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  • Making a Wrapper class for ActiveMQ

    - by DarthVader
    I want to make a Wrapper class for ActiveMQ which will have only send and get functions. I want to wrap them in a static class. Users can use this client and send, get messages to the activemq instance. I want this process to be transparent. There are two classes in this link My only handicap is, i need to this in c++ and not sure where to start. I havent used c++ for ages and now not sure how I can create this wrapper class. I m giving it a try as follows: // .h file #include <stdlib.h> #include <iostream> using namespace std; class ActiveMQWrapper { public: static void send(std::string message); static std::string get(); }; // .cpp file #include<string> #include<iostream> #include "ActiveMQWrapper.h" void ActiveMQWrapper::send(std::string message){ std::cout<<message; } std::string ActiveMQWrapper::get(){ return "test"; } // test file #include <string> #include <iostream> #include "ActiveMQWrapper.h" int main() { std::string foo ="test"; ActiveMQWrapper::send(foo); std::cout<<ActiveMQWrapper::get(); return 1; } When I added the following to .h file, hell breaks loose. Do you think I should seperate this impl to a factory and initialize and instance and return to the wrapper above? How do i deal with all the dependencies? private: Connection* connection; Session* session; Destination* destination; MessageProducer* producer; int numMessages; bool useTopic; bool sessionTransacted; std::string brokerURI; and the header files, i get several messages as errors, which complains about the path. How can i get this correct? I eventually want to build a Factory, get an instance and send or get the messages to the queue. is there a code sample i can look into to get this right? essential i want to use the functionality of only this producer and consumer. Edit: I understand there is no such thing as static class in C++ . This is my reference.

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  • factory class, wrong number of arguments being passed to subclass constructor

    - by Hugh Bothwell
    I was looking at Python: Exception in the separated module works wrong which uses a multi-purpose GnuLibError class to 'stand in' for a variety of different errors. Each sub-error has its own ID number and error format string. I figured it would be better written as a hierarchy of Exception classes, and set out to do so: class GNULibError(Exception): sub_exceptions = 0 # patched with dict of subclasses once subclasses are created err_num = 0 err_format = None def __new__(cls, *args): print("new {}".format(cls)) # DEBUG if len(args) and args[0] in GNULibError.sub_exceptions: print(" factory -> {} {}".format(GNULibError.sub_exceptions[args[0]], args[1:])) # DEBUG return super(GNULibError, cls).__new__(GNULibError.sub_exceptions[args[0]], *(args[1:])) else: print(" plain {} {}".format(cls, args)) # DEBUG return super(GNULibError, cls).__new__(cls, *args) def __init__(self, *args): cls = type(self) print("init {} {}".format(cls, args)) # DEBUG self.args = args if cls.err_format is None: self.message = str(args) else: self.message = "[GNU Error {}] ".format(cls.err_num) + cls.err_format.format(*args) def __str__(self): return self.message def __repr__(self): return '{}{}'.format(type(self).__name__, self.args) class GNULibError_Directory(GNULibError): err_num = 1 err_format = "destination directory does not exist: {}" class GNULibError_Config(GNULibError): err_num = 2 err_format = "configure file does not exist: {}" class GNULibError_Module(GNULibError): err_num = 3 err_format = "selected module does not exist: {}" class GNULibError_Cache(GNULibError): err_num = 4 err_format = "{} is expected to contain gl_M4_BASE({})" class GNULibError_Sourcebase(GNULibError): err_num = 5 err_format = "missing sourcebase argument: {}" class GNULibError_Docbase(GNULibError): err_num = 6 err_format = "missing docbase argument: {}" class GNULibError_Testbase(GNULibError): err_num = 7 err_format = "missing testsbase argument: {}" class GNULibError_Libname(GNULibError): err_num = 8 err_format = "missing libname argument: {}" # patch master class with subclass reference # (TO DO: auto-detect all available subclasses instead of hardcoding them) GNULibError.sub_exceptions = { 1: GNULibError_Directory, 2: GNULibError_Config, 3: GNULibError_Module, 4: GNULibError_Cache, 5: GNULibError_Sourcebase, 6: GNULibError_Docbase, 7: GNULibError_Testbase, 8: GNULibError_Libname } This starts out with GNULibError as a factory class - if you call it with an error number belonging to a recognized subclass, it returns an object belonging to that subclass, otherwise it returns itself as a default error type. Based on this code, the following should be exactly equivalent (but aren't): e = GNULibError(3, 'missing.lib') f = GNULibError_Module('missing.lib') print e # -> '[GNU Error 3] selected module does not exist: 3' print f # -> '[GNU Error 3] selected module does not exist: missing.lib' I added some strategic print statements, and the error seems to be in GNULibError.__new__: >>> e = GNULibError(3, 'missing.lib') new <class '__main__.GNULibError'> factory -> <class '__main__.GNULibError_Module'> ('missing.lib',) # good... init <class '__main__.GNULibError_Module'> (3, 'missing.lib') # NO! ^ why? I call the subclass constructor as subclass.__new__(*args[1:]) - this should drop the 3, the subclass type ID - and yet its __init__ is still getting the 3 anyway! How can I trim the argument list that gets passed to subclass.__init__?

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  • Is this the correct way to build a Perl hash that utilizes arrays?

    - by Structure
    This is the first time I have manipulated hashes and arrays in this way -- and it is working. Basically, for every key there are multiple values that I want to record and then print out in the form "key -- value -- value -- val..." My code is as follows. I am surprised that it works, so concerned that it works "by mistake". Is this the correct way to accomplish this task, or is there a more efficient or appropriate method? while ($source =~ m/(regex)/g) { #Get all key names from source $listkey = $1; #Set current list key to the current regex result. $list{$listkey} = ++$i unless $list{$listkey}; #Add the key to the hash unless it already exists. $list{$listkey} = [] unless exists $list{$listkey}; #Add an array for the hash unless the hash already exists. while ($loopcount==0) { if ($ifcount==0) { $listvalue=result_of_some_function_using_list_key; #Get the first list value from the list key. $ifcount++; #Increment so we only get the first list value once. } else { $listvalue=result_of_some_function_using_list_value; #Update the last list value. } if ($listvalue) { #If the function returned a value... push @{$list{$listkey}}, $listvalue; #...then add the value to the hash array for the key. } else { #There are no more values and we need a new key. $listkey=0; #Reset variable. $domain=0; #Reset variable. $loopcount++; #Increment loop counter to exit loop. } } $ifcount=0; #Reset count variable so the next listvalue can be generated from the new key. $loopcount=0; #Reset count variable so another loop can begin for a new key. } foreach $listkey (keys %list) { #For each key in the hash. print "$listkey --> "; #Print the key. @values = @{$list{$listkey}}; #Reference the arrays of the hash. print join ' --> ', @values; #Print the values. print "\n"; #Print new line. }

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  • c++ template function compiles in header but not implementation

    - by flies
    I'm trying to learn templates and I've run into this confounding error. I'm declaring some functions in a header file and I want to make a separate implementation file where the functions will be defined. Here's the code that calls the header (dum.cpp): #include <iostream> #include <vector> #include <string> #include "dumper2.h" int main() { std::vector<int> v; for (int i=0; i<10; i++) { v.push_back(i); } test(); std::string s = ", "; dumpVector(v,s); } now, here's a working header file (dumper2.h): #include <iostream> #include <string> #include <vector> void test(); template <class T> void dumpVector( std::vector<T> v,std::string sep); template <class T> void dumpVector(std::vector<T> v, std::string sep) { typename std::vector<T>::iterator vi; vi = v.begin(); std::cout << *vi; vi++; for (;vi<v.end();vi++) { std::cout << sep << *vi ; } std::cout << "\n"; return; } with implentation (dumper2.cpp): #include <iostream> #include "dumper2.h" void test() { std::cout << "!olleh dlrow\n"; } the weird thing is that if I move the code that defines dumpVector from the .h to the .cpp file, I get the following error: g++ -c dumper2.cpp -Wall -Wno-deprecated g++ dum.cpp -o dum dumper2.o -Wall -Wno-deprecated /tmp/ccKD2e3G.o: In function `main': dum.cpp:(.text+0xce): undefined reference to `void dumpVector<int>(std::vector<int, std::allocator<int> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >)' collect2: ld returned 1 exit status make: *** [dum] Error 1 So why does it work one way and not the other? Clearly the compiler can find test(), so why can't it find dumpVector?

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  • Mobile Safari text selection after input field focus

    - by Andy
    I have some legacy html that needs to work on old and new browsers (down to IE7) as well as the iPad. The iPad is the biggest issues because of how text selection is handled. On a page there is a textarea as well as some text instructions. The instructions are in a <div> and the user needs to be able to select the instructions. The problem is that once focus is placed in the textarea, the user cannot subsequently select the text instructions in the <div>. This is because the text cannot receive focus. According to the Safari Web Content Guide: Handling Events (especially, "Making Elements Clickable"), you can add a onclick event handler to the div you want to receive focus. This solution works (although it is not ideal) in iOS 6x but it does not work in iOS 5x. Does anyone have a suggestion that minimizes changes to our existing code and produces consistant user interaction. Here is sample code that shows the problem. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <script src="http://code.jquery.com/jquery-1.8.2.js"></script> <!-- Resources: Safari Web Content Guide: Handling Events (especially, "Making Elements Clickable") http://developer.apple.com/library/safari/#documentation/appleapplications/reference/safariwebcontent/HandlingEvents/HandlingEvents.html#//apple_ref/doc/uid/TP40006511-SW1 --> </head> <body> <div style="width:550"> <div onclick='function() { void(0); }'> <p>On the iPad, I want to be able to select this text after the textarea has had focus.</p> </div> <textarea rows="20" cols="80">After focus is in the textarea, can you select the text above?</textarea> </div> </body> </html>

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  • JQM dialog is opening in new page instead of dialog

    - by K D
    Thank you for taking the time to read my question. I'm trying to get a dialog box to open using Jquery mobile. I followed the documentation and used the data-rel="dialog" notation along with the data-transition="pop". Instead of a dialog appearing on the same page, I get a brand new page with the dialog appearing. Can someone kindly assist me on how to fix this functionality. Here is my code for the initial main page: <article> <ul data-role="listview" data-split-icon="star" data-split-theme="d" data-inset="true"> <li><a href="#black_seed_desc" data-rel="dialog" ><img src="black_seed.jpg"/> <h3>Black Seed Oil</h3> </a> <a href="#black_seed_purchase" data-rel="dialog" data-transition="pop">Purchase Black Seed Oil</a> </li> </ul> </article> Here is my code for the dialog page: <div data-role="dialog" id="black_seed_purchase" data-theme="c"> <section data-role="content"> <h1>Purchase Black Seed Oil?</h1> <p>By purchasing Black Seed Oil you will receive an email receipt copy sent to you for your reference.</p> <a href="#purchase_blackseed" data-inline="true" data-corners="true" data-rel="back" data-role="button" data-shadow="true" data-iconshadow="true" data-wrapperrels="span"> <span> <span>Buy: $49.99</span> <span>&nbsp;</span> </span> </a> <a href="#" data-role="button" data-rel="back" data-inline="true" data-corners="true" data-wrapperrels="span" data-shadow="true" data-iconshawdow="true"> <span> Cancel </span> </a> </section> </div> Here is a working example. http://jsfiddle.net/Gajotres/w3ptm/?

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  • pointer to preallocated memory as an input parameter and have the function fill it

    - by djones2010
    test code: void modify_it(char * mystuff) { char test[7] = "123456"; //last element is null i presume for c style strings here. //static char test[] = "123123"; //when i do this i thought i should be able to gain access to this bit of memory when the function is destroyed but that does not seem to be the case. //char * test = new char[7]; //this is also creating memory on stack and not the heap i reckon and gets destroyed once the function is done with. strcpy_s(mystuff,7,test); //this does the job as long as memory for mystuff has been allocated outside the function. mystuff = test; //this does not work. I know with c style strings you can't just do string assignments they have to be actually copied. in this case I was using this in conjunction with static char test thinking by having it as static the memory would not get destroyed and i can then simply point mystuff to test and be done with it. i would later have address the memory cleanup in the main function. but anyway this never worked. } int main(void) { char * mystuff = new char [7]; //allocate memory on heap where the pointer will point cool(mystuff); std::string test_case(mystuff); std::cout<<test_case.c_str(); //this is the only way i know how to use cout by making it into a string c++ string. delete [] mystuff; return 0; } in the case, of a static array in the function why would it not work. in the case, when i allocated memory using new in the function does it get created on the stack or heap? in the case, i have string which needs to be copied into a char * form. everything i see usually requires const char* instead of just char*. I know i could use reference to take care of this easy. Or char ** to send in the pointer and do it that way. But i just wanted to know if I could do it with just char *. Anyway your thoughts and comments plus any examples would be very helpful.

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  • How does the CLR (.NET) internally allocate and pass around custom value types (structs)?

    - by stakx
    Question: Do all CLR value types, including user-defined structs, live on the evaluation stack exclusively, meaning that they will never need to be reclaimed by the garbage-collector, or are there cases where they are garbage-collected? Background: I have previously asked a question on SO about the impact that a fluent interface has on the runtime performance of a .NET application. I was particuarly worried that creating a large number of very short-lived temporary objects would negatively affect runtime performance through more frequent garbage-collection. Now it has occured to me that if I declared those temporary objects' types as struct (ie. as user-defined value types) instead of class, the garbage collector might not be involved at all if it turns out that all value types live exclusively on the evaluation stack. What I've found out so far: I did a brief experiment to see what the differences are in the CIL generated for user-defined value types and reference types. This is my C# code: struct SomeValueType { public int X; } class SomeReferenceType { public int X; } . . static void TryValueType(SomeValueType vt) { ... } static void TryReferenceType(SomeReferenceType rt) { ... } . . var vt = new SomeValueType { X = 1 }; var rt = new SomeReferenceType { X = 2 }; TryValueType(vt); TryReferenceType(rt); And this is the CIL generated for the last four lines of code: .locals init ( [0] valuetype SomeValueType vt, [1] class SomeReferenceType rt, [2] valuetype SomeValueType <>g__initLocal0, // [3] class SomeReferenceType <>g__initLocal1, // why are these generated? [4] valuetype SomeValueType CS$0$0000 // ) L_0000: ldloca.s CS$0$0000 L_0002: initobj SomeValueType // no newobj required, instance already allocated L_0008: ldloc.s CS$0$0000 L_000a: stloc.2 L_000b: ldloca.s <>g__initLocal0 L_000d: ldc.i4.1 L_000e: stfld int32 SomeValueType::X L_0013: ldloc.2 L_0014: stloc.0 L_0015: newobj instance void SomeReferenceType::.ctor() L_001a: stloc.3 L_001b: ldloc.3 L_001c: ldc.i4.2 L_001d: stfld int32 SomeReferenceType::X L_0022: ldloc.3 L_0023: stloc.1 L_0024: ldloc.0 L_0025: call void Program::TryValueType(valuetype SomeValueType) L_002a: ldloc.1 L_002b: call void Program::TryReferenceType(class SomeReferenceType) What I cannot figure out from this code is this: Where are all those local variables mentioned in the .locals block allocated? How are they allocated? How are they freed? Why are so many anonymous local variables needed and copied to-and-fro only to initialize my two local variables rt and vt?

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  • Magento - How to select mysql rows by max value?

    - by Damodar Bashyal
    mysql> SELECT * FROM `log_customer` WHERE `customer_id` = 224 LIMIT 0, 30; +--------+------------+-------------+---------------------+-----------+----------+ | log_id | visitor_id | customer_id | login_at | logout_at | store_id | +--------+------------+-------------+---------------------+-----------+----------+ | 817 | 50139 | 224 | 2011-03-21 23:56:56 | NULL | 1 | | 830 | 52317 | 224 | 2011-03-27 23:43:54 | NULL | 1 | | 1371 | 136549 | 224 | 2011-11-16 04:33:51 | NULL | 1 | | 1495 | 164024 | 224 | 2012-02-08 01:05:48 | NULL | 1 | | 2130 | 281854 | 224 | 2012-11-13 23:44:13 | NULL | 1 | +--------+------------+-------------+---------------------+-----------+----------+ 5 rows in set (0.00 sec) mysql> SELECT * FROM `customer_entity` WHERE `entity_id` = 224; +-----------+----------------+---------------------------+----------+---------------------+---------------------+ | entity_id | entity_type_id | email | group_id | created_at | updated_at | +-----------+----------------+---------------------------+----------+---------------------+---------------------+ | 224 | 1 | [email protected] | 3 | 2011-03-21 04:59:17 | 2012-11-13 23:46:23 | +-----------+----------------+---------------------------+----------+--------------+----------+-----------------+ 1 row in set (0.00 sec) How can i search for customers who hasn't logged in for last 10 months and their account has not been updated for last 10 months. I tried below but failed. $collection = Mage::getModel('customer/customer')->getCollection(); $collection->getSelect()->joinRight(array('l'=>'log_customer'), "customer_id=entity_id AND MAX(l.login_at) <= '" . date('Y-m-d H:i:s', strtotime('10 months ago')) . "'")->group('e.entity_id'); $collection->addAttributeToSelect('*'); $collection->addFieldToFilter('updated_at', array( 'lt' => date('Y-m-d H:i:s', strtotime('10 months ago')), 'datetime'=>true, )); $collection->addAttributeToFilter('group_id', array( 'neq' => 5, )); Above tables have one customer for reference. I have no idea how to use MAX() on joins. Thanks UPDATE: This seems returning correct data, but I would like to do magento way using resource collection, so i don't need to do load customer again on for loop. $read = Mage::getSingleton('core/resource')->getConnection('core_read'); $sql = "select * from ( select e.*,l.login_at from customer_entity as e left join log_customer as l on l.customer_id=e.entity_id group by e.entity_id order by l.login_at desc ) as l where ( l.login_at <= '".date('Y-m-d H:i:s', strtotime('10 months ago'))."' or ( l.created_at <= '".date('Y-m-d H:i:s', strtotime('10 months ago'))."' and l.login_at is NULL ) ) and group_id != 5"; $result = $read->fetchAll($sql); I have loaded full shell script to github https://github.com/dbashyal/Magento-ecommerce-Shell-Scripts/blob/master/shell/suspendCustomers.php

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  • With custom binding for Masonry how would I resize the container appropriately

    - by BigDubb
    Based on the suggestion give here, and the information given here on how to make a custom bindingHandler for a forEach, I decided to attempt to write my own custom binding for a forEach and Masonry. Because the elements are added on the fly the redrawing and moving around of elements to fill the space doesn't occur. So, this functionality needed to be moved after the elements have been rendered or called after each item has been added. Here is my bindingHandler ko.bindingHandlers.masonry = { init: function (element, valueAccessor, allBindingsAccessor) { var $element = $(element), originalContent = $element.html(); $element.data("original-content", originalContent); //var msnry = new Masonry($element); return { controlsDescendantBindings: true } }, update: function (element, valueAccessor, allBindingsAccessor) { var value = ko.utils.unwrapObservable(valueAccessor()), //get the list of items items = value.items(), //get a jQuery reference to the element $element = $(element), //get the current content of the element elementContent = $element.data("original-content"); $element.html(""); var container = $element[0]; var msnry = new Masonry(container); for (var index = 0; index < items.length; index++) { (function () { //get the list of items var item = ko.utils.unwrapObservable(items[index]), $childElement = $(elementContent); ko.applyBindings(item, $childElement[0]); //add the child to the parent $element.append($childElement); msnry.appended($childElement[0]); })(); msnry.layout(); msnry.bindResize(); } } }; and the HTML implementing the handler. <div id="criteriaContainer" data-bind="masonry: { items: SearchItems.Items }"> <div class="searchCriterion control-group"> <label class="control-label" data-bind="text: Description"></label> <div class="controls"> <input type="hidden" data-bind="value: Value, select2: { minimumInputLength: 3, queryUri: SearchUri(), placeholder: Placeholder(), allowClear: true }" style="width: 450px"> </div> <p data-bind="text: Value"></p> </div> </div> When this shows up on the page It stacks all if the elements rendered via the append method right on top of each other. You can see in my bindingHandler I am calling bindResize as well as layout(), neither of which seem to be having any effect. Here's a screenshot of what it looks like in the UI.

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  • How to custom query using ORM in Fuelphp?

    - by viyancs
    I have a problem when I want to query table using ORM ,example I have article table with field id,author,text. My code like this : // Single where $article = Model_Article::find()->where('id', 4); print_r($article); that't code will be fetch all field on table article, it's like select * from article where id = 4 Try Possibility $article = Model_Article::find(null, array('id','title'))->where('id', 3); the response is object(Orm\Query)#89 (14) { ["model":protected]=> string(10) "Model_Article" ["connection":protected]=> NULL ["view":protected]=> NULL ["alias":protected]=> string(2) "t0" ["relations":protected]=> array(0) { } ["joins":protected]=> array(0) { } ["select":protected]=> array(1) { ["t0_c0"]=> string(5) "t0.id" } ["limit":protected]=> NULL ["offset":protected]=> NULL ["rows_limit":protected]=> NULL ["rows_offset":protected]=> NULL ["where":protected]=> array(1) { [0]=> array(2) { [0]=> string(9) "and_where" [1]=> array(3) { [0]=> string(5) "t0.id" [1]=> string(1) "=" [2]=> int(3) } } } ["order_by":protected]=> array(0) { } ["values":protected]=> array(0) { } } that's is not return id or title field. but when i'm try by adding get_one() method $article = Model_Article::find(null, array('id','title'))->where('id', 3)->get_one(); id is return , but title is not and another field, i don't know why ? Reference ORM Discussion FuelPHP it's say ORM currently will be select all column, no plans to change that at the moment. My Goal I want to query in orm like this select id,owner from article where id = 4 it's will be return only id & owner, how i can get that using orm ?

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  • Specializing function template for both std::string and char*

    - by sad_man
    As the title says I want to specialize a function template for both string and char pointer, so far I did this but I can not figure out passing the string parameters by reference. #include <iostream> #include <string> template<typename T> void xxx(T param) { std::cout << "General : "<< sizeof(T) << std::endl; } template<> void xxx<char*>(char* param) { std::cout << "Char ptr: "<< strlen(param) << std::endl; } template<> void xxx<const char* >(const char* param) { std::cout << "Const Char ptr : "<< strlen(param)<< std::endl; } template<> void xxx<const std::string & >(const std::string & param) { std::cout << "Const String : "<< param.size()<< std::endl; } template<> void xxx<std::string >(std::string param) { std::cout << "String : "<< param.size()<< std::endl; } int main() { xxx("word"); std::string aword("word"); xxx(aword); std::string const cword("const word"); xxx(cword); } Also template<> void xxx<const std::string & >(const std::string & param) thing just does not working. If I rearranged the opriginal template to accept parameters as T& then the char * is required to be char * & which is not good for static text in code. Please help !

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  • Joining the same model twice in a clean way, but making the code reusable

    - by Shako
    I have a model Painting which has a Paintingtitle in each language and a Paintingdescription in each language: class Painting < ActiveRecord::Base has_many :paintingtitles, :dependent => :destroy has_many :paintingdescriptions, :dependent => :destroy end class Paintingtitle < ActiveRecord::Base belongs_to :painting belongs_to :language end class Paintingdescription < ActiveRecord::Base belongs_to :painting belongs_to :language end class Language < ActiveRecord::Base has_many :paintingtitles, :dependent => :nullify has_many :paintingdescriptions, :dependent => :nullify has_many :paintings, :through => :paintingtitles end As you might notice, I reference the Language model from my Painting model via both the Paintingtitle model and Paintingdescription model. This works for me when getting a list of paintings with their title and description in a specific language: cond = {"paintingdescription_languages.code" => language_code, "paintingtitle_languages.code" => language_code} cond['paintings.publish'] = 1 unless admin paginate( :all, :select => ["paintings.id, paintings.publish, paintings.photo_file_name, paintingtitles.title, paintingdescriptions.description"], :joins => " INNER JOIN paintingdescriptions ON (paintings.id = paintingdescriptions.painting_id) INNER JOIN paintingtitles ON (paintings.id = paintingtitles.painting_id) INNER JOIN languages paintingdescription_languages ON (paintingdescription_languages.id = paintingdescriptions.language_id) INNER JOIN languages paintingtitle_languages ON (paintingtitle_languages.id = paintingtitles.language_id) ", :conditions => cond, :page => page, :per_page => APP_CONFIG['per_page'], :order => "id DESC" ) Now I wonder if this is a correct way of doing this. I need to fetch paintings with their title and description in different functions, but I don't want to specify this long join statement each time. Is there a cleaner way, for instance making use of the has_many through? e.g. has_many :paintingdescription_languages, :through => :paintingdescriptions, :source => :language has_many :paintingtitle_languages, :through => :paintingtitles, :source => :language But if I implement above 2 lines together with the following ones, then only paintingtitles are filtered by language, and not the paintingdescriptions: cond = {"languages.code" => language_code} cond['paintings.publish'] = 1 unless admin paginate( :all, :select => ["paintings.id, paintings.publish, paintings.photo_file_name, paintingtitles.title, paintingdescriptions.description"], :joins => [:paintingdescription_languages, :paintingtitle_languages], :conditions => cond, :page => page, :per_page => APP_CONFIG['per_page'], :order => "id DESC" )

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  • Where can I find "canonical" sample programs that give quick refreshers for any given language? [on hold]

    - by acheong87
    Note to those close-voting this question: I understand this isn't a conventional programming question and I can agree with the reasoning that it's in the subjective domain (like best-of lists). In other ways though I think it's appropriate because, though it's not a "a specific programming problem," nor concerning "a software algorithm", nor (strictly) concerning "software tools commonly used by programmers", I think it is a "practical, answerable [problem that is] unique to the programming profession," and I think it is "based on an actual [problem I] face." I've been wanting this for some time now, because both approaches of (a) Googling for samples as I write every other line of code and (b) just winging it and seeing what errors crop up, distract me from coding efficiently. This note will be removed if the question gains popularity; this question will be deleted otherwise. I spend most of my time developing in C++, PHP, or Javascript, and every once in a while I have to do something in, say, VBA. In those times, it'd be convenient if I could just put up some sample code on a second monitor, something in between a cheat sheet (often too compact; and doesn't resemble anything that could actually compile/run), and a language reference (often too verbose, or segmented; requires extra steps to search or click through an index), so I can just glance at it and recall things, like how to loop through non-empty cells in a column. I think there's a hidden benefit to seeing formed code, that triggers the right spots in our brains to get back into a language we only need to brush up on. Similar in spirit is how http://ideone.com lets you click "Template" in any given language so you can get started without even doing a search. That template alone tells a lot, sometimes! Case-sensitivity, whitespace conventions, identifier conventions, the spelling of certain types, etc. I couldn't find a resource that pulled together such samples, so if there indeed doesn't exist such a repository, I was hoping this question would inspire professionals and experts to contribute links to the most useful sample code they've used for just this purpose: a keep-on-the-side, form-as-well-as-content, compilable/executable, reminder of a language's basic and oft-used features. Personally I am interested in seeing "samplers" for: VBA, Perl, Python, Java, C# (though for some of these autocompleters in Eclipse, Visual Studio, etc. help enough), awk, and sed. I'm tagging c++, php, and javascript because these are languages for which I'd best be able to evaluate whether proffered sample code matches what I had in mind.

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  • The big last_insert_id() problem, again.

    - by wretrOvian
    Note - this follows my question here: http://stackoverflow.com/questions/2983685/jdbc-does-the-connection-break-if-i-lose-reference-to-the-connection-object Now i have a created a class so i can deal with JDBC easily for the rest of my code - public class Functions { private String DB_SERVER = ""; private String DB_NAME = "test"; private String DB_USERNAME = "root"; private String DB_PASSWORD = "password"; public Connection con; public PreparedStatement ps; public ResultSet rs; public ResultSetMetaData rsmd; public void connect() throws java.io.FileNotFoundException, java.io.IOException, SQLException, Exception { String[] dbParms = Parameters.load(); DB_SERVER = dbParms[0]; DB_NAME = dbParms[1]; DB_USERNAME = dbParms[2]; DB_PASSWORD = dbParms[3]; // Connect. Class.forName("com.mysql.jdbc.Driver").newInstance(); con = DriverManager.getConnection("jdbc:mysql://" + DB_SERVER + "/" + DB_NAME, DB_USERNAME, DB_PASSWORD); } public void disconnect() throws SQLException { // Close. con.close(); } } As seen Parameters.load() refreshes the connection parameters from a file every-time, so that any changes to the same may be applied on the next immediate connection. An example of this class in action - public static void add(String NAME) throws java.io.FileNotFoundException, java.io.IOException, SQLException, Exception { Functions dbf = new Functions(); dbf.connect(); String query = "INSERT INTO " + TABLE_NAME + "(" + "NAME" + ") VALUES(?)"; PreparedStatement ps = dbf.con.prepareStatement(query); ps.setString(1, NAME); ps.executeUpdate(); dbf.disconnect(); } Now here is the problem - for adding a record to the table above, the add() method will open a connection, add the record - and then call disconnect() . What if i want to get the ID of the inserted record after i call add() -like this : Department.add("new dept"); int ID = getlastID(); Isn't it possible that another add() was called between those two statements?

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  • (Strange) C++ linker error in constructor

    - by Microkernel
    I am trying to write a template class in C++ and getting this strange linker error and can't figureout the cause, please let me know whats wrong with this! Here is the error message I am getting in Visula C++ 2010. 1>------ Rebuild All started: Project: FlashEmulatorTemplates, Configuration: Debug Win32 ------ 1> main.cpp 1> emulator.cpp 1> Generating Code... 1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall flash_emulator<char>::flash_emulator<char>(char const *,struct FLASH_PROPERTIES *)" (??0?$flash_emulator@D@@QAE@PBDPAUFLASH_PROPERTIES@@@Z) referenced in function _main 1>C:\Projects\FlashEmulator_templates\VS\FlashEmulatorTemplates\Debug\FlashEmulatorTemplates.exe : fatal error LNK1120: 1 unresolved externals ========== Rebuild All: 0 succeeded, 1 failed, 0 skipped ========== Error message in g++ main.cpp: In function âint main()â: main.cpp:8: warning: deprecated conversion from string constant to âchar*â /tmp/ccOJ8koe.o: In function `main': main.cpp:(.text+0x21): undefined reference to `flash_emulator<char>::flash_emulator(char*, FLASH_PROPERTIES*)' collect2: ld returned 1 exit status There are 2 .cpp files and 1 header file, and I have given them below. emulator.h #ifndef __EMULATOR_H__ #define __EMULATOR_H__ typedef struct { int property; }FLASH_PROPERTIES ; /* Flash emulation class */ template<class T> class flash_emulator { private: /* Private data */ int key; public: /* Constructor - Opens an existing flash by name flashName or creates one with given FLASH_PROPERTIES if it doesn't exist */ flash_emulator( const char *flashName, FLASH_PROPERTIES *properties ); /* Constructor - Opens an existing flash by name flashName or creates one with given properties given in configFIleName */ flash_emulator<T>( char *flashName, char *configFileName ); /* Destructor for the emulator */ ~flash_emulator(){ } }; #endif /* End of __EMULATOR_H__ */ emulator.cpp #include <Windows.h> #include "emulator.h" using namespace std; template<class T>flash_emulator<T>::flash_emulator( const char *flashName, FLASH_PROPERTIES *properties ) { return; } template<class T>flash_emulator<T>::flash_emulator(char *flashName, char *configFileName) { return; } main.cpp #include <Windows.h> #include "emulator.h" int main() { FLASH_PROPERTIES properties = {0}; flash_emulator<char> myEmulator("C:\newEMu.flash", &properties); return 0; }

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  • Second query to SQLite (on iPhone) errors.

    - by Luke
    Hi all, On the iPhone, I am developing a class for a cart that connects directly to a database. To view the cart, all items can be pulled from the database, however, it seems that removing them doesn't work. It is surprising to me because the error occurs during connection to the database, except not the second time I connect even after the DB has been closed. #import "CartDB.h" #import "CartItem.h" @implementation CartDB @synthesize database, databasePath; - (NSMutableArray *) getAllItems { NSMutableArray *items = [[NSMutableArray alloc] init]; if([self openDatabase]) { const char *sqlStatement = "SELECT * FROM items;"; sqlite3_stmt *compiledStatement; if(sqlite3_prepare_v2(cartDatabase, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { while(sqlite3_step(compiledStatement) == SQLITE_ROW) { int rowId = sqlite3_column_int(compiledStatement, 0); int productId = sqlite3_column_int(compiledStatement, 1); NSString *features = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)]; int quantity = sqlite3_column_int(compiledStatement, 3); CartItem *cartItem = [[CartItem alloc] initWithRowId:rowId productId:productId features:features quantity:quantity]; [items addObject:cartItem]; [cartItem release]; } } sqlite3_finalize(compiledStatement); } [self closeDatabase]; return items; } - (BOOL) removeCartItem:(CartItem *)item { sqlite3_stmt *deleteStatement; [self openDatabase]; const char *sql = "DELETE FROM items WHERE id = ?"; if(sqlite3_prepare_v2(cartDatabase, sql, -1, &deleteStatement, NULL) != SQLITE_OK) { return NO; } sqlite3_bind_int(deleteStatement, 1, item.rowId); if(SQLITE_DONE != sqlite3_step(deleteStatement)) { sqlite3_reset(deleteStatement); [self closeDatabase]; return NO; } else { sqlite3_reset(deleteStatement); [self closeDatabase]; return YES; } } - (BOOL) openDatabase { if(sqlite3_open([databasePath UTF8String], &cartDatabase) == SQLITE_OK) { return YES; } else { return NO; } } - (void) closeDatabase { sqlite3_close(cartDatabase); } The error occurs on the line where the connection is opened in openDatabase. Any ideas? Need to flush something? Something gets autoreleased? I really can't figure it out. --Edit-- The error that I receive is GDB: Program received signal "EXC_BAD_ACCESS". --Edit-- I ended up just connecting in the init and closing in the free methods, which might not be the proper way, but that's another question altogether so it's effectively persistent instead of connecting multiple times. Still would be nice to know what was up with this for future reference.

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  • The Incremental Architect&rsquo;s Napkin - #5 - Design functions for extensibility and readability

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities.   PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

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  • Scripting with the Sun ZFS Storage 7000 Appliance

    - by Geoff Ongley
    The Sun ZFS Storage 7000 appliance has a user friendly and easy to understand graphical web based interface we call the "BUI" or "Browser User Interface".This interface is very useful for many tasks, but in some cases a script (or workflow) may be more appropriate, such as:Repetitive tasksTasks which work on (or obtain information about) a large number of shares or usersTasks which are triggered by an alert threshold (workflows)Tasks where you want a only very basic input, but a consistent output (workflows)The appliance scripting language is based on ECMAscript 3 (close to javascript). I'm not going to cover ECMAscript 3 in great depth (I'm far from an expert here), but I would like to show you some neat things you can do with the appliance, to get you started based on what I have found from my own playing around.I'm making the assumption you have some sort of programming background, and understand variables, arrays, functions to some extent - but of course if something is not clear, please let me know so I can fix it up or clarify it.Variable Declarations and ArraysVariablesECMAScript is a dynamically and weakly typed language. If you don't know what that means, google is your friend - but at a high level it means we can just declare variables with no specific type and on the fly.For example, I can declare a variable and use it straight away in the middle of my code, for example:projects=list();Which makes projects an array of values that are returned from the list(); function (which is usable in most contexts). With this kind of variable, I can do things like:projects.length (this property on array tells you how many objects are in it, good for for loops etc). Alternatively, I could say:projects=3;and now projects is just a simple number.Should we declare variables like this so loosely? In my opinion, the answer is no - I feel it is a better practice to declare variables you are going to use, before you use them - and given them an initial value. You can do so as follows:var myVariable=0;To demonstrate the ability to just randomly assign and change the type of variables, you can create a simple script at the cli as follows (bold for input):fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("Number of projects is: %d\n",projects.length);("." to run)> projects=152;("." to run)> printf("Value of the projects variable as an integer is now: %d\n",projects);("." to run)> .Number of projects is: 7Value of the projects variable as an integer is now: 152You can also confirm this behaviour by checking the typeof variable we are dealing with:fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> projects=152;("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> .var projects is of type objectvar projects is of type numberArraysSo you likely noticed that we have already touched on arrays, as the list(); (in the shares context) stored an array into the 'projects' variable.But what if you want to declare your own array? Easy! This is very similar to Java and other languages, we just instantiate a brand new "Array" object using the keyword new:var myArray = new Array();will create an array called "myArray".A quick example:fishy10:> script("." to run)> testArray = new Array();("." to run)> testArray[0]="This";("." to run)> testArray[1]="is";("." to run)> testArray[2]="just";("." to run)> testArray[3]="a";("." to run)> testArray[4]="test";("." to run)> for (i=0; i < testArray.length; i++)("." to run)> {("." to run)>    printf("Array element %d is %s\n",i,testArray[i]);("." to run)> }("." to run)> .Array element 0 is ThisArray element 1 is isArray element 2 is justArray element 3 is aArray element 4 is testWorking With LoopsFor LoopFor loops are very similar to those you will see in C, java and several other languages. One of the key differences here is, as you were made aware earlier, we can be a bit more sloppy with our variable declarations.The general way you would likely use a for loop is as follows:for (variable; test-case; modifier for variable){}For example, you may wish to declare a variable i as 0; and a MAX_ITERATIONS variable to determine how many times this loop should repeat:var i=0;var MAX_ITERATIONS=10;And then, use this variable to be tested against some case existing (has i reached MAX_ITERATIONS? - if not, increment i using i++);for (i=0; i < MAX_ITERATIONS; i++){ // some work to do}So lets run something like this on the appliance:fishy10:> script("." to run)> var i=0;("." to run)> var MAX_ITERATIONS=10;("." to run)> for (i=0; i < MAX_ITERATIONS; i++)("." to run)> {("." to run)>    printf("The number is %d\n",i);("." to run)> }("." to run)> .The number is 0The number is 1The number is 2The number is 3The number is 4The number is 5The number is 6The number is 7The number is 8The number is 9While LoopWhile loops again are very similar to other languages, we loop "while" a condition is met. For example:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n",counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Counter is 10Loop has ended and Counter is 11So what do we notice here? Something has actually gone wrong - counter will technically be 11 once the loop completes... Why is this?Well, if we have a loop like this, where the 'while' condition that will end the loop may be set based on some other condition(s) existing (such as the counter has reached 10) - we must ensure that we  terminate this iteration of the loop when the condition is met - otherwise the rest of the code will be followed which may not be desirable. In other words, like in other languages, we will only ever check the loop condition once we are ready to perform the next iteration, so any other code after we set "isTen" to be true, will still be executed as we can see it was above.We can avoid this by adding a break into our loop once we know we have set the condition - this will stop the rest of the logic being processed in this iteration (and as such, counter will not be incremented). So lets try that again:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>            break;("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n", counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Loop has ended and Counter is 10Much better!Methods to Obtain and Manipulate DataGet MethodThe get method allows you to get simple properties from an object, for example a quota from a user. The syntax is fairly simple:var myVariable=get('property');An example of where you may wish to use this, is when you are getting a bunch of information about a user (such as quota information when in a shares context):var users=list();for(k=0; k < users.length; k++){     user=users[k];     run('select ' + user);     var username=get('name');     var usage=get('usage');     var quota=get('quota');...Which you can then use to your advantage - to print or manipulate infomation (you could change a user's information with a set method, based on the information returned from the get method). The set method is explained next.Set MethodThe set method can be used in a simple manner, similar to get. The syntax for set is:set('property','value'); // where value is a string, if it was a number, you don't need quotesFor example, we could set the quota on a share as follows (first observing the initial value):fishy10:shares default/test-geoff> script("." to run)> var currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> set('quota','30G');("." to run)> run('commit');("." to run)> currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> .Current Quota is: 0Current Quota is: 32212254720This shows us using both the get and set methods as can be used in scripts, of course when only setting an individual share, the above is overkill - it would be much easier to set it manually at the cli using 'set quota=3G' and then 'commit'.List MethodThe list method can be very powerful, especially in more complex scripts which iterate over large amounts of data and manipulate it if so desired. The general way you will use list is as follows:var myVar=list();Which will make "myVar" an array, containing all the objects in the relevant context (this could be a list of users, shares, projects, etc). You can then gather or manipulate data very easily.We could list all the shares and mountpoints in a given project for example:fishy10:shares another-project> script("." to run)> var shares=list();("." to run)> for (i=0; i < shares.length; i++)("." to run)> {("." to run)>    run('select ' + shares[i]);("." to run)>    var mountpoint=get('mountpoint');("." to run)>    printf("Share %s discovered, has mountpoint %s\n",shares[i],mountpoint);("." to run)>    run('done');("." to run)> }("." to run)> .Share and-another discovered, has mountpoint /export/another-project/and-anotherShare another-share discovered, has mountpoint /export/another-project/another-shareShare bob discovered, has mountpoint /export/another-projectShare more-shares-for-all discovered, has mountpoint /export/another-project/more-shares-for-allShare yep discovered, has mountpoint /export/another-project/yepWriting More Complex and Re-Usable CodeFunctionsThe best way to be able to write more complex code is to use functions to split up repeatable or reusable sections of your code. This also makes your more complex code easier to read and understand for other programmers.We write functions as follows:function functionName(variable1,variable2,...,variableN){}For example, we could have a function that takes a project name as input, and lists shares for that project (assuming we're already in the 'project' context - context is important!):function getShares(proj){        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                printf("Discovered share: %s\n",shares[i]);        }        run('done'); // exit selected project}Commenting your CodeLike any other language, a large part of making it readable and understandable is to comment it. You can use the same comment style as in C and Java amongst other languages.In other words, sngle line comments use://at the beginning of the comment.Multi line comments use:/*at the beginning, and:*/ at the end.For example, here we will use both:fishy10:> script("." to run)> // This is a test comment("." to run)> printf("doing some work...\n");("." to run)> /* This is a multi-line("." to run)> comment which I will span across("." to run)> three lines in total */("." to run)> printf("doing some more work...\n");("." to run)> .doing some work...doing some more work...Your comments do not have to be on their own, they can begin (particularly with single line comments this is handy) at the end of a statement, for examplevar projects=list(); // The variable projects is an array containing all projects on the system.Try and Catch StatementsYou may be used to using try and catch statements in other languages, and they can (and should) be utilised in your code to catch expected or unexpected error conditions, that you do NOT wish to stop your code from executing (if you do not catch these errors, your script will exit!):try{  // do some work}catch(err) // Catch any error that could occur{ // do something here under the error condition}For example, you may wish to only execute some code if a context can be reached. If you can't perform certain actions under certain circumstances, that may be perfectly acceptable.For example if you want to test a condition that only makes sense when looking at a SMB/NFS share, but does not make sense when you hit an iscsi or FC LUN, you don't want to stop all processing of other shares you may not have covered yet.For example we may wish to obtain quota information on all shares for all users on a share (but this makes no sense for a LUN):function getShareQuota(shar) // Get quota for each user of this share{        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","----");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}Running Scripts Remotely over SSHAs you have likely noticed, writing and running scripts for all but the simplest jobs directly on the appliance is not going to be a lot of fun.There's a couple of choices on what you can do here:Create scripts on a remote system and run them over sshCreate scripts, wrapping them in workflow code, so they are stored on the appliance and can be triggered under certain circumstances (like a threshold being reached)We'll cover the first one here, and then cover workflows later on (as these are for the most part just scripts with some wrapper information around them).Creating a SSH Public/Private SSH Key PairLog on to your handy Solaris box (You wouldn't be using any other OS, right? :P) and use ssh-keygen to create a pair of ssh keys. I'm storing this separate to my normal key:[geoff@lightning ~] ssh-keygen -t rsa -b 1024Generating public/private rsa key pair.Enter file in which to save the key (/export/home/geoff/.ssh/id_rsa): /export/home/geoff/.ssh/nas_key_rsaEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /export/home/geoff/.ssh/nas_key_rsa.Your public key has been saved in /export/home/geoff/.ssh/nas_key_rsa.pub.The key fingerprint is:7f:3d:53:f0:2a:5e:8b:2d:94:2a:55:77:66:5c:9b:14 geoff@lightningInstalling the Public Key on the ApplianceOn your Solaris host, observe the public key:[geoff@lightning ~] cat .ssh/nas_key_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc= geoff@lightningNow, copy and paste everything after "ssh-rsa" and before "user@hostname" - in this case, geoff@lightning. That is, this bit:AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc=Logon to your appliance and get into the preferences -> keys area for this user (root):[geoff@lightning ~] ssh [email protected]: Last login: Mon Dec  6 17:13:28 2010 from 192.168.0.2fishy10:> configuration usersfishy10:configuration users> select rootfishy10:configuration users root> preferences fishy10:configuration users root preferences> keysOR do it all in one hit:fishy10:> configuration users select root preferences keysNow, we create a new public key that will be accepted for this user and set the type to RSA:fishy10:configuration users root preferences keys> createfishy10:configuration users root preferences key (uncommitted)> set type=RSASet the key itself using the string copied previously (between ssh-rsa and user@host), and set the key ensuring you put double quotes around it (eg. set key="<key>"):fishy10:configuration users root preferences key (uncommitted)> set key="AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc="Now set the comment for this key (do not use spaces):fishy10:configuration users root preferences key (uncommitted)> set comment="LightningRSAKey" Commit the new key:fishy10:configuration users root preferences key (uncommitted)> commitVerify the key is there:fishy10:configuration users root preferences keys> lsKeys:NAME     MODIFIED              TYPE   COMMENT                                  key-000  2010-10-25 20:56:42   RSA    cycloneRSAKey                           key-001  2010-12-6 17:44:53    RSA    LightningRSAKey                         As you can see, we now have my new key, and a previous key I have created on this appliance.Running your Script over SSH from a Remote SystemHere I have created a basic test script, and saved it as test.ecma3:[geoff@lightning ~] cat test.ecma3 script// This is a test script, By Geoff Ongley 2010.printf("Testing script remotely over ssh\n");.Now, we can run this script remotely with our keyless login:[geoff@lightning ~] ssh -i .ssh/nas_key_rsa root@fishy10 < test.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Testing script remotely over sshPutting it Together - An Example Completed Quota Gathering ScriptSo now we have a lot of the basics to creating a script, let us do something useful, like, find out how much every user is using, on every share on the system (you will recognise some of the code from my previous examples): script/************************************** Quick and Dirty Quota Check script ** Written By Geoff Ongley            ** 25 October 2010                    **************************************/function getUserQuota(usr){        run('select ' + usr);        var username=get('name');        var usage=get('usage');        var quota=get('quota');        var usage_g=usage / 1073741824; // convert bytes to gigabytes        var quota_g=quota / 1073741824; // as above        var quota_percent=0        if (quota > 0)        {                quota_percent=(usage / quota)*(100/1);        }        printf("    %20s        %8.2f           %8.2f           %d%%\n",username,usage_g,quota_g,quota_percent);        run('done'); // done with this selected user}function getShareQuota(shar){        //printf("DEBUG: selecting share %s\n", shar);        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","--------");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}function getShares(proj){        //printf("DEBUG: selecting project %s\n",proj);        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                share=shares[j];                getShareQuota(share);        }        run('done'); // exit selected project}function getProjects(){        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                var project=projects[i];                getShares(project);        }        run('done'); // exit context for all projects}getProjects();.Which can be run as follows, and will print information like this:[geoff@lightning ~/FISHWORKS_SCRIPTS] ssh -i ~/.ssh/nas_key_rsa root@fishy10 < get_quota_utilisation.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Project: another-project  SHARE: and-another                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                 geoffro            0.05            0.00        0%                   Billy            0.10            0.00        0%                    root            0.00            0.00        0%            testing-user            0.05            0.00        0%  SHARE: another-share                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                 geoffro            0.05            0.49        9%            testing-user            0.05            0.02        249%                   Billy            0.10            0.29        33%  SHARE: bob                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%  SHARE: more-shares-for-all                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                   Billy            0.10            0.00        0%            testing-user            0.05            0.00        0%                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%                 geoffro            0.05            0.00        0%  SHARE: yep                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                   Billy            0.10            0.01        999%            testing-user            0.05            0.49        9%                 geoffro            0.05            0.00        0%Project: default  SHARE: Test-LUN    SKIPPING Test-LUN - This is NOT a NFS or CIFs share, not looking for users  SHARE: test-geoff                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                 geoffro            0.05            0.00        0%                    root            3.18           10.00        31%                    uucp            0.00            0.00        0%                  nobody            0.59            0.49        119%^CKilled by signal 2.Creating a WorkflowWorkflows are scripts that we store on the appliance, and can have the script execute either on request (even from the BUI), or on an event such as a threshold being met.Workflow BasicsA workflow allows you to create a simple process that can be executed either via the BUI interface interactively, or by an alert being raised (for some threshold being reached, for example).The basics parameters you will have to set for your "workflow object" (notice you're creating a variable, that embodies ECMAScript) are as follows (parameters is optional):name: A name for this workflowdescription: A Description for the workflowparameters: A set of input parameters (useful when you need user input to execute the workflow)execute: The code, the script itself to execute, which will be function (parameters)With parameters, you can specify things like this (slightly modified sample taken from the System Administration Guide):          ...parameters:        variableParam1:         {                             label: 'Name of Share',                             type: 'String'                  },                  variableParam2                  {                             label: 'Share Size',                             type: 'size'                  },execute: ....};  Note the commas separating the sections of name, parameters, execute, and so on. This is important!Also - there is plenty of properties you can set on the parameters for your workflow, these are described in the Sun ZFS Storage System Administration Guide.Creating a Basic Workflow from a Basic ScriptTo make a basic script into a basic workflow, you need to wrap the following around your script to create a 'workflow' object:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function() {// (basic script goes here, minus the "script" at the beginning, and "." at the end)}};However, it appears (at least in my experience to date) that the workflow object may only be happy with one function in the execute parameter - either that or I'm doing something wrong. As far as I can tell, after execute: you should only have a basic one function context like so:execute: function(){}To deal with this, and to give an example similar to our script earlier, I have created another simple quota check, to show the same basic functionality, but in a workflow format:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function () {        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                run('select ' + projects[i]);                shares=list('filesystem');                printf("Project: %s\n", projects[i]);                for(j=0; j < shares.length; j++)                {                        run('select ' +shares[j]);                        try                        {                                run('users');                                printf("  SHARE: %s\n", shares[j]);                                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","-------");                                users=list();                                for(k=0; k < users.length; k++)                                {                                        run('select ' + users[k]);                                        username=get('name');                                        usage=get('usage');                                        quota=get('quota');                                        usage_g=usage / 1073741824; // convert bytes to gigabytes                                        quota_g=quota / 1073741824; // as above                                        quota_percent=0                                        if (quota > 0)                                        {                                                quota_percent=(usage / quota)*(100/1);                                        }                                        printf("    %20s        %8.2f   %8.2f   %d%%\n",username,usage_g,quota_g,quota_percent);                                        run('done');                                }                                run('done'); // exit user context                        }                        catch(err)                        {                        //      printf("    %s is a LUN, Not looking for users\n", shares[j]);                        }                        run('done'); // exit selected share context                }                run('done'); // exit project context        }        }};SummaryThe Sun ZFS Storage 7000 Appliance offers lots of different and interesting features to Sun/Oracle customers, including the world renowned Analytics. Hopefully the above will help you to think of new creative things you could be doing by taking advantage of one of the other neat features, the internal scripting engine!Some references are below to help you continue learning more, I'll update this post as I do the same! Enjoy...More information on ECMAScript 3A complete reference to ECMAScript 3 which will help you learn more of the details you may be interested in, can be found here:http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdfMore Information on Administering the Sun ZFS Storage 7000The Sun ZFS Storage 7000 System Administration guide can be a useful reference point, and can be found here:http://wikis.sun.com/download/attachments/186238602/2010_Q3_2_ADMIN.pdf

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  • Powershell script to change screen Orientation

    - by user161964
    I wrote a script to change Primary screen orientation to portrait. my screen is 1920X1200 It runs and no error reported. But the screen does not rotated as i expected. The code was modified from Set-ScreenResolution (Andy Schneider) Does anybody can help me take a look? some reference site: 1.set-screenresolution http://gallery.technet.microsoft.com/ScriptCenter/2a631d72-206d-4036-a3f2-2e150f297515/ 2.C code for change oridentation (MSDN) Changing Screen Orientation Programmatically http://msdn.microsoft.com/en-us/library/ms812499.aspx my code as below: Function Set-ScreenOrientation { $pinvokeCode = @" using System; using System.Runtime.InteropServices; namespace Resolution { [StructLayout(LayoutKind.Sequential)] public struct DEVMODE1 { [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string dmDeviceName; public short dmSpecVersion; public short dmDriverVersion; public short dmSize; public short dmDriverExtra; public int dmFields; public short dmOrientation; public short dmPaperSize; public short dmPaperLength; public short dmPaperWidth; public short dmScale; public short dmCopies; public short dmDefaultSource; public short dmPrintQuality; public short dmColor; public short dmDuplex; public short dmYResolution; public short dmTTOption; public short dmCollate; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string dmFormName; [MarshalAs(UnmanagedType.U4)] public short dmDisplayOrientation public short dmLogPixels; public short dmBitsPerPel; public int dmPelsWidth; public int dmPelsHeight; public int dmDisplayFlags; public int dmDisplayFrequency; public int dmICMMethod; public int dmICMIntent; public int dmMediaType; public int dmDitherType; public int dmReserved1; public int dmReserved2; public int dmPanningWidth; public int dmPanningHeight; }; class User_32 { [DllImport("user32.dll")] public static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE1 devMode); [DllImport("user32.dll")] public static extern int ChangeDisplaySettings(ref DEVMODE1 devMode, int flags); public const int ENUM_CURRENT_SETTINGS = -1; public const int CDS_UPDATEREGISTRY = 0x01; public const int CDS_TEST = 0x02; public const int DISP_CHANGE_SUCCESSFUL = 0; public const int DISP_CHANGE_RESTART = 1; public const int DISP_CHANGE_FAILED = -1; } public class PrmaryScreenOrientation { static public string ChangeOrientation() { DEVMODE1 dm = GetDevMode1(); if (0 != User_32.EnumDisplaySettings(null, User_32.ENUM_CURRENT_SETTINGS, ref dm)) { dm.dmDisplayOrientation = DMDO_90 dm.dmPelsWidth = 1200; dm.dmPelsHeight = 1920; int iRet = User_32.ChangeDisplaySettings(ref dm, User_32.CDS_TEST); if (iRet == User_32.DISP_CHANGE_FAILED) { return "Unable To Process Your Request. Sorry For This Inconvenience."; } else { iRet = User_32.ChangeDisplaySettings(ref dm, User_32.CDS_UPDATEREGISTRY); switch (iRet) { case User_32.DISP_CHANGE_SUCCESSFUL: { return "Success"; } case User_32.DISP_CHANGE_RESTART: { return "You Need To Reboot For The Change To Happen.\n If You Feel Any Problem After Rebooting Your Machine\nThen Try To Change Resolution In Safe Mode."; } default: { return "Failed"; } } } } else { return "Failed To Change."; } } private static DEVMODE1 GetDevMode1() { DEVMODE1 dm = new DEVMODE1(); dm.dmDeviceName = new String(new char[32]); dm.dmFormName = new String(new char[32]); dm.dmSize = (short)Marshal.SizeOf(dm); return dm; } } } "@ Add-Type $pinvokeCode -ErrorAction SilentlyContinue [Resolution.PrmaryScreenOrientation]::ChangeOrientation() }

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  • External USB drive is failing

    - by dma_k
    I have an external USB 2.0 drive WD My Book Mirror Edition, running in RAID 1 (mirroring) mode. A while ago the hard drive started to fail: it stops responding (directories are not listed returning an error after a big timeout). Sometimes it works for weeks before a failure, sometimes – few hours. Small write operations (like removing few files or editing a small file) do not harm, but when copying large files to the drive over the network, or creating the archive locally, the kernel dumps. Also interesting to note that once kernel has failed, Linux does not want to reboot normally (reboot hangs); when Linux box is shutdown with power button, WD drive does not go to sleep mode (as it usually does): leds continue to run, pressing and holding the "shutdown" button on drive's back panel does not do anything; only unplugging the power cord helps. Here goes the boot log: Aug 16 00:32:21 kernel: [ 1.514106] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver Aug 16 00:32:21 kernel: [ 1.657738] ehci_hcd 0000:00:1d.7: PCI INT A -> GSI 23 (level, low) -> IRQ 23 Aug 16 00:32:21 kernel: [ 1.673747] ehci_hcd 0000:00:1d.7: setting latency timer to 64 Aug 16 00:32:21 kernel: [ 1.673751] ehci_hcd 0000:00:1d.7: EHCI Host Controller Aug 16 00:32:21 kernel: [ 1.725224] ehci_hcd 0000:00:1d.7: new USB bus registered, assigned bus number 1 Aug 16 00:32:21 kernel: [ 1.741647] ehci_hcd 0000:00:1d.7: using broken periodic workaround Aug 16 00:32:21 kernel: [ 1.761790] ehci_hcd 0000:00:1d.7: cache line size of 32 is not supported Aug 16 00:32:21 kernel: [ 1.761873] ehci_hcd 0000:00:1d.7: irq 23, io mem 0xfdfff000 Aug 16 00:32:21 kernel: [ 1.796043] ehci_hcd 0000:00:1d.7: USB 2.0 started, EHCI 1.00 Aug 16 00:32:21 kernel: [ 1.879069] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002 Aug 16 00:32:21 kernel: [ 1.895446] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 Aug 16 00:32:21 kernel: [ 1.911796] usb usb1: Product: EHCI Host Controller Aug 16 00:32:21 kernel: [ 1.928015] usb usb1: Manufacturer: Linux 2.6.32-5-686 ehci_hcd Aug 16 00:32:21 kernel: [ 1.944331] usb usb1: SerialNumber: 0000:00:1d.7 Aug 16 00:32:21 kernel: [ 1.961285] usb usb1: configuration #1 chosen from 1 choice Aug 16 00:32:21 kernel: [ 1.994412] hub 1-0:1.0: USB hub found Aug 16 00:32:21 kernel: [ 2.010864] hub 1-0:1.0: 8 ports detected Aug 16 00:32:21 kernel: [ 2.085939] uhci_hcd: USB Universal Host Controller Interface driver Aug 16 00:32:21 kernel: [ 2.191945] uhci_hcd 0000:00:1d.0: PCI INT A -> GSI 23 (level, low) -> IRQ 23 Aug 16 00:32:21 kernel: [ 2.226029] uhci_hcd 0000:00:1d.0: setting latency timer to 64 Aug 16 00:32:21 kernel: [ 2.226034] uhci_hcd 0000:00:1d.0: UHCI Host Controller Aug 16 00:32:21 kernel: [ 2.243237] uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus number 2 Aug 16 00:32:21 kernel: [ 2.260390] uhci_hcd 0000:00:1d.0: irq 23, io base 0x0000fe00 Aug 16 00:32:21 kernel: [ 2.277517] usb usb2: New USB device found, idVendor=1d6b, idProduct=0001 Aug 16 00:32:21 kernel: [ 2.294815] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1 Aug 16 00:32:21 kernel: [ 2.312173] usb usb2: Product: UHCI Host Controller Aug 16 00:32:21 kernel: [ 2.329534] usb usb2: Manufacturer: Linux 2.6.32-5-686 uhci_hcd Aug 16 00:32:21 kernel: [ 2.346828] usb usb2: SerialNumber: 0000:00:1d.0 Aug 16 00:32:21 kernel: [ 2.412989] usb usb2: configuration #1 chosen from 1 choice Aug 16 00:32:21 kernel: [ 2.430651] usb 1-2: new high speed USB device using ehci_hcd and address 2 Aug 16 00:32:21 kernel: [ 2.449046] hub 2-0:1.0: USB hub found Aug 16 00:32:21 kernel: [ 2.466514] hub 2-0:1.0: 2 ports detected Aug 16 00:32:21 kernel: [ 2.484639] uhci_hcd 0000:00:1d.1: PCI INT B -> GSI 19 (level, low) -> IRQ 19 Aug 16 00:32:21 kernel: [ 2.537750] uhci_hcd 0000:00:1d.1: setting latency timer to 64 Aug 16 00:32:21 kernel: [ 2.537756] uhci_hcd 0000:00:1d.1: UHCI Host Controller Aug 16 00:32:21 kernel: [ 2.555085] uhci_hcd 0000:00:1d.1: new USB bus registered, assigned bus number 3 Aug 16 00:32:21 kernel: [ 2.572231] uhci_hcd 0000:00:1d.1: irq 19, io base 0x0000fd00 Aug 16 00:32:21 kernel: [ 2.589593] usb usb3: New USB device found, idVendor=1d6b, idProduct=0001 Aug 16 00:32:21 kernel: [ 2.606869] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1 Aug 16 00:32:21 kernel: [ 2.624134] usb usb3: Product: UHCI Host Controller Aug 16 00:32:21 kernel: [ 2.641329] usb usb3: Manufacturer: Linux 2.6.32-5-686 uhci_hcd Aug 16 00:32:21 kernel: [ 2.658505] usb usb3: SerialNumber: 0000:00:1d.1 Aug 16 00:32:21 kernel: [ 2.675843] usb usb3: configuration #1 chosen from 1 choice Aug 16 00:32:21 kernel: [ 2.692864] hub 3-0:1.0: USB hub found Aug 16 00:32:21 kernel: [ 2.709651] hub 3-0:1.0: 2 ports detected Aug 16 00:32:21 kernel: [ 2.727378] uhci_hcd 0000:00:1d.2: PCI INT C -> GSI 18 (level, low) -> IRQ 18 Aug 16 00:32:21 kernel: [ 2.768252] uhci_hcd 0000:00:1d.2: setting latency timer to 64 Aug 16 00:32:21 kernel: [ 2.768258] uhci_hcd 0000:00:1d.2: UHCI Host Controller Aug 16 00:32:21 kernel: [ 2.806679] uhci_hcd 0000:00:1d.2: new USB bus registered, assigned bus number 4 Aug 16 00:32:21 kernel: [ 2.824117] uhci_hcd 0000:00:1d.2: irq 18, io base 0x0000fc00 Aug 16 00:32:21 kernel: [ 2.841405] usb 1-2: New USB device found, idVendor=1058, idProduct=1104 Aug 16 00:32:21 kernel: [ 2.858448] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Aug 16 00:32:21 kernel: [ 2.875347] usb 1-2: Product: My Book Aug 16 00:32:21 kernel: [ 2.892113] usb 1-2: Manufacturer: Western Digital Aug 16 00:32:21 kernel: [ 2.908915] usb 1-2: SerialNumber: 575532553130303530353538 Aug 16 00:32:21 kernel: [ 2.943242] usb usb4: New USB device found, idVendor=1d6b, idProduct=0001 Aug 16 00:32:21 kernel: [ 2.960405] usb usb4: New USB device strings: Mfr=3, Product=2, SerialNumber=1 Aug 16 00:32:21 kernel: [ 2.977615] usb usb4: Product: UHCI Host Controller Aug 16 00:32:21 kernel: [ 2.994687] usb usb4: Manufacturer: Linux 2.6.32-5-686 uhci_hcd Aug 16 00:32:21 kernel: [ 3.011711] usb usb4: SerialNumber: 0000:00:1d.2 Aug 16 00:32:21 kernel: [ 3.029589] usb usb4: configuration #1 chosen from 1 choice Aug 16 00:32:21 kernel: [ 3.082027] sd 2:0:0:0: [sda] Attached SCSI disk Aug 16 00:32:21 kernel: [ 3.103953] usb 1-2: configuration #1 chosen from 1 choice Aug 16 00:32:21 kernel: [ 3.122625] hub 4-0:1.0: USB hub found Aug 16 00:32:21 kernel: [ 3.140484] hub 4-0:1.0: 2 ports detected Aug 16 00:32:21 kernel: [ 3.161680] uhci_hcd 0000:00:1d.3: PCI INT D -> GSI 16 (level, low) -> IRQ 16 Aug 16 00:32:21 kernel: [ 3.181257] uhci_hcd 0000:00:1d.3: setting latency timer to 64 Aug 16 00:32:21 kernel: [ 3.181263] uhci_hcd 0000:00:1d.3: UHCI Host Controller Aug 16 00:32:21 kernel: [ 3.198614] uhci_hcd 0000:00:1d.3: new USB bus registered, assigned bus number 5 Aug 16 00:32:21 kernel: [ 3.216012] uhci_hcd 0000:00:1d.3: irq 16, io base 0x0000fb00 Aug 16 00:32:21 kernel: [ 3.249877] Uniform CD-ROM driver Revision: 3.20 Aug 16 00:32:21 kernel: [ 3.267765] usb usb5: New USB device found, idVendor=1d6b, idProduct=0001 Aug 16 00:32:21 kernel: [ 3.284947] usb usb5: New USB device strings: Mfr=3, Product=2, SerialNumber=1 Aug 16 00:32:21 kernel: [ 3.302023] usb usb5: Product: UHCI Host Controller Aug 16 00:32:21 kernel: [ 3.319215] usb usb5: Manufacturer: Linux 2.6.32-5-686 uhci_hcd Aug 16 00:32:21 kernel: [ 3.336298] usb usb5: SerialNumber: 0000:00:1d.3 Aug 16 00:32:21 kernel: [ 3.368377] Initializing USB Mass Storage driver... Aug 16 00:32:21 kernel: [ 3.390652] usbcore: registered new interface driver hiddev Aug 16 00:32:21 kernel: [ 3.408109] scsi4 : SCSI emulation for USB Mass Storage devices Aug 16 00:32:21 kernel: [ 3.425281] sr 0:0:1:0: Attached scsi CD-ROM sr0 Aug 16 00:32:21 kernel: [ 3.438978] sr 0:0:1:0: Attached scsi generic sg0 type 5 Aug 16 00:32:21 kernel: [ 3.456328] usbcore: registered new interface driver usb-storage Aug 16 00:32:21 kernel: [ 3.474564] usb-storage: device found at 2 Aug 16 00:32:21 kernel: [ 3.474567] usb-storage: waiting for device to settle before scanning Aug 16 00:32:21 kernel: [ 3.475320] sd 2:0:0:0: Attached scsi generic sg1 type 0 Aug 16 00:32:21 kernel: [ 3.492587] USB Mass Storage support registered. Aug 16 00:32:21 kernel: [ 3.510930] usb usb5: configuration #1 chosen from 1 choice Aug 16 00:32:21 kernel: [ 3.531076] hub 5-0:1.0: USB hub found Aug 16 00:32:21 kernel: [ 3.548399] hub 5-0:1.0: 2 ports detected Aug 16 00:32:21 kernel: [ 3.591743] input: Western Digital My Book as /devices/pci0000:00/0000:00:1d.7/usb1/1-2/1-2:1.1/input/input2 Aug 16 00:32:21 kernel: [ 3.609515] generic-usb 0003:1058:1104.0001: input,hidraw0: USB HID v1.11 Device [Western Digital My Book] on usb-0000:00:1d.7-2/input1 Aug 16 00:32:21 kernel: [ 3.627466] usbcore: registered new interface driver usbhid Aug 16 00:32:21 kernel: [ 8.581664] usb-storage: device scan complete Aug 16 00:32:21 kernel: [ 8.624270] scsi 4:0:0:0: Direct-Access WD My Book 1008 PQ: 0 ANSI: 4 Aug 16 00:32:21 kernel: [ 8.655135] scsi 4:0:0:1: Enclosure WD My Book Device 1008 PQ: 0 ANSI: 4 Aug 16 00:32:21 kernel: [ 8.675393] sd 4:0:0:0: Attached scsi generic sg2 type 0 Aug 16 00:32:21 kernel: [ 8.698669] scsi 4:0:0:1: Attached scsi generic sg3 type 13 Aug 16 00:32:21 kernel: [ 8.723370] sd 4:0:0:0: [sdb] 1953513472 512-byte logical blocks: (1.00 TB/931 GiB) Aug 16 00:32:21 kernel: [ 8.750477] sd 4:0:0:0: [sdb] Write Protect is off Aug 16 00:32:21 kernel: [ 8.769411] sd 4:0:0:0: [sdb] Mode Sense: 10 00 00 00 Aug 16 00:32:21 kernel: [ 8.769414] sd 4:0:0:0: [sdb] Assuming drive cache: write through Aug 16 00:32:21 kernel: [ 8.822971] sd 4:0:0:0: [sdb] Assuming drive cache: write through Aug 16 00:32:21 kernel: [ 8.841978] sdb: sdb1 Aug 16 00:32:21 kernel: [ 8.905580] sd 4:0:0:0: [sdb] Assuming drive cache: write through Aug 16 00:32:21 kernel: [ 8.924173] sd 4:0:0:0: [sdb] Attached SCSI disk Aug 16 00:32:21 kernel: [ 11.600492] XFS mounting filesystem sdb1 Aug 16 00:32:21 kernel: [ 12.222948] Ending clean XFS mount for filesystem: sdb1 After a while the following appears in a log: Aug 16 09:30:56 kernel: [32359.112029] usb 1-2: reset high speed USB device using ehci_hcd and address 2 Aug 16 09:31:59 kernel: [32422.112035] usb 1-2: reset high speed USB device using ehci_hcd and address 2 Aug 16 09:33:00 kernel: [32483.112029] usb 1-2: reset high speed USB device using ehci_hcd and address 2 And then it is followed by few kernel dumps, which I think, are not good: Aug 16 09:33:40 kernel: [32520.428027] INFO: task xfssyncd:1002 blocked for more than 120 seconds. Aug 16 09:33:40 kernel: [32520.462689] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Aug 16 09:33:40 kernel: [32520.497422] xfssyncd D c3d84a60 0 1002 2 0x00000000 Aug 16 09:33:40 kernel: [32520.532117] f6c9aa80 00000046 c1132742 c3d84a60 00000286 c1418100 c1418100 00000000 Aug 16 09:33:40 kernel: [32520.566867] f6c9ac3c c2808100 00000000 f653b18b 00001d76 00000001 f6c9aa80 c3c3f0e0 Aug 16 09:33:40 kernel: [32520.601343] 08e59242 f6c9ac3c 2e41392b 00000000 08e59242 00000000 c3f7fb48 0067385a Aug 16 09:33:40 kernel: [32520.635533] Call Trace: Aug 16 09:33:40 kernel: [32520.668991] [<c1132742>] ? cfq_set_request+0x0/0x290 Aug 16 09:33:40 kernel: [32520.702804] [<c126b532>] ? io_schedule+0x5f/0x98 Aug 16 09:33:40 kernel: [32520.736555] [<c1128be0>] ? get_request_wait+0xcb/0x146 Aug 16 09:33:40 kernel: [32520.770360] [<c10437ba>] ? autoremove_wake_function+0x0/0x2d Aug 16 09:33:40 kernel: [32520.804110] [<c112907c>] ? __make_request+0x2cc/0x3d9 Aug 16 09:33:40 kernel: [32520.837713] [<c1128230>] ? blk_peek_request+0x135/0x143 Aug 16 09:33:40 kernel: [32520.871265] [<f8582987>] ? scsi_dispatch_cmd+0x185/0x1e5 [scsi_mod] Aug 16 09:33:40 kernel: [32520.904407] [<c1127cf1>] ? generic_make_request+0x266/0x2b4 Aug 16 09:33:40 kernel: [32520.937007] [<c10cf821>] ? bvec_alloc_bs+0x95/0xaf Aug 16 09:33:40 kernel: [32520.969033] [<c1127dfb>] ? submit_bio+0xbc/0xd6 Aug 16 09:33:40 kernel: [32521.000485] [<c10cffd1>] ? bio_add_page+0x28/0x2e Aug 16 09:33:40 kernel: [32521.031403] [<f8918d38>] ? _xfs_buf_ioapply+0x206/0x22b [xfs] Aug 16 09:33:40 kernel: [32521.061888] [<f89197bd>] ? xfs_buf_iorequest+0x38/0x60 [xfs] Aug 16 09:33:40 kernel: [32521.091845] [<f8907230>] ? xlog_bdstrat_cb+0x16/0x3d [xfs] Aug 16 09:33:40 kernel: [32521.121222] [<f8905781>] ? XFS_bwrite+0x32/0x64 [xfs] Aug 16 09:33:40 kernel: [32521.150007] [<f89059be>] ? xlog_sync+0x20b/0x311 [xfs] Aug 16 09:33:40 kernel: [32521.178214] [<f89112fc>] ? xfs_trans_ail_tail+0x12/0x27 [xfs] Aug 16 09:33:40 kernel: [32521.205914] [<f8906261>] ? xlog_state_sync_all+0xa2/0x141 [xfs] Aug 16 09:33:40 kernel: [32521.233074] [<f8906611>] ? _xfs_log_force+0x51/0x68 [xfs] Aug 16 09:33:40 kernel: [32521.259664] [<c103abaf>] ? process_timeout+0x0/0x5 Aug 16 09:33:40 kernel: [32521.285662] [<f8906636>] ? xfs_log_force+0xe/0x27 [xfs] Aug 16 09:33:40 kernel: [32521.311171] [<f89202df>] ? xfs_sync_worker+0x17/0x5c [xfs] Aug 16 09:33:40 kernel: [32521.336117] [<f891fbb7>] ? xfssyncd+0x134/0x17d [xfs] Aug 16 09:33:40 kernel: [32521.360498] [<f891fa83>] ? xfssyncd+0x0/0x17d [xfs] Aug 16 09:33:40 kernel: [32521.384211] [<c1043588>] ? kthread+0x61/0x66 Aug 16 09:33:40 kernel: [32521.407890] [<c1043527>] ? kthread+0x0/0x66 Aug 16 09:33:40 kernel: [32521.430876] [<c1003d47>] ? kernel_thread_helper+0x7/0x10 Aug 16 09:33:40 kernel: [32521.453394] INFO: task flush-8:16:12945 blocked for more than 120 seconds. Aug 16 09:33:40 kernel: [32521.476116] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Aug 16 09:33:40 kernel: [32521.498579] flush-8:16 D 00000000 0 12945 2 0x00000000 Aug 16 09:33:40 kernel: [32521.520649] f4e4d540 00000046 e412e940 00000000 00000002 c1418100 c1418100 c14136ac Aug 16 09:33:40 kernel: [32521.542426] f4e4d6fc c2808100 00000000 00000000 000008b4 00000001 f4e4d540 c3c3f0e0 Aug 16 09:33:40 kernel: [32521.563745] 02e905a8 f4e4d6fc 007a5399 00000000 02e905a8 00000000 f4e2db48 00670b98 Aug 16 09:33:40 kernel: [32521.585077] Call Trace: Aug 16 09:33:40 kernel: [32521.605790] [<c126b532>] ? io_schedule+0x5f/0x98 Aug 16 09:33:40 kernel: [32521.626184] [<c1128be0>] ? get_request_wait+0xcb/0x146 Aug 16 09:33:40 kernel: [32521.646133] [<c10437ba>] ? autoremove_wake_function+0x0/0x2d Aug 16 09:33:40 kernel: [32521.665659] [<c112907c>] ? __make_request+0x2cc/0x3d9 Aug 16 09:33:40 kernel: [32521.684716] [<f891796e>] ? xfs_convert_page+0x30a/0x331 [xfs] Aug 16 09:33:40 kernel: [32521.703366] [<c1127cf1>] ? generic_make_request+0x266/0x2b4 Aug 16 09:33:40 kernel: [32521.721644] [<c10cf821>] ? bvec_alloc_bs+0x95/0xaf Aug 16 09:33:40 kernel: [32521.739465] [<c1127dfb>] ? submit_bio+0xbc/0xd6 Aug 16 09:33:40 kernel: [32521.756896] [<c10cfa45>] ? bio_alloc_bioset+0x7b/0xba Aug 16 09:33:40 kernel: [32521.774046] [<f8917af0>] ? xfs_submit_ioend_bio+0x3b/0x44 [xfs] Aug 16 09:33:40 kernel: [32521.790694] [<f8917ba3>] ? xfs_submit_ioend+0xaa/0xc4 [xfs] Aug 16 09:33:40 kernel: [32521.806736] [<f891817d>] ? xfs_page_state_convert+0x5c0/0x61c [xfs] Aug 16 09:33:40 kernel: [32521.822859] [<c113705b>] ? __lookup_tag+0x8e/0xee Aug 16 09:33:40 kernel: [32521.838958] [<f891840d>] ? xfs_vm_writepage+0x91/0xc4 [xfs] Aug 16 09:33:40 kernel: [32521.855039] [<c108bbcc>] ? __writepage+0x8/0x22 Aug 16 09:33:40 kernel: [32521.871067] [<c108c17b>] ? write_cache_pages+0x1af/0x29f Aug 16 09:33:40 kernel: [32521.886616] [<c108bbc4>] ? __writepage+0x0/0x22 Aug 16 09:33:40 kernel: [32521.901593] [<c108c285>] ? generic_writepages+0x1a/0x21 Aug 16 09:33:40 kernel: [32521.916455] [<f8918338>] ? xfs_vm_writepages+0x0/0x38 [xfs] Aug 16 09:33:40 kernel: [32521.931484] [<c108c2a5>] ? do_writepages+0x19/0x25 Aug 16 09:33:40 kernel: [32521.946648] [<c10c80d9>] ? writeback_single_inode+0xc7/0x273 Aug 16 09:33:40 kernel: [32521.961675] [<c10c8c44>] ? writeback_inodes_wb+0x3dd/0x49c Aug 16 09:33:40 kernel: [32521.976831] [<c10c8e18>] ? wb_writeback+0x115/0x178 Aug 16 09:33:40 kernel: [32521.991778] [<c10c901f>] ? wb_do_writeback+0x121/0x131 Aug 16 09:33:40 kernel: [32522.006538] [<c103abaf>] ? process_timeout+0x0/0x5 Aug 16 09:33:40 kernel: [32522.021091] [<c10c9050>] ? bdi_writeback_task+0x21/0x89 Aug 16 09:33:40 kernel: [32522.035493] [<c10979e5>] ? bdi_start_fn+0x59/0xa4 Aug 16 09:33:40 kernel: [32522.049765] [<c109798c>] ? bdi_start_fn+0x0/0xa4 Aug 16 09:33:40 kernel: [32522.063792] [<c1043588>] ? kthread+0x61/0x66 Aug 16 09:33:40 kernel: [32522.077612] [<c1043527>] ? kthread+0x0/0x66 Aug 16 09:33:40 kernel: [32522.091260] [<c1003d47>] ? kernel_thread_helper+0x7/0x10 Aug 16 09:33:40 kernel: [32522.104966] INFO: task smartctl:13098 blocked for more than 120 seconds. Aug 16 09:33:40 kernel: [32522.118883] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Aug 16 09:33:40 kernel: [32522.133012] smartctl D 00000020 0 13098 13097 0x00000000 Aug 16 09:33:40 kernel: [32522.147221] e50b9540 00000086 c11d28a8 00000020 00000770 c1418100 c1418100 c14136ac Aug 16 09:33:40 kernel: [32522.161720] e50b96fc c2808100 00000000 e53e8800 00000000 00000020 c3cec000 c13886c0 Aug 16 09:33:40 kernel: [32522.176217] f99dab68 e50b96fc 007a4f1e 00000001 c4082f24 c4082ed8 00000001 c3c3f0e0 Aug 16 09:33:40 kernel: [32522.190737] Call Trace: Aug 16 09:33:40 kernel: [32522.205038] [<c11d28a8>] ? __netdev_alloc_skb+0x14/0x2d Aug 16 09:33:40 kernel: [32522.219605] [<c126b799>] ? schedule_timeout+0x20/0xb0 Aug 16 09:33:40 kernel: [32522.234144] [<c112820d>] ? blk_peek_request+0x112/0x143 Aug 16 09:33:40 kernel: [32522.248649] [<f85873b6>] ? scsi_request_fn+0x3c1/0x47a [scsi_mod] Aug 16 09:33:40 kernel: [32522.263233] [<c103aba8>] ? del_timer+0x55/0x5c Aug 16 09:33:40 kernel: [32522.277773] [<c126b6a2>] ? wait_for_common+0xa4/0x100 Aug 16 09:33:40 kernel: [32522.292342] [<c102cd8d>] ? default_wake_function+0x0/0x8 Aug 16 09:33:40 kernel: [32522.306958] [<c112b3d1>] ? blk_execute_rq+0x8b/0xb2 Aug 16 09:33:40 kernel: [32522.321569] [<c112b2ac>] ? blk_end_sync_rq+0x0/0x23 Aug 16 09:33:40 kernel: [32522.336070] [<c112b58b>] ? blk_recount_segments+0x13/0x20 Aug 16 09:33:40 kernel: [32522.350583] [<c1127307>] ? blk_rq_bio_prep+0x44/0x74 Aug 16 09:33:40 kernel: [32522.365059] [<c112b0b2>] ? blk_rq_map_kern+0xc5/0xee Aug 16 09:33:40 kernel: [32522.379439] [<c112e2a5>] ? sg_scsi_ioctl+0x221/0x2aa Aug 16 09:33:40 kernel: [32522.393801] [<c112e672>] ? scsi_cmd_ioctl+0x344/0x39a Aug 16 09:33:40 kernel: [32522.408140] [<c1024c87>] ? update_curr+0x106/0x1b3 Aug 16 09:33:40 kernel: [32522.422566] [<c1024c87>] ? update_curr+0x106/0x1b3 Aug 16 09:33:40 kernel: [32522.436832] [<f87676aa>] ? sd_ioctl+0x90/0xb5 [sd_mod] Aug 16 09:33:40 kernel: [32522.451228] [<c112c35f>] ? __blkdev_driver_ioctl+0x53/0x63 Aug 16 09:33:40 kernel: [32522.465689] [<c112cbbf>] ? blkdev_ioctl+0x850/0x891 Aug 16 09:33:40 kernel: [32522.479982] [<c1020474>] ? __wake_up_common+0x34/0x59 Aug 16 09:33:40 kernel: [32522.494138] [<c10244cd>] ? complete+0x28/0x36 Aug 16 09:33:40 kernel: [32522.507986] [<c1086c64>] ? find_get_page+0x1f/0x81 Aug 16 09:33:40 kernel: [32522.521671] [<c10abed5>] ? add_partial+0xe/0x40 Aug 16 09:33:40 kernel: [32522.535285] [<c1086e68>] ? lock_page+0x8/0x1d Aug 16 09:33:40 kernel: [32522.548797] [<c1087432>] ? filemap_fault+0xb5/0x2e6 Aug 16 09:33:40 kernel: [32522.562141] [<c109941c>] ? __do_fault+0x381/0x3b1 Aug 16 09:33:40 kernel: [32522.575441] [<c10d0c30>] ? block_ioctl+0x27/0x2c Aug 16 09:33:40 kernel: [32522.588708] [<c10d0c09>] ? block_ioctl+0x0/0x2c Aug 16 09:33:40 kernel: [32522.601858] [<c10bcd78>] ? vfs_ioctl+0x1c/0x5f Aug 16 09:33:40 kernel: [32522.614917] [<c10bd30c>] ? do_vfs_ioctl+0x4aa/0x4e5 Aug 16 09:33:40 kernel: [32522.627961] [<c10350db>] ? __do_softirq+0x115/0x151 Aug 16 09:33:40 kernel: [32522.640901] [<c126e270>] ? do_page_fault+0x2f1/0x307 Aug 16 09:33:40 kernel: [32522.653803] [<c10bd388>] ? sys_ioctl+0x41/0x58 Aug 16 09:33:40 kernel: [32522.666674] [<c10030fb>] ? sysenter_do_call+0x12/0x28 Then again few messages reset high speed USB device using ehci_hcd and address 2. I have browsed and read similar error reports here and there and I tried: I have upgraded the kernel from v2.6.26-2 to 2.6.32-5, which has not solved the problem. They say, this might a cable problem. I have tried to replace the USB-to-miniUSB cable (that connects external drive with computer) with another one. No changes. Somebody suggests to try another USB port. I have only 4 external USB ports, tried another one with no success. They say to try uhci_hcd. I have unmounted the device, unloaded ehci_hcd and mounted again. The difference was that now in log I get reset full speed USB device using uhci_hcd and address 2 and similar kernel dumps after a while. They say to echo 128 > /sys/block/sdb/device/max_sectors. I tried it with ehci_hcd with no success (note: I have issued this command after the drive was mounted but before using it actively). I have lauched smartmond and checking periodically the output of smartctl: drive temperature is OK, number of bad sectors and uncorrectable errors is 0. Nothing suspicious is reported by S.M.A.R.T. except maybe the following: Aug 16 12:40:12 kernel: [43715.314566] program smartctl is using a deprecated SCSI ioctl, please convert it to SG_IO Aug 16 12:40:13 kernel: [43715.705622] program smartctl is using a deprecated SCSI ioctl, please convert it to SG_IO Of course, I have not tried all combinations of above. But unfortunately, I am run out of cardinal ideas. If anybody can advice something specific about the problem, you are very welcome.

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  • Configuring Cisco 877W router from scratch for DHCP, WiFi, ADSL2+, NAT

    - by David M Williams
    Hi all, I apologise if this is a BIG question but I am quite lost with the Cisco IOS. I know what I want to achieve just not how to do it :( I have a Cisco 877W router with 4 FastEthernet interfaces, 1 ATM interface and 1 802.11 Radio. I want to set it up for a small network and am trying to construct a configuration below. I was using Google to try and flesh it out but I think I need help and guidance from actual experts! If it helps, output from show ver says Cisco IOS software, C870 software (C870-ADVSECURITYK9-M), version 12.4(4)T7, release software (fc1) ROM: System bootstrap, version 12.3(8r)YI4, release software Here's what I have so far, which hopefully outlines clearly enough what I am wanting to do. The bits in angle brackets are placeholders (eg the secret password). ! ! Set router hostname ! hostname Shazam ! ! Set usernames and passwords ! username david privilege 15 secret 0 <PASSWORD> enable secret <SECRETPASSWORD> ! ! Configure SSH and telnet access ! line vty 0 4 privilege level 15 login local transport input telnet ssh ! ! Local logging ! logging buffered 51200 warning ! ! Set date and time for NSW, Australia (GMT +10h) ! ! ! Set router IP address to 192.168.1.1 on FastEthernet0 port ! interface FastEthernet0 ip address 192.168.1.1 255.255.255.0 no shut ip nat inside ! ! Forward any unknown DNS requests to Google ! ip dns server ip name-server 8.8.8.8 ip name-server 8.8.4.4 ! ! Set up DHCP ! DHCP pool covers 192.168.1.100 - .199 ! Set gateway and DNS server to be the router, ie 192.168.1.1 ! service dhcp ip routing ip dhcp excluded-address 192.168.1.1 192.168.1.99 ip dhcp excluded-address 192.168.1.200 192.168.1.255 ip dhcp pool <DHCPPOOLNAME> network 192.168.1.0 255.255.255.0 default-router 192.168.1.1 dns-server 192.168.1.1 lease 7 ! ! DHCP reservations ! ! Assign IP address 192.168.1.105 to MAC address 00-21-5D-2F-58-04 ! ! Configure ADSL2 connection details ! interface atm dsl operating-mode adsl2+ ! ! Set up NAT rules ! ! Forward port 35394 to 192.168.1.105 ! ! Set up WiFi ! ! SSID visible, WPA2 security, Pre-shared key I'm hoping most of this is boiler-plate stuff to you guys. I'm keen to not just get a working script but to actually understand it also. Unfortunately, I'm finding the Cisco reference material online very complex. Thank you!

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  • How to bridge Debian guest VM to VPN via Cisco AnyConnect Client running on Windows Vista host

    - by bgoodr
    I am running Cisco Anyconnect VPN Client version 2.5.3054 on a laptop running Windows Vista Home Premium (version 6.0.6002) Service Pack 2. I am running the VMware Player version 4.0.2 build-591240. The host operating system running under VMware Player is Debian 6.0.2.1 i386. The laptop is connected to a wireless connection, and I can browse the web from Windows Vista using Firefox just fine. I am able to boot into the Debian VM and open up a browser and access websites on the WAN from within the VM just fine. I can ping real Linux hosts on my LAN via: ping <lan_system>.local where <lan_system> is the hostname returned from uname -a on that system on my LAN. From a DOS CMD shell, I am able to ping hosts that exist on the remote network served by the Cisco AnyConnect Client's VPN network (and without the .local suffix applied as above): ping <remote_system> However, from within the Debian VM, I expect to be able to also ping those same remote hosts (<remote_system>) that are tunnelled over the VPN set up by Cisco AnyConnect Client. Let's say that I can ping a <remote_system> called flubber from a DOS CMD prompt just fine. When I execute Linux ping command from inside the Debian VM via: ping flubber It returns immediately with this output: ping: unknown host flubber For reference since I suspect it will be useful, here is the output of the route print command from the DOS CMD prompt: route print =========================================================================== Interface List 30 ...00 05 9a 3c 7a 00 ...... Cisco AnyConnect VPN Virtual Miniport Adapter for Windows 11 ...00 1b 9e c4 de e5 ...... Atheros AR5007EG Wireless Network Adapter 26 ...00 50 56 c0 00 01 ...... VMware Virtual Ethernet Adapter for VMnet1 28 ...00 50 56 c0 00 08 ...... VMware Virtual Ethernet Adapter for VMnet8 1 ........................... Software Loopback Interface 1 12 ...02 00 54 55 4e 01 ...... Teredo Tunneling Pseudo-Interface 13 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3 32 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #4 27 ...00 00 00 00 00 00 00 e0 isatap.{E5292CF6-4FBB-4320-806D-A6B366769255} 17 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2 20 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #8 22 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #10 24 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #11 25 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #12 29 ...00 00 00 00 00 00 00 e0 isatap.{C3852986-5053-4E2E-BE60-52EA2FCF5899} 41 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #14 =========================================================================== At the top window border of the VM, clicking on Virtual Machine, then clicking on Virtual Machine Settings, then clicking on Network Adapter, I have these two options checked: [X] Bridged: Connected directly to the physical Network [X] Replicate physical network connection state [ ] NAT: used to share the hosts's IP address [ ] Host-only: A private network shared with the host [ ] LAN segment: [ ] <LAN Segments...> <Advanced> I've toyed with the other options such as NAT and Host-only but that had no effect. Is there some way to allow the VM to access those <remote_system>'s?

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  • Rsync: how to mount truecrypt on-the-fly on the receiving side?

    - by deepc
    The short version: how can I keep an rsync backup on a truecrypt volume? The hard part is to mount/unmount this volume on the fly when it is needed for rsync. Details This is my current backup configuration (which works fairly well for the most part): backup source is on Win7 64 bit, destination is a remote Linux box (Debian) actual data transfer is done by rsync via ssh (cwRsync with cygwin) rsync daemon is started on demand via ssh On the Linux box the backup is protected by file permissions only. I want to increase security here and put the backup into a truecrypt volume. I can fuse-mount that volume manually in the shell. The question is now how can I make rsync not only open an ssh connection and starting the rsync daemon, but also to mount the truecrypt volume before (and unmount it after)? My money is on option --rsync-path which can be used to pass a command line to ssh - provided that stdin and stdout still work the same. I guess that command would have to be a shell script. Is this possible, and what would the script look like? For reference, here's a quote of that option: --rsync-path=PROGRAM Use this to specify what program is to be run on the remote machine to start-up rsync. Often used when rsync is not in the default remote-shell's path (e.g. --rsync-path=/usr/local/bin/rsync). Note that PROGRAM is run with the help of a shell, so it can be any program, script, or command sequence you'd care to run, so long as it does not corrupt the standard-in & standard-out that rsync is using to communicate. One tricky example is to set a different default directory on the remote machine for use with the --relative option. For instance: rsync -avR --rsync-path="cd /a/b && rsync" host:c/d /e/ This is the full rsync man page. Truecrypt volume auto-mount Solved! Turns out this option is actually key to auto-mounting the truecrypt volume on the remote side. The following command line does the trick (one line!): rsync $options -e "ssh -p $port -i ../.ssh/id_dsa" --rsync-path="/usr/local/bin/truecrypt -d && /usr/local/bin/truecrypt --fs-options=rw,sync,utf8,uid=$UID,umask=0007 --non-interactive -p $password $pathToVolume $remoteMountDir && rsync" $localSourceDir $user:$remoteMountMountDir Truecrypt volume auto-dismount Still open: how can I unmount the volume when rsync is done? Not sure if the following makes sense to anyone but I give it a try... Right now I am unmounting (truecrypt -d), then mounting again, then continuing with rsync. At this time rsync needs to do its thing but I dont know when its done. Adding ... rsync && truecrypt -d to the command line does not work because then the rsync daemon does not start. This is because rsync starts the daemon with parameter --server on the remote side and that parameter would go to the final truecrypt -d.

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  • Does Apache ever give incorrect "out of threads" errors?

    - by Eli Courtwright
    Lately our Apache web server has been giving us this error multiple times per day: [Tue Apr 06 01:07:10 2010] [error] Server ran out of threads to serve requests. Consider raising the ThreadsPerChild setting We raised our ThreadsPerChild setting from 50 to 100, but we still get the error. Our access logs indicate that these errors never even happen at periods of high load. For example, here's an excerpt from our access log (ip addresses and some urls are edited for privacy). As you can see, the above error happened at 1:07 and only a small handful of requests occurred in the several minutes leading up to the error: 99.88.77.66 - - [06/Apr/2010:00:59:33 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-icons_222222_256x240.png HTTP/1.1" 304 - 99.88.77.66 - - [06/Apr/2010:00:59:34 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-bg_glass_75_dadada_1x400.png HTTP/1.1" 200 111 99.88.77.66 - - [06/Apr/2010:00:59:34 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-bg_glass_75_dadada_1x400.png HTTP/1.1" 200 111 99.88.77.66 - mpeu [06/Apr/2010:00:59:40 -0400] "GET /some/dynamic/content HTTP/1.1" 200 145049 55.44.33.22 - mpeu [06/Apr/2010:01:06:56 -0400] "GET /other/dynamic/content HTTP/1.1" 200 12311 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/jquery-ui-1.7.1.custom.css HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/js/jquery-1.3.2.min.js HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/js/jquery-ui-1.7.1.custom.min.js HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/jquery.tablesorter.min.js HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/date.js HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image1.gif HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image2.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image3.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image4.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image5.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image6.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:56 -0400] "GET /WebRepository/pdfs/image7.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:57 -0400] "GET /WebRepository/pdfs/image8.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:57 -0400] "GET /WebRepository/pdfs/image9.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:57 -0400] "GET /WebRepository/pdfs/imageA.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:57 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-bg_flat_75_ffffff_40x100.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:59 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-bg_highlight-soft_75_cccccc_1x100.png HTTP/1.1" 304 - 55.44.33.22 - - [06/Apr/2010:01:06:59 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-bg_glass_75_e6e6e6_1x400.png HTTP/1.1" 200 110 55.44.33.22 - - [06/Apr/2010:01:06:59 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/images/ui-bg_glass_75_e6e6e6_1x400.png HTTP/1.1" 200 110 11.22.33.44 - mpeu [06/Apr/2010:01:18:03 -0400] "GET /other/dynamic/content HTTP/1.1" 200 12311 11.22.33.44 - - [06/Apr/2010:01:18:03 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/js/jquery-1.3.2.min.js HTTP/1.1" 304 - 11.22.33.44 - - [06/Apr/2010:01:18:04 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/css/smoothness/jquery-ui-1.7.1.custom.css HTTP/1.1" 200 27374 11.22.33.44 - - [06/Apr/2010:01:18:04 -0400] "GET /WebRepository/jquery/jquery-ui-1.7.1.custom/js/jquery-ui-1.7.1.custom.min.js HTTP/1.1" 304 - 11.22.33.44 - - [06/Apr/2010:01:18:04 -0400] "GET /WebRepository/jquery.tablesorter.min.js HTTP/1.1" 200 12795 11.22.33.44 - - [06/Apr/2010:01:18:04 -0400] "GET /WebRepository/date.js HTTP/1.1" 200 25809 For what it's worth, we're running the version of Apache that ships with Oracle 10g (some 2.0 version), and we're using mod_plsql to generate our dynamic content. Since the Apache server runs as a separate process and the database doesn't record any problems when this error occurs, I'm doubtful that Oracle is the problem. Unfortunately, the errors are freaking out our sysadmins, who are inclined to blame any and all problems which occur with the server on this error. Is this a known bug in Apache that I simply haven't been able to find any reference to through Google?

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