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  • Hosted Monitoring

    - by Grant Fritchey
    The concept of using services to take the place of writing a lot of your own code goes way, way back in computing history. The fundamentals of the concept go back to the dawn of computing with places like IBM hosting time-shares for computing power that you could rent for short periods of time. But things really took off with the building of the Web. Now, all the growth with virtual machines, hosted machines, hosted services from vendors like Amazon and Microsoft, the need to keep all of your software locally on physical boxes is just going the way of the dodo. There will likely always be some pieces of software that you keep on machines on your property or on your person, but the concept of keeping fundamental services locally is going away. As someone put it to me once, if you were starting a business right now, would you bother setting up an Exchange server to manage your email or would you just go to one of the external mail services for everything? For most of us (who are not Exchange admins) the answer is pretty easy. With all this momentum to having external services manage more and more of the infrastructure that’s not business unique, why would you burn up a server and license instance setting up monitoring for your SQL Servers? Of course, some of you are dealing with hyper-sensitive data that might require, through law or treaty, that you lock it down and never expose it to the intertubes, but most of us are not. So, what if someone else took on the basic hassle of setting up monitoring on your systems? That’s what we’re working on here at Red Gate. Right now it’s a private test, but we’re growing it and developing it and it’ll be going to a public beta, probably (hopefully) this year. I’m running it on my machines right now. The concept is pretty simple. You put a relay on your server, poke a hole in your firewall for it, and we start monitoring your server using SQL Monitor. It’s actually shocking how easy it is to get going. You still have to adjust your alerting thresholds, but that’s a standard part of alerting. Your pain threshold and my pain threshold for any given alert may be different. But from there, we do all the heavy lifting, keeping your data online and available, providing you with access to the information about how your servers are behaving, everything. Maybe it’s just me, but I’m really excited by this. I think we’re getting to a place where we can really help the small and medium sized businesses get a monitoring solution in place, quickly and easily. All you crazy busy, and possibly accidental, DBAs and system admins finally can set up monitoring without taking all the time to configure systems, run installs, and all the rest. You just have to tweak your alerts and you’re ready to run. If you are interested in checking it out, you can apply for the closed beta through the Monitor web page.

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  • ADF Real World Developers Guide Book Review

    - by Grant Ronald
    I'm half way through my review of "Oracle ADF Real World Developer's Guide" by Jobinesh Purushothaman - unfortunately some work deadlines de-railed me from having completed my review by now but here goes.  First thing, Jobinesh works in the Oracle Product Management team with me, so is a colleague. That declaration aside, its clear that this is someone who has done the "real world" side of ADF development and that comes out in the book. In this book he addresses both the newbies and the experience developers alike.  He introduces the ADF building blocks like entity objects and view obejcts, but also goes into some of the nitty gritty details as well.  There is a pro and con to this approach; having only just learned about an entity or view object, you might then be blown away by some of the lower details of coding or lifecycle.  In that respect, you might consider this a book which you could read 3 or 4 times; maybe skipping some elements in the first read but on the next read you have a better grounding to learn the more advanced topics. One of the key issues he addresses is breaking down what happens behind the scenes.  At first, this may not seem important since you trust the framework to do everything for you - but having an understanding of what goes on is essential as you move through development.  For example, page 58 he explains the full lifecycle of what happens when you execute a query.  I think this is a great feature of his book. You see this elsewhere, for example he explains the full lifecycle of what goes on when a page is accessed : which files are involved,the JSF lifecycle etc. He also sprinkes the book with some best practices and advice which go beyond the standard features of ADF and really hits the mark in terms of "real world" advice. So in summary, this is a great ADF book, well written and covering a mass of information.  If you are brand new to ADF its still valid given it does start with the basics.  But you might want to read the book 2 or 3 times, skipping the advanced stuff on the first read.  For those who have some basics already then its going to be an awesome way to cement your knowledge and take it to the next levels.  And for the ADF experts, you are still going to pick up some great ADF nuggets.  Advice: every ADF developer should have one!

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  • ADF Hands on Training &ndash; Prerequisites for 22nd March 2011

    - by Grant Ronald
    For those of you coming to the ADF Hands on training on the 22nd March in London, there was a link to the prerequisites.  Unfortunately, in a reshuffle of content on OTN, this page was removed.  So, over the next day or so I’m hoping to the pull together the relevant information into this blog post.  So keep checking back! Firstly, you need to being your laptop with you to do the hands on exercises.  No laptop, no hands on. Recommended 2GB RAM running Microsoft Windows XP SP2, 2003 Server SP2, Vista (32 bit only), Windows 7 or Linux or Mac 2GHz Processor (less will be acceptable but slower) Mozilla Firefox 2.0 or higher, Internet Explorer 7 or higher, Safari 3.0 and higher, Google Chrome 1.0 or higher Winzip or other extracting software Adobe Acrobat reader Flash (if you want to see dynamic graphs in your application) As for software, you will need have installed JDeveloper 11g.  The hands on instructions are based on 11.1.1.2 (or is it 11.1.1.3)! anyway, either of those or 11.1.1.4 would be required. You also need an Oracle database on your machine and access to the HR schema (which should be unlocked).  Don’t expect to have access to a network and VPN to a database. A simple test, unplug your laptop from your corporate network, run up JDev  and select File –> New –> Database connection and make sure you can connect to HR database and see the Emp/Dept etc tables.  If you can do that, you should be good to go. I would strongly recommend ensuring you have this in place before you arrive on Tuesday. Look forward to seeing you there.

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  • Introduction to Agile Development

    - by Grant Fritchey
    Even though my current job is a little weird, I still consider myself to be a DBA. I didn’t start that way in IT. I came through support and into development. I loved development. There was a constant struggle to attempt to improve your code, your understanding, and, most importantly, the process of development itself. Development can be slow and tedious. Left alone, developers can simply disappear to build a project and not come back for two years, at which time they deliver it. But, maybe that software isn’t what you wanted, or it’s no longer needed, or who knows what. So developers are constantly attempting to improve their processes in order to deliver more relavent software quicker (something DBAs could learn about). I really admire it. One of the many processes that has come out of that constant striving is known as Agile. As the name implies, Agile development attempts to come up with a quick, fast turning, business aware, well, for want of a word, agile, process that is more responsive to the needs of the business. There are tons and tons of books and blogs and videos on the subject that can get you going. But, Agile isn’t easy (note, Easy is not part of the name). Agile processes can be hard. I’ve worked on multiple agile teams, some successful, some not. The two principal differences between the teams were their discipline and their knowledge of the process. Discipline, that comes from within. But knowledge, ah, well there I can help. Red Gate is bringing a series of free instructional events to the United States in a few weeks time focused primarily on SQL Server (click here right now to register while there’s still space). We’re also offering some .NET instruction too. That’s a full day, free, with top experts in the business. But, the next day, there’s a full day session introducing Agile. You can go to this and learn how to do Agile. Develop that knowledge that will enable you to successfully use the Agile process. Go to this web site to check it out. No, this event is not free, but not everything can be. And it’s not just for developers. DBAs, you need to learn this stuff too. Management could also benefit from understanding these processes (because you guys can help to enforce discipline). It’s really for everyone involved in the development process.

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  • Tutorial on Hudson, JUnit and Ant

    - by Grant Ronald
    Often when discussing ADF we often show the features for developing applications. However, writing applications is only one part.  Building in a team, integrating code, testing it...these are equally important to the success of the project.  If you would like to find out how features in JDeveloper can help you build, maintain, integrate and test your application then check out this tutorial.

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  • What is New in ASP.NET 4.0 Code Access Security

    - by Xiaohong
    ASP.NET Code Access Security (CAS) is a feature that helps protect server applications on hosting multiple Web sites, ASP.NET lets you assign a configurable trust level that corresponds to a predefined set of permissions. ASP.NET has predefined ASP.NET Trust Levels and Policy Files that you can assign to applications, you also can assign custom trust level and policy files. Most web hosting companies run ASP.NET applications in Medium Trust to prevent that one website affect or harm another site etc. As .NET Framework's Code Access Security model has evolved, ASP.NET 4.0 Code Access Security also has introduced several changes and improvements. The main change in ASP.NET 4.0 CAS In ASP.NET v4.0 partial trust applications, application domain can have a default partial trust permission set as opposed to being full-trust, the permission set name is defined in the <trust /> new attribute permissionSetName that is used to initialize the application domain . By default, the PermissionSetName attribute value is "ASP.Net" which is the name of the permission set you can find in all predefined partial trust configuration files. <trust level="Something" permissionSetName="ASP.Net" /> This is ASP.NET 4.0 new CAS model. For compatibility ASP.NET 4.0 also support legacy CAS model where application domain still has full trust permission set. You can specify new legacyCasModel attribute on the <trust /> element to indicate whether the legacy CAS model is enabled. By default legacyCasModel is false which means that new 4.0 CAS model is the default. <trust level="Something" legacyCasModel="true|false" /> In .Net FX 4.0 Config directory, there are two set of predefined partial trust config files for each new CAS model and legacy CAS model, trust config files with name legacy.XYZ.config are for legacy CAS model: New CAS model: Legacy CAS model: web_hightrust.config legacy.web_hightrust.config web_mediumtrust.config legacy.web_mediumtrust.config web_lowtrust.config legacy.web_lowtrust.config web_minimaltrust.config legacy.web_minimaltrust.config   The figure below shows in ASP.NET 4.0 new CAS model what permission set to grant to code for partial trust application using predefined partial trust levels and policy files:    There also some benefits that comes with the new CAS model: You can lock down a machine by making all managed code no-execute by default (e.g. setting the MyComputer zone to have no managed execution code permissions), it should still be possible to configure ASP.NET web applications to run as either full-trust or partial trust. UNC share doesn’t require full trust with CASPOL at machine-level CAS policy. Side effect that comes with the new CAS model: processRequestInApplicationTrust attribute is deprecated  in new CAS model since application domain always has partial trust permission set in new CAS model.   In ASP.NET 4.0 legacy CAS model or ASP.NET 2.0 CAS model, even though you assign partial trust level to a application but the application domain still has full trust permission set. The figure below shows in ASP.NET 4.0 legacy CAS model (or ASP.NET 2.0 CAS model) what permission set to grant to code for partial trust application using predefined partial trust levels and policy files:     What $AppDirUrl$, $CodeGen$, $Gac$ represents: $AppDirUrl$ The application's virtual root directory. This allows permissions to be applied to code that is located in the application's bin directory. For example, if a virtual directory is mapped to C:\YourWebApp, then $AppDirUrl$ would equate to C:\YourWebApp. $CodeGen$ The directory that contains dynamically generated assemblies (for example, the result of .aspx page compiles). This can be configured on a per application basis and defaults to %windir%\Microsoft.NET\Framework\{version}\Temporary ASP.NET Files. $CodeGen$ allows permissions to be applied to dynamically generated assemblies. $Gac$ Any assembly that is installed in the computer's global assembly cache (GAC). This allows permissions to be granted to strong named assemblies loaded from the GAC by the Web application.   The new customization of CAS Policy in ASP.NET 4.0 new CAS model 1. Define which named permission set in partial trust configuration files By default the permission set that will be assigned at application domain initialization time is the named "ASP.Net" permission set found in all predefined partial trust configuration files. However ASP.NET 4.0 allows you set PermissionSetName attribute to define which named permission set in a partial trust configuration file should be the one used to initialize an application domain. Example: add "ASP.Net_2" named permission set in partial trust configuration file: <PermissionSet class="NamedPermissionSet" version="1" Name="ASP.Net_2"> <IPermission class="FileIOPermission" version="1" Read="$AppDir$" PathDiscovery="$AppDir$" /> <IPermission class="ReflectionPermission" version="1" Flags ="RestrictedMemberAccess" /> <IPermission class="SecurityPermission " version="1" Flags ="Execution, ControlThread, ControlPrincipal, RemotingConfiguration" /></PermissionSet> Then you can use "ASP.Net_2" named permission set for the application domain permission set: <trust level="Something" legacyCasModel="false" permissionSetName="ASP.Net_2" /> 2. Define a custom set of Full Trust Assemblies for an application By using the new fullTrustAssemblies element to configure a set of Full Trust Assemblies for an application, you can modify set of partial trust assemblies to full trust at the machine, site or application level. The configuration definition is shown below: <fullTrustAssemblies> <add assemblyName="MyAssembly" version="1.1.2.3" publicKey="hex_char_representation_of_key_blob" /></fullTrustAssemblies> 3. Define <CodeGroup /> policy in partial trust configuration files ASP.NET 4.0 new CAS model will retain the ability for developers to optionally define <CodeGroup />with membership conditions and assigned permission sets. The specific restriction in ASP.NET 4.0 new CAS model though will be that the results of evaluating custom policies can only result in one of two outcomes: either an assembly is granted full trust, or an assembly is granted the partial trust permission set currently associated with the running application domain. It will not be possible to use custom policies to create additional custom partial trust permission sets. When parsing the partial trust configuration file: Any assemblies that match to code groups associated with "PermissionSet='FullTrust'" will run at full trust. Any assemblies that match to code groups associated with "PermissionSet='Nothing'" will result in a PolicyError being thrown from the CLR. This is acceptable since it provides administrators with a way to do a blanket-deny of managed code followed by selectively defining policy in a <CodeGroup /> that re-adds assemblies that would be allowed to run. Any assemblies that match to code groups associated with other permissions sets will be interpreted to mean the assembly should run at the permission set of the appdomain. This means that even though syntactically a developer could define additional "flavors" of partial trust in an ASP.NET partial trust configuration file, those "flavors" will always be ignored. Example: defines full trust in <CodeGroup /> for my strong named assemblies in partial trust config files: <CodeGroup class="FirstMatchCodeGroup" version="1" PermissionSetName="Nothing"> <IMembershipCondition    class="AllMembershipCondition"    version="1" /> <CodeGroup    class="UnionCodeGroup"    version="1"    PermissionSetName="FullTrust"    Name="My_Strong_Name"    Description="This code group grants code signed full trust. "> <IMembershipCondition      class="StrongNameMembershipCondition" version="1"       PublicKeyBlob="hex_char_representation_of_key_blob" /> </CodeGroup> <CodeGroup   class="UnionCodeGroup" version="1" PermissionSetName="ASP.Net">   <IMembershipCondition class="UrlMembershipCondition" version="1" Url="$AppDirUrl$/*" /> </CodeGroup> <CodeGroup class="UnionCodeGroup" version="1" PermissionSetName="ASP.Net">   <IMembershipCondition class="UrlMembershipCondition" version="1" Url="$CodeGen$/*"   /> </CodeGroup></CodeGroup>   4. Customize CAS policy at runtime in ASP.NET 4.0 new CAS model ASP.NET 4.0 new CAS model allows to customize CAS policy at runtime by using custom HostSecurityPolicyResolver that overrides the ASP.NET code access security policy. Example: use custom host security policy resolver to resolve partial trust web application bin folder MyTrustedAssembly.dll to full trust at runtime: You can create a custom host security policy resolver and compile it to assembly MyCustomResolver.dll with strong name enabled and deploy in GAC: public class MyCustomResolver : HostSecurityPolicyResolver{ public override HostSecurityPolicyResults ResolvePolicy(Evidence evidence) { IEnumerator hostEvidence = evidence.GetHostEnumerator(); while (hostEvidence.MoveNext()) { object hostEvidenceObject = hostEvidence.Current; if (hostEvidenceObject is System.Security.Policy.Url) { string assemblyName = hostEvidenceObject.ToString(); if (assemblyName.Contains(“MyTrustedAssembly.dll”) return HostSecurityPolicyResult.FullTrust; } } //default fall-through return HostSecurityPolicyResult.DefaultPolicy; }} Because ASP.NET accesses the custom HostSecurityPolicyResolver during application domain initialization, and a custom policy resolver requires full trust, you also can add a custom policy resolver in <fullTrustAssemblies /> , or deploy in the GAC. You also need configure a custom HostSecurityPolicyResolver instance by adding the HostSecurityPolicyResolverType attribute in the <trust /> element: <trust level="Something" legacyCasModel="false" hostSecurityPolicyResolverType="MyCustomResolver, MyCustomResolver" permissionSetName="ASP.Net" />   Note: If an assembly policy define in <CodeGroup/> and also in hostSecurityPolicyResolverType, hostSecurityPolicyResolverType will win. If an assembly added in <fullTrustAssemblies/> then the assembly has full trust no matter what policy in <CodeGroup/> or in hostSecurityPolicyResolverType.   Other changes in ASP.NET 4.0 CAS Use the new transparency model introduced in .Net Framework 4.0 Change in dynamically compiled code generated assemblies by ASP.NET: In new CAS model they will be marked as security transparent level2 to use Framework 4.0 security transparent rule that means partial trust code is treated as completely Transparent and it is more strict enforcement. In legacy CAS model they will be marked as security transparent level1 to use Framework 2.0 security transparent rule for compatibility. Most of ASP.NET products runtime assemblies are also changed to be marked as security transparent level2 to switch to SecurityTransparent code by default unless SecurityCritical or SecuritySafeCritical attribute specified. You also can look at Security Changes in the .NET Framework 4 for more information about these security attributes. Support conditional APTCA If an assembly is marked with the Conditional APTCA attribute to allow partially trusted callers, and if you want to make the assembly both visible and accessible to partial-trust code in your web application, you must add a reference to the assembly in the partialTrustVisibleAssemblies section: <partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" />/partialTrustVisibleAssemblies>   Most of ASP.NET products runtime assemblies are also changed to be marked as conditional APTCA to prevent use of ASP.NET APIs in partial trust environments such as Winforms or WPF UI controls hosted in Internet Explorer.   Differences between ASP.NET new CAS model and legacy CAS model: Here list some differences between ASP.NET new CAS model and legacy CAS model ASP.NET 4.0 legacy CAS model  : Asp.net partial trust appdomains have full trust permission Multiple different permission sets in a single appdomain are allowed in ASP.NET partial trust configuration files Code groups Machine CAS policy is honored processRequestInApplicationTrust attribute is still honored    New configuration setting for legacy model: <trust level="Something" legacyCASModel="true" ></trust><partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" /></partialTrustVisibleAssemblies>   ASP.NET 4.0 new CAS model: ASP.NET will now run in homogeneous application domains. Only full trust or the app-domain's partial trust grant set, are allowable permission sets. It is no longer possible to define arbitrary permission sets that get assigned to different assemblies. If an application currently depends on fine-tuning the partial trust permission set using the ASP.NET partial trust configuration file, this will no longer be possible. processRequestInApplicationTrust attribute is deprecated Dynamically compiled assemblies output by ASP.NET build providers will be updated to explicitly mark assemblies as transparent. ASP.NET partial trust grant sets will be independent from any enterprise, machine, or user CAS policy levels. A simplified model for locking down web servers that only allows trusted managed web applications to run. Machine policy used to always grant full-trust to managed code (based on membership conditions) can instead be configured using the new ASP.NET 4.0 full-trust assembly configuration section. The full-trust assembly configuration section requires explicitly listing each assembly as opposed to using membership conditions. Alternatively, the membership condition(s) used in machine policy can instead be re-defined in a <CodeGroup /> within ASP.NET's partial trust configuration file to grant full-trust.   New configuration setting for new model: <trust level="Something" legacyCASModel="false" permissionSetName="ASP.Net" hostSecurityPolicyResolverType=".NET type string" ></trust><fullTrustAssemblies> <add assemblyName=”MyAssembly” version=”1.0.0.0” publicKey="hex_char_representation_of_key_blob" /></fullTrustAssemblies><partialTrustVisibleAssemblies> <add assemblyName="MyAssembly" publicKey="hex_char_representation_of_key_blob" /></partialTrustVisibleAssemblies>     Hope this post is helpful to better understand the ASP.Net 4.0 CAS. Xiaohong Tang ASP.NET QA Team

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  • Windows Server 2008 R2 - IIS7.5 - Web site permissions

    - by dmckenna
    Why when I remove the MACHINENAME\Users group permission set from a websites physical folder and and grant a similar permission set to MACHINENAME\IIS_IUSRS group my website will not start. Why do I have to grant Read & Execute, List folder contents and Read to the MACHINENAME\Users group physical website folder?

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  • SQL Service Broker enabled causes 100% CPU

    - by user40373
    I have new set of code for a website that is using SqlCacheDependencies based on sql commands. I have enabled SQL Service Broker and some triggers on update/insert/delete and it is causing 100% CPU. Any ideas if I am doing something wrong or suggestions to improve? Here are the SQLchanges I ran: alter database DATABASE_NAME set enable_broker WITH ROLLBACK IMMEDIATE grant subscribe query notifications to CONNECTION_USER_NAME grant send on service::sqlquerynotificationservice to CONNECTION_USER_NAME ALTER AUTHORIZATION ON DATABASE::DATABASE_NAME TO CONNECTION_USER_NAME;

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  • Is there a way to check if a user has specific rights?

    - by Vadim
    In my application I'm using ntrights.exe, that is part of Windows Resource Kit, to grant and revoke a specific user right. For example to grant a user "Log on as a server" right, I execute using shell object following command: ntrights -u User +r SeServiceLogonRight However ntrights doesn't allow you to check if a user has a specific right. Can you tell me how I can check if a user has a specific right?

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  • Allow Windows Domain users Local Admin rights on subset of Domain Computers

    - by growse
    I'm a bit new to AD management, so would appreciate some help in what may be a very simple task. I've got a domain that manages a bunch of different servers, and I want to grant local administrative rights to some domain users to some of the servers (the development webservers). I appreciate the group concept, so I imagine I would have to create a group containing the users in question another group containing the computers to grant them access to. What's the best way of going about this?

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  • icacls batch file multiple directories with wildcards help needed

    - by user153521
    I have written the following batch file that does a great job combing through all folders beginning with the number 3 and applying folder permissions to any 2010 subfolder. Example of the batch filesis below: for /D %%f in (D:\Data\3*) do icacls "%%f\2010" /inheritance:r /grant:r "Domain Admins":(OI)(CI)F Question : How can I improve this script to allow for me to apply the permissions to a specific folder below ANY folder within the folders beginning with 3? here is an example of my failed attempt: for /D %%f in (D:\Data\3*) do icacls "%%f*\specificfolder" /inheritance:r /grant:r "Domain Admins":(OI)(CI)F

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  • Allowing wildcard (%) access on MySQL db, getting error "access denied for '<user>'@'localhost'"

    - by Wayne M
    I've created a database and a user, and allowed access via the following: create user 'someuser'@'%' identified by 'password'; grant all privileges on somedb.* to 'someuser' with grant option; however, when I try to connect to MySQL I get the following error: $ mysql -u someuser -p > Enter Password: > ERROR 1045 (28000): Access denied for user 'someuser'@'localhost' (using password: YES) If "%" is the wildcard, then wouldn't it also enable localhost?

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  • sudoers entries

    - by Pochi
    Is there a way to have a sudoers entry that allows executing of only a particular command, without any extra arguments? I can't seem to find a resource that describes how command matching works with sudoers. Say I want to grant sudo for /path/to/executable arg. Does an entry like the following: user ALL=(ALL) /path/to/executable arg strictly allow sudo access to a command exactly matching that? That is, it doesn't grant user sudo privileges for /path/to/executable arg arg2?

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  • Access Control Lists basics

    - by vtortola
    Hi, I'm gonna add authorization, user and groups management to my application, basically... you will can define a set of permissions for a concrete user or group. For example, you could specify whom can use a concrete resource. So I want to ensure that my assumptions about ACLs are right: A basic rule could be "Grant", "Deny", "NoSet". User permissions have priority over group permissions. "Deny" statement has priority over "Grant". For example, user "u1" belongs to group "A", the resource "X" has this ACL "u1:grant,A:deny" user "u1" should be able to access the resource, shouldn't it? If a resource has no ACL set... does it means that anyone can access it? should I provide a default ACL? Any document about ACL in a general way? Cheers.

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  • dojo.io.iframe erroring when uploading a file

    - by Grant Collins
    Hi, Hit an interesting problem today when trying to upload an image file < 2MB using dojo.io.iframe. My function to process the form is called, but before the form is posted to the server I am getting the following error: TypeError: ifd.getElementsByTagName("textarea")[0] is undefined My function that is used to action the post of the form is : function uploadnewlogo(){ var logoDiv = dojo.byId('userlogo'); var logoMsg = dojo.byId('uploadmesg'); //prep the io frame to send logo data. dojo.io.iframe.send({ url: "/users/profile/changelogo/", method: "post", handleAs: "text", form: dojo.byId('logoUploadFrm'), handle: function(data,ioArgs){ var response = dojo.fromJson(data); if(response.status == 'success'){ //first clear the image //dojo.style(logoDiv, "display", "none"); logoDiv.innerHTML = ""; //then we update the image logoDiv.innerHTML = response.image; }else if(response.status == 'error'){ logoMsg.innerHTML = data.mesg; }else{ logoMsg.innerHTML = '<div class="error">Whoops! We can not process your image.</div>'; } }, error: function(data, ioArgs){ logoMsg.innerHTML = '<div class="error">' + data + '</div>'; } }); } The form is very basic with just a File input component and a simple button that calls this bit of javascript and dojo. I've got very similar code in my application that uploads word/pdf documents and that doesn't error, but for some reason this does. Any ideas or pointers on what I should try to get this to work without errors? Oh I'm using php and Zend framework for the backend if that has anything to do with it, but I doubt it as it's not even hitting the server before it fails. Many thanks, Grant

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  • Add Zend_Navigation to the View with old legacy bootstrap

    - by Grant Collins
    Hi, I've been struggling with Zend_Navigation all weekend, and now I have another problem, which I believe has been the cause of a lot of my issues. I am trying to add Zend_Navigation to a legacy 1.7.6 Zend Framework application, i've updated the Zend Library to 1.9.0 and updated the bootstrap to allow this library update. The problem is that I don't know how, and the examples show the new bootstrap method of how to add the Navigation object to the view, I've tried this: //initialise the application layouts with the MVC helpers $layout = Zend_Layout::startMvc(array('layoutPath' => '../application/layouts')); $view = $layout->getView(); $configNav = new Zend_Config_Xml('../application/config/navigation.xml', 'navigation'); $navigation = new Zend_Navigation($configNav); $view->navigation($navigation); $viewRenderer = new Zend_Controller_Action_Helper_ViewRenderer(); $viewRenderer->setView($view); This seems to run through fine, but when I go to use the breadcrumb view helper in my layout, it errors with: Strict Standards: Creating default object from empty value in C:\www\moobia\development\website\application\modules\employers\controllers\IndexController.php on line 27 This is caused by the following code in the init() function of my controller. $uri = $this->_request->getPathInfo(); $activeNav = $this->view->navigation()->findByUri($uri); <- this is null when called $activeNav->active = true; I believe it's because the Zend_Navigation object is not in the view. I would look at migrating the bootstrap to the current method, but at present I am running out of time for a release. Thanks, Grant

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  • NAnt errors when generating assembly info after project is upgraded to VS2010

    - by Grant Palin
    I have a project I recently upgraded to VS2010 - the project/solution files are updated, but I'm still targeting .NET 3.5. Until now, my standard NAnt build script has not given me any trouble. However, it appears that after updating the project, and updating the NAnt config to be aware of the new tooling, I am now receiving an error when autogenerating assembly information, which fails the build. The relevant build task is below: <asminfo output="${dir.src}\${file.commonAssemblyInfo}" language="${project.codeLanguage}"> <imports> <import namespace="System.Reflection" /> </imports> <attributes> <attribute type="AssemblyVersionAttribute" value="${project.fullversion}" /> <attribute type="AssemblyFileVersionAttribute" value="${project.fullversion}" /> <attribute type="AssemblyInformationalVersionAttribute" value="${project.fullversion}" /> <attribute type="AssemblyCopyrightAttribute" value="${assembly.copyright}" /> <attribute type="AssemblyCompanyAttribute" value="${assembly.company}" /> <attribute type="AssemblyConfigurationAttribute" value="${project.config}" /> <attribute type="AssemblyTrademarkAttribute" value="${assembly.trademark}" /> <attribute type="AssemblyProductAttribute" value="${assembly.product}" /> </attributes> </asminfo> The error is highlighted for the first line of the asminfo task. It reads: AssemblyInfo file 'C:\Users\Grant\Projects\VisualStudio\Checklist\src\CommonAssemblyInfo.cs' could not be generated. This method implicitly uses CAS policy, which has been obsoleted by the .NET Framework. In order to enable CAS policy for compatibility reasons, please use the NetFx40_LegacySecurityPolicy configuration switch. Please see http://go.microsoft.com/fwlink/?LinkID=155570 for more information. I've gathered so far that this is something new to .NET 4. Has anyone had to address this error before? Does anyone know what it is about asminfo that may be triggering the error?

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  • Create database in Shell Script - convert from PHP

    - by snaken
    I have the following PHP code that i use to create a databaase and grant permissions to a user: $con = mysql_connect("IP.ADDRESS","user","pass"); mysql_query("CREATE DATABASE ".$dbuser."",$con)or die(mysql_error()); mysql_query("grant all on ".$dbuser.".* to ".$dbname." identified by '".$dbpass."'",$con) or die(mysql_error()); I want to perform these same actions but from within a shell script. Is it just something like this: MyUSER="user" MyPASS="pass" MYSQL -u $MyUSER -h -p$MyPASS -Bse "CREATE DATABASE $dbuser;' MYSQL -u $MyUSER -h -p$MyPASS -Bse "GRANT ALL ON ${DBUSER}.* to $DBNAME identified by $DBPASS;"

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  • removing phone number from a document.

    - by Grant Collins
    Hi, I've got a challenge that I am hoping that the SO community is able to help me with. I trying to parse a lot of html documents in my PHP application to remove personal details, such as names, addresses and phone numbers. I can remove most of these details without too much trouble, however the phone number is a real problem for me. My idea is to take the text from these documents and the use a regex to identify the phone numbers and replace them with another value such as 'xxxx'. I've got 2 regex that I am using one for UK landline numbers and one for UK cell/mobile numbers. However when I try and run them against the text it just returns an empty string. I am using the following preg_replace code: $pattens = array( '/^(((\+44\s?\d{4}|\(?0\d{4}\)?)\s?\d{3}\s?\d{3})|((\+44\s?\d{3}|\(?0\d{3}\)?)\s?\d{3}\s?\d{4})|((\+44\s?\d{2}|\(?0\d{2}\)?)\s?\d{4}\s?\d{4}))(\s?\#(\d{4}|\d{3}))?$/', '/^(\+44\s?7\d{3}|\(?07\d{3}\)?)\s?\d{3}\s?\d{3}$/' ); $replace = array('xxxxx', 'xxxxx'); //do the search for the numbers. $updatedContents = preg_replace($pattens, $replace, $htmlContents); At the moment this is causing me a lot of head scratching as I thought that I had this nailed, but at the moment I can't see what's wrong?? I am sure that it is something really simple. Thanks, Grant

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  • Stop writing blank line at the end of CSV file (using MATLAB)

    - by Grant M.
    Hello all ... I'm using MATLAB to open a batch of CSV files containing column headers and data (using the 'importdata' function), then I manipulate the data a bit and write the headers and data to new CSV files using the 'dlmwrite' function. I'm using the '-append' and 'newline' attributes of 'dlmwrite' to add each line of text/data on a new line. Each of my new CSV files has a blank line at the end, whereas this blank line was not there before when I read in the data ... and I'm not using 'newline' on my final call of 'dlmwrite'. Does anyone know how I can keep from writing this blank line to the end of my CSV files? Thanks for your help, Grant EDITED 5/18/10 1:35PM CST - Added information about code and text file per request ... you'll notice after performing the procedure below that there appears to be a carriage return at the end of the last line in the new text file. Consider a text file named 'textfile.txt' that looks like this: Column1, Column2, Column3, Column4, Column 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 Here's a sample of the code I am using: % import data importedData = importdata('textfile.txt'); % manipulate data importedData.data(:,1) = 100; % store column headers into single comma-delimited % character array (for easy writing later) columnHeaders = importedData.textdata{1}; for counter = 2:size(importedData.textdata,2) columnHeaders = horzcat(columnHeaders,',',importedData.textdata{counter}); end % write column headers to new file dlmwrite('textfile_updated.txt',columnHeaders,'Delimiter','','newline','pc') % append all but last line of data to new file for dataCounter = 1:(size(importedData.data,2)-1) dlmwrite('textfile_updated.txt',importedData.data(dataCounter,:),'Delimiter',',','newline','pc','-append') end % append last line of data to new file, not % creating new line at end dlmwrite('textfile_updated.txt',importedData.data(end,:),'Delimiter',',','-append')

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  • Running a simple integration scenario using the Oracle Big Data Connectors on Hadoop/HDFS cluster

    - by hamsun
    Between the elephant ( the tradional image of the Hadoop framework) and the Oracle Iron Man (Big Data..) an english setter could be seen as the link to the right data Data, Data, Data, we are living in a world where data technology based on popular applications , search engines, Webservers, rich sms messages, email clients, weather forecasts and so on, have a predominant role in our life. More and more technologies are used to analyze/track our behavior, try to detect patterns, to propose us "the best/right user experience" from the Google Ad services, to Telco companies or large consumer sites (like Amazon:) ). The more we use all these technologies, the more we generate data, and thus there is a need of huge data marts and specific hardware/software servers (as the Exadata servers) in order to treat/analyze/understand the trends and offer new services to the users. Some of these "data feeds" are raw, unstructured data, and cannot be processed effectively by normal SQL queries. Large scale distributed processing was an emerging infrastructure need and the solution seemed to be the "collocation of compute nodes with the data", which in turn leaded to MapReduce parallel patterns and the development of the Hadoop framework, which is based on MapReduce and a distributed file system (HDFS) that runs on larger clusters of rather inexpensive servers. Several Oracle products are using the distributed / aggregation pattern for data calculation ( Coherence, NoSql, times ten ) so once that you are familiar with one of these technologies, lets says with coherence aggregators, you will find the whole Hadoop, MapReduce concept very similar. Oracle Big Data Appliance is based on the Cloudera Distribution (CDH), and the Oracle Big Data Connectors can be plugged on a Hadoop cluster running the CDH distribution or equivalent Hadoop clusters. In this paper, a "lab like" implementation of this concept is done on a single Linux X64 server, running an Oracle Database 11g Enterprise Edition Release 11.2.0.4.0, and a single node Apache hadoop-1.2.1 HDFS cluster, using the SQL connector for HDFS. The whole setup is fairly simple: Install on a Linux x64 server ( or virtual box appliance) an Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 server Get the Apache Hadoop distribution from: http://mir2.ovh.net/ftp.apache.org/dist/hadoop/common/hadoop-1.2.1. Get the Oracle Big Data Connectors from: http://www.oracle.com/technetwork/bdc/big-data-connectors/downloads/index.html?ssSourceSiteId=ocomen. Check the java version of your Linux server with the command: java -version java version "1.7.0_40" Java(TM) SE Runtime Environment (build 1.7.0_40-b43) Java HotSpot(TM) 64-Bit Server VM (build 24.0-b56, mixed mode) Decompress the hadoop hadoop-1.2.1.tar.gz file to /u01/hadoop-1.2.1 Modify your .bash_profile export HADOOP_HOME=/u01/hadoop-1.2.1 export PATH=$PATH:$HADOOP_HOME/bin export HIVE_HOME=/u01/hive-0.11.0 export PATH=$PATH:$HADOOP_HOME/bin:$HIVE_HOME/bin (also see my sample .bash_profile) Set up ssh trust for Hadoop process, this is a mandatory step, in our case we have to establish a "local trust" as will are using a single node configuration copy the new public keys to the list of authorized keys connect and test the ssh setup to your localhost: We will run a "pseudo-Hadoop cluster", in what is called "local standalone mode", all the Hadoop java components are running in one Java process, this is enough for our demo purposes. We need to "fine tune" some Hadoop configuration files, we have to go at our $HADOOP_HOME/conf, and modify the files: core-site.xml hdfs-site.xml mapred-site.xml check that the hadoop binaries are referenced correctly from the command line by executing: hadoop -version As Hadoop is managing our "clustered HDFS" file system we have to create "the mount point" and format it , the mount point will be declared to core-site.xml as: The layout under the /u01/hadoop-1.2.1/data will be created and used by other hadoop components (MapReduce = /mapred/...) HDFS is using the /dfs/... layout structure format the HDFS hadoop file system: Start the java components for the HDFS system As an additional check, you can use the GUI Hadoop browsers to check the content of your HDFS configurations: Once our HDFS Hadoop setup is done you can use the HDFS file system to store data ( big data : )), and plug them back and forth to Oracle Databases by the means of the Big Data Connectors ( which is the next configuration step). You can create / use a Hive db, but in our case we will make a simple integration of "raw data" , through the creation of an External Table to a local Oracle instance ( on the same Linux box, we run the Hadoop HDFS one node cluster and one Oracle DB). Download some public "big data", I use the site: http://france.meteofrance.com/france/observations, from where I can get *.csv files for my big data simulations :). Here is the data layout of my example file: Download the Big Data Connector from the OTN (oraosch-2.2.0.zip), unzip it to your local file system (see picture below) Modify your environment in order to access the connector libraries , and make the following test: [oracle@dg1 bin]$./hdfs_stream Usage: hdfs_stream locationFile [oracle@dg1 bin]$ Load the data to the Hadoop hdfs file system: hadoop fs -mkdir bgtest_data hadoop fs -put obsFrance.txt bgtest_data/obsFrance.txt hadoop fs -ls /user/oracle/bgtest_data/obsFrance.txt [oracle@dg1 bg-data-raw]$ hadoop fs -ls /user/oracle/bgtest_data/obsFrance.txt Found 1 items -rw-r--r-- 1 oracle supergroup 54103 2013-10-22 06:10 /user/oracle/bgtest_data/obsFrance.txt [oracle@dg1 bg-data-raw]$hadoop fs -ls hdfs:///user/oracle/bgtest_data/obsFrance.txt Found 1 items -rw-r--r-- 1 oracle supergroup 54103 2013-10-22 06:10 /user/oracle/bgtest_data/obsFrance.txt Check the content of the HDFS with the browser UI: Start the Oracle database, and run the following script in order to create the Oracle database user, the Oracle directories for the Oracle Big Data Connector (dg1 it’s my own db id replace accordingly yours): #!/bin/bash export ORAENV_ASK=NO export ORACLE_SID=dg1 . oraenv sqlplus /nolog <<EOF CONNECT / AS sysdba; CREATE OR REPLACE DIRECTORY osch_bin_path AS '/u01/orahdfs-2.2.0/bin'; CREATE USER BGUSER IDENTIFIED BY oracle; GRANT CREATE SESSION, CREATE TABLE TO BGUSER; GRANT EXECUTE ON sys.utl_file TO BGUSER; GRANT READ, EXECUTE ON DIRECTORY osch_bin_path TO BGUSER; CREATE OR REPLACE DIRECTORY BGT_LOG_DIR as '/u01/BG_TEST/logs'; GRANT READ, WRITE ON DIRECTORY BGT_LOG_DIR to BGUSER; CREATE OR REPLACE DIRECTORY BGT_DATA_DIR as '/u01/BG_TEST/data'; GRANT READ, WRITE ON DIRECTORY BGT_DATA_DIR to BGUSER; EOF Put the following in a file named t3.sh and make it executable, hadoop jar $OSCH_HOME/jlib/orahdfs.jar \ oracle.hadoop.exttab.ExternalTable \ -D oracle.hadoop.exttab.tableName=BGTEST_DP_XTAB \ -D oracle.hadoop.exttab.defaultDirectory=BGT_DATA_DIR \ -D oracle.hadoop.exttab.dataPaths="hdfs:///user/oracle/bgtest_data/obsFrance.txt" \ -D oracle.hadoop.exttab.columnCount=7 \ -D oracle.hadoop.connection.url=jdbc:oracle:thin:@//localhost:1521/dg1 \ -D oracle.hadoop.connection.user=BGUSER \ -D oracle.hadoop.exttab.printStackTrace=true \ -createTable --noexecute then test the creation fo the external table with it: [oracle@dg1 samples]$ ./t3.sh ./t3.sh: line 2: /u01/orahdfs-2.2.0: Is a directory Oracle SQL Connector for HDFS Release 2.2.0 - Production Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved. Enter Database Password:] The create table command was not executed. The following table would be created. CREATE TABLE "BGUSER"."BGTEST_DP_XTAB" ( "C1" VARCHAR2(4000), "C2" VARCHAR2(4000), "C3" VARCHAR2(4000), "C4" VARCHAR2(4000), "C5" VARCHAR2(4000), "C6" VARCHAR2(4000), "C7" VARCHAR2(4000) ) ORGANIZATION EXTERNAL ( TYPE ORACLE_LOADER DEFAULT DIRECTORY "BGT_DATA_DIR" ACCESS PARAMETERS ( RECORDS DELIMITED BY 0X'0A' CHARACTERSET AL32UTF8 STRING SIZES ARE IN CHARACTERS PREPROCESSOR "OSCH_BIN_PATH":'hdfs_stream' FIELDS TERMINATED BY 0X'2C' MISSING FIELD VALUES ARE NULL ( "C1" CHAR(4000), "C2" CHAR(4000), "C3" CHAR(4000), "C4" CHAR(4000), "C5" CHAR(4000), "C6" CHAR(4000), "C7" CHAR(4000) ) ) LOCATION ( 'osch-20131022081035-74-1' ) ) PARALLEL REJECT LIMIT UNLIMITED; The following location files would be created. osch-20131022081035-74-1 contains 1 URI, 54103 bytes 54103 hdfs://localhost:19000/user/oracle/bgtest_data/obsFrance.txt Then remove the --noexecute flag and create the external Oracle table for the Hadoop data. Check the results: The create table command succeeded. CREATE TABLE "BGUSER"."BGTEST_DP_XTAB" ( "C1" VARCHAR2(4000), "C2" VARCHAR2(4000), "C3" VARCHAR2(4000), "C4" VARCHAR2(4000), "C5" VARCHAR2(4000), "C6" VARCHAR2(4000), "C7" VARCHAR2(4000) ) ORGANIZATION EXTERNAL ( TYPE ORACLE_LOADER DEFAULT DIRECTORY "BGT_DATA_DIR" ACCESS PARAMETERS ( RECORDS DELIMITED BY 0X'0A' CHARACTERSET AL32UTF8 STRING SIZES ARE IN CHARACTERS PREPROCESSOR "OSCH_BIN_PATH":'hdfs_stream' FIELDS TERMINATED BY 0X'2C' MISSING FIELD VALUES ARE NULL ( "C1" CHAR(4000), "C2" CHAR(4000), "C3" CHAR(4000), "C4" CHAR(4000), "C5" CHAR(4000), "C6" CHAR(4000), "C7" CHAR(4000) ) ) LOCATION ( 'osch-20131022081719-3239-1' ) ) PARALLEL REJECT LIMIT UNLIMITED; The following location files were created. osch-20131022081719-3239-1 contains 1 URI, 54103 bytes 54103 hdfs://localhost:19000/user/oracle/bgtest_data/obsFrance.txt This is the view from the SQL Developer: and finally the number of lines in the oracle table, imported from our Hadoop HDFS cluster SQL select count(*) from "BGUSER"."BGTEST_DP_XTAB"; COUNT(*) ---------- 1151 In a next post we will integrate data from a Hive database, and try some ODI integrations with the ODI Big Data connector. Our simplistic approach is just a step to show you how these unstructured data world can be integrated to Oracle infrastructure. Hadoop, BigData, NoSql are great technologies, they are widely used and Oracle is offering a large integration infrastructure based on these services. Oracle University presents a complete curriculum on all the Oracle related technologies: NoSQL: Introduction to Oracle NoSQL Database Using Oracle NoSQL Database Big Data: Introduction to Big Data Oracle Big Data Essentials Oracle Big Data Overview Oracle Data Integrator: Oracle Data Integrator 12c: New Features Oracle Data Integrator 11g: Integration and Administration Oracle Data Integrator: Administration and Development Oracle Data Integrator 11g: Advanced Integration and Development Oracle Coherence 12c: Oracle Coherence 12c: New Features Oracle Coherence 12c: Share and Manage Data in Clusters Oracle Coherence 12c: Oracle GoldenGate 11g: Fundamentals for Oracle Oracle GoldenGate 11g: Fundamentals for SQL Server Oracle GoldenGate 11g Fundamentals for Oracle Oracle GoldenGate 11g Fundamentals for DB2 Oracle GoldenGate 11g Fundamentals for Teradata Oracle GoldenGate 11g Fundamentals for HP NonStop Oracle GoldenGate 11g Management Pack: Overview Oracle GoldenGate 11g Troubleshooting and Tuning Oracle GoldenGate 11g: Advanced Configuration for Oracle Other Resources: Apache Hadoop : http://hadoop.apache.org/ is the homepage for these technologies. "Hadoop Definitive Guide 3rdEdition" by Tom White is a classical lecture for people who want to know more about Hadoop , and some active "googling " will also give you some more references. About the author: Eugene Simos is based in France and joined Oracle through the BEA-Weblogic Acquisition, where he worked for the Professional Service, Support, end Education for major accounts across the EMEA Region. He worked in the banking sector, ATT, Telco companies giving him extensive experience on production environments. Eugen currently specializes in Oracle Fusion Middleware teaching an array of courses on Weblogic/Webcenter, Content,BPM /SOA/Identity-Security/GoldenGate/Virtualisation/Unified Comm Suite) throughout the EMEA region.

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  • Got an idea for an application, but part of it is patented, any suggestions?

    - by tekiegreg
    Hi there, so I've been working on developing an idea for an application that I think has the potential to be successful, however after some initial research I've discovered that at least part of my ideas are covered by a patent out there, the patent in particular is held by a really large company (I don't want to give away specifics for fear I'd draw their attention for sure). I'm debating a few options: 1) Develop patents around my ideas that don't conflict and maybe approach the company in question for a license exchange 2) Just approach them for a license outright 3) Just develop around it anyways and hope for the best :-p What have other people done in these situations? Are companies generally willing to grant patent licenses? Are they willing to grant them at reasonable prices? Thoughts?

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  • Welcome to Jackstown

    - by fatherjack
    I live in a small town, the population count isn't that great but let me introduce you to some of the population. We'll start with Martin the Doc, he fixes up anything that gets poorly, so much so that he could be classed as the doctor, the vet and even the garage mechanic. He's got a reputation that he can fix anything and that hasn't been proved wrong yet. He's great friends with Brian (who gets called "Brains") the teacher who seems to have a sound understanding of any topic you care to pass his way. If he isn't sure he tells you and then goes to find out and comes back with a full answer real quick. Its good to have that sort of research capability close at hand. Brains is also great at encouraging anyone who needs a bit of support to get them up to speed and working on their jobs. Steve sees Brains regularly, that's because he is the librarian, he keeps all sorts of reading material and nowadays there's even video to watch about any topic you like. Steve keeps scouring all sorts of places to get the content that's needed and he keeps it in good order so that what ever is needed can be found quickly. He also has to make sure that old stuff gets marked as probably out of date so that anyone reading it wont get mislead. Over the road from him is Greg, he's the town crier. We don't have a newspaper here so Greg keeps us all informed of what's going on "out of town" - what new stuff we might make use of and what wont work in a small place like this. If we are interested he goes ahead and gets people in to demonstrate their products  and tell us about the details. Greg is pretty good at getting us discounts too. Now Greg's brother Ian works for the mayors office in the "waste management department" nowadays its all about the recycling but he still has to make sure that the stuff that cant be used any more gets disposed of properly. It depends on the type of waste he's dealing with that decides how it need to be treated and he has to know a lot about the different methods and when to use which ones. There are two people that keep the peace in town, Brent is the detective, investigating wrong doings and applying justice where necessary and Bart is the diplomat who smooths things over when any people have a dispute or disagreement. Brent is meticulous in his investigations and fair in the way he handles any situation he finds. Discretion is his byword. There's a rumour that Bart used to work for the United Nations but what ever his history there is no denying his ability to get apparently irreconcilable parties working together to their combined benefit. Someone who works closely with Bart is Brad, he is the translator in town. He has several languages that he can converse in but he can also explain things from someone's point of view or  and make it understandable to someone else. To keep things on the straight and narrow from a legal perspective is Ben the solicitor, making sure we all abide by the rules.Two people who make for an interesting evening's conversation if you get them together are Aaron and Grant, Aaron is the local planning inspector and Grant is an inventor of some reputation. Anything being constructed around here needs Aarons agreement. He's quite flexible in his rules though; if you can justify what you want to do with solid logic but he wont stand for any development going on without his inclusion. That gets a demolition notice and there's no argument. Grant as I mentioned is the inventor in town, if something can be improved or created then Grant is your man. He mainly works on his own but isnt averse to getting specific advice and assistance from specialist from out of town if they can help him finish his creations.There aren't too many people left for you to meet in the town, there's Rob, he's an ex professional sportsman. He played Hockey, Football, Cricket, you name it. He was in his element as goal keeper / wicket keeper and that shows in his personal life. He just goes about his business and people often don't even know that he's helped them. Really low profile, doesn't get any glory but saves people from lots of problems, even disasters on occasion. There goes Neil, he's a bit of an odd person, some people say he's gifted with special clairvoyant powers, personally I think he's got his ear to the ground and knows where to find out the important news as soon as its made public. Anyone getting a visit from Neil is best off to follow his advice though, he's usually spot on and you wont be caught by surprise if you follow his recommendations – wherever it comes from.Poor old Andrew is the last person to introduce you to. Andrew doesn't show himself too often but when he does it seems that people find a reason to blame him for their problems, whether he had anything to do with their predicament or not. In all honesty, without fail, and to his great credit, he takes it in good grace and never retaliates or gets annoyed when he's out and about.  It pays off too as its very often the case that those who were blaming him recently suddenly find they need his help and they readily forget the issues pretty rapidly.And then there's me, what do I do in town? Well, I'm just a DBA with a lot of hats. (Jackstown Pop. 1)

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  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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