubuntu' execute 'apt-get -y autoremove' execute 'apt-get clean' # Re-check what updates are available soon. when 'centos', 'fedora', 'redhat', 'scientific' node[:packages][:last_time_we_looked_at_yum] = 0 end untag('upgraded') end end But it's clear that it fails since the dpkg.log has 2011-11-14 11:22:25 install apache2-mpm-worker 2.2.14-5ubuntu8.7 on a system which does not currently have apache2-mpm-worker. I will have to discuss this with the author, thanks again.

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• LINQ Query using Multiple From and Multiple Collections

  1: using System; 2: using System.Collections.Generic; 3: using System.Linq; 4: using System.Text; 5:  6: namespace ConsoleApplication2 7: { 8: class Program 9: { 10: static void Main(string[] args) 11: { 12: var emps = GetEmployees(); 13: var deps = GetDepartments(); 14:  15: var results = from e in emps 16: from d in deps 17: where e.EmpNo >= 1 && d.DeptNo <= 30 18: select new { Emp = e, Dept = d }; 19: 20: foreach (var item in results) 21: { 22: Console.WriteLine("{0},{1},{2},{3}", item.Dept.DeptNo, item.Dept.DName, item.Emp.EmpNo, item.Emp.EmpName); 23: } 24: } 25:  26: private static List<Emp> GetEmployees() 27: { 28: return new List<Emp>() { 29: new Emp() { EmpNo = 1, EmpName = "Smith", DeptNo = 10 }, 30: new Emp() { EmpNo = 2, EmpName = "Narayan", DeptNo = 20 }, 31: new Emp() { EmpNo = 3, EmpName = "Rishi", DeptNo = 30 }, 32: new Emp() { EmpNo = 4, EmpName = "Guru", DeptNo = 10 }, 33: new Emp() { EmpNo = 5, EmpName = "Priya", DeptNo = 20 }, 34: new Emp() { EmpNo = 6, EmpName = "Riya", DeptNo = 10 } 35: }; 36: } 37:  38: private static List<Department> GetDepartments() 39: { 40: return new List<Department>() { 41: new Department() { DeptNo=10, DName="Accounts" }, 42: new Department() { DeptNo=20, DName="Finance" }, 43: new Department() { DeptNo=30, DName="Travel" } 44: }; 45: } 46: } 47:  48: class Emp 49: { 50: public int EmpNo { get; set; } 51: public string EmpName { get; set; } 52: public int DeptNo { get; set; } 53: } 54:  55: class Department 56: { 57: public int DeptNo { get; set; } 58: public String DName { get; set; } 59: } 60: } span.fullpost {display:none;}

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• JMX Based Monitoring - Part Four - Business App Server Monitoring

  - by Anthony Shorten

  In the last blog entry I talked about the Oracle Utilities Application Framework V4 feature for monitoring and managing aspects of the Web Application Server using JMX. In this blog entry I am going to discuss a similar new feature that allows JMX to be used for management and monitoring the Oracle Utilities business application server component. This feature is primarily focussed on performance tracking of the product. In first release of Oracle Utilities Customer Care And Billing (V1.x I am talking about), we used to use Oracle Tuxedo as part of the architecture. In Oracle Utilities Application Framework V2.0 and above, we removed Tuxedo from the architecture. One of the features that some customers used within Tuxedo was the performance tracking ability. The idea was that you enabled performance logging on the individual Tuxedo servers and then used a utility named txrpt to produce a performance report. This report would list every service called, the number of times it was called and the average response time. When I worked a performance consultant, I used this report to identify badly performing services and also gauge the overall performance characteristics of a site. When Tuxedo was removed from the architecture this information was also lost. While you can get some information from access.log and some Mbeans supplied by the Web Application Server it was not at the same granularity as txrpt or as useful. I am happy to say we have not only reintroduced this facility in Oracle Utilities Application Framework but it is now accessible via JMX and also we have added more detail into the performance tracking. Most of this new design was working with customers around the world to make sure we introduced a new feature that not only satisfied their performance tracking needs but allowed for finer grained performance analysis. As with the Web Application Server, the Business Application Server JMX monitoring is enabled by specifying a JMX port number in RMI Port number for JMX Business and initial credentials in the JMX Enablement System User ID and JMX Enablement System Password configuration options. These options are available using the configureEnv[.sh] -a utility. These credentials are shared across the Web Application Server and Business Application Server for authorization purposes. Once this is information is supplied a number of configuration files are built (by the initialSetup[.sh] utility) to configure the facility: spl.properties - contains the JMX URL, the security configuration and the mbeans that are enabled. For example, on my demonstration machine: spl.runtime.management.rmi.port=6750 spl.runtime.management.connector.url.default=service:jmx:rmi:///jndi/rmi://localhost:6750/oracle/ouaf/ejbAppConnector jmx.remote.x.password.file=scripts/ouaf.jmx.password.file jmx.remote.x.access.file=scripts/ouaf.jmx.access.file ouaf.jmx.com.splwg.ejb.service.management.PerformanceStatistics=enabled ouaf.jmx.* files - contain the userid and password. The default configuration uses the JMX default configuration. You can use additional security features by altering the spl.properties file manually or using a custom template. For more security options see JMX Security for more details. Once it has been configured and the changes reflected in the product using the initialSetup[.sh] utility the JMX facility can be used. For illustrative purposes I will use jconsole but any JSR160 complaint browser or client can be used (with the appropriate configuration). Once you start jconsole (ensure that splenviron[.sh] is executed prior to execution to set the environment variables or for remote connection, ensure java is in your path and jconsole.jar in your classpath) you specify the URL in the spl.runtime.management.connnector.url.default entry. For example: You are then able to track performance of the product using the PerformanceStatistics Mbean. The attributes of the PerformanceStatistics Mbean are counts of each object type. This is where this facility differs from txrpt. The information that is collected includes the following: The Service Type is captured so you can filter the results in terms of the type of service. For maintenance type services you can even see the transaction type (ADD, CHANGE etc) so you can see the performance of updates against read transactions. The Minimum and Maximum are also collected to give you an idea of the spread of performance. The last call is recorded. The date, time and user of the last call are recorded to give you an idea of the timeliness of the data. The Mbean maintains a set of counters per Service Type to give you a summary of the types of transactions being executed. This gives you an overall picture of the types of transactions and volumes at your site. There are a number of interesting operations that can also be performed: reset - This resets the statistics back to zero. This is an important operation. For example, txrpt is restricted to collecting statistics per hour, which is ok for most people. But what if you wanted to be more granular? This operation allows to set the collection period to anything you wish. The statistics collected will represent values since the last restart or last reset. completeExecutionDump - This is the operation that produces a CSV in memory to allow extraction of the data. All the statistics are extracted (see the Server Administration Guide for a full list). This can be then loaded into a database, a tool or simply into your favourite spreadsheet for analysis. Here is an extract of an execution dump from my demonstration environment to give you an idea of the format: ServiceName, ServiceType, MinTime, MaxTime, Avg Time, # of Calls, Latest Time, Latest Date, Latest User ... CFLZLOUL, EXECUTE_LIST, 15.0, 64.0, 22.2, 10, 16.0, 2009-12-16::11-25-36-932, ASHORTEN CILBBLLP, READ, 106.0, 1184.0, 466.3333333333333, 6, 106.0, 2009-12-16::11-39-01-645, BOBAMA CILBBLLP, DELETE, 70.0, 146.0, 108.0, 2, 70.0, 2009-12-15::12-53-58-280, BPAYS CILBBLLP, ADD, 860.0, 4903.0, 2243.5, 8, 860.0, 2009-12-16::17-54-23-862, LELLISON CILBBLLP, CHANGE, 112.0, 3410.0, 815.1666666666666, 12, 112.0, 2009-12-16::11-40-01-103, ASHORTEN CILBCBAL, EXECUTE_LIST, 8.0, 84.0, 26.0, 22, 23.0, 2009-12-16::17-54-01-643, LJACKMAN InitializeUserInfoService, READ_SYSTEM, 49.0, 962.0, 70.83777777777777, 450, 63.0, 2010-02-25::11-21-21-667, ASHORTEN InitializeUserService, READ_SYSTEM, 130.0, 2835.0, 234.85777777777778, 450, 216.0, 2010-02-25::11-21-21-446, ASHORTEN MenuLoginService, READ_SYSTEM, 530.0, 1186.0, 703.3333333333334, 9, 530.0, 2009-12-16::16-39-31-172, ASHORTEN NavigationOptionDescriptionService, READ_SYSTEM, 2.0, 7.0, 4.0, 8, 2.0, 2009-12-21::09-46-46-892, ASHORTEN ... There are other operations and attributes available. Refer to the Server Administration Guide provided with your product to understand the full et of operations and attributes. This is one of the many features I am proud that we implemented as it allows flexible monitoring of the performance of the product.

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• Parallel LINQ - PLINQ

  - by nmarun

  Turns out now with .net 4.0 we can run a query like a multi-threaded application. Say you want to query a collection of objects and return only those that meet certain conditions. Until now, we basically had one ‘control’ that iterated over all the objects in the collection, checked the condition on each object and returned if it passed. We obviously agree that if we can ‘break’ this task into smaller ones, assign each task to a different ‘control’ and ask all the controls to do their job - in-parallel, the time taken the finish the entire task will be much lower. Welcome to PLINQ. Let’s take some examples. I have the following method that uses our good ol’ LINQ. 1: private static void Linq(int lowerLimit, int upperLimit) 2: { 3: // populate an array with int values from lowerLimit to the upperLimit 4: var source = Enumerable.Range(lowerLimit, upperLimit); 5:  6: // Start a timer 7: Stopwatch stopwatch = new Stopwatch(); 8: stopwatch.Start(); 9:  10: // set the expectation => build the expression tree 11: var evenNumbers =   from num in source 12: where IsDivisibleBy(num, 2) 13: select num; 14: 15: // iterate over and print the returned items 16: foreach (var number in evenNumbers) 17: { 18: Console.WriteLine(string.Format("** {0}", number)); 19: } 20:  21: stopwatch.Stop(); 22:  23: // check the metrics 24: Console.WriteLine(String.Format("Elapsed {0}ms", stopwatch.ElapsedMilliseconds)); 25: } I’ve added comments for the major steps, but the only thing I want to talk about here is the IsDivisibleBy() method. I know I could have just included the logic directly in the where clause. I called a method to add ‘delay’ to the execution of the query - to simulate a loooooooooong operation (will be easier to compare the results). 1: private static bool IsDivisibleBy(int number, int divisor) 2: { 3: // iterate over some database query 4: // to add time to the execution of this method; 5: // the TableB has around 10 records 6: for (int i = 0; i < 10; i++) 7: { 8: DataClasses1DataContext dataContext = new DataClasses1DataContext(); 9: var query = from b in dataContext.TableBs select b; 10: 11: foreach (var row in query) 12: { 13: // Do NOTHING (wish my job was like this) 14: } 15: } 16:  17: return number % divisor == 0; 18: } Now, let’s look at how to modify this to PLINQ. 1: private static void Plinq(int lowerLimit, int upperLimit) 2: { 3: // populate an array with int values from lowerLimit to the upperLimit 4: var source = Enumerable.Range(lowerLimit, upperLimit); 5:  6: // Start a timer 7: Stopwatch stopwatch = new Stopwatch(); 8: stopwatch.Start(); 9:  10: // set the expectation => build the expression tree 11: var evenNumbers = from num in source.AsParallel() 12: where IsDivisibleBy(num, 2) 13: select num; 14:  15: // iterate over and print the returned items 16: foreach (var number in evenNumbers) 17: { 18: Console.WriteLine(string.Format("** {0}", number)); 19: } 20:  21: stopwatch.Stop(); 22:  23: // check the metrics 24: Console.WriteLine(String.Format("Elapsed {0}ms", stopwatch.ElapsedMilliseconds)); 25: } That’s it, this is now in PLINQ format. Oh and if you haven’t found the difference, look line 11 a little more closely. You’ll see an extension method ‘AsParallel()’ added to the ‘source’ variable. Couldn’t be more simpler right? So this is going to improve the performance for us. Let’s test it. So in my Main method of the Console application that I’m working on, I make a call to both. 1: static void Main(string[] args) 2: { 3: // set lower and upper limits 4: int lowerLimit = 1; 5: int upperLimit = 20; 6: // call the methods 7: Console.WriteLine("Calling Linq() method"); 8: Linq(lowerLimit, upperLimit); 9: 10: Console.WriteLine(); 11: Console.WriteLine("Calling Plinq() method"); 12: Plinq(lowerLimit, upperLimit); 13:  14: Console.ReadLine(); // just so I get enough time to read the output 15: } YMMV, but here are the results that I got:    It’s quite obvious from the above results that the Plinq() method is taking considerably less time than the Linq() version. I’m sure you’ve already noticed that the output of the Plinq() method is not in order. That’s because, each of the ‘control’s we sent to fetch the results, reported with values as and when they obtained them. This is something about parallel LINQ that one needs to remember – the collection cannot be guaranteed to be undisturbed. This could be counted as a negative about PLINQ (emphasize ‘could’). Nevertheless, if we want the collection to be sorted, we can use a SortedSet (.net 4.0) or build our own custom ‘sorter’. Either way we go, there’s a good chance we’ll end up with a better performance using PLINQ. And there’s another negative of PLINQ (depending on how you see it). This is regarding the CPU cycles. See the usage for Linq() method (used ResourceMonitor): I have dual CPU’s and see the height of the peak in the bottom two blocks and now compare to what happens when I run the Plinq() method. The difference is obvious. Higher usage, but for a shorter duration (width of the peak). Both these points make sense in both cases. Linq() runs for a longer time, but uses less resources whereas Plinq() runs for a shorter time and consumes more resources. Even after knowing all these, I’m still inclined towards PLINQ. PLINQ rocks! (no hard feelings LINQ)

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• ubuntu 12.04 python problem or?

  - by Trki

  Hi i am trying to fix this for a long time but without success. When i open my zsh terminal i get this error: (terminal is working but error appear) Welcome to the world of tomorrow! virtualenvwrapper_run_hook:12: permission denied: virtualenvwrapper.sh: There was a problem running the initialization hooks. If Python could not import the module virtualenvwrapper.hook_loader, check that virtualenv has been installed for VIRTUALENVWRAPPER_PYTHON= and that PATH is set properly. I tried few things but... dont know how to solve it. Somehow during looking for a search i found i should post here an output of: ? sudo dpkg --configure -a Setting up python-pip (1.0-1build1) ... /var/lib/dpkg/info/python-pip.postinst: 6: /var/lib/dpkg/info/python-pip.postinst: pycompile: not found dpkg: error processing python-pip (--configure): subprocess installed post-installation script returned error exit status 127 Setting up libc-dev-bin (2.15-0ubuntu10.5) ... Setting up gnome-control-center-data (1:3.4.2-0ubuntu0.13) ... Setting up linux-libc-dev (3.2.0-56.86) ... Setting up python-virtualenv (1.7.1.2-1) ... /var/lib/dpkg/info/python-virtualenv.postinst: 6: /var/lib/dpkg/info/python-virtualenv.postinst: pycompile: not found dpkg: error processing python-virtualenv (--configure): subprocess installed post-installation script returned error exit status 127 Setting up libglib2.0-0 (2.32.4-0ubuntu1) ... Setting up libglib2.0-0:i386 (2.32.4-0ubuntu1) ... Setting up gimp (2.6.12-1ubuntu1.2) ... /var/lib/dpkg/info/gimp.postinst: 11: /var/lib/dpkg/info/gimp.postinst: pycompile: not found dpkg: error processing gimp (--configure): subprocess installed post-installation script returned error exit status 127 Setting up libpolkit-gobject-1-0 (0.104-1ubuntu1.1) ... Setting up libgnome-control-center1 (1:3.4.2-0ubuntu0.13) ... Setting up libnm-util2 (0.9.4.0-0ubuntu4.3) ... Setting up libc6-dev (2.15-0ubuntu10.5) ... Setting up libpulse-mainloop-glib0 (1:1.1-0ubuntu15.4) ... dpkg: dependency problems prevent configuration of virtualenvwrapper: virtualenvwrapper depends on python-virtualenv; however: Package python-virtualenv is not configured yet. dpkg: error processing virtualenvwrapper (--configure): dependency problems - leaving unconfigured Setting up libpolkit-agent-1-0 (0.104-1ubuntu1.1) ... Setting up libupower-glib1 (0.9.15-3git1ubuntu0.1) ... Setting up libaccountsservice0 (0.6.15-2ubuntu9.6.1) ... Setting up libpolkit-backend-1-0 (0.104-1ubuntu1.1) ... Setting up libglib2.0-bin (2.32.4-0ubuntu1) ... Setting up libnm-glib4 (0.9.4.0-0ubuntu4.3) ... Setting up policykit-1 (0.104-1ubuntu1.1) ... Setting up gnome-settings-daemon (3.4.2-0ubuntu0.6.4) ... Setting up accountsservice (0.6.15-2ubuntu9.6.1) ... dpkg: error processing ubuntu-system-service (--configure): Package is in a very bad inconsistent state - you should reinstall it before attempting configuration. Processing triggers for libc-bin ... ldconfig deferred processing now taking place Errors were encountered while processing: python-pip python-virtualenv gimp virtualenvwrapper ubuntu-system-service Also: ? python --version zsh: command not found: python Part of my ~/.zshrc # python virtual env wrapper if [ -f ~/.local/bin/virtualenvwrapper.sh ]; then export WORKON_HOME=~/.virtualenvs source ~/.local/bin/virtualenvwrapper.sh plugins=("${plugins[@]}" virtualenvwrapper) fi # pythonbrew [[ -s ~/.pythonbrew/etc/bashrc ]] && source ~/.pythonbrew/etc/bashrc Part os zsh -xv # # Invoke the initialization functions # virtualenvwrapper_initialize +/home/trki/.local/bin/virtualenvwrapper.sh:1179> virtualenvwrapper_initialize +virtualenvwrapper_initialize:1> virtualenvwrapper_derive_workon_home +virtualenvwrapper_derive_workon_home:1> typeset 'workon_home_dir=/home/trki/.virtualenvs' +virtualenvwrapper_derive_workon_home:5> [ /home/trki/.virtualenvs '=' '' ']' +virtualenvwrapper_derive_workon_home:12> echo /home/trki/.virtualenvs +virtualenvwrapper_derive_workon_home:12> unset GREP_OPTIONS +virtualenvwrapper_derive_workon_home:12> grep '^[^/~]' +virtualenvwrapper_derive_workon_home:21> echo /home/trki/.virtualenvs +virtualenvwrapper_derive_workon_home:21> unset GREP_OPTIONS +virtualenvwrapper_derive_workon_home:21> egrep '([\$~]|//)' +virtualenvwrapper_derive_workon_home:30> echo /home/trki/.virtualenvs +virtualenvwrapper_derive_workon_home:31> return 0 +virtualenvwrapper_initialize:1> export 'WORKON_HOME=/home/trki/.virtualenvs' +virtualenvwrapper_initialize:3> virtualenvwrapper_verify_workon_home -q +virtualenvwrapper_verify_workon_home:1> RC=0 +virtualenvwrapper_verify_workon_home:2> [ ! -d /home/trki/.virtualenvs/ ']' +virtualenvwrapper_verify_workon_home:11> return 0 +virtualenvwrapper_initialize:6> [ /home/trki/.virtualenvs '=' '' ']' +virtualenvwrapper_initialize:11> virtualenvwrapper_run_hook initialize +virtualenvwrapper_run_hook:1> typeset hook_script +virtualenvwrapper_run_hook:2> typeset result +virtualenvwrapper_run_hook:4> hook_script=+virtualenvwrapper_run_hook:4> virtualenvwrapper_tempfile initialize-hook +virtualenvwrapper_tempfile:2> typeset 'suffix=initialize-hook' +virtualenvwrapper_tempfile:3> typeset file +virtualenvwrapper_tempfile:5> file=+virtualenvwrapper_tempfile:5> virtualenvwrapper_mktemp -t virtualenvwrapper-initialize-hook-XXXXXXXXXX +virtualenvwrapper_mktemp:1> mktemp -t virtualenvwrapper-initialize-hook-XXXXXXXXXX +virtualenvwrapper_tempfile:5> file=/tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 +virtualenvwrapper_tempfile:6> [ 0 -ne 0 ']' +virtualenvwrapper_tempfile:6> [ -z /tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 ']' +virtualenvwrapper_tempfile:6> [ ! -f /tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 ']' +virtualenvwrapper_tempfile:11> echo /tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 +virtualenvwrapper_tempfile:12> return 0 +virtualenvwrapper_run_hook:4> hook_script=/tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 +virtualenvwrapper_run_hook:11> cd /home/trki/.virtualenvs +cd:1> [[ x/home/trki/.virtualenvs == x... ]] +cd:3> [[ x/home/trki/.virtualenvs == x.... ]] +cd:5> [[ x/home/trki/.virtualenvs == x..... ]] +cd:7> [[ x/home/trki/.virtualenvs == x...... ]] +cd:9> [ -d /home/trki/.autoenv ']' +cd:13> cd /home/trki/.virtualenvs +virtualenvwrapper_run_hook:12> '' -m virtualenvwrapper.hook_loader --script /tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 initialize virtualenvwrapper_run_hook:12: permission denied: +virtualenvwrapper_run_hook:15> result=126 +virtualenvwrapper_run_hook:17> [ 126 -eq 0 ']' +virtualenvwrapper_run_hook:27> [ initialize '=' initialize ']' +virtualenvwrapper_run_hook:29> cat - virtualenvwrapper.sh: There was a problem running the initialization hooks. If Python could not import the module virtualenvwrapper.hook_loader, check that virtualenv has been installed for VIRTUALENVWRAPPER_PYTHON= and that PATH is set properly. +virtualenvwrapper_run_hook:38> rm -f /tmp/virtualenvwrapper-initialize-hook-OhY86PXmo7 +virtualenvwrapper_run_hook:39> return 126 +virtualenvwrapper_initialize:13> virtualenvwrapper_setup_tab_completion +virtualenvwrapper_setup_tab_completion:1> [ -n '' ']' +virtualenvwrapper_setup_tab_completion:20> [ -n 4.3.17 ']' +virtualenvwrapper_setup_tab_completion:30> compctl -K _virtualenvs workon rmvirtualenv cpvirtualenv showvirtualenv +virtualenvwrapper_setup_tab_completion:31> compctl -K _cdvirtualenv_complete cdvirtualenv +virtualenvwrapper_setup_tab_completion:32> compctl -K _cdsitepackages_complete cdsitepackages +virtualenvwrapper_initialize:15> return 0 +/home/trki/.zshrc:17> plugins=( git python django symfony2 zsh-syntax-highlighting composer history-substring-search virtualenvwrapper ) # pythonbrew [[ -s ~/.pythonbrew/etc/bashrc ]] && source ~/.pythonbrew/etc/bashrc +/home/trki/.zshrc:21> [[ -s /home/trki/.pythonbrew/etc/bashrc ]] Also when i try to open ubuntu software center absolutly nothing happens. No idea what to do now.

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• Develop DBA skills with MySQL for Database Administrators course

  - by Antoinette O'Sullivan

  MySQL is the world's number one open source database and the number one database for the Web. Join top companies by developing your MySQL Database Administrator skills. The MySQL for Database Administrators course is for DBAs and other database professionals who want to install the MySQL Server, set up replication and security, perform database backups and performance tuning, and protect MySQL databases. You can take this 5 day course as Training on Demand: Start training within 24 hours of registration. You will follow the lecture material via streaming video and perform hands-on activities at a date and time that suits you. Live-Virtual Event:  Take this instructor-led course from your own desk. Choose from the 19 events currently on the schedule and find an event that suits you in terms of timezone and date. In-Class Event: Travel to an education center. Here is a sample of events on the schedule:    Location  Date  Delivery Language  Mechelen, Belgium  25 February 2013  English  London, England  26 November 2012  English  Nice, France  3 December 2012  French  Paris, France  11 February 2013  French  Budapest, Hungary  26 November 2012  Hungarian  Belfast, Ireland  24 June 2013  English  Milan, Italy  14 January 2013  Japanese  Rome, Italy  18 February 2013  Japanese  Amsterdam, Netherlands  24 June 2013  Dutch  Nieuwegein, Netherlands  8 April 2013  Dutch  Warsaw, Poland  10 December 2012  Polish  Lisbon, Portugal  21 January 2013  European Portugese  Porto, Portugal  21 January 2013  European Portugese  Barcelona, Spain  4 February 2013  Spanish  Madrid, Spain  21 January 2013  Spanish  Nairobi, Kenya  26 November 2012  English  Johannesburg, South Africa  9 December 2013  English  Tokyo, Japan  10 December 2012  Japanese  Singapore  28 January 2013  English  Brisbane, Australia  10 December 2012  English  Edmonton, Canada  7 January 2013  English  Montreal, Canada  28 January 2013  English  Ottawa, Canada  28 January 2013  English  Toronto, Canada  28 January 2013  English  Vancouver, Canada  7 January 2013  English  Mexico City, Mexico  10 December 2012  Spanish  Sao Paolo, Brazil  10 December 2012  Brazilian Portugese For more information on this course or on other courses on the authentic MySQL Curriculum, go to http://oracle.com/education/mysql. Note, many organizations deploy both Oracle Database and MySQL side by side to serve different needs, and as a database professional you can find training courses on both topics at Oracle University! Check out the upcoming Oracle Database training courses and MySQL training courses. Even if you're only managing Oracle Databases at this point of time, getting familiar with MySQL will broaden your career path with growing job demand.

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• Optimizing AES modes on Solaris for Intel Westmere

  - by danx

  Optimizing AES modes on Solaris for Intel Westmere Review AES is a strong method of symmetric (secret-key) encryption. It is a U.S. FIPS-approved cryptographic algorithm (FIPS 197) that operates on 16-byte blocks. AES has been available since 2001 and is widely used. However, AES by itself has a weakness. AES encryption isn't usually used by itself because identical blocks of plaintext are always encrypted into identical blocks of ciphertext. This encryption can be easily attacked with "dictionaries" of common blocks of text and allows one to more-easily discern the content of the unknown cryptotext. This mode of encryption is called "Electronic Code Book" (ECB), because one in theory can keep a "code book" of all known cryptotext and plaintext results to cipher and decipher AES. In practice, a complete "code book" is not practical, even in electronic form, but large dictionaries of common plaintext blocks is still possible. Here's a diagram of encrypting input data using AES ECB mode: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ AESKey-->(AES Encryption) AESKey-->(AES Encryption) | | | | \/ \/ CipherTextOutput CipherTextOutput Block 1 Block 2 What's the solution to the same cleartext input producing the same ciphertext output? The solution is to further process the encrypted or decrypted text in such a way that the same text produces different output. This usually involves an Initialization Vector (IV) and XORing the decrypted or encrypted text. As an example, I'll illustrate CBC mode encryption: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ IV >----->(XOR) +------------->(XOR) +---> . . . . | | | | | | | | \/ | \/ | AESKey-->(AES Encryption) | AESKey-->(AES Encryption) | | | | | | | | | \/ | \/ | CipherTextOutput ------+ CipherTextOutput -------+ Block 1 Block 2 The steps for CBC encryption are: Start with a 16-byte Initialization Vector (IV), choosen randomly. XOR the IV with the first block of input plaintext Encrypt the result with AES using a user-provided key. The result is the first 16-bytes of output cryptotext. Use the cryptotext (instead of the IV) of the previous block to XOR with the next input block of plaintext Another mode besides CBC is Counter Mode (CTR). As with CBC mode, it also starts with a 16-byte IV. However, for subsequent blocks, the IV is just incremented by one. Also, the IV ix XORed with the AES encryption result (not the plain text input). Here's an illustration: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ AESKey-->(AES Encryption) AESKey-->(AES Encryption) | | | | \/ \/ IV >----->(XOR) IV + 1 >---->(XOR) IV + 2 ---> . . . . | | | | \/ \/ CipherTextOutput CipherTextOutput Block 1 Block 2 Optimization Which of these modes can be parallelized? ECB encryption/decryption can be parallelized because it does more than plain AES encryption and decryption, as mentioned above. CBC encryption can't be parallelized because it depends on the output of the previous block. However, CBC decryption can be parallelized because all the encrypted blocks are known at the beginning. CTR encryption and decryption can be parallelized because the input to each block is known--it's just the IV incremented by one for each subsequent block. So, in summary, for ECB, CBC, and CTR modes, encryption and decryption can be parallelized with the exception of CBC encryption. How do we parallelize encryption? By interleaving. Usually when reading and writing data there are pipeline "stalls" (idle processor cycles) that result from waiting for memory to be loaded or stored to or from CPU registers. Since the software is written to encrypt/decrypt the next data block where pipeline stalls usually occurs, we can avoid stalls and crypt with fewer cycles. This software processes 4 blocks at a time, which ensures virtually no waiting ("stalling") for reading or writing data in memory. Other Optimizations Besides interleaving, other optimizations performed are Loading the entire key schedule into the 128-bit %xmm registers. This is done once for per 4-block of data (since 4 blocks of data is processed, when present). The following is loaded: the entire "key schedule" (user input key preprocessed for encryption and decryption). This takes 11, 13, or 15 registers, for AES-128, AES-192, and AES-256, respectively The input data is loaded into another %xmm register The same register contains the output result after encrypting/decrypting Using SSSE 4 instructions (AESNI). Besides the aesenc, aesenclast, aesdec, aesdeclast, aeskeygenassist, and aesimc AESNI instructions, Intel has several other instructions that operate on the 128-bit %xmm registers. Some common instructions for encryption are: pxor exclusive or (very useful), movdqu load/store a %xmm register from/to memory, pshufb shuffle bytes for byte swapping, pclmulqdq carry-less multiply for GCM mode Combining AES encryption/decryption with CBC or CTR modes processing. Instead of loading input data twice (once for AES encryption/decryption, and again for modes (CTR or CBC, for example) processing, the input data is loaded once as both AES and modes operations occur at in the same function Performance Everyone likes pretty color charts, so here they are. I ran these on Solaris 11 running on a Piketon Platform system with a 4-core Intel Clarkdale processor @3.20GHz. Clarkdale which is part of the Westmere processor architecture family. The "before" case is Solaris 11, unmodified. Keep in mind that the "before" case already has been optimized with hand-coded Intel AESNI assembly. The "after" case has combined AES-NI and mode instructions, interleaved 4 blocks at-a-time. « For the first table, lower is better (milliseconds). The first table shows the performance improvement using the Solaris encrypt(1) and decrypt(1) CLI commands. I encrypted and decrypted a 1/2 GByte file on /tmp (swap tmpfs). Encryption improved by about 40% and decryption improved by about 80%. AES-128 is slighty faster than AES-256, as expected. The second table shows more detail timings for CBC, CTR, and ECB modes for the 3 AES key sizes and different data lengths. » The results shown are the percentage improvement as shown by an internal PKCS#11 microbenchmark. And keep in mind the previous baseline code already had optimized AESNI assembly! The keysize (AES-128, 192, or 256) makes little difference in relative percentage improvement (although, of course, AES-128 is faster than AES-256). Larger data sizes show better improvement than 128-byte data. Availability This software is in Solaris 11 FCS. It is available in the 64-bit libcrypto library and the "aes" Solaris kernel module. You must be running hardware that supports AESNI (for example, Intel Westmere and Sandy Bridge, microprocessor architectures). The easiest way to determine if AES-NI is available is with the isainfo(1) command. For example, $ isainfo -v 64-bit amd64 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu 32-bit i386 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov sep cx8 tsc fpu No special configuration or setup is needed to take advantage of this software. Solaris libraries and kernel automatically determine if it's running on AESNI-capable machines and execute the correctly-tuned software for the current microprocessor. Summary Maximum throughput of AES cipher modes can be achieved by combining AES encryption with modes processing, interleaving encryption of 4 blocks at a time, and using Intel's wide 128-bit %xmm registers and instructions. References "Block cipher modes of operation", Wikipedia Good overview of AES modes (ECB, CBC, CTR, etc.) "Advanced Encryption Standard", Wikipedia "Current Modes" describes NIST-approved block cipher modes (ECB,CBC, CFB, OFB, CCM, GCM)

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• Unable to install Inkscape on ubuntu 14.02

  - by Anum Khan

  Hi I am new to Linux Ubuntu 14.04. I wanted to install Inkscape but it has shown following error(Dependencies as it says): inkscape: Depends: python:any (>= 2.7.1-0ubuntu2) but it is a virtual package Depends: libaspell15 (>= 0.60.7~20110707) but 0.60.7~20110707-1ubuntu1 is to be installed Depends: libatkmm-1.6-1 (>= 2.22.1) but 2.22.7-2ubuntu1 is to be installed Depends: libc6 (>= 2.7) but 2.19-0ubuntu6.1 is to be installed Depends: libcairo2 (>= 1.10.0) but 1.13.0~20140204-0ubuntu1 is to be installed Depends: libcairomm-1.0-1 (>= 1.6.4) but 1.10.0-1ubuntu3 is to be installed Depends: libfontconfig1 (>= 2.9.0) but 2.11.0-0ubuntu4.1 is to be installed Depends: libfreetype6 (>= 2.2.1) but 2.5.2-1ubuntu2.2 is to be installed Depends: libgc1c2 (>= 1:7.2d) but 1:7.2d-5ubuntu2 is to be installed Depends: libgcc1 (>= 1:4.1.1) but 1:4.9-20140406-0ubuntu1 is to be installed Depends: libgdk-pixbuf2.0-0 (>= 2.22.0) but 2.30.7-0ubuntu1 is to be installed Depends: libglib2.0-0 (>= 2.35.9) but 2.40.0-2 is to be installed Depends: libglibmm-2.4-1c2a (>= 2.36.2) but 2.39.93-0ubuntu1 is to be installed Depends: libgnomevfs2-0 (>= 1:2.17.90) but it is not going to be installed Depends: libgomp1 (>= 4.2.1) but 4.8.2-19ubuntu1 is to be installed Depends: libgsl0ldbl (>= 1.9) but it is not going to be installed Depends: libgtk2.0-0 (>= 2.24.0) but 2.24.23-0ubuntu1.1 is to be installed Depends: libgtkmm-2.4-1c2a (>= 1:2.24.0) but 1:2.24.4-1ubuntu1 is to be installed Depends: libgtkspell0 (>= 2.0.10) but it is not going to be installed Depends: liblcms2-2 (>= 2.2+git20110628) but 2.5-0ubuntu4 is to be installed Depends: libmagick++5 (>= 8:6.7.7.10) but it is not going to be installed Depends: libpango-1.0-0 (>= 1.14.0) but 1.36.3-1ubuntu1 is to be installed Depends: libpangocairo-1.0-0 (>= 1.14.0) but 1.36.3-1ubuntu1 is to be installed Depends: libpangoft2-1.0-0 (>= 1.14.0) but 1.36.3-1ubuntu1 is to be installed Depends: libpangomm-1.4-1 (>= 2.27.1) but 2.34.0-1ubuntu1 is to be installed Depends: libpng12-0 (>= 1.2.13-4) but 1.2.50-1ubuntu2 is to be installed Depends: libpopt0 (>= 1.14) but 1.16-8ubuntu1 is to be installed Depends: libsigc++-2.0-0c2a (>= 2.0.2) but 2.2.10-0.2ubuntu2 is to be installed Depends: libstdc++6 (>= 4.6) but 4.8.2-19ubuntu1 is to be installed Depends: libxml2 (>= 2.7.4) but 2.9.1+dfsg1-3ubuntu4.3 is to be installed Depends: libxslt1.1 (>= 1.1.25) but 1.1.28-2build1 is to be installed Depends: zlib1g (>= 1:1.1.4) but 1:1.2.8.dfsg-1ubuntu1 is to be installed What am I missing?

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• My Package Version Number Appears Greater Yet apt-get Doesn't Select It

  - by nutznboltz

  Backstory: It was determined that when using lxc container VMs the Nagios nrpe shutdown script when run on the host of the containers would kill the nrpe processes inside the containers. This was remediated by changing the script to use pidfiles instead of searching the process table for the nrpe process. Regrettably start-stop-daemon is a C program that resulted from translating a Perl script and it shows. There are far too many global varibles in start-stop-daemon.c and although there are some nice blocks of comments there are far to few comments that explain the intent behind variable names such as "schedule" (the string "schedule" appears in many contexts.) The manual page for start-stop-daemon strongly suggests that unless you use the "--retry" option the start-stop-daemon program may return before the process it sent a signal to actually calls exit() and terminates, however it doesn't actually state this in plain English. The obtuseness of start-stop-daemon is most likely the reason that the "fixed" version of the script includes a dubious comment indicating that sometimes the pid file has not been removed. I can easily see why someone would not understand that he left the --retry option missing. This bug also causes failures when the script is given the "restart" option; the nrpe daemon will shutdown but not start up again. Did I mention that since applying the update our nrpe servers started crashing over and over? Repairing this is why I am doing this work. I have been working on remediating the fix. You can see my current work in this PPA. Actual Question: The upstream version number of nagios-nrpe-server in lucid-updates is 2.12-4ubuntu1.10.04.1 My PPA uses this version number 2.12-4ubuntu1.10.04.1.1~ppa1~lucid1 I check the rules here and use this test program and I am lead to believe that the version number I use in my PPA is greater than the one in lucid-updates yet when I ran: sudo add-apt-repository ppa:nutznboltz/nrpe-unbreak-lp-600941 sudo apt-get update sudo aptitiude dist-upgrade The replacement package was not installed. I was able to install it using sudo aptitude install nagios-nrpe-server=2.12-4ubuntu1.10.04.1.1~ppa1~lucid1 Can anyone explain this behavior? Why didn't my version number appear greater to "aptitude dist-upgrade"? Thanks $ cat /etc/apt/preferences Package: * Pin: release a=lucid-backports Pin-Priority: 400 Package: * Pin: release a=lucid-security Pin-Priority: 990 Package: * Pin: release a=lucid-updates Pin-Priority: 900 Package: * Pin: release a=lucid-proposed Pin-Priority: 400 $ ls /etc/apt/preferences.d/ $ Should not make any difference as a PPA cannot be in any of those pockets. I went ahead and bumped the version number in the PPA to 2.12-4ubuntu1.10.04.2~ppa1~lucid1. I'll see if that makes a difference. I do notice that lintian complains: W: nagios-nrpe-server: debian-revision-not-well-formed 2.12-4ubuntu1.10.04.2~ppa1~lucid1

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• Tap into MySQL's Amazing Performance Results with the Performance Tuning Course

  - by Antoinette O'Sullivan

  Want to leverage the high-speed load utilities, distinctive memory caches, full text indexes, and other performance-enhancing mechanisms that MySQL offers to fuel today's critical business systems. The authentic MySQL Performance Tuning course, in 4 days, teaches you to evaluate the MySQL architecture, learn to use the tools, configure the database for performance, tune application and SQL code, tune the server, examine the storage engines, assess the application architecture, and learn general tuning concepts. You can take this course in one the following three ways: Training-on-Demand: Access the streaming video, instructor delivery of this course from your own desk, at your own pace. Book time for hands-on practice when it suits you. Live-Virtual Class: Take this instructor-led class live from your own desk. With 700 events on the schedule you are sure to find a time and date to suit you! In-Class: Travel to a classroom to take this class. A sample of events on the schedule are as follows.  Location  Date  Delivery Language  Hamburg, Germany  22 October 2012  German  Prague, Czech Republic  1 October 2012  Czech  Warsaw, Poland  3 December 2012  Polish  London, England  19 November 2012  English  Rome, Italy  23 October 2012  Italian Lisbon, Portugal  6 November 2012  European Portugese  Aix en Provence, France  4 September 2012   French  Strasbourg, France 16 October 2012   French  Nieuwegein, Netherlands 26 November 2012   Dutch  Madrid, Spain 17 December 2012   Spanish  Mechelen, Belgium  1 October 2012  English  Riga, Latvia  10 December 2012  Latvian  Petaling Jaya, Malaysia  10 September 2012 English   Edmonton, Canada 10 December 2012   English  Vancouver, Canada 10 December 2012   English  Ottawa, Canada 26 November 2012   English  Toronto, Canada 26 November 2012   English  Montreal, Canada 26 November 2012   English  Mexico City, Mexico 10 September 2012   Spanish  Sao Paolo, Brazil 26 November 2012  Brazilian Portugese   Tokyo, Japan 19 November 2012   Japanese  Tokyo, Japan  19 November 2012  Japanese For further information on this class, or to register your interest in additional events, go to the Oracle University Portal: http://oracle.com/education/mysql

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