Search Results

Search found 4125 results on 165 pages for 'hash cluster'.

Page 125/165 | < Previous Page | 121 122 123 124 125 126 127 128 129 130 131 132  | Next Page >

• Automatic counter in Ruby for each?

  - by yar

  I know you Ruby people will laugh at my bad Ruby code: i=0 for blah in blahs puts i.to_s + " " + blah i+=1 end I want to use a for-each and a counter... is there a better way to do it? Note: I don't know if blahs is an array or a hash, but having to do blahs[i] wouldn't make it much sexier. Also I'd like to know how to write i++ in Ruby. Edit: Technically, Matt's and Squeegy's answer came in first, but I'm giving best answer to paradoja so spread around the points a bit on SO. Also his answer had the note about versions, which is still relevant (as long as my Ubuntu 8.04 is using Ruby 1.8.6). Edit: Should've used puts "#{i} #{blah}" which is a lot more succinct.

  Read the article

• Identify cause of hundreds of AJP threads in Tomcat

  - by Rich

  We have two Tomcat 6.0.20 servers fronted by Apache, with communication between the two using AJP. Tomcat in turn consumes web services on a JBoss cluster. This morning, one of the Tomcat machines was using 100% of CPU on 6 of the 8 cores on our machine. We took a heap dump using JConsole, and then tried to connect JVisualVM to get a profile to see what was taking all the CPU, but this caused Tomcat to crash. At least we had the heap dump! I have loaded the heap dump into Eclipse MAT, where I have found that we have 565 instances of java.lang.Thread. Some of these, obviously, are entirely legitimate, but the vast majority are named "ajp-6009-XXX" where XXX is a number. I know my way around Eclipse MAT pretty well, but haven't been able to find an explanation for it. If anyone has some pointers as to why Tomcat may be doing this, or some hints on finding out why using Eclipse MAT, that'd be appreciated!

  Read the article

• How to walk through two files simultaneously in Perl?

  - by Alex Reynolds

  I have two text files that contain columnar data of the variety position-value. Here is an example of the first file (file A): 100 1 101 1 102 0 103 2 104 1 ... Here is an example of the second file (B): 20 0 21 0 ... 100 2 101 1 192 3 193 1 ... Instead of reading one of the two files into a hash table, which is prohibitive due to memory constraints, what I would like to do is walk through two files simultaneously, in a stepwise fashion. What this means is that I would like to stream through lines of either A or B and compare position values. If the two positions are equal, then I perform a calculation on the values associated with that position. Otherwise, if the positions are not equal, I move through lines of file A or file B until the positions are equal (when I again perform my calculation) or I reach EOF of both files. Is there a way to do this in Perl?

  Read the article

• How do I handle a missing mandatory argument in Ruby OptionParser?

  - by Rob Jones

  In OptionParser I can make an option mandatory, but if I leave out that value it will take the name of any following option as the value, screwing up the rest of the command line parsing. Here is a test case that echoes the values of the options: $ ./test_case.rb --input foo --output bar output bar input foo Now leave out the value for the first option: $ ./test_case.rb --input --output bar input --output Is there some way to prevent it taking another option name as a value? Thanks! Here is the test case code: #!/usr/bin/env ruby require 'optparse' files = Hash.new option_parser = OptionParser.new do |opts| opts.on('-i', '--input FILENAME', 'Input filename - required') do |filename| files[:input] = filename end opts.on('-o', '--output FILENAME', 'Output filename - required') do |filename| files[:output] = filename end end begin option_parser.parse!(ARGV) rescue OptionParser::ParseError $stderr.print "Error: " + $! + "\n" exit end files.keys.each do |key| print "#{key} #{files[key]}\n" end

  Read the article

• Does it take time to deallocate memory?

  - by jm1234567890

  I have a C++ program which, during execution, will allocate about 3-8Gb of memory to store a hash table (I use tr1/unordered_map) and various other data structures. However, at the end of execution, there will be a long pause before returning to shell. For example, at the very end of my main function I have std::cout << "End of execution" << endl; But the execution of my program will go something like $ ./program do stuff... End of execution [long pause of maybe 2 min] $ -- returns to shell Is this expected behavior or am I doing something wrong? I'm guessing that the program is deallocating the memory at the end. But, commercial applications which use large amounts of memory (such as photoshop) do not exhibit this pause when you close the application. Please advise :)

  Read the article

• What is the most efficient Java Collections library?

  - by dehmann

  What is the most efficient Java Collections library? A few years ago, I did a lot of Java and had the impression back then that trove is the best (most efficient) Java Collections implementation. But when I read the answers to the question "Most useful free Java libraries?" I noticed that trove is hardly mentioned. So which Java Collections library is best now? UPDATE: To clarify, I mostly want to know what library to use when I have to store millions of entries in a hash table etc. (need a small runtime and memory footprint).

  Read the article

• [java] Efficiency of while(true) ServerSocket Listen

  - by Submerged

  I am wondering if a typical while(true) ServerSocket listen loop takes an entire core to wait and accept a client connection (Even when implementing runnable and using Thread .start()) I am implementing a type of distributed computing cluster and each computer needs every core it has for computation. A Master node needs to communicate with these computers (invoking static methods that modify the algorithm's functioning). The reason I need to use sockets is due to the cross platform / cross language capabilities. In some cases, PHP will be invoking these java static methods. I used a java profiler (YourKit) and I can see my running ServerSocket listen thread and it never sleeps and it's always running. Is there a better approach to do what I want? Or, will the performance hit be negligible? Please, feel free to offer any suggestion if you can think of a better way (I've tried RMI, but it isn't supported cross-language. Thanks everyone

  Read the article

• Filesystem synchronization library?

  - by IsaacB

  Hi, I've got 10 GB of files to back up daily to another site. The client is way out in the country so bandwidth is an issue. Does anyone know of any existing software or libraries out there that help with keeping a folder with its files synchronized across a slow link, that is it only sends files across if they have changed? Some kind of hash checking would be nice, too, to at least confirm the two sides are the same. I don't mind paying some money for it, seeing as how it might take me several weeks to a month to implement something decent on my own. I just don't want to re-invent the wheel, here. BTW it is a windows shop (they have an in house windows IT guy) so windows is preferred. I also have 10 GB of SQL Server 2000 databases to go across. Is the SQL server replication mode reliable? Thanks!

  Read the article

• Is there any simple way to test two PNGs for equality?

  - by Mason Wheeler

  I've got a bunch of PNG images, and I'm looking for a way to identify duplicates. By duplicates I mean, specifically, two PNG files whose uncompressed image data are identical, not necessarily whose files are identical. This means I can't do something simple like compare CRC hash values. I figure this can actually be done reliably since PNGs use lossless compression, but I'm worried about speed. I know I can winnow things down a little by testing for equal dimensions first, but when it comes time to actually compare the images against each other, is there any way to do it reasonably efficiently? (ie. faster than the "double-for-loop checking pixel values against each other" brute-force method?)

  Read the article

• MAD method compression function

  - by Jacques

  I ran across the question below in an old exam. My answers just feels a bit short and inadequate. Any extra ideas I can look into or reasons I have overlooked would be great. Thanx Consider the MAD method compression function, mapping an object with hash code i to element [(3i + 7)mod9027]mod6000 of the 6000-element bucket array. Explain why this is a poor choice of compression function, and how it could be improved. I basically just say that the function could be improved by changing the value for p (or 9027) to an prime number and choosing an other constant for a (or 3) could also help.

  Read the article

• What does the "ApplicaionDirectory" Membership condition mean in .NET Code Access Security?

  - by smwikipedia

  I am not sure about the semantic of "ApplicationDirectory" membership condition. I am trying to use it in the .NET Framework 2.0 configuration tool. The tool's explanation to it is as below: The Application Directory membership condition is true for all assemblies in the same directory or in a child directory of the running application. Assemblies that meet this membership condition will be granted the permissions associated with this code group. All the other membership conditions such as strong name, hash, need me to input some criterias, only the Application Directory has not. How to use it? Could someone give an explanation by example? Many thanks.

  Read the article

• What are some best practises and "rules of thumb" for creating database indexes?

  - by Ash

  I have an app, which cycles through a huge number of records in a database table and performs a number of SQL and .Net operations on records within that database (currently I am using Castle.ActiveRecord on PostgreSQL). I added some basic btree indexes on a couple of the feilds, and as you would expect, the peformance of the SQL operations increased substantially. Wanting to make the most of dbms performance I want to make some better educated choices about what I should index on all my projects. I understand that there is a detrement to performance when doing inserts (as the database needs to update the index, as well as the data), but what suggestions and best practices should I consider with creating database indexes? How do I best select the feilds/combination of fields for a set of database indexes (rules of thumb)? Also, how do I best select which index to use as a clustered index? And when it comes to the access method, under what conditions should I use a btree over a hash or a gist or a gin (what are they anyway?).

  Read the article

• Confused by Perl grep function

  - by titaniumdecoy

  I don't understand the last line of this function from Programming Perl 3e. Here's how you might write a function that does a kind of set intersection by returning a list of keys occurring in all the hashes passed to it: @common = inter( \%foo, \%bar, \%joe ); sub inter { my %seen; for my $href (@_) { while (my $k = each %$href) { $seen{$k}++; } } return grep { $seen{$_} == @_ } keys %seen; } I understand that %seen is a hash which maps each key to the number of times it was encountered in any of the hashes provided to the function.

  Read the article

• Prototype.js: How can i return an array without all the methods Prototypes extends Array with?

  - by Morten

  Hi! Is there a way to return a new version of an array/hash that does not contain all the methods/functions that prototype extends the array object with? Example: var myArray = $A(); myArray['test'] = '1'; myArray['test2'] = '2'; var myVariableToPassToAjax = myArray; If I debug myVariableToPassToAjax it looks like this: Array ( [test] = 1 [test2] = 2 [each] = function each(iterator, context) { .......... .......... } ...and all the other extended array functions ); Is there a way to solve this? :-/ Morten

  Read the article

• Perl XML::Simple XMLout function

  - by Jeremey

  I pass in the following XML to XMLin: <root foo="bar" foo2="bar2"> <pizzas> <pizza>Pepperoni</pizza> </pizzas> </root> I then edit part of the root element via hash array. I don't care about the pizza, but i do need that XML to come back out exactly as it was. However, I get the following from XMLout: <root foo="bar" foo2="bar2"> <pizzas pizza="Pepperoni"</pizzas> </root> Thoughts?

  Read the article

• Server authorization with MD5 and SQL.

  - by Charles

  I currently have a SQL database of passwords stored in MD5. The server needs to generate a unique key, then sends to the client. In the client, it will use the key as a salt then hash together with the password and send back to the server. The only problem is that the the SQL DB has the passwords in MD5 already. Therefore for this to work, I would have to MD5 the password client side, then MD5 it again with the salt. Am I doing this wrong, because it doesn't seem like a proper solution. Any information is appreciated.

  Read the article

• NLB and Host Header Value

  - by Hafeez

  Background: We are using MOSS 2007 in farm configuration, 2 WFE, 1 Indexer and SQL Server. MS NLB is used for load balancing. Host header value mapped to Virtual IP of Cluster in DNS, is used while creating the web applications in MOSS and all are sharing port 80. Problem: When client tries to access the web application that are configured with host header values. Both of WFEs Hangs for 5 minutes, they stop responding to ping and browser shows 'Page not found'. In the Application Log on the WFE, this error is registered "provider: TCP Provider, error: 0 - The semaphore timeout period has expired". Interestingly, the web application with no host header value and hosted on different ports is working correctly. Any clue to solve this problem will be helpful. Thks. Hafeez

  Read the article

• Out of memory error while using clusterdata in MATLAB

  - by Hossein

  Hi, I am trying to cluster a Matrix (size: 20057x2).: T = clusterdata(X,cutoff); but I get this error: ??? Error using == pdistmex Out of memory. Type HELP MEMORY for your options. Error in == pdist at 211 Y = pdistmex(X',dist,additionalArg); Error in == linkage at 139 Z = linkagemex(Y,method,pdistArg); Error in == clusterdata at 88 Z = linkage(X,linkageargs{1},pdistargs); Error in == kmeansTest at 2 T = clusterdata(X,1); can someone help me. I have 4GB of ram, but think that the problem is from somewhere else..

  Read the article

• What's the best general programming book to review basic development concepts?

  - by Charles S.

  I'm looking for for a programming book that reviews basic concepts like implementing linked lists, stacks, queues, hash tables, tree traversals, search algorithms, etc. etc. Basically, I'm looking for a review of everything I learned in college but have forgotten. I prefer something written in the last few years that includes at least a decent amount of code in object-oriented languages. This is to study for job interview questions but I already have the "solving interview questions" books. I'm looking for something with a little more depth and explanation. Any good recommendations?

  Read the article

• Complex queries using Rails query language

  - by Daniel Johnson

  I have a query used for statistical purposes. It breaks down the number of users that have logged-in a given number of times. User has_many installations and installation has a login_count. select total_login as 'logins', count(*) as `users` from (select u.user_id, sum(login_count) as total_login from user u inner join installation i on u.user_id = i.user_id group by u.user_id) g group by total_login; +--------+-------+ | logins | users | +--------+-------+ | 2 | 3 | | 6 | 7 | | 10 | 2 | | 19 | 1 | +--------+-------+ Is there some elegant ActiveRecord style find to obtain this same information? Ideally as a hash collection of logins and users: { 2=>3, 6=>7, ... I know I can use sql directly but wanted to know how this could be solved in rails 3.

  Read the article

• Rails: translations for table's column.

  - by Andrew

  In rails application I have two models: Food and Drink. Both food and drink have a name, which has to be stored in two languages. How do I better realize translations for theese tables? First solution I realized was to replace name column with name_en and name_ru. Another solution is to encode with YAML hash like { :en => 'eng', :ru => 'rus' } and store yaml as a name. What would you recommend, assuming content is not static? Maybe there's good article?

  Read the article

• Hadoop on windows server

  - by Luca Martinetti

  Hello, I'm thinking about using hadoop to process large text files on my existing windows 2003 servers (about 10 quad core machines with 16gb of RAM) The questions are: Is there any good tutorial on how to configure an hadoop cluster on windows? What are the requirements? java + cygwin + sshd ? Anything else? HDFS, does it play nice on windows? I'd like to use hadoop in streaming mode. Any advice, tool or trick to develop my own mapper / reducers in c#? What do you use for submitting and monitoring the jobs? Thanks

  Read the article

• OpenID and Authlogic - login and password?

  - by skrat

  How can I get rid of validation messages telling me that: Login is too short (minimum is 3 characters) Login should use only letters, numbers, spaces, and .-_@ please. Password is too short (minimum is 4 characters) Password confirmation is too short (minimum is 4 characters) this happens even before map_openid_registration is called, thus not giving me any chance to fill login with something from returned registration Hash. I would like to have OpenID auto-registration (on login) without requiring user to supply login/password. I also won't make this fields "not required" or "not validated", since I still need them with old school login/password registration. Thank you

  Read the article

• MYSQL KEY-VALUE PAIR Viability

  - by Amit

  Hi, I am new to mysql and I am looking for some answers to the follwoing questions: a) Can mysql community server can be leveraged for a key-value pair type database.?? b) Which mysql engine is best suited for a key-value pair type database ?? c) Is Mysql cluster a must for horizontal scaling of key-value based datastore or can it be acheived using MySQL replication?? d) Are there any docs or whitepapers for best practices when implementiing a kv datastore on mysql?? e) Are there any known big implementations other that friendfeed doing kv pair using MYSQL?? Would really appreciate some advise from all you Mysql gurus out there !! Thanks In Advance, Amit

  Read the article

• How to call a Thor task multiple times?

  - by deepak

  Thor like Rake (and Make) has task management. If I call a task multiple times, it will effectively call the task only once. How can I call a task multiple times? I tried modifying the @_invocations hash, but that did not work: require 'csv' require './config/environment' class MisReport < Thor desc "all", "generate mysql and postgres mis" def all generate("pg_mis_report", "pg") generate("mysql_mis_report", "mysql") end desc "generate", "generate mis report" def generate(file_name = "mis_report_#{Time.now.to_s(:number)}", connection = "postgres") if connection == "pg" puts "== postgres database" ActiveRecord::Base.establish_connection :development_mysql else puts "== mysql database" ActiveRecord::Base.establish_connection :development end # generate MIS puts puts "mis file is at: #{file_path}" end end

  Read the article

< Previous Page | 121 122 123 124 125 126 127 128 129 130 131 132  | Next Page >