Search Results

Search found 14282 results on 572 pages for 'performance counter'.

Page 73/572 | < Previous Page | 69 70 71 72 73 74 75 76 77 78 79 80  | Next Page >

  • Tools to monitor guest OS performance in vSphere

    - by Quick Joe Smith
    I am looking for some tool or way to retrieve performance data from guest VMs running under vSphere 4.1. I am currently interested in the 4 basic metrics: CPU(%), Memory(%), Disk availability(%) & Network utilisation(Kb/s). The issue I have is that all of vSphere's performance data is from a ESXi host perspective (active, shared, consumed, overhead, swapped etc.) which is far removed from the data from the VM's own perspective. For instance, I have a Windows server VM idling, using around 410MB (~25% of its allocated 2GB) as reported by Task Manager, and this is the value I'm after. vSphere's metrics seem unable to arrive at this figure by any reliable and repeatable means. Is anyone aware of tools that can obtain this kind of data? The simpler, the better.

    Read the article

  • Cassandra on heterogeneous servers

    - by happy-coding
    I am currently running 4 cassandra nodes with the following hardware in a Apache Cassandra cluster: AMD Athlon 64 X2 6000+ 8G RAM 750G hard disk It shows not such a good writing performance and a really bad read performance with sometimes also timeouts. I was wondering if it makes sense to add 2 nodes with a different hardware (8 CPUs and more RAM) to improve this. Or does a cassandra cluster works best with the same hardware in every node? Thanks & best regards

    Read the article

  • TCP/IP performance tuning under KVM/Qemu

    - by vpetersson
    With more and more companies switching to public cloud services, I'm curious what you guys' thoughts are on TCP/IP tuning in the cloud. Is it worth bothering with? Given that you don't have access to the host-server, you're somewhat limited I presume Let's say for the sake of the argument that you're running three MongoDB-servers in a replica-set on FreeBSD or Linux that all sync over an internal network. I'd also be curious if anyone made any actual performance benchmarks to back up their arguments. I benchmarked the various network drivers available for KVM/Qemu here, but I'm curious what the gurus here suggest to tune further. I started playing around a bit with the tuning-recommendations as suggested over here, but interestingly enough I saw a decrease in performance, rather than an increase, but perhaps I didn't fully understand the tweaks. Update: I did a few more benchmarks and posted the result here. Unfortunately the result wasn't really what I expected.

    Read the article

  • a load balancing scenario using HAProxy and keepalived shows no performance advantage

    - by chakoshi
    Hi, I am trying to setup a load balanced web server scenario, using two HAproxy load balancers and two debian web servers following this guide http://www.howtoforge.com/setting-up-a-high-availability-load-balancer-with-haproxy-keepalived-on-debian-lenny. the setup is working but the results of simple performance benchmarking is not what I expected. I tried apache benchmark tool to send lots of requests to servers (one time directly testing one of the web servers and the other time testing through the load balancer) using the command "ab -n 1000000 -c 500 http://IP/index.html", but the test results shows better performance for the single server without load balancer. can any one tell me if I'm going wrong on some thing?

    Read the article

  • iSCSI SAN RAID 10 Performance -- Poor Read, Good Write

    - by Litzner
    I have a EqualLogic PS4000 SAN unit with the latest firmware, setup in RAID 10. I have 3 2TB Volumes on the SAN shared out via iSCSI on 2 eth ports on two different subnets. I have moved a test server over to this newly setup SAN, and my testing is showing me a problem. I am getting dismal read performance in everything except a test with 32 queue depth (see attach image) Write performance seems to be right about where it should be. I have tried MPIO on and off, on was slightly better but not much.

    Read the article

  • Addons which actually make Firefox run faster?

    - by Zombies
    I would like to know of addons which actually enhance firefox's performance, both intentionally and unintentionally. I find that firefox tends to have major performance issues with certain websites. These websites tend to have a fair amount of javascript and css, and probably a large dom tree which may even be growing dynamically through javascript too. The worse offenders are those with heavy javascript, use heavy facebook integration, websites with non performant javascript, excessive javascript and websites with too many advertisements.

    Read the article

  • What is the best way to secure MySQL data on a laptop *without* whole-disk-encryption?

    - by GJ
    I need to have the mysql data on my laptop stored in an encrypted state so that in case of the laptop being lost/stolen it will extremely difficult to recover the data without the password. I don't wish to use whole disk encryption, due to the performance impact it will have on other disk-intensive programs' usage. What could be the ideal solution for me balancing security and performance? Thanks!

    Read the article

  • Improving Windows Authentication performance on IIS

    - by flalar
    We're struggling with performance issues with a ASP.NET MVC site that is using Windows Authentication. Response time is very slow on the first request to the site when the user is being authenticated. Further, every time the Authorization header is sent from the browser the response time increases with many seconds. The same issue occurs for both executed files and static content like CSS and JS. Access to the application is restricted to users within a certain role and we are now planning to allow access to static files for all authenticated users to see if that helps. The authentication method in use is NTLM. How should we go forward in pinpointing why authentication decreases performance drastically?

    Read the article

  • nginx: URL rewrites and performance

    - by j0nes
    I have a website where I need to change the URL structure. The old URLs look like /olddir/part1_de.htm, the new ones will look like /newdir/sub/category/anotherpage.htm. There are a lot of URL rewrites I need to do, I assume about 500 distinct rewrites in the end. As my website gets quite a lot of traffic, my main concern is about performance at the moment. My questions are: I assume that for each request, the rewrites block will be parsed and the regex will be evaluated. Am I right? Will there be a performance penalty if I use these rewrites? Can nginx handle this? Are there any "best practices" to follow when doing a lot of rewrites?

    Read the article

  • SSD Performance for PHP?

    - by Andrew Fashion
    My programmer just built an application with PHP using Doctrine ORM (will be a high traffic social networking website), and it's very heavy in PHP/Apache and CPU. The queries are wonderfully fast, and MySQL is barely using any CPU, it's just Apache. I was curious to if an SSD would help speed up PHP/Apache, because I know the bottleneck is in PHP reading multiple files, class files, and loading up a bunch of data. So common sense makes me think if PHP is reading multiple PHP files, an SSD would only help as far as read/write? I was thinking of doing a high performance SSD for the PHP application, but for user image uploads, I would just continue using a 15k SAS. Is there any performance issues regarding using an SSD in this kind of situation? And would it prove to help speed up PHP/Apache, and help the CPU problem out?

    Read the article

  • How to Check the Performance of VPS?

    - by Ngu Soon Hui
    I have subscribed to a VPS offered by a hosting provider. The guaranteed performance 1GB RAM, 1M bandwidth. But I found that from time to time the websites can be very slow, so slow that it could take more than 30 seconds to load a simple Joomla website. However the website resumed the usual speed after a few minutes. This created a problem for me when I want to report the performance problem to the hosting provider. They would say to me "see, no problem". Of course there is no problem because the problem is only there for a few minutes , and everything is normal. This ocassionally-slow problem will bug me a few days later and the cycle repeats. Any idea how to solve this problem?

    Read the article

  • Are there any known issues with Windows-8 installed on a VHD?

    - by Richard
    I installed Windows 8 preview on a VHD image and it seemed to work until I actually started using it. I´m seeing terrible performance. Installing anything makes everything else "stutter" or freeze for up to a couple of seconds at a time. I looked up hard disk performance in the task manager and this is what I found: It doesn't seem right it has 2500ms response time while reading/writing at those speeds. Is this an issue with my drive, installation or VHDs in general?

    Read the article

  • Which type of motherboard i should by and why?

    - by metal gear solid
    If budged is not matter. I just need best performance with less power consumption. I can purchase any cabinet , power supply and Motherboard. Is Power supply has any relation with Form factor? Is the size of motherboard and number of Slots only difference between all form factors? Is there any difference related to performance of motherboard? Is bigger in Size (ATX) motherboard always better?

    Read the article

  • Soap client call has slow performance

    - by Alon_A
    OS is Centos 6.2 with PHP 5.3.15. We have a Facebook application that is using PHP soap web services. We sometimes experince slow preformance when connecting to these services, but we cant understand what exacly is causing the problem. We've try to analyse the behavior using the profiling tool Kcachgrind. Here is a call graph from the index.php page that took 21 seconds to load. You can clearly see that calling the soap client is the bottle neck. I've also noticed that exactly before the page finishes to load, this file is being created in our serve's /tmp folder: wsdl-apache-d1032d85dfd16c0d91a6b70facc70e43 These are the permission of /tmp drwxrwxrwt 6 root root 40960 Aug 30 10:39 tmp I know its not the most specific question, but if any one had similar performance issues with soap client, We would love some ideas about what can cause this kind of performance problem, what can we do to investigate more accurately or how to overcome the problem ? Thanks.

    Read the article

  • How to handle EntityExistsException properly?

    - by Ivan Yatskevich
    I have two entities: Question and FavoritesCounter. FavoritesCounter should be created when the question is added to favorites for the first time. Consider a use case when two users tries to add a question to favorites simultaneously - this will cause EntityExistsException when entityManager.persist(counter) is called for the second user. But the code below doesn't work, because when EntityExistsException is thrown, container marks transaction as rollback only and attempt to return getFavoritesCounter(question) fails with javax.resource.ResourceException: Transaction is not active @Stateless public class FavoritesServiceBean implements FavoritesService { ... public void addToFavorites(Question question) { FavoritesCounter counter = getCounter(question); if (counter == null) { counter = createCounter(question); } //increase counter } private FavoritesCounter createCounter(Question question) { try { FavoritesCounter counter = new FavoritesCounter(); counter.setQuestion(question); entityManager.persist(counter); entityManager.flush(); return counter; } catch (EntityExistsException e) { return getFavoritesCounter(question); } } private FavoritesCounter getFavoritesCounter(Question question) { Query counterQuery = entityManager.createQery("SELECT counter FROM FavoritesCounter counter WHERE counter.question = :question"); counterQuery.setParameter("question", question); List<FavoritesCounter> result = counterQuery.getResultList(); if (result.isEmpty()) return null; return result.get(0); } } Question @Entity public class Question implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } FavoritesCounter @Entity public class FavoritesCounter implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @OneToOne @Column(unique = true) private Question question; //getter and setter } What is the best way to handle such a situation - return already created entity after EntityExistsException?

    Read the article

  • Is it possible in Perl to require a subroutine call is made?

    - by MitchelWB
    I don't know enough about Perl to even know what I'm asking for exactly, but I'm writing a series of subroutines to be available for many individual scripts that all process different incoming flat files. The process is far from perfect, but it's what I've got to deal with and I'm trying to build myself a small library of subs that make it easier for me to manage it all. Each script handles a different incoming flat file with it's own formatting, sorting, grouping and outputting requirements. One common aspect is that we have small text files that house counters that are used to name the output files so that we have no duplicate file names. Because the processing of the data is different for each file, I need to open the file to get my counter value, because this is a common operation, I'd like to put it in a sub to retrieve the counter. But then need to write specific code to process the data. And would like a second sub that allows me to update the counter with the counter once I've processed the data. Is there a way to make the second sub call a requirement if the first one is called? Ideally if it could even be an error that would prevent the script from running at all much like a syntax error. EDIT: Here is a little [ugly and simplified] psuedo-code to give a better feel for what the current process is: require "importLibrary.plx"; #open data source file open DataIn, $filename; #call getCounterInfo from importLibrary.plx to get the counter value from counter file $counter = &getCounterInfo($counterFileName); while (<DataIn>) { #Process data based on unique formatting and requirements #output to task files based on requirements and name files using the $counter #increment $counter } #update counter file with new value of $counter &updateCounterInfo($counter);

    Read the article

  • Plan Caching and Query Memory Part II (Hash Match) – When not to use stored procedure - Most common performance mistake SQL Server developers make.

    - by sqlworkshops
    SQL Server estimates Memory requirement at compile time, when stored procedure or other plan caching mechanisms like sp_executesql or prepared statement are used, the memory requirement is estimated based on first set of execution parameters. This is a common reason for spill over tempdb and hence poor performance. Common memory allocating queries are that perform Sort and do Hash Match operations like Hash Join or Hash Aggregation or Hash Union. This article covers Hash Match operations with examples. It is recommended to read Plan Caching and Query Memory Part I before this article which covers an introduction and Query memory for Sort. In most cases it is cheaper to pay for the compilation cost of dynamic queries than huge cost for spill over tempdb, unless memory requirement for a query does not change significantly based on predicates.   This article covers underestimation / overestimation of memory for Hash Match operation. Plan Caching and Query Memory Part I covers underestimation / overestimation for Sort. It is important to note that underestimation of memory for Sort and Hash Match operations lead to spill over tempdb and hence negatively impact performance. Overestimation of memory affects the memory needs of other concurrently executing queries. In addition, it is important to note, with Hash Match operations, overestimation of memory can actually lead to poor performance.   To read additional articles I wrote click here.   The best way to learn is to practice. To create the below tables and reproduce the behavior, join the mailing list by using this link: www.sqlworkshops.com/ml and I will send you the table creation script. Most of these concepts are also covered in our webcasts: www.sqlworkshops.com/webcasts  Let’s create a Customer’s State table that has 99% of customers in NY and the rest 1% in WA.Customers table used in Part I of this article is also used here.To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'. --Example provided by www.sqlworkshops.com drop table CustomersState go create table CustomersState (CustomerID int primary key, Address char(200), State char(2)) go insert into CustomersState (CustomerID, Address) select CustomerID, 'Address' from Customers update CustomersState set State = 'NY' where CustomerID % 100 != 1 update CustomersState set State = 'WA' where CustomerID % 100 = 1 go update statistics CustomersState with fullscan go   Let’s create a stored procedure that joins customers with CustomersState table with a predicate on State. --Example provided by www.sqlworkshops.com create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1) end go  Let’s execute the stored procedure first with parameter value ‘WA’ – which will select 1% of data. set statistics time on go --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' goThe stored procedure took 294 ms to complete.  The stored procedure was granted 6704 KB based on 8000 rows being estimated.  The estimated number of rows, 8000 is similar to actual number of rows 8000 and hence the memory estimation should be ok.  There was no Hash Warning in SQL Profiler. To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'.   Now let’s execute the stored procedure with parameter value ‘NY’ – which will select 99% of data. -Example provided by www.sqlworkshops.com exec CustomersByState 'NY' go  The stored procedure took 2922 ms to complete.   The stored procedure was granted 6704 KB based on 8000 rows being estimated.    The estimated number of rows, 8000 is way different from the actual number of rows 792000 because the estimation is based on the first set of parameter value supplied to the stored procedure which is ‘WA’ in our case. This underestimation will lead to spill over tempdb, resulting in poor performance.   There was Hash Warning (Recursion) in SQL Profiler. To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'.   Let’s recompile the stored procedure and then let’s first execute the stored procedure with parameter value ‘NY’.  In a production instance it is not advisable to use sp_recompile instead one should use DBCC FREEPROCCACHE (plan_handle). This is due to locking issues involved with sp_recompile, refer to our webcasts, www.sqlworkshops.com/webcasts for further details.   exec sp_recompile CustomersByState go --Example provided by www.sqlworkshops.com exec CustomersByState 'NY' go  Now the stored procedure took only 1046 ms instead of 2922 ms.   The stored procedure was granted 146752 KB of memory. The estimated number of rows, 792000 is similar to actual number of rows of 792000. Better performance of this stored procedure execution is due to better estimation of memory and avoiding spill over tempdb.   There was no Hash Warning in SQL Profiler.   Now let’s execute the stored procedure with parameter value ‘WA’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go  The stored procedure took 351 ms to complete, higher than the previous execution time of 294 ms.    This stored procedure was granted more memory (146752 KB) than necessary (6704 KB) based on parameter value ‘NY’ for estimation (792000 rows) instead of parameter value ‘WA’ for estimation (8000 rows). This is because the estimation is based on the first set of parameter value supplied to the stored procedure which is ‘NY’ in this case. This overestimation leads to poor performance of this Hash Match operation, it might also affect the performance of other concurrently executing queries requiring memory and hence overestimation is not recommended.     The estimated number of rows, 792000 is much more than the actual number of rows of 8000.  Intermediate Summary: This issue can be avoided by not caching the plan for memory allocating queries. Other possibility is to use recompile hint or optimize for hint to allocate memory for predefined data range.Let’s recreate the stored procedure with recompile hint. --Example provided by www.sqlworkshops.com drop proc CustomersByState go create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1, recompile) end go  Let’s execute the stored procedure initially with parameter value ‘WA’ and then with parameter value ‘NY’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go exec CustomersByState 'NY' go  The stored procedure took 297 ms and 1102 ms in line with previous optimal execution times.   The stored procedure with parameter value ‘WA’ has good estimation like before.   Estimated number of rows of 8000 is similar to actual number of rows of 8000.   The stored procedure with parameter value ‘NY’ also has good estimation and memory grant like before because the stored procedure was recompiled with current set of parameter values.  Estimated number of rows of 792000 is similar to actual number of rows of 792000.    The compilation time and compilation CPU of 1 ms is not expensive in this case compared to the performance benefit.   There was no Hash Warning in SQL Profiler.   Let’s recreate the stored procedure with optimize for hint of ‘NY’. --Example provided by www.sqlworkshops.com drop proc CustomersByState go create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1, optimize for (@State = 'NY')) end go  Let’s execute the stored procedure initially with parameter value ‘WA’ and then with parameter value ‘NY’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go exec CustomersByState 'NY' go  The stored procedure took 353 ms with parameter value ‘WA’, this is much slower than the optimal execution time of 294 ms we observed previously. This is because of overestimation of memory. The stored procedure with parameter value ‘NY’ has optimal execution time like before.   The stored procedure with parameter value ‘WA’ has overestimation of rows because of optimize for hint value of ‘NY’.   Unlike before, more memory was estimated to this stored procedure based on optimize for hint value ‘NY’.    The stored procedure with parameter value ‘NY’ has good estimation because of optimize for hint value of ‘NY’. Estimated number of rows of 792000 is similar to actual number of rows of 792000.   Optimal amount memory was estimated to this stored procedure based on optimize for hint value ‘NY’.   There was no Hash Warning in SQL Profiler.   This article covers underestimation / overestimation of memory for Hash Match operation. Plan Caching and Query Memory Part I covers underestimation / overestimation for Sort. It is important to note that underestimation of memory for Sort and Hash Match operations lead to spill over tempdb and hence negatively impact performance. Overestimation of memory affects the memory needs of other concurrently executing queries. In addition, it is important to note, with Hash Match operations, overestimation of memory can actually lead to poor performance.   Summary: Cached plan might lead to underestimation or overestimation of memory because the memory is estimated based on first set of execution parameters. It is recommended not to cache the plan if the amount of memory required to execute the stored procedure has a wide range of possibilities. One can mitigate this by using recompile hint, but that will lead to compilation overhead. However, in most cases it might be ok to pay for compilation rather than spilling sort over tempdb which could be very expensive compared to compilation cost. The other possibility is to use optimize for hint, but in case one sorts more data than hinted by optimize for hint, this will still lead to spill. On the other side there is also the possibility of overestimation leading to unnecessary memory issues for other concurrently executing queries. In case of Hash Match operations, this overestimation of memory might lead to poor performance. When the values used in optimize for hint are archived from the database, the estimation will be wrong leading to worst performance, so one has to exercise caution before using optimize for hint, recompile hint is better in this case.   I explain these concepts with detailed examples in my webcasts (www.sqlworkshops.com/webcasts), I recommend you to watch them. The best way to learn is to practice. To create the above tables and reproduce the behavior, join the mailing list at www.sqlworkshops.com/ml and I will send you the relevant SQL Scripts.  Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   Disclaimer and copyright information:This article refers to organizations and products that may be the trademarks or registered trademarks of their various owners. Copyright of this article belongs to R Meyyappan / www.sqlworkshops.com. You may freely use the ideas and concepts discussed in this article with acknowledgement (www.sqlworkshops.com), but you may not claim any of it as your own work. This article is for informational purposes only; you use any of the suggestions given here entirely at your own risk.   R Meyyappan [email protected] LinkedIn: http://at.linkedin.com/in/rmeyyappan

    Read the article

  • Bad performance function in PHP. With large files memory blows up! How can I refactor?

    - by André
    Hi I have a function that strips out lines from files. I'm handling with large files(more than 100Mb). I have the PHP Memory with 256MB but the function that handles with the strip out of lines blows up with a 100MB CSV File. What the function must do is this: Originally I have the CSV like: Copyright (c) 2007 MaxMind LLC. All Rights Reserved. locId,country,region,city,postalCode,latitude,longitude,metroCode,areaCode 1,"O1","","","",0.0000,0.0000,, 2,"AP","","","",35.0000,105.0000,, 3,"EU","","","",47.0000,8.0000,, 4,"AD","","","",42.5000,1.5000,, 5,"AE","","","",24.0000,54.0000,, 6,"AF","","","",33.0000,65.0000,, 7,"AG","","","",17.0500,-61.8000,, 8,"AI","","","",18.2500,-63.1667,, 9,"AL","","","",41.0000,20.0000,, When I pass the CSV file to this function I got: locId,country,region,city,postalCode,latitude,longitude,metroCode,areaCode 1,"O1","","","",0.0000,0.0000,, 2,"AP","","","",35.0000,105.0000,, 3,"EU","","","",47.0000,8.0000,, 4,"AD","","","",42.5000,1.5000,, 5,"AE","","","",24.0000,54.0000,, 6,"AF","","","",33.0000,65.0000,, 7,"AG","","","",17.0500,-61.8000,, 8,"AI","","","",18.2500,-63.1667,, 9,"AL","","","",41.0000,20.0000,, It only strips out the first line, nothing more. The problem is the performance of this function with large files, it blows up the memory. The function is: public function deleteLine($line_no, $csvFileName) { // this function strips a specific line from a file // if a line is stripped, functions returns True else false // // e.g. // deleteLine(-1, xyz.csv); // strip last line // deleteLine(1, xyz.csv); // strip first line // Assigna o nome do ficheiro $filename = $csvFileName; $strip_return=FALSE; $data=file($filename); $pipe=fopen($filename,'w'); $size=count($data); if($line_no==-1) $skip=$size-1; else $skip=$line_no-1; for($line=0;$line<$size;$line++) if($line!=$skip) fputs($pipe,$data[$line]); else $strip_return=TRUE; return $strip_return; } It is possible to refactor this function to not blow up with the 256MB PHP Memory? Give me some clues. Best Regards,

    Read the article

  • Multi-tenant ASP.NET MVC – Introduction

    - by zowens
    I’ve read a few different blogs that talk about multi-tenancy and how to resolve some of the issues surrounding multi-tenancy. What I’ve come to realize is that these implementations overcomplicate the issues and give only a muddy implementation! I’ve seen some really illogical code out there. I have recently been building a multi-tenancy framework for internal use at eagleenvision.net. Through this process, I’ve realized a few different techniques to make building multi-tenant applications actually quite easy. I will be posting a few different entries over the issue and my personal implementation. In this first post, I will discuss what multi-tenancy means and how my implementation will be structured.   So what’s the problem? Here’s the deal. Multi-tenancy is basically a technique of code-reuse of web application code. A multi-tenant application is an application that runs a single instance for multiple clients. Here the “client” is different URL bindings on IIS using ASP.NET MVC. The problem with different instances of the, essentially, same application is that you have to spin up different instances of ASP.NET. As the number of running instances of ASP.NET grows, so does the memory footprint of IIS. Stack Exchange shifted its architecture to multi-tenancy March. As the blog post explains, multi-tenancy saves cost in terms of memory utilization and physical disc storage. If you use the same code base for many applications, multi-tenancy just makes sense. You’ll reduce the amount of work it takes to synchronize the site implementations and you’ll thank your lucky stars later for choosing to use one application for multiple sites. Multi-tenancy allows the freedom of extensibility while relying on some pre-built code.   You’d think this would be simple. I have actually seen a real lack of reference material on the subject in terms of ASP.NET MVC. This is somewhat surprising given the number of users of ASP.NET MVC. However, I will certainly fill the void ;). Implementing a multi-tenant application takes a little thinking. It’s not straight-forward because the possibilities of implementation are endless. I have yet to see a great implementation of a multi-tenant MVC application. The only one that comes close to what I have in mind is Rob Ashton’s implementation (all the entries are listed on this page). There’s some really nasty code in there… something I’d really like to avoid. He has also written a library (MvcEx) that attempts to aid multi-tenant development. This code is even worse, in my honest opinion. Once I start seeing Reflection.Emit, I have to assume the worst :) In all seriousness, if his implementation makes sense to you, use it! It’s a fine implementation that should be given a look. At least look at the code. I will reference MvcEx going forward as a comparison to my implementation. I will explain why my approach differs from MvcEx and how it is better or worse (hopefully better).   Core Goals of my Multi-Tenant Implementation The first, and foremost, goal is to use Inversion of Control containers to my advantage. As you will see throughout this series, I pass around containers quite frequently and rely on their use heavily. I will be using StructureMap in my implementation. However, you could probably use your favorite IoC tool instead. <RANT> However, please don’t be stupid and abstract your IoC tool. Each IoC is powerful and by abstracting the capabilities, you’re doing yourself a real disservice. Who in the world swaps out IoC tools…? No one!</RANT> (It had to be said.) I will outline some of the goodness of StructureMap as we go along. This is really an invaluable tool in my tool belt and simple to use in my multi-tenant implementation. The second core goal is to represent a tenant as easily as possible. Just as a dependency container will be a first-class citizen, so will a tenant. This allows us to easily extend and use tenants. This will also allow different ways of “plugging in” tenants into your application. In my implementation, there will be a single dependency container for a single tenant. This will enable isolation of the dependencies of the tenant. The third goal is to use composition as a means to delegate “core” functions out to the tenant. More on this later.   Features In MvcExt, “Modules” are a code element of the infrastructure. I have simplified this concept and have named this “Features”. A feature is a simple element of an application. Controllers can be specified to have a feature and actions can have “sub features”. Each tenant can select features it needs and the other features will be hidden to the tenant’s users. My implementation doesn’t require something to be a feature. A controller can be common to all tenants. For example, (as you will see) I have a “Content” controller that will return the CSS, Javascript and Images for a tenant. This is common logic to all tenants and shouldn’t be hidden or considered a “feature”; Content is a core component.   Up next My next post will be all about the code. I will reveal some of the foundation to the way I do multi-tenancy. I will have posts dedicated to Foundation, Controllers, Views, Caching, Content and how to setup the tenants. Each post will be in-depth about the issues and implementation details, while adhering to my core goals outlined in this post. As always, comment with questions of DM me on twitter or send me an email.

    Read the article

  • SQL Server 2008 uses half the CPU’s

    - by ACALVETT
    I recently got my hands on a couple of 4 socket servers with Intel E7-4870's (10 cores per cpu) and with hyper threading enabled that gave me 80 logical CPU's. The server has Windows 2008 R2 SP1 along with SQL 2008 (Currently we can not deploy SQL 2008 R2 for the application being hosted). When SQL Server started I noticed only 2 NUMA nodes were configured and 40 logical cores where there should have been 4 NUMA nodes and 80 logical cores (see below). The problem is caused by that fact that...(read more)

    Read the article

  • Do not use “using” in WCF Client

    - by oazabir
    You know that any IDisposable object must be disposed using using. So, you have been using using to wrap WCF service’s ChannelFactory and Clients like this: using(var client = new SomeClient()) {. ..} Or, if you are doing it the hard and slow way (without really knowing why), then: using(var factory = new ChannelFactory<ISomeService>()) {var channel= factory.CreateChannel();...} That’s what we have all learnt in school right? We have learnt it wrong! When there’s a network related error or the connection is broken, or the call is timed out before Dispose is called by the using keyword, then it results in the following exception when the using keyword tries to dispose the channel: failed: System.ServiceModel.CommunicationObjectFaultedException : The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state. Server stack trace: at System.ServiceModel.Channels.CommunicationObject.Close(TimeSpan timeout) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout) at System.ServiceModel.ClientBase`1.System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout) at System.ServiceModel.ClientBase`1.Close() at System.ServiceModel.ClientBase`1.System.IDisposable.Dispose() There are various reasons for which the underlying connection can be at broken state before the using block is completed and the .Dispose() is called. Common problems like network connection dropping, IIS doing an app pool recycle at that moment, some proxy sitting between you and the service dropping the connection for various reasons and so on. The point is, it might seem like a corner case, but it’s a likely corner case. If you are building a highly available client, you need to treat this properly before you go-live. So, do NOT use using on WCF Channel/Client/ChannelFactory. Instead you need to use an alternative. Here’s what you can do: First create an extension method. public static class WcfExtensions{ public static void Using<T>(this T client, Action<T> work) where T : ICommunicationObject { try { work(client); client.Close(); } catch (CommunicationException e) { client.Abort(); } catch (TimeoutException e) { client.Abort(); } catch (Exception e) { client.Abort(); throw; } }} Then use this instead of the using keyword: new SomeClient().Using(channel => { channel.Login(username, password);}); Or if you are using ChannelFactory then: new ChannelFactory<ISomeService>().Using(channel => { channel.Login(username, password);}); Enjoy!

    Read the article

  • Does just-ping determine a website's accessibility and/or speed?

    - by Yves
    While looking for a webhost I wanted one that had good connectivity around the world, and ran their (shared hosting) test IPs on just-ping.com. This is a part of a sample result: München, Germany: Packets lost (10%) 24.8 24.9 25.1 178.xx.xx.xxx Cologne, Germany: Okay 5.6 5.7 5.8 178.xx.xx.xxx New York, U.S.A.: Packets lost (30%) 80.3 80.4 80.7 178.xx.xx.xxx Stockholm, Sweden: Packets lost (100%) 178.xx.xx.xxx Santa Clara, U.S.A.: Packets lost (30%) 158.1 158.4 158.7 178.xx.xx.xxx Vancouver, Canada: Packets lost (70%) 189.4 189.5 189.5 178.xx.xx.xxx London, United Kingdom: Packets lost (100%) Am I correct in thinking that hosts with several "Packets lost" messages from different locations have less stable or slower connections than hosts with all "Okays"?

    Read the article

< Previous Page | 69 70 71 72 73 74 75 76 77 78 79 80  | Next Page >