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  • Reducing Dimension For SVM in Sensor Network

    - by iinception
    Hi Everyone, I am looking for some suggestions on a problem that I am currently facing. I have a set of sensor say S1-S100 which is triggered when some event E1-E20 is performed. Assume, normally E1 triggers S1-S20, E2 triggers S15-S30, E3 triggers S20-s50 etc and E1-E20 are completely independent events. Occasionally an event E might trigger any other unrelated sensor. I am using ensemble of 20 svm to analyze each event separately. My features are sensor frequency F1-F100, number of times each sensor is triggered and few other related features. I am looking for a technique that can reduce the dimensionality of the sensor feature(F1-F100)/ or some techniques that encompasses all of the sensor and reduces the dimension too(i was looking for some information theory concept for last few days) . I dont think averaging, maximization is a good idea as I risk loosing information(it did not give me good result). Can somebody please suggest what am I missing here? A paper or some starting idea... Thanks in advance.

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  • Analyzing an IronPython Scope

    - by Vercinegetorix
    I'm trying to write C# code with an embedded IronPython script. Then want to analyze the contents of the script, i.e. list all variables, functions, class and their members/methods. There's an easy way to start, assuming I've got a scope defined and code executed in it already: dynamic variables=pyScope.GetVariables(); foreach (string v in variables) { dynamic dynamicV=pyScope.GetVariable(); /*seems to return everything. variables, functions, classes, instances of classes*/ } But how do I figure out what the type of a variable is? For the following python 'objects', dynamicV.GetType() will return different values: x=5 --system.Int32 y="asdf" --system.String def func():... --IronPython.Runtime.PythonFunction z=class() -- IronPython.Runtime.Types.OldInstance, how can I identify what the actual python class is? class NewClass -- throws an error, GetType() is unavailable. This is almost what I'm looking for. I could capture the exception thrown when unavailable and assume it's a class declaration, but that seems unclean. Is there a better approach? To discover the members/methods of a class it looks like I can use: ObjectOperations op = pyEngine.Operations; object instance = op.Call("className"); foreach (string j in op.GetMemberNames("className")) { object member=op.GetMember(instance, j); Console.WriteLine(member.GetType()); /*once again, GetType() provides some info about the type of the member, but returns null sometimes*/ } Also, how do I get the parameters to a method? Thanks!

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  • Improve a regex statement in order to be as efficient as it can be

    - by user551625
    I have a PHP program that, at some point, needs to analyze a big amount of HTML+javascript text to parse info. All I want to parse needs to be in two parts. Seperate all "HTML goups" to parse Parse each HTML group to get the needed information. In the 1st parse it needs to find: <div id="myHome" And start capturing after that tag. Then stop capturing before <span id="nReaders" And capture the number that comes after this tag and stop. In the 2nd parse use the capture nº 1 (0 has the whole thing and 2 has the number) from the parse made before and then find . I already have code to do that and it works. Is there a way to improve this, make it easier for the machine to parse? preg_match_all('%<div id="myHome"[^>]>(.*?)<span id="nReaders[^>]>([0-9]+)<"%msi', $data, $results, PREG_SET_ORDER); foreach($results AS $result){ preg_match_all('%<div class="myplacement".*?[.]php[?]((?:next|before))=([0-9]+).*?<tbody.*?<td[^>]>.*?[0-9]+"%msi', $result[1], $mydata, PREG_SET_ORDER); //takes care of the data and finish the program Note: I need this for a freeware program so it must be as general as possible and, if possible, not use php extensions ADD: I ommitted some parts here because I didn't expect for answers like those. There is also a need to parse text inside one of the tags that is in the document. It may be the 6th 7th or 8th tag but I know it is after a certain tag. The parser I've checked (thx profitphp) does work to find the script tag. What now? There are more than 1 tag with the same class. I want them all. But I want only with also one of a list of classes..... Where can I find instructions and demos and limitations of DOM parsers (like the one in http://simplehtmldom.sourceforge.net/)? I need something that will work on, at least, a big amount of free servers.

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  • Why is there so much XML in Java these days?

    - by BD at Rivenhill
    This is really more of a philosophy/design issue. I did some work in Java back in the middle 90's and again in the early 2000's and now I'm coming back to it after spending a lot of time in C/C++ and it seems like there was an explosion of XML dependency while I was gone. Major build system tools like ant and maven depend on XML for their configuration, but I'm actually more concerned with all the frameworks, such as Spring, Hibernate, etc. My experience is that powerful supporting libraries like these are where a developer can really get leverage for building programs with lots of features without writing a lot of code, but it really seems like I'm getting one language for the price of two here. I write a bunch of Java classes, but then I also write a bunch of XML files to glue them together. The things that get done in the XML are things that I can see reasonable ways of doing in straight code without the middleman, and they don't really seem to be treated exactly like configuration files: they change rarely and they end up getting committed to source code control like the Java code itself, but they are distributed with the resulting application and need to be unpacked and installed in the classpath in order to get the application to work. I'm working with server applications that are not web-based, so maybe the domain is a bit different from what most people are doing, but I just can't help feeling that I must be doing something wrong here. Can someone point me to a good source of information for why these design choices were made and what problems they are meant to solve so that I can analyze my own experiences in this context?

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  • Gettingn Started with Facebook API

    - by Btibert3
    I have a friend that owns a small business and has a Page on Facebook. I want to help her manage it from a marketing perspective, and figure that it may be best to do so through their API. I have skimmed their API documentation, and have a basic working knowledge of Python. What I can't figure out is if I can access their page's data with Python and grab the data on wall posts, who liked posts, etc. Is this possible? I can't find a decent tutorial for someone who is new to programming. To provide context, I have been scraping the Twitter Search API for some time now and I am hoping there is something similar (request certain data elements, and have it returned as structured data I can analyze). I find their API extremely straight forward, and for Facebook, I don't know where to begin. I don't want to create an application, I simply want to access the data that is related to my friend's page. I am hoping to find some decent tutorials and help on what I will need to get started. Any help you can provide will be greatly appreciated.

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  • Using PHP Frameworks to get Web 2.0 or Ajax and Other Special Features

    - by user504958
    I'm still struggling to understand when or how to use a framework such as Zend or Yii. Here's some of the features I'm going to need on my next project and I don't understand frameworks well enough to know where the framework fits into the picture. I won't say exactly what the project is but think about something like Yelp or Merchant Circle, on a smaller scale of course - a directory project. It will contain a search box and links to all and/or popular categories. 1) Autosuggest in Search box. (I already know how to do this using jQuery) 2) Analyze the search terms entered into the search box to determine if they misspelled a word. Offer to correct the misspelling or automatically correct the word and show relevant results. 3) Offer items, links, or ads that are related to their search term. 4) Allow users to determine which fields are shown. 5) Allow users to sort the results however they choose. 6) Allow editing of records on a grid/list view. Post form without refreshing the page. Delete or Add records without going to a different page or reloading the current page.

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  • Efficient Multiplication of Varying-Length #s [Conceptual]

    - by Milan Patel
    Write the pseudocode of an algorithm that takes in two arbitrary length numbers (provided as strings), and computes the product of these numbers. Use an efficient procedure for multiplication of large numbers of arbitrary length. Analyze the efficiency of your algorithm. I decided to take the (semi) easy way out and use the Russian Peasant Algorithm. It works like this: a * b = a/2 * 2b if a is even a * b = (a-1)/2 * 2b + a if a is odd My pseudocode is: rpa(x, y){ if x is 1 return y if x is even return rpa(x/2, 2y) if x is odd return rpa((x-1)/2, 2y) + y } I have 3 questions: Is this efficient for arbitrary length numbers? I implemented it in C and tried varying length numbers. The run-time in was near-instant in all cases so it's hard to tell empirically... Can I apply the Master's Theorem to understand the complexity...? a = # subproblems in recursion = 1 (max 1 recursive call across all states) n / b = size of each subproblem = n / 1 - b = 1 (problem doesn't change size...?) f(n^d) = work done outside recursive calls = 1 - d = 0 (the addition when a is odd) a = 1, b^d = 1, a = b^d - complexity is in n^d*log(n) = log(n) this makes sense logically since we are halving the problem at each step, right? What might my professor mean by providing arbitrary length numbers "as strings". Why do that? Many thanks in advance

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  • Time gaps between host clEnqueue_xxx calls

    - by dialer
    Consider these OpenCL calls (3 memcpy DtoH, 4313 cl_float elements each): clEnqueueReadBuffer(CommandQueue, SpectrumAbsMem, CL_FALSE, 0, SpectrumMemSize, SpectrumAbs, 0, NULL, NULL); clEnqueueReadBuffer(CommandQueue, SpectrumReMem, CL_FALSE, 0, SpectrumMemSize, SpectrumRe, 0, NULL, NULL); clEnqueueReadBuffer(CommandQueue, SpectrumImMem, CL_FALSE, 0, SpectrumMemSize, SpectrumIm, 0, NULL, NULL); When I analyze these with the NVIDIA visual profiler, I see that the actual memcpy operation only takes 8 us, but there is a significant gap of around 130 us after each memcpy. I'm already using the supposedly asynchronous method (the CL_FALSE in the argument list). When I use only one operation, but with three times the size, the operation is way faster. Why is the time gap between the actual memcpy operations so huge, whereas the gap between the kernel execution (exactly before these three operations) and the first memcpy is only 7us? Can I get rid of it, or do I need to accumulate more data before starting a memcpy? If so, is there a convenient way how I could combine mutliple arrays into a single contiguous block of memory, but still have a cl_mem object as a separate device memory pointer to each section?

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  • Extremely Difficult Problem with ASP.Net 4.0 WebForms app using Routing

    - by dudeNumber4
    I have a completed app running in a QA environment. Everything works fine under most circumstances. If you hit a plain URL (no identifying information in the URL), you see an intro page with a button (generated by an asp LinkButton control) that posts back and directs you to another page. The markup looks the same when it fails and when it doesn't. When such a URL is followed from, e.g., Word and the default browser is IE, the intro page loads fine, but clicking the button causes an error. When not debugging, this behavior occurs every time. While debugging, the error occurs only ~ 1 in 10 times (closing the browser instance and starting over every time). When the error occurs, the intro page Page_Load fires and IsPostBack is false. Somehow, instead of a post, a get is being issued. When I run fiddler to try to analyze the actual calls (can't use firebug because it never happens using Firefox), everything works every time. I don't know whether this issue has anything to do with routing, and I've no idea even what to look at next. The strange thing is, when I debug, the intro page doesn't fully load every time. Only about 1 in 3 times does it fully load even if I've just cleared browser cache. When I run it through fiddler, it fully loads and works fine every time.

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  • Terminate function on System.in .. possible?

    - by Ronald
    I am currently working on a project where I have to make an agent to interact with a server. Each 50ms, the server will receive the last thing I outputted to System.out and send me a new set of lines as a 'state' through the System.in printstream to analyze and send my next message to System.out. Also, if the server receives multiple outputs from me, it only regards the most recent one. .. As for my question: My program originally constructed a tree and then analyzed each leaf node to see which would be optimal, and then waited around for the next input, but I can recursively do a deeper tree search that would make my output 'better' (and again and again to keep returning a better result). Using this and the fact that if the server receives multiple outputs, it only takes the most recent one, I could do each level, print my result and start the next level. But here comes my problem... I can't be stuck in some complex algorithm while I am supposed to receiving the next input as I will then miss it. So I was wondering if there is a way to cancel anything else I am doing when I receive something via System.in and then go back to the beginning of the function and start the search again with the new set of input (and rinse and repeat..) I hope this all makes sense, Thank ye all

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  • implementation musical instrument using audio unit

    - by Develop.Kim
    post same question at apple developer forum ,too hi first sorry that my english is poor.. i want develop iphone application that playing musical instrument like 'ocarina' but don't need blow mic features. so first i tried to find that how implementation 'virtual musical instrument ' in iphone development. the during the decide implementation using 'Audio Unit' to report this article (link) so i want two kind of questions. i recognize that the 'musical instrument' can be divided into three sound that 'attack', 'sustain' , 'release'. 'decay' maybe included (link) . How implementation when audio unit base 'AUInstrumentBase' each sound ? i download sample 'SinSynth' (link) . i want play note this instrument unit for analyze source and study. Is there way to using AULab? expected the way using MIDI input . but i don't have MIDI. in addition, i wonder that i would think it right the way. to ask the advice... thank for reading poor english my article.

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  • Parsing Windows Event Logs, is it possible?

    - by xceph
    Hello, I am doing a little research into the feasibility of a project I have in mind. It involves doing a little forensic work on images of hard drives, and I have been looking for information on how to analyze saved windows event log files. I do not require the ability to monitor current events, I simply want to be able to view events which have been created, and record the time and application/process which created those events. However I do not have much experience in the inner workings of the windows system specifics, and am wondering if this is possible? The plan is to create images of a hard drive, and then do the analysis on a second machine. Ideally this would be done in either Java or Python, as they are my most proficient languages. The main concerns I have are as follows: Is this information encrypted in anyway? Are there any existing API for parsing this data directly? Is there information available regarding the format in which these logs are stored, and how does it differ from windows versions? This must be possible from analyzing the drive itself, as ideally the installation of windows on the drive would not be running, (as it would be a mounted image on another system) The closest thing I could find in my searches is http://www.j-interop.org/ but that seems to be aimed at remote clients. Ideally nothing would have to be installed on the imaged drive. The other solution which seemed to also pop up is the JNI library, but that also seems to be more so in the area of monitoring a running system. Any help at all is greatly appreciated. :)

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  • please help me to solve problem

    - by davit-datuashvili
    first of all this is not homework and nobody tag it as homewrok i did not understand this porblem can anybody explain me?this is not english problem it is just misunderstanding what problem say Consider the problem of neatly printing a paragraph on a printer. The input text is a sequence of n words of lengths l1 , l2 , . . . , ln , measured in characters. We want to print this paragraph neatly on a number of lines that hold a maximum of M characters each. Our criterion of “neatness” is as follows. If a given line contains words i through j , where i = j , and we leave exactly one space between words, the number of extra space characters at the end of the line is M - j + i -(k=i,k< j,k++) lk , which must be nonnegative so that the words fit on the line. We wish to minimize the sum, over all lines except the last, of the cubes of the numbers of extra space characters at the ends of lines. Give a dynamic-programming algorithm to print a paragraph of n words neatly on a printer. Analyze the running time and space requirements of your algorithm.

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  • Is it okay to violate the principle that collection properties should be readonly for performance?

    - by uriDium
    I used FxCop to analyze some code I had written. I had exposed a collection via a setter. I understand why this is not good. Changing the backing store when I don't expect it is a very bad idea. Here is my problem though. I retrieve a list of business objects from a Data Access Object. I then need to add that collection to another business class and I was doing it with the setter method. The reason I did this was that it is going to be faster to make an assignment than to insert hundreds of thousands of objects one at a time to the collection again via another addElement method. Is it okay to have a getter for a collection in some scenarios? I though of rather having a constructor which takes a collection? I thought maybe I could pass the object in to the Dao and let the Dao populate it directly? Are there any other better ideas?

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  • How to iteratively generate k elements subsets from a set of size n in java?

    - by Bea Metitiri
    Hi, I'm working on a puzzle that involves analyzing all size k subsets and figuring out which one is optimal. I wrote a solution that works when the number of subsets is small, but it runs out of memory for larger problems. Now I'm trying to translate an iterative function written in python to java so that I can analyze each subset as it's created and get only the value that represents how optimized it is and not the entire set so that I won't run out of memory. Here is what I have so far and it doesn't seem to finish even for very small problems: public static LinkedList<LinkedList<Integer>> getSets(int k, LinkedList<Integer> set) { int N = set.size(); int maxsets = nCr(N, k); LinkedList<LinkedList<Integer>> toRet = new LinkedList<LinkedList<Integer>>(); int remains, thresh; LinkedList<Integer> newset; for (int i=0; i<maxsets; i++) { remains = k; newset = new LinkedList<Integer>(); for (int val=1; val<=N; val++) { if (remains==0) break; thresh = nCr(N-val, remains-1); if (i < thresh) { newset.add(set.get(val-1)); remains --; } else { i -= thresh; } } toRet.add(newset); } return toRet; } Can anybody help me debug this function or suggest another algorithm for iteratively generating size k subsets? EDIT: I finally got this function working, I had to create a new variable that was the same as i to do the i and thresh comparison because python handles for loop indexes differently.

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  • Speeding up a group by date query on a big table in postgres

    - by zaius
    I've got a table with around 20 million rows. For arguments sake, lets say there are two columns in the table - an id and a timestamp. I'm trying to get a count of the number of items per day. Here's what I have at the moment. SELECT DATE(timestamp) AS day, COUNT(*) FROM actions WHERE DATE(timestamp) >= '20100101' AND DATE(timestamp) < '20110101' GROUP BY day; Without any indices, this takes about a 30s to run on my machine. Here's the explain analyze output: GroupAggregate (cost=675462.78..676813.42 rows=46532 width=8) (actual time=24467.404..32417.643 rows=346 loops=1) -> Sort (cost=675462.78..675680.34 rows=87021 width=8) (actual time=24466.730..29071.438 rows=17321121 loops=1) Sort Key: (date("timestamp")) Sort Method: external merge Disk: 372496kB -> Seq Scan on actions (cost=0.00..667133.11 rows=87021 width=8) (actual time=1.981..12368.186 rows=17321121 loops=1) Filter: ((date("timestamp") >= '2010-01-01'::date) AND (date("timestamp") < '2011-01-01'::date)) Total runtime: 32447.762 ms Since I'm seeing a sequential scan, I tried to index on the date aggregate CREATE INDEX ON actions (DATE(timestamp)); Which cuts the speed by about 50%. HashAggregate (cost=796710.64..796716.19 rows=370 width=8) (actual time=17038.503..17038.590 rows=346 loops=1) -> Seq Scan on actions (cost=0.00..710202.27 rows=17301674 width=8) (actual time=1.745..12080.877 rows=17321121 loops=1) Filter: ((date("timestamp") >= '2010-01-01'::date) AND (date("timestamp") < '2011-01-01'::date)) Total runtime: 17038.663 ms I'm new to this whole query-optimization business, and I have no idea what to do next. Any clues how I could get this query running faster?

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  • when i set property(retain), one "self" = one "retain"?

    - by Walter
    although I'm about to finish my first app, I'm still confused about the very basic memory management..I've read through many posts here and apple document, but I'm still puzzled.. For example..I'm currently doing things like this to add a label programmatically: @property (retain, nonatomic) UILabel *showTime; @sythesize showTime; showTime = [[UILabel alloc] initWithFrame:CGRectMake(45, 4, 200, 36)]; [self.showTime setText:[NSString stringWithFormat:@"%d", time]]; [self.showTime setFont:[UIFont fontWithName:@"HelveticaRoundedLT-Bold" size:23]]; [self.showTime setTextColor:numColor]; self.showTime.backgroundColor = [UIColor clearColor]; [self addSubview:self.showTime]; [showTime release]; this is my current practice, for UILabel, UIButton, UIImageView, etc... [Alloc init] it without self., coz I know this will retain twice.. but after the allocation, I put back the "self." to set the attributes.. My gut feel tells me I am doing wrong, but it works superficially and I found no memory leak in analyze and instruments.. can anyone give my advice? when I use "self." to set text and set background color, does it retain one automatically? THX so much!

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  • Why isn't my leak detected by Xcode Intrumensts?

    - by Arlaharen
    I am trying to analyze some code of mine, looking for memory leaks. My problem is that some of my objects are leaking (at least as far as I can see), but the Leaks tool doesn't detect the leaks. My guess is that some iPhone OS object still holds pointers to my leaked objects. The objects I am talking about are subclasses of UIViewController that I use like this: MyController *controller = [[MyController alloc] initWithNibName:@"MyController" bundle:nil]; [self.navigationController pushViewController:controller animated:YES]; When these objects are no longer needed I do: [self.navigationController popViewControllerAnimated:YES]; Without a [controller release] call right now. Now when I look at what objects that gets created I see a lot of MyController instances that never gets destroyed. To me these are memory leaks, but to the Leaks tool they are not. Can someone here tell me if there is some way Instruments can tell me what objects are pointing to my MyController instances and thereby making them not count as memory leaks? Or better yet, tell me why these leaks are not detecetd.

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  • why is Active Record firing extra query when I use Includes method to fetch data

    - by riddhi_agrawal
    I have the following model structure: class Group < ActiveRecord::Base has_many :group_products, :dependent => :destroy has_many :products, :through => :group_products end class Product < ActiveRecord::Base has_many :group_products, :dependent => :destroy has_many :groups, :through => :group_products end class GroupProduct < ActiveRecord::Base belongs_to :group belongs_to :product end I wanted to minimize my database queries so I decided to use includes.In the console I tried something like, groups = Group.includes(:products) my development logs show the following calls, Group Load (403.0ms) SELECT `groups`.* FROM `groups` GroupProduct Load (60.0ms) SELECT `group_products`.* FROM `group_products` WHERE (`group_products`.group_id IN (1,3,14,15,16,18,19,20,21,22,23,24,25,26,27,28,29,30,33,42,49,51)) Product Load (22.0ms) SELECT `products`.* FROM `products` WHERE (`products`.`id` IN (382,304,353,12,63,103,104,105,262,377,263,264,265,283,284,285,286,287,302,306,307,308,328,335,336,337,340,355,59,60,61,247,309,311,66,30,274,294,324,350,140,176,177,178,64,240,327,332,338,380,383,252,254,255,256,257,325,326)) Product Load (10.0ms) SELECT `products`.* FROM `products` WHERE (`products`.`id` = 377) LIMIT 1 I could analyze the initial three calls were necessary but don't get the reason why the last database call is made, Product Load (10.0ms) SELECT `products`.* FROM `products` WHERE (`products`.`id` = 377) LIMIT 1 Any idea why this is happening? Thanks in advance. :)

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  • Migrate from MySQL to PostgreSQL on Linux (Kubuntu)

    - by Dave Jarvis
    Storyline Trying to migrate a database from MySQL to PostgreSQL. All the documentation I have read covers, in great detail, how to migrate the structure. I have found very little documentation on migrating the data. The schema has 13 tables (which have been migrated successfully) and 9 GB of data. MySQL version: 5.1.x PostgreSQL version: 8.4.x I want to use the R programming language to analyze the data using SQL select statements; PostgreSQL has PL/R, but MySQL has nothing (as far as I can tell). A long time ago in a galaxy far, far away... Create the database location (/var has insufficient space; also dislike having the PostgreSQL version number everywhere -- upgrading would break scripts!): sudo mkdir -p /home/postgres/main sudo cp -Rp /var/lib/postgresql/8.4/main /home/postgres sudo chown -R postgres.postgres /home/postgres sudo chmod -R 700 /home/postgres sudo usermod -d /home/postgres/ postgres All good to here. Next, restart the server and configure the database using these installation instructions: sudo apt-get install postgresql pgadmin3 sudo /etc/init.d/postgresql-8.4 stop sudo vi /etc/postgresql/8.4/main/postgresql.conf Change data_directory to /home/postgres/main sudo /etc/init.d/postgresql-8.4 start sudo -u postgres psql postgres \password postgres sudo -u postgres createdb climate pgadmin3 Use pgadmin3 to configure the database and create a schema. A New Hope The episode began in a remote shell known as bash, with both databases running, and the installation of a command with a most unusual logo: SQL Fairy. perl Makefile.PL sudo make install sudo apt-get install perl-doc (strangely, it is not called perldoc) perldoc SQL::Translator::Manual Extract a PostgreSQL-friendly DDL and all the MySQL data: sqlt -f DBI --dsn dbi:mysql:climate --db-user user --db-password password -t PostgreSQL > climate-pg-ddl.sql mysqldump --skip-add-locks --complete-insert --no-create-db --no-create-info --quick --result-file="climate-my.sql" --databases climate --skip-comments -u root -p The Database Strikes Back Recreate the structure in PostgreSQL as follows: pgadmin3 (switch to it) Click the Execute arbitrary SQL queries icon Open climate-pg-ddl.sql Search for TABLE " replace with TABLE climate." (insert the schema name climate) Search for on " replace with on climate." (insert the schema name climate) Press F5 to execute This results in: Query returned successfully with no result in 122 ms. Replies of the Jedi At this point I am stumped. Where do I go from here (what are the steps) to convert climate-my.sql to climate-pg.sql so that they can be executed against PostgreSQL? How to I make sure the indexes are copied over correctly (to maintain referential integrity; I don't have constraints at the moment to ease the transition)? How do I ensure that adding new rows in PostgreSQL will start enumerating from the index of the last row inserted (and not conflict with an existing primary key from the sequence)? Resources A fair bit of information was needed to get this far: https://help.ubuntu.com/community/PostgreSQL http://articles.sitepoint.com/article/site-mysql-postgresql-1 http://wiki.postgresql.org/wiki/Converting_from_other_Databases_to_PostgreSQL#MySQL http://pgfoundry.org/frs/shownotes.php?release_id=810 http://sqlfairy.sourceforge.net/ Thank you!

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  • Random servers in Citrix servers suddenly bluescreens (mostly 0x0000008e and 0x0000007e)

    - by Rasmus Rask
    I'm responsible for a Citrix Presentation Server 4.5 farm. Starting Friday 30. November, my servers started to crash randomly. So far we've experienced 80 crashes, so it's obviously becoming an increasingly big problem for us. I have 12+ years experience with IT, so I know the difference between 0 and 1, but I have a hard time cracking this. We've rolled back any recent changes I can think of for different groups of servers, but all groups still seem to crash. I don't have the skills to interpret the memory dumps to find the culprit. Has anyone encountered the same or a similar problem? - might be a generic Windows issue Other than executing "analyze -v" in WinDbg, how do I work my way through the memory dumps to see what actually triggered the BSOD? Any suggested steps in getting to the bottom of this? Any help is greatly appreciated. I can also provide links to kernel memory dumps or WinDbg output if necessary. Thanks! Problem description The majority of the STOP errors we encounter are: 0x0000008e KERNEL_MODE_EXCEPTION_NOT_HANDLED (50%) 0x0000007e SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (26%) 0x00000050 PAGE_FAULT_IN_NONPAGED_AREA (21%) We also see a few 0x0000000a IRQL_NOT_LESS_OR_EQUAL (3%). For both 0x0000008e and 0x0000007e bug checks, the exception code is 0xc0000005 (Access Violation). When opening dump files in WinDbg, most details are exactly the same, for all the 0x0000008e and 0x0000007e bug checks respectively: 0x0000008e Exception address: 0x808bc9e3 Trap frame: [varies] FAILURE_BUCKET_ID: 0x8E_nt!HvpGetCellMapped+97 Probably Caused by (IMAGE_NAME): ntkrpamp.exe 0x0000007e Exception address: 0x808369b6 Exception record address: 0xf70d3be0 Context record address: 0xf70d38dc FAILURE_BUCKET_ID: 0x7E_nt!MmPurgeSection+14 Probably Caused by: memory_corruption About 30% of the crashes happens between 17:00 and 19:00, which leads me to believe this tend to happen more often during logoffs. But then again, only ~15% occurs between 15:00 and 17:00. Summary of farm Citrix Presentation Server 4.5 R06 on Windows Server 2003 R2 SP2 All high priority patches, at least as of October installed Virtualized using VMWare ESX/vSphere 4.1 on HP Proliant BL460c G6 blade servers About 53 Presentation Servers in production, divided into three silos - only one of which, the largest, is affected 2 vCPU's (5 GHz reserved), 8 GB RAM (all reserved) for each Presentation Server Plenty of free disk space Very few printer drivers - automated deletion of non-approved drivers every night ~1.000 peak concurrent users, which is reached at around 10:30 (on weekdays) Number of sessions steadily decline between 15:00 and 19:00 to ~230

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  • BAD DC transfering FSMO Roles to ADC

    - by Suleman
    I have a DC (FQDN:server.icmcpk.local) and an ADC (FQDN:file-server.icmcpk.local). Recently my DC is facing a bad sector problem so I changed the Operation Masters to file-server for all five roles. but when ever i turn off the OLD DC the file-server also stops wroking with AD and GPMC further i m also unable to join any other computer to this domain. For Test purpose i also added a new ADC (FQDN:wds-server.icmcpk.local) but no succes with the old DC off i had to turn the old DC on and then joined it. I m attaching the Dcdiags for all three servers. Kindly help me so that i b able to reinstall new HDD and it can go online again. --------------------------------------- Server --------------------------------------- C:\Program Files\Support Tools>dcdiag Domain Controller Diagnosis Performing initial setup: Done gathering initial info. Doing initial required tests Testing server: Default-First-Site-Name\SERVER Starting test: Connectivity ......................... SERVER passed test Connectivity Doing primary tests Testing server: Default-First-Site-Name\SERVER Starting test: Replications [Replications Check,SERVER] A recent replication attempt failed: From FILE-SERVER to SERVER Naming Context: DC=ForestDnsZones,DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. [Replications Check,SERVER] A recent replication attempt failed: From WDS-SERVER to SERVER Naming Context: DC=ForestDnsZones,DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. [Replications Check,SERVER] A recent replication attempt failed: From FILE-SERVER to SERVER Naming Context: DC=DomainDnsZones,DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. [Replications Check,SERVER] A recent replication attempt failed: From WDS-SERVER to SERVER Naming Context: DC=DomainDnsZones,DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. [Replications Check,SERVER] A recent replication attempt failed: From FILE-SERVER to SERVER Naming Context: CN=Schema,CN=Configuration,DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. [Replications Check,SERVER] A recent replication attempt failed: From WDS-SERVER to SERVER Naming Context: CN=Schema,CN=Configuration,DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. [Replications Check,SERVER] A recent replication attempt failed: From WDS-SERVER to SERVER Naming Context: DC=icmcpk,DC=local The replication generated an error (1908): Could not find the domain controller for this domain. The failure occurred at 2012-05-04 14:07:13. The last success occurred at 2012-05-04 13:48:39. 1 failures have occurred since the last success. Kerberos Error. A KDC was not found to authenticate the call. Check that sufficient domain controllers are available. ......................... SERVER passed test Replications Starting test: NCSecDesc ......................... SERVER passed test NCSecDesc Starting test: NetLogons ......................... SERVER passed test NetLogons Starting test: Advertising ......................... SERVER passed test Advertising Starting test: KnowsOfRoleHolders ......................... SERVER passed test KnowsOfRoleHolders Starting test: RidManager ......................... SERVER passed test RidManager Starting test: MachineAccount ......................... SERVER passed test MachineAccount Starting test: Services ......................... SERVER passed test Services Starting test: ObjectsReplicated ......................... SERVER passed test ObjectsReplicated Starting test: frssysvol ......................... SERVER passed test frssysvol Starting test: frsevent There are warning or error events within the last 24 hours after the SYSVOL has been shared. Failing SYSVOL replication problems may cause Group Policy problems. ......................... SERVER failed test frsevent Starting test: kccevent ......................... SERVER passed test kccevent Starting test: systemlog An Error Event occured. EventID: 0x80001778 Time Generated: 05/04/2012 14:05:39 Event String: The previous system shutdown at 1:26:31 PM on An Error Event occured. EventID: 0x825A0011 Time Generated: 05/04/2012 14:07:45 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 05/04/2012 14:13:40 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 05/04/2012 14:14:25 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 05/04/2012 14:14:25 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 05/04/2012 14:14:38 (Event String could not be retrieved) An Error Event occured. EventID: 0xC1010020 Time Generated: 05/04/2012 14:16:14 Event String: Dependent Assembly Microsoft.VC80.MFCLOC could An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:16:14 Event String: Resolve Partial Assembly failed for An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:16:14 Event String: Generate Activation Context failed for An Error Event occured. EventID: 0xC1010020 Time Generated: 05/04/2012 14:16:14 Event String: Dependent Assembly Microsoft.VC80.MFCLOC could An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:16:14 Event String: Resolve Partial Assembly failed for An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:16:14 Event String: Generate Activation Context failed for An Error Event occured. EventID: 0x825A0011 Time Generated: 05/04/2012 14:22:57 (Event String could not be retrieved) An Error Event occured. EventID: 0xC1010020 Time Generated: 05/04/2012 14:22:59 Event String: Dependent Assembly Microsoft.VC80.MFCLOC could An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:22:59 Event String: Resolve Partial Assembly failed for An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:22:59 Event String: Generate Activation Context failed for An Error Event occured. EventID: 0xC1010020 Time Generated: 05/04/2012 14:22:59 Event String: Dependent Assembly Microsoft.VC80.MFCLOC could An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:22:59 Event String: Resolve Partial Assembly failed for An Error Event occured. EventID: 0xC101003B Time Generated: 05/04/2012 14:22:59 Event String: Generate Activation Context failed for ......................... SERVER failed test systemlog Starting test: VerifyReferences ......................... SERVER passed test VerifyReferences Running partition tests on : ForestDnsZones Starting test: CrossRefValidation ......................... ForestDnsZones passed test CrossRefValidation Starting test: CheckSDRefDom ......................... ForestDnsZones passed test CheckSDRefDom Running partition tests on : DomainDnsZones Starting test: CrossRefValidation ......................... DomainDnsZones passed test CrossRefValidation Starting test: CheckSDRefDom ......................... DomainDnsZones passed test CheckSDRefDom Running partition tests on : Schema Starting test: CrossRefValidation ......................... Schema passed test CrossRefValidation Starting test: CheckSDRefDom ......................... Schema passed test CheckSDRefDom Running partition tests on : Configuration Starting test: CrossRefValidation ......................... Configuration passed test CrossRefValidation Starting test: CheckSDRefDom ......................... Configuration passed test CheckSDRefDom Running partition tests on : icmcpk Starting test: CrossRefValidation ......................... icmcpk passed test CrossRefValidation Starting test: CheckSDRefDom ......................... icmcpk passed test CheckSDRefDom Running enterprise tests on : icmcpk.local Starting test: Intersite ......................... icmcpk.local passed test Intersite Starting test: FsmoCheck ......................... icmcpk.local passed test FsmoCheck ---------------------- File-Server ---------------------- C:\Users\Administrator.ICMCPK>dcdiag Directory Server Diagnosis Performing initial setup: Trying to find home server... Home Server = FILE-SERVER * Identified AD Forest. Done gathering initial info. Doing initial required tests Testing server: Default-First-Site-Name\FILE-SERVER Starting test: Connectivity ......................... FILE-SERVER passed test Connectivity Doing primary tests Testing server: Default-First-Site-Name\FILE-SERVER Starting test: Advertising Warning: DsGetDcName returned information for \\Server.icmcpk.local, when we were trying to reach FILE-SERVER. SERVER IS NOT RESPONDING or IS NOT CONSIDERED SUITABLE. ......................... FILE-SERVER failed test Advertising Starting test: FrsEvent ......................... FILE-SERVER passed test FrsEvent Starting test: DFSREvent ......................... FILE-SERVER passed test DFSREvent Starting test: SysVolCheck ......................... FILE-SERVER passed test SysVolCheck Starting test: KccEvent ......................... FILE-SERVER passed test KccEvent Starting test: KnowsOfRoleHolders ......................... FILE-SERVER passed test KnowsOfRoleHolders Starting test: MachineAccount ......................... FILE-SERVER passed test MachineAccount Starting test: NCSecDesc Error NT AUTHORITY\ENTERPRISE DOMAIN CONTROLLERS doesn't have Replicating Directory Changes In Filtered Set access rights for the naming context: DC=ForestDnsZones,DC=icmcpk,DC=local Error NT AUTHORITY\ENTERPRISE DOMAIN CONTROLLERS doesn't have Replicating Directory Changes In Filtered Set access rights for the naming context: DC=DomainDnsZones,DC=icmcpk,DC=local ......................... FILE-SERVER failed test NCSecDesc Starting test: NetLogons Unable to connect to the NETLOGON share! (\\FILE-SERVER\netlogon) [FILE-SERVER] An net use or LsaPolicy operation failed with error 67, The network name cannot be found.. ......................... FILE-SERVER failed test NetLogons Starting test: ObjectsReplicated ......................... FILE-SERVER passed test ObjectsReplicated Starting test: Replications ......................... FILE-SERVER passed test Replications Starting test: RidManager ......................... FILE-SERVER passed test RidManager Starting test: Services ......................... FILE-SERVER passed test Services Starting test: SystemLog An Error Event occurred. EventID: 0x00000469 Time Generated: 05/04/2012 14:01:10 Event String: The processing of Group Policy failed because of lack of network con nectivity to a domain controller. This may be a transient condition. A success m essage would be generated once the machine gets connected to the domain controll er and Group Policy has succesfully processed. If you do not see a success messa ge for several hours, then contact your administrator. An Warning Event occurred. EventID: 0x8000A001 Time Generated: 05/04/2012 14:07:11 Event String: The Security System could not establish a secured connection with th e server ldap/icmcpk.local/[email protected]. No authentication protocol was available. An Warning Event occurred. EventID: 0x00000BBC Time Generated: 05/04/2012 14:30:34 Event String: Windows Defender Real-Time Protection agent has detected changes. Mi crosoft recommends you analyze the software that made these changes for potentia l risks. You can use information about how these programs operate to choose whet her to allow them to run or remove them from your computer. Allow changes only if you trust the program or the software publisher. Windows Defender can't undo changes that you allow. An Warning Event occurred. EventID: 0x00000BBC Time Generated: 05/04/2012 14:30:36 Event String: Windows Defender Real-Time Protection agent has detected changes. Mi crosoft recommends you analyze the software that made these changes for potentia l risks. You can use information about how these programs operate to choose whet her to allow them to run or remove them from your computer. Allow changes only if you trust the program or the software publisher. Windows Defender can't undo changes that you allow. ......................... FILE-SERVER failed test SystemLog Starting test: VerifyReferences ......................... FILE-SERVER passed test VerifyReferences Running partition tests on : ForestDnsZones Starting test: CheckSDRefDom ......................... ForestDnsZones passed test CheckSDRefDom Starting test: CrossRefValidation ......................... ForestDnsZones passed test CrossRefValidation Running partition tests on : DomainDnsZones Starting test: CheckSDRefDom ......................... DomainDnsZones passed test CheckSDRefDom Starting test: CrossRefValidation ......................... DomainDnsZones passed test CrossRefValidation Running partition tests on : Schema Starting test: CheckSDRefDom ......................... Schema passed test CheckSDRefDom Starting test: CrossRefValidation ......................... Schema passed test CrossRefValidation Running partition tests on : Configuration Starting test: CheckSDRefDom ......................... Configuration passed test CheckSDRefDom Starting test: CrossRefValidation ......................... Configuration passed test CrossRefValidation Running partition tests on : icmcpk Starting test: CheckSDRefDom ......................... icmcpk passed test CheckSDRefDom Starting test: CrossRefValidation ......................... icmcpk passed test CrossRefValidation Running enterprise tests on : icmcpk.local Starting test: LocatorCheck ......................... icmcpk.local passed test LocatorCheck Starting test: Intersite ......................... icmcpk.local passed test Intersite --------------------- WDS-Server --------------------- C:\Users\Administrator.ICMCPK>dcdiag Directory Server Diagnosis Performing initial setup: Trying to find home server... Home Server = WDS-SERVER * Identified AD Forest. Done gathering initial info. Doing initial required tests Testing server: Default-First-Site-Name\WDS-SERVER Starting test: Connectivity ......................... WDS-SERVER passed test Connectivity Doing primary tests Testing server: Default-First-Site-Name\WDS-SERVER Starting test: Advertising Warning: DsGetDcName returned information for \\Server.icmcpk.local, when we were trying to reach WDS-SERVER. SERVER IS NOT RESPONDING or IS NOT CONSIDERED SUITABLE. ......................... WDS-SERVER failed test Advertising Starting test: FrsEvent There are warning or error events within the last 24 hours after the SYSVOL has been shared. Failing SYSVOL replication problems may cause Group Policy problems. ......................... WDS-SERVER passed test FrsEvent Starting test: DFSREvent ......................... WDS-SERVER passed test DFSREvent Starting test: SysVolCheck ......................... WDS-SERVER passed test SysVolCheck Starting test: KccEvent ......................... WDS-SERVER passed test KccEvent Starting test: KnowsOfRoleHolders ......................... WDS-SERVER passed test KnowsOfRoleHolders Starting test: MachineAccount ......................... WDS-SERVER passed test MachineAccount Starting test: NCSecDesc Error NT AUTHORITY\ENTERPRISE DOMAIN CONTROLLERS doesn't have Replicating Directory Changes In Filtered Set access rights for the naming context: DC=ForestDnsZones,DC=icmcpk,DC=local Error NT AUTHORITY\ENTERPRISE DOMAIN CONTROLLERS doesn't have Replicating Directory Changes In Filtered Set access rights for the naming context: DC=DomainDnsZones,DC=icmcpk,DC=local ......................... WDS-SERVER failed test NCSecDesc Starting test: NetLogons Unable to connect to the NETLOGON share! (\\WDS-SERVER\netlogon) [WDS-SERVER] An net use or LsaPolicy operation failed with error 67, The network name cannot be found.. ......................... WDS-SERVER failed test NetLogons Starting test: ObjectsReplicated ......................... WDS-SERVER passed test ObjectsReplicated Starting test: Replications ......................... WDS-SERVER passed test Replications Starting test: RidManager ......................... WDS-SERVER passed test RidManager Starting test: Services ......................... WDS-SERVER passed test Services Starting test: SystemLog An Error Event occurred. EventID: 0x0000041E Time Generated: 05/04/2012 14:02:55 Event String: The processing of Group Policy failed. Windows could not obtain the name of a domain controller. This could be caused by a name resolution failure. Verify your Domain Name Sysytem (DNS) is configured and working correctly. An Error Event occurred. EventID: 0x0000041E Time Generated: 05/04/2012 14:08:33 Event String: The processing of Group Policy failed. Windows could not obtain the name of a domain controller. This could be caused by a name resolution failure. Verify your Domain Name Sysytem (DNS) is configured and working correctly. ......................... WDS-SERVER failed test SystemLog Starting test: VerifyReferences ......................... WDS-SERVER passed test VerifyReferences Running partition tests on : ForestDnsZones Starting test: CheckSDRefDom ......................... ForestDnsZones passed test CheckSDRefDom Starting test: CrossRefValidation ......................... ForestDnsZones passed test CrossRefValidation Running partition tests on : DomainDnsZones Starting test: CheckSDRefDom ......................... DomainDnsZones passed test CheckSDRefDom Starting test: CrossRefValidation ......................... DomainDnsZones passed test CrossRefValidation Running partition tests on : Schema Starting test: CheckSDRefDom ......................... Schema passed test CheckSDRefDom Starting test: CrossRefValidation ......................... Schema passed test CrossRefValidation Running partition tests on : Configuration Starting test: CheckSDRefDom ......................... Configuration passed test CheckSDRefDom Starting test: CrossRefValidation ......................... Configuration passed test CrossRefValidation Running partition tests on : icmcpk Starting test: CheckSDRefDom ......................... icmcpk passed test CheckSDRefDom Starting test: CrossRefValidation ......................... icmcpk passed test CrossRefValidation Running enterprise tests on : icmcpk.local Starting test: LocatorCheck ......................... icmcpk.local passed test LocatorCheck Starting test: Intersite ......................... icmcpk.local passed test Intersite

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  • Why is site serving different SSL certs to different browsers?

    - by TRiG
    The SSL certificate on menswearireland.com and on www.menswearireland.com works fine on Safari, Chrome, SeaMonkey, K-Meleon, QtWeb, Firefox, and Opera. However, Internet Explorer claims that there is an error: The security certificate presented by this website was not issued by a trusted certificate authority. The security certificate presented by this website was issued for a different website's address. Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server. Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0; Trident/5.0) Another site hosted on the same managed server shows no errors: achill-fieldschool.com and www.achill-fieldschool.com work fine on IE, even though as far as I can tell the certificate is set up identically. What am I doing wrong? This is a LAMPP server running Plesk. It looks like the server is showing different certificates to different clients. To some clients it shows a RapidSSL certificate made out to www.menswearireland.com with menswearireland.com as a valid alternative name. To other clients, it shows a Parallels Panel certificate, made out to Parallels Panel. Here are results from a few different online SSL checkers: most say it's fine, while two show errors. Three online checkers say it's valid Comodo SSL Check shows it as valid DigiCert SSL Check shows it as valid SSL Shopper SSL Check shows it as valid Common name: www.menswearireland.com SANs: www.menswearireland.com, menswearireland.com Valid from October 2, 2012 to November 4, 2013 Serial Number: 559425 (0x88941) Signature Algorithm: sha1WithRSAEncryption Issuer: RapidSSL CA Another online checker seems to see a completely different certificate GeoCerts SSL Check shows it as invalid Common name: Parallels Panel Organization: Parallels Valid from August 15, 2012 to August 15, 2013 Issuer: Parallels Panel Another online checker sees more than one certificate Symantic SSL Check shows it as invalid The certificate installation checker connected to the Web server and read its certificates, but could not determine which is the primary certificate for the Web server. Incidentally, on both menswearireland.com and achill-fieldschool.com the homepage will redirect from HTTPS to HTTP. To see SSL details, visit the page /account on both (that page will redirect from HTTP to HTTPS). I’ve found more information in a more detailed online SSL checker. https://www.ssllabs.com/ssltest/analyze.html?d=menswearireland.com This site works only in browsers with SNI support My understanding is that SNI (RFC 6066) is a method for putting many SSL sites on one shared IP address and port. This does not work on Internet Explorer on older versions of Windows (this has to do with the version of Windows, not the version of Internet Explorer). However, all our SSL sites are on a unique IP address, so we shouldn’t need SNI.

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  • Apache + Tomcat error 120006 Using mod_proxy_ajp for Load Balance

    - by Wakaru44
    I have an apache 2 frontend with two nodes, and a backend with two instances of tomcat 6 balance with mod_proxy_ajp. The bbdd is in a separate machine. All machines use RHEL, 6.2 on the frontend, 5.5 on the backend. The infraestructure is virtualized using VMware. # This is the apache config in one of the virtualHost. ProxyPreserveHost On ProxyPass / balancer://liferay/ <Proxy balancer://liferay> BalancerMember ajp://lrab:8009 route=liferaya BalancerMember ajp://lrbb:8009 route=liferayb status=+H ProxySet lbmethod=byrequests nofailover=on </Proxy> The conector in tomcat is now configured like this: <!-- Define an AJP 1.3 Connector on port 8009 --> <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" URIEncoding="UTF-8" enableLookups="false" allowTrace="true" /> Do you think it could be useful to set a maxThreads parameter, like in this post?? in that case, How can i determine a proper number of threads? From time to time, we get errors like this [Tue Sep 18 17:57:02 2012] [error] ajp_read_header: ajp_ilink_receive failed [Tue Sep 18 17:57:02 2012] [error] (120006)APR does not understand this error code: proxy: read response failed from 192.168.1.104:8009 (lrab) And apache switches to the pasive node (if its active) or fails with 503. Some things i have tried so far: I think that i have some performance issues with one of the applications, Here you can see a threadDump But i'm not quite sure about it. I also started to monitor the network connection. I have noticed that there are some pings lost when i have a "ping -f " so maybe it could be a network issue, but the success rate is 100% (so the lost packets are only a few among the flood, but maybe, i don't know, enough to break the link betwen apache and tomcat). I wrote a python script to check connectivity with timestamps on the pings, so i can know when the network fails. After sniffing the network , i can also see some RST packets, but i don't know if that is a normal behaviour (some applications do that to end a network communication). I have also noticed that the applications have problems communicating with the database, but im not even sure if this could be related or not. If you think so, i can post more info about it. I changed the connector on the tomcats to use the native one, but still the same. I need not even a solution to this, but maybe some guidance on how can i troubleshoot this better ¿Analyze threads, monitor mysql performance, sniff the traffic between apaches and tomcats? Ultimately, all i need is to balance the tomcat instances in Active/pasive mode, so if there is another way to do it, i could give it a try.

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  • CentOS 5.8 dig is not resolving ip-address

    - by travisbotello
    I'm running centos 5.8 on a local machine at home. Today I was trying to analyze the DNS-Lookup via dig. $ dig +trace -t A www.heise.de. This is giving me something like this as a response de. 172800 IN NS f.nic.de. de. 172800 IN NS z.nic.de. de. 172800 IN NS s.de.net. de. 172800 IN NS n.de.net. de. 172800 IN NS a.nic.de. de. 172800 IN NS l.de.net. ;; Received 344 bytes from 192.58.128.30#53(192.58.128.30) in 49 ms In contrast my dedicated CentOS machine is returning the following de. 172800 IN NS a.nic.de. de. 172800 IN NS n.de.net. de. 172800 IN NS f.nic.de. de. 172800 IN NS z.nic.de. de. 172800 IN NS l.de.net. de. 172800 IN NS s.de.net. ;; Received 344 bytes from 192.58.128.30#53(j.root-servers.net) in 32 ms As you can see, the last line is different. Any idea why my dedicated machine is giving me the host name of the responding DNS-Server and my local machine is only returning the ip-address? Thanks in advance UPDATE The reverse DNS-Lookup is working without any problems. Also, I just checked this on my local mac and...exactly the same problem occurs. Is it possible that this has to do with the local router/modem/ISP?

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