Tuesday, January 28, 2014

Comparision of different concurrency models: Actors, CSP, Disruptor and Threads

In order to make use of modern multi core/socket hardware, Java offers threads and locks for concurrent programming. It is well known this model suffers of a number of problems:
  • Deadlocks
  • Bad scaling due to "over-synchronization" or contention on common resources
  • Errors caused by invalid synchronization are timing dependent and hard to reproduce. It is common they appear under special conditions (load, hardware) in production.
  • As a software project grows, it gets hard to safely modify the application. A programmer needs global awareness of an applications control flow and data access patterns in order to change the software without introducing errors.
  • The subtleties of the Java Memory Model are not well known to most Java programmers. Even if JMM is known, incorrect programming isn't obvious and will fail rarely. It can be a nightmare to spot them from production logs of large applications.
So I am looking for alternative models to express concurrency. Therefore a simple benchmark of the most popular "alternative" concurrency models is done: Actors, CSP and Disruptor.



Actors


Real Life Analogy: People cooperating by sending mails to each other.

An Actor is like an object instance executed by a single thread. Instead of direct calls to methods, messages are put into the Actors "mailbox" (~queue). The actor single threaded reads and processes messages from the queue sequentially (with exceptions).
Internal state is exposed/shared by passing messages (with copied state) to other Actors.







CSP (Communicating Sequential Processes)


Real Life Analogy: People phoning each other.

Though a different terminology is used, CSP systems can be seen as a special actor system having bounded mailboxes (queues) of size 0.

So if one process (~Actor) wants to pass a message to another process, the caller is blocked until the receiver accepts the message. Alternatively to being blocked, a CSP-process can choose to do other things e.g. check for incoming messages (this introduces  non determinism to the order of outgoing messages). A receiver cannot accept incoming messages if he is occupied with processing a prior one.





Disruptor


The disruptor data structure came up some years ago and was invented and pioneered by Martin Thompson, Mike Barker, and Dave Farley at LMAX exchange.

Real Life Analogy: Assembly line




The disruptor is a bounded queue (implemented by a ring buffer) where producers add to the head of the queue (if slots are available, else the producer is blocked).
Consumers access the queue at different points, so each consumer has its own read position (cursor) inside the queue. Sequencing is used to manage queue access and processing order.



Thread + locking of shared data


contention
Ok, everybody knows this. Its Java's default to model concurrent execution. Actually these are the primitives (+CAS) used to build higher level concurrent models like those described above.











Conclusion


While the CSP/Actor-Model realizes inter-thread communication by passing/copying thread-local data to some queue or process, the Disruptor keeps data in place and assures only one thread (consumer or producer) is owner of a data item (=queue slot) at a time.
This model seems to fit existing CPU, memory and VM architectures better resulting in high throughput and superior performance. It avoids high allocation rates and reduces the probability of cache misses. Additionally it implicitly balances processing speed of interdependent consumers without growing queues somewhere.
There is no silver bullet for concurrent programming, one still has to plan carefully and needs to know what's going on.

While I am writing this, I realize each of these patterns has its set of best-fit problem domains, so my initial intention using a single benchmark to compare performance of different concurrency models might be somewhat off :-).


 

The Benchmark Application


 

Update: Jason Koch implemented a custom executor performing significantly better than the stock JDK executors. See his blog post.

The benchmark approximates the value of PI concurrently. Therefore N jobs are created, and the result of each job must be added to finally get an approximation of PI. For maximum performance one would create one large job for each Core of the CPU used. With this setup all solutions roughly would perform the same as there is no significant concurrent access and scheduling overhead.

However if we compute PI by creating 1 million jobs, each computing a 0..100-loop slice of PI, we get an impression of:
  • cost of accessing shared data when the result of each job is added to one single result value
  • overhead created by the concurrency control mechanics (e.g. sending messages/scheduling Runnables to a thread pool, CAS, Locks, volatile r/w ..).
The test is run with 2 configurations
  • 100 iterations per pi-slice-job, 1,000,000 jobs
  • 1,000 iterations per pi-slice-job, 100,000 jobs
As hardware I use
  • AMD Opteron 6274 Dual Socket 2,2 Ghz. Each socket has 8 cores + 8 Hardware Threads (so overall 16 cores + 16 HW Threads)
  • Intel XEON@3Ghz dual socket six core (12 cores + Hyperthreading turned off). (2011 release)
I never use more threads as there are "real" cores.



Stop the blabber, gimme results ! 


See bottom of this post for the benchmark source.
  • Threads - somewhat naive thread based implementation of the Pi computation. Enough effort invested it is possible to match any of the other results of course. At the core of the VM, threads, locks (+atomic, volatile r/w + CAS) are the only concurrent primitives. However there is no point in creating an ad-hoc copy of the Disruptor or an Actor system in order to compare concurrency approaches.
  • Akka - a popular Actor implementation on the VM. The benchmark has been reviewed and revised (especially the ActorSystem configuration can make a big difference) by the Akka crew. Threads are scheduled using Java 7's fork join pool. Actually the Pi computation is one of Akka's tutorial examples. 
  • Abstraktor - my experimental Actor/CSP implementation. It's using short bounded queues (so leans more to the CSP side) and avoids deadlocks by maintaining 2 queues per Actor (in and out). If the out-queue is blocked, it just reads from the in-queue.
    I am using Nitsan Wakarts excellent MPSC queue implementation (check his blog or github jaq-in-a-box) and that's the major reason it shows kind of competitive performance+scaling.
    I use this to get a rough baseline for comparision and experiment with different flavours of Actors/CSP. Probably the only thing one can do with it is to run the Pi bench ;-).
    Update: The experimental version benchmarked here has been consolidated + improved. You can find it ohttps://github.com/RuedigerMoeller/kontraktor
  • Disruptor - my naive approach implementing the benchmark based on the Disruptor 3.2. It turned out that I used a not-yet-polished utility class, however I keep this benchmark just to illustrate how smallish differences in implementation may have big consequences.
  • Disruptor2 - As Michael Barker would have implemented it (Thanks :-) ). Its actually more than twice as fast for the 1 million test as the closest runner up.
Intel (Xeon 2 socket each 6 cores, Hyperthreading off)

Well, it seems with 100k jobs of 1000 iterations, the benchmark is dominated by computation, not concurrency control. Therefore I retry with 1 million jobs each computing a 100 iteration slice.

Ok, we probably can see differences here :-)



AMD Opteron 6274 Dual Socket 2,2 Ghz (=16 real cores, 16 HW Threads)


Again the 1 million tiny-job variant spreads the difference amongst the approaches (and their implementation):


Note there is like 5% run to run jitter (GC and stuff), however that does not change the big picture.

Last but not least: Best results per CPU architecture per lib:




Discussion of Results


We see that scaling behaviour can be significantly different depending on the hardware platform used.

Akka loses a lot of CPU time doing GC and allocation. If I modify Abstraktor to use unbounded Concurrent Linked Queue (Akka uses those), it performs similar to Akka and builds up temporary queues >100k elements. This is an inherent issue of the Actor model. By leaning towards CSP (use very short bounded blocking queues with size <100), performance also suffers, as threads are blocked/spinning for input too often. However with a queue size of 5000 elements, things work out pretty well (introducing other problems like deadlocks in case of cyclic Actor graphs).
The Disruptor library is very well implemented, so a good part of the performance advantage could be attributed to the excellent quality of implementation.

Cite from the Disruptor documentation regarding queuing:
3.5 The Problems of Queues
[...]  If an in-memory queue is allowed to be unbounded then for many classes of problem it can grow unchecked until it reaches the point of catastrophic failure by exhausting memory. This happens when producers outpace the consumers. Unbounded queues can be useful in systems where the producers are guaranteed not to outpace the consumers and memory is a precious resource, but there is always a risk if this assumption doesn’t hold and queue grows without limit. [...]
When in use, queues are typically always close to full or close to empty due to the differences in pace between consumers and producers. They very rarely operate in a balanced middle ground where the rate of production and consumption is evenly matched. [...]
Couldn't have said it better myself =).



Conclusion


Although the Disruptor worked best for this example, I think looking for "the concurrency model to go for" is wrong. If we look at the real world, we see all 4 patterns used dependent on use case.
So a broad concurrency library ideally would integrate the assembly-line pattern (~Disruptor), queued messaging (~Actors) and unqueued communication (~CSP).



Benchmark source


AKKA




Multi Threading




Abstraktor




Disruptor naive




Disruptor optimized


206 comments:

  1. Rudiger, is hard to arrive to a conclusion. There are too many variables and misconceptions. But are we looking at the same thing. CSP and actors are both high level abstractions. And disruptor seems to me a very sophisticated queue implementation. Couldn't CSP and/or Actors be implemented with ring queues and memory barriers under the hood? Clearly platforms that rely too much on garbage collection may be at odds with the disruptor approach. But we could eventually see CSP and/or Actors catch up.

    ReplyDelete
  2. I don't think there is a general "best" model, it depends on use case.

    CSP has inherent problems with blocking, if one wants to avoid that, one has to accept indeterministic order of processing, which is a no go for many applications.
    Actors do not work well with any kind of bounded queue. As soon you limit queue size there is a deadlock scenario if your actor graph contains cycles.

    However the disruptor is more than a "queue" implementation. While actors need a queue for each processing unit following "move data not code", disruptor does this vice-versa "move code, not data". The analogy of a "mailbox" system and an "assembly line" pretty good illustrates the difference of the approaches. There are queues involved, but still the approach is quite diferrent.

    ReplyDelete
  3. And what about software transactional memory?

    ReplyDelete
    Replies
    1. There are no serious pure-software attempts for benchmarking available. However there are attempts to support this in hardware (Intel). I am not deep enough into the details to judge/guess viability of this approach. I'd assume it performes well for low contention but not so good in high contention cases. Additionally its not clear how and when the JVM will make this hardware feature avaiable.
      At time of writing I wasn't even aware of STM :-)

      Delete
  4. Useful read for me. Apart from throughput comparison I am also interested in know which concurrency model did you find easy to use and which one gives best safety guarantees. I am yet to dig to into concurrency models to reason about correctness and safety. Could you throw some light based on your experience?

    ReplyDelete
    Replies
    1. I think there is no "fits all" model.

      I found the Disruptor quite usable to setup high speed event/request processing engines, however it requires a different style to represent business logic and proper planning.
      As soon you hit some blocking API you'll need other ways to deal with concurrency.

      Actors: From my experience its manageable if you use it very course grained, as soon you setup complex actor systems with cyclic messaging/dependencies accross many actors, you'll run into serious trouble once real load is put on (queue overflows or deadlocks with bounded actor queues). Its by far not the "silver bullet" some folks try to make it.

      Try to think+design "reactive" e.g. a server component should be seen as a component processing a stream of incoming events single threaded (use NIO). If that is too slow, try to parallize sub-tasks, not the complete application flow. If that's still too slow, try partitioning. Avoid synchonous stuff (e.g. synchronous WebServices or remote calls, synchronous data base queries ). There are tricks to wrap blocking operations in order to avoid multithreading. Get used to queuing in order pass data from one processing unit to another.

      Unfortunately many of the old API's (e.g. servlets, jdbc) still are hard to use for a reactive style of programming and encourage/require creation of many threads without gaining anything but complexity.

      Delete
  5. This comment has been removed by the author.

    ReplyDelete
  6. Nice article, I think you have to consider reactive-streams as it is giving "asynchronous stream processing with non-blocking back pressure" which is meaning that it is reactive but consumer "subscriber" can control the pressure of the reactive calling, implementing dynamic push-pull way is giving benefits of reactive plus iterating, one of its implementations reactor using Disruptor implicitly.

    ReplyDelete
    Replies
    1. I implemented remoted reactive streams here: https://github.com/RuedigerMoeller/kontraktor/tree/trunk/modules/reactive-streams

      Though it might look "new" to many its in essence a simplified version of credit based flow control known from networking.
      A shortfall of current spec is the non-adaptive nature of "request(n)" pull sizes [tcp is better here] which is not an issue in-memory, but an issue at network grade latency. As the "request(n)" message has some travel time (depending on physical network conditions) the publisher might run dry. Its not too bad if libraries allow for manual tweaking, but not all allow for adjustment of "pull" size which leads to some whacky throughput variation when streaming over network.

      Delete
    2. Also note that Reactive Streams require queuing so its way slower than pure Disruptor processing. However its much easier to built up large scale, adaptive complex event processing pipelines using flow controlled Reactive Streams

      Delete
  7. Great article with clarity, Rüdiger! Just one question: how would you compare Asynchronous Programming to those paradigms? Thanks!

    ReplyDelete
  8. Hi, very clear. What about the "design" fact that in CSP one entity sends a message to a channel and another entity reads it from a channel, while in Actors actors sends directly messages one to another, so i can pass around the channel, it looks like a different abstractions which can be useful or not depending on use case, but in general having a channel I send events to sounds more reasnoable to me than objects talking directly (in many cases they should not know one another but when you read actor code you see that they are aware one of another a bad design by the fact of ease of misuse).

    ReplyDelete
  9. Devops is not a Tool.Devops Is a Practice, Methodology, Culture or process used in an Organization or Company for fast collaboration, integration and communication between Development and Operational Teams. In order to increase, automate the speed of productivity and delivery with reliability.



    digital marketing courses in Bangalore With placement

    digital marketing training in Bangalore

    seo training in Bangalore

    ReplyDelete
  10. Very Nice Information! Brainy helps children's to develop their creativity and social skills.
    At Brainy, There are many child brain development activities.
    Also you can apply for educational franchise opportunity India.

    ReplyDelete
  11. Maniry anao foana ny fifaliana sy ny fahasambarana. Manantena ianao fa manana lahatsoratra tsara kokoa ianao.

    Phối chó bull pháp

    Phối giống chó Corgi

    Phối chó Pug

    Phối giống chó alaska

    ReplyDelete
  12. This comment has been removed by the author.

    ReplyDelete
  13. Thanks for one marvelous posting! I enjoyed reading it; you are a great author. I will make sure to bookmark your blog and may come back someday. I want to encourage that you continue your great posts...
    Cloud Computing Online Training

    ReplyDelete
  14. I really like your blog. You make it interesting to read and entertaining at the same time. I cant wait to read more from you.
    salesforce online Certification

    ReplyDelete
  15. After looking at a number of the blog articles on your web site, I seriously appreciate your technique of blogging. I bookmarked it to my bookmark website list and will be checking back soon. Take a look at my website as well and let me know your opinion. motorola display repair bangaloreThis web site certainly has all the information I wanted concerning this subject and didn’t know who to ask. lg service center Bangalore There is definately a lot to find out about this topic. I like all of the points you made. vivo charging port replacement

    ReplyDelete
  16. I used to be able to find good information from your content. huawei display repair bangalore Great post! We will be linking to this particularly great article on our site. Keep up the good writing. asus display replacement This is a great tip particularly to those new to the blogosphere. Short but very accurate information… Thank you for sharing this one. A must read article! onsite mobile repair bangalore

    ReplyDelete


  17. Whatever we gathered information from the blogs, we should implement that in practically then only we can understand that exact thing clearly, but it’s no need to do it, because you have explained the concepts very well. It was crystal clear.i also want to inform you the best salesforce developer . thankyou . keep sharing..

    ReplyDelete
  18. Poker online situs terbaik yang kini dapat dimainkan seperti Bandar Poker yang menyediakan beberapa situs lainnya seperti http://62.171.128.49/hondaqq/ , kemudian http://62.171.128.49/gesitqq/, http://62.171.128.49/gelangqq/, dan http://62.171.128.49/seniqq. yang paling akhir yaitu http://62.171.128.49/pokerwalet/. Jangan lupa mendaftar di panenqq silakan dicoba ya boss

    ReplyDelete
  19. I admire the valuable information you offer in your articles. I learn a lot of new things here
    Node JS Online training
    Node JS training in Hyderabad

    ReplyDelete
  20. This post is really nice and informative. The explanation given is really comprehensive and informative.I want to inform you about the salesforce business analyst training and video tutorials . thankyou . keep sharing..

    ReplyDelete
  21. Thanks for Sharing This Article.It is very so much valuable content. I hope these Commenting lists will help to my website
    welcome to akilmanati
    akilmanati

    ReplyDelete
  22. It's really a nice and useful piece of information about Cloud Computing. I'm satisfied that you shared this helpful information with us.Please keep us informed like this. Thank you for sharing.

    Java training in chennai | Java training in annanagar | Java training in omr | Java training in porur | Java training in tambaram | Java training in velachery

    ReplyDelete
  23. A backlink is a link created when one website links to another. Backlinks are important to SEO & impact for higher ranking. In my 7+ years seo Career i see, without backlinks a website doesn't rank higher on google SERP.

    Get Your 300+ High Quality DoFollow Backlinks Here!

    Order Now with Full Confidence & 100% satisfaction.

    ReplyDelete
  24. Thanks for sharing the great information, I hope really enjoyed while reading the article.
    Java Online Training
    Python Online Training
    PHP Online Training

    ReplyDelete
  25. Forex Signals, MT4 and MT5 Indicators, Strategies, Expert Advisors, Forex News, Technical Analysis and Trade Updates in the FOREX IN WORLD

    Forex Signals Forex Strategies Forex Indicators Forex News Forex World

    ReplyDelete
  26. yahoo mail forgot passwordYahoo mail forgot password Are you one of them who forgot their string of secret characters, don't panic you are counted in that of users who forgot password. and solve for this problem.

    ReplyDelete
  27. Thank you for sharing this informative article with us. I got lots of information from this website. Keep sharing more article like this.

    ReplyDelete
  28. very interesting, good job and thanks for sharing such a good blog. Youtube Mp3 Converter

    ReplyDelete
  29. You have a big talent! Don't waste it, I advise you to create youtube channel too and post video. On this site https://soclikes.com/ you can get cheap youtube subscribers, buy at least your first subscribers

    ReplyDelete
  30. jungle ka paryayvachi – जंगल शब्द का पर्यायवाची है (The word jungle is synonymous -)–

    ReplyDelete
  31. Kim Ravida is a lifestyle and business coach who helps women in business take powerful money actions and make solid, productiveIamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder IamLinkfeeder

    ReplyDelete
  32. This comment has been removed by the author.

    ReplyDelete
  33. I got very good information in this post, thank you very much from my side, keep giving this kind of information.
    1.Hindi studio

    ReplyDelete
  34. Looking for amazing and latest technical updates?
    Do visit us at
    https://geekermag.com/

    ReplyDelete
  35. Thanks for crafting this beautiful information. I’m thankful and humbled to you. This is the best blog I have ever read. I’m going to make sure that I will share. Rubix Market Research

    ReplyDelete
  36. Thats great post !! I like ur every post they always give me some new knowledge.

    VidMate | VidMate for PC |
    VidMate 2014

    ReplyDelete
  37. This comment has been removed by the author.

    ReplyDelete
  38. Thanks for the interesting content. I like your post and your blog is amazing.
    If you are interested in Video Downloader apps you can check my blog site. It is new and really informative.

    utorrent pro mod apk free download

    ReplyDelete
  39. Thanks for the interesting content. I like your post and your blog is amazing.
    If you are interested in Video Downloader apps you can check my blog site. It is new and really informative.

    shareit

    ReplyDelete
  40. Windows Live Hotmail is the second popular email service available in the world, after Yahoo! Yes, it is even more popular than Gmail, given Microsoft is the developer of it. Hotmail comes in two different versions, free and paid. Here is the complete gudie on hotmail.com.signin process.

    ReplyDelete
  41. How to make yahoo my homepage on Firefox?

    If you have no idea about how to make yahoo my homepage on Firefox, go through the steps mentioned here . First of all, launch the Firefox browser and then click on the Menu icon . Choose the Preferences icon under it. Now, under the General page, click on Show my home page option. Next, under the Home Page field, you need to enter www.Yahoo.com. Now, Yahoo will be made as your default homepage for Firefox browser.




    ReplyDelete
  42. Situs Nonton movie, film dan tv series terbaru dengan subtitle indonesia diupdate setiap hari, dari situs terpopuler nonton disini link
    di bawah ini
    layarkaca21
    bioskopkeren
    daymovie
    terbit21
    boomthis

    Situs judi online terpercaya
    http://199.188.201.133
    http://162.213.251.13
    bonekaqq
    indoqq99
    sahabatqq

    ReplyDelete
  43. java has really become the new c, as it has taken over in many domains.
    just like gmail register

    ReplyDelete
  44. Airpods have become a part of our lives. I don’t see anyone owning an iPhone that does not use AirPods. It is easy to use, carry anywhere, and even charge. Usually, the battery life of the first- and second-generation AirPods on a single charge lasts for around 5 hours while the user is listening to music and is 3 hours while having a phone conversation. Here is the complete guest for check airpods battery.

    ReplyDelete
  45. Much of our Sofa Maintaining Services is amazingly unique. We make use of different variety of tools to help you sanitize any corner from your sofa. You use choose to dry memory foam or expressly formalized soap solution designed for sensitization assuring optimum gains. The drying out process can take maximum 3 hours additionally, the couch decide to use within too busy. We you should not use any specific chemicals to help you spoil ones own fabric and risk yourself. We Have got unmatched high-quality Upholstery Maintaining Services on Dubai. cleaning services in dubai

    ReplyDelete
  46. According to the official statement, IPL 2nd phase is going be launched from 19th September. There are 31 remaining matches pending and they will be continued till 10th October, the day final match will be played. Check out Vivo IPL 2021 UAE Schedule, IPL UAE Match Timings in india, Points Table, Team positions & Player stats in this article.

    ReplyDelete
  47. Are you in a confusion in choosing the best option between renting a laptop & owning a laptop ?Before talking about the renting a laptop, once imagine yourself in a situation, I am about to mention.Amateur or an expert you will still google and find out what laptops you can get depending on the budget, need, offers.

    ReplyDelete
  48. These comparison is amazing and good for the knowledge purpose.
    Movierulz4

    ReplyDelete
  49. Do you need an urgent loan of any kind? Loans to liquidate debts or need to loan to improve your business have you been rejected by any other banks and financial institutions? Do you need a loan or a mortgage? This is the place to look, we are here to solve all your financial problems. We borrow money for the public. Need financial help with a bad credit in need of money. To pay for a commercial investment at a reasonable rate of 3%, let me use this method to inform you that we are providing reliable and helpful assistance and we will be ready to lend you. Contact us today by email: daveloganloanfirm@gmail.com Call/Text: +1(501)800-0690 And whatsapp: +1 (501) 214‑1395

    NEED A LOAN?
    Ask Me.

    ReplyDelete
  50. Hello Sir I saw your blog, It was very nice blog, and your blog content is awesome, i read it and i am impressed of your blog, i read your more blogs, thanks for share this summary.
    How to change yahoo mail password

    ReplyDelete
  51. I have to convey my respect for your kindness for all those that require guidance on this one field. Your special commitment to passing the solution up and down has been incredibly functional and has continually empowered most people just like me to achieve their dreams. Your amazing insightful information entails much to me and especially to my peers.
    hướng dẫn đi máy bay từ mỹ về việt nam

    Máy bay từ Hàn Quốc về Việt Nam

    Ve may bay Bamboo tu Nhat Ban ve Viet Nam

    vé máy bay từ singapore về hà nội vietjet

    Bảng giá vé máy bay Vietjet Air tu Dai Loan ve Viet Nam

    thông tin chuyến bay từ canada về việt nam

    ReplyDelete
  52. vst4crack comes with a simple and friendly interface, allowing you to optimize your system registry with just a few mouse clicks.








    ReplyDelete
  53. Thanks for sharing valuable article having good information and also gain worthful knowledge. We are also providing the best services click on below links to visit our website.
    Oracle Fusion HCM Training
    Workday Training
    Okta Training
    Palo Alto Training
    Adobe Analytics Training

    ReplyDelete
  54. https://koladblog.com.ng/2021/10/08/top-6-really-free-vpn-for-android/

    https://koladblog.com.ng/2021/10/16/how-to-apply-for-opay-pos-in-nigeria/

    opay pos

    ReplyDelete
  55. I’ve been following your web site for some time now and finally, I decided to write this post in order to thank you for providing us such a fine content!!! Feel free to visit my website; 바카라사이트

    ReplyDelete
  56. Thanks for sharing the info. I located the information very useful. That’s a brilliant story you posted. I will come back to read some more. Feel free to visit my website; 바카라사이트

    ReplyDelete
  57. You may be wondering what Hotmail is and how it can help you. Hotmail is an email service that has been around since the 1990s. It was originally created by Microsoft, but in 2012 Hotmail was rebranded to outlook.com email. Here is the complete guide for Hotmail signin.

    ReplyDelete
  58. i think that java is in the past now.

    ReplyDelete
  59. It’s not difficult to open a Hotmail account, and everyone can do it on their own. It may be any age group or profession; non-savvy individuals of all kinds are welcome! Here is the complete guide for www.Hotmail.com.

    It’s really simple to set up a hotmail.com account on your own. All you have to do is follow the on-screen directions, and you’ll be good to go. You need only a laptop/smartphone with an internet connection for this to work.

    ReplyDelete
  60. Combining the three free tools included in idm serial number are an excellent way to improve privacy online.








    ReplyDelete
  61. Thanks for Sharing This Article.It is very so much valuable content. Alignment near me

    ReplyDelete
  62. I really enjoyed your blog Thanks for sharing such an informative post.
    moving services near me
    commercial movers near me

    ReplyDelete
  63. Thanks for the informative article. This is one of the best resources I have found in quite some time. Nicely written and great info.
    Beauty Salon Near Me
    Piercing Near Me
    Laser Hair Removal Near Me

    ReplyDelete
  64. One of the new technologies and sources of income is the lucrative and risky digital currency market. Over time, https://isiarticles.com/blog/143 money has changed shape, and with the advancement of science in every industry, the science of economics has grown.

    ReplyDelete
  65. Thanks so much for sharing this incredible information it's really very helpful I really appreciate your hard work for clearing this article once again thanks

    It would be great if you leave your review on this article that will help me to modify this article for better User experience thanks in advance.

    women beauty cream

    ReplyDelete
  66. Gain better scores in every assignment and exam with Finite Mathematics And Applied Calculus 6th Edition Test Bank. Be on the top of your class.

    ReplyDelete
  67. Really an awesome blog. Nice information and knowledgeable content. Keep sharing more articles with us. Thank you.
    Best Data Science Certification Courses in Hyderabad with Placements

    ReplyDelete
  68. I would like to take this opportunity to thank the author for his incredible work. I believe Customer relationship management is essential for every business to create a loyal customer base. keep doing it. all the best
    Best School Management Software

    ReplyDelete
  69. These are very good post and i like your post...hindi skill

    ReplyDelete
  70. The 'Google Voice Number Lookup' app is made to expose the unknown Google voice phone number. This search is easy and takes no time. So, if you are being disturbed by constant calls, you need to enter the Google voice phone number into the Google Voice Number Lookup tool, which is free to use, and begin the process. The moment you enter the phone number. You will be taken to a different page where all activities will take place. It can take 3 minutes to display all the information and give you a report with all the details about the Google Voice number in question in minutes.

    ReplyDelete
  71. One of the option of doing investement is by investing in Crypto currencies. You can invest in Fudxcoin company that deals in the selling and purchasing of Crypto Currency. It is a reliable company. One need not doubt in investing in it as i have also bought crypto currency from it and feeling very satisfied with their services.
    crypto currency blockchain technology

    ReplyDelete
  72. Hiring a carpet steam cleaner is a great way to get your carpets clean without having to do the work yourself. Not only is it a time-saving option, but it's also a great way to get your carpets looking and smelling fresh again. If you're in need of a carpet steam cleaner, be sure to contact your local rental company and ask about their rates and availability.

    ReplyDelete
  73. Nice Post Thanks for sharing . You can also visit our Website if you need any help related to
    Furniture Delivery
    Courier Services
    Car Transport
    Man And Van
    Motorcycle Transport

    ReplyDelete
  74. Hello, I am Margot Robbie from Long Beach, California, United States. I am Professional IT Manager. Hello, I am linda jones from Long Beach, California, United States. I am Professional IT Manager. I love writing and written some blogs you can check them.

    Canon IJ Setup
    Setup IJ Start Canon TR4500
    Setup Canon Pixma TR4520 Printer

    ReplyDelete
  75. This comment has been removed by the author.

    ReplyDelete
  76. Whether you haven't received an important email you've been waiting for or don't receive any emails, it can be a big problem. You should try some things if your Yahoo email not receiving. The first thing is to check your spam folder. Yahoo's automatic bulk-mail filter does a good job of preventing unwanted emails from reaching your inbox, but it occasionally makes mistakes

    ReplyDelete

  77. AFM Logistics Pvt.Ltd. is a International freight forwarding and customs clearing company established in Delhi. It has its headoffice in Mahipalpur Extn., New Delhi. IT also has a branch in Walnut, CA. It has its own expanded network through out the world. If anyone wants to avail its service, that person can contact them on https://afm.net.in/ or mail them on

    info@afm.net.in
    +91 11 42198540,+1 330 845 7979

    ReplyDelete
  78. Effortlessly find reliable freight or Best Haulage Services In The UK at budget-friendly prices.
    Cut on your business expenses with Any Movers free quotes.

    ReplyDelete
  79. In the past, students had to take economics homework help from their teachers or professors. Nowadays there are many different options for students to choose from.
    economics assignment help usa

    ReplyDelete
  80. Our globe is gradually entering a post-pandemic reality that presents many hurdles for market researchers and businesses alike. Customers'
    Market Research in the Post-pandemic World

    ReplyDelete
  81. Learn to Solve Yahoo Mail Loading Slow on Android

    Often, Android users face issues like Yahoo Mail loading slowly on their devices. If you are an Android user and experience a Yahoo mail loading problem, the most likely cause is that the outdated Yahoo Mail app is installed on your device. If you want to use Yahoo Mail on your Android device without errors, make sure that you have the most recent version installed. To upgrade, select 'Applications' and type 'Yahoo Mail' on the search bar. Check for the 'Update' button under 'Yahoo Mail' in your list of suggestions. If you see the 'Update' button, the app needs to be updated. If it does, tap on 'Update' to do so. Once Yahoo is updated, relaunch the application and check if it works properly.

    ReplyDelete
  82. I would like to thank you for the efforts you have made in writing this article. I am hoping the same best work from you in the future as well. Thanks…
    world series of free chips

    ReplyDelete
  83. Perpa kurye

    (0212) 210 55 57
    Perpa Kurye
    Perpa Moto kurye, sektöründe uzmanlaşmış ekip çalışanları ile birlikte sizlere haftanın 6 günü mesai saatleri içinde kurye hizmeti sağlamaktadır. Teslimat ihtiyaçlarınıza uygun olarak, trafik problemi yaşatmadan, günün her saatinde ulaştırılması gereken materyallerinizi sizlerden teslim alarak güvenli bir şekilde adresine teslim etmektedir. Müşteri memnuniyetini önceleyen nitelikli bir hizmet anlayışıyla Perpa Ticaret merkezi başta olmak üzere İstanbul’un bütün ilçelerinde güvenli bir teslimat hizmeti sağlamaktayız. Müşterilerimizin ihtiyaçları doğrultusunda, alternatif ihtiyaçlarına uygun çözümler üreterek; motorlu ya da ticari araçlarımız ile hizmet verdiğimiz kadar şehirlerarası teslimat için havayolu taşımacılık hizmetlerinide sunmaktayız. Siz de hizmetlerimiz ile ilgili detayları öğrenmek ve Moto kurye hizmetlerimizden faydalanmak için bizlere telefon açabilir, WhatsApp üzerinden bizlere ulaşabilir ya da sitemizden iletişim sağlayabilirsiniz.

    ReplyDelete
  84. Thank you so much for your post. I learned a lot from it, now I'm a bit clearer. Keep us updated. Unresponsive spacebars are one of the most common problems that users encounter, and they can be quite annoying as well. Visit latest blog on spacebar not working. Here are some hacks and methods you can try to fix the issue..

    ReplyDelete
  85. Das Expertenteam von Sanitär, Heizung & Klimaanlage ist hier, um Hausbesitzern jederzeit und jeden Tag mit Notdiensten zu helfen. Jedes der hochqualifizierten Experten ist bereit, in Aktion zu treten, wenn Sie Hilfe am dringendsten benötigen. Wir sind bereit, uns um alle Probleme mit Sanitär, Heizung oder Klimaanlage zu kümmern.
    abflussreinigungsdienst berlin

    ReplyDelete
  86. The goal of Routers.Guru is to assist people in extracting the most value possible from the technology that permeates every aspect of our lives today. We offer context for the most recent technological news, in addition to an extensive library of up-to-date educational how-to articles and impartial product advice and reviews.부천스웨디시
    광명스웨디시
    동두천스웨디시
    평택스웨디시
    안산스웨디시
    고양스웨디시
    과천스웨디시
    구리스웨디시

    ReplyDelete
  87. In the meantime, which site information Google will show to the viewer as the leading and main site, or which site viewers and service users will choose, depends on the use of techniques to increase Google visits.

    ReplyDelete
  88. Even women who were healthy before pregnancy may experience complications. These complications may turn the pregnancy into a high-risk

    ReplyDelete
  89. Thank you for sharing such a really admire your post. Your post is great! . major-donors

    ReplyDelete
  90. This comment has been removed by the author.

    ReplyDelete
  91. This comment has been removed by the author.

    ReplyDelete
  92. nice post, thanks for shearing this information, really helpful.
    Java Course In Amravati

    ReplyDelete
  93. Here are some of the resources available for Dell Boomi training:

    Boomi website: The Boomi website has a wealth of resources for learning about the platform, including documentation, tutorials, and training videos.
    Boomi community: The Boomi community is a great place to connect with other Boomi users and learn from their experiences.
    Third-party training providers: There are a number of third-party training providers that offer Boomi training. These providers can offer more specialized training or training that is tailored to your specific needs.dellbhoomi

    ReplyDelete
  94. Dazzle all night with your cocktail look in meena bazaar dresses from exclusive collection! Shop for the trendiest and stylish Cocktail Dresses For Women online from Mbz. We have a wide range of dresses for you to glam up on cocktail night.

    ReplyDelete
  95. Thanks for awesome info. The information here will surely be of some help to me. visit my blog on House of fun free coins</a

    ReplyDelete
  96. Looking forward to reading more. Great post. Really looking forward to reading more. Will read on…
    SCCM 2019 Training Classes
    SAP BW On HANA Training from Hyderabad
    Best Selenium With Python Training

    ReplyDelete
  97. Thank you , it helps me alot for my research you have posted usefull information
    Exploring the Hardware Architecture of Embedded Systems

    ReplyDelete
  98. Great information Thank you..

    ELearn Infotech offers Real-time Node JS Training in Hyderabad. Our Node JS course includes from Basic to Advanced Level Node JS Concepts. We have designed our Node JS course content based on students Requirement to Achieve Goal. We offer both Node JS class room training in Hyderabad and Node JS Course online training by 10+ years Realtime Experts.

    ReplyDelete


  99. very useful article , this is what i want

    ReplyDelete
  100. Meena Bazaar has unique yet tasteful Kurta Sets! Kurta Sets express and hold the Indian heritage with trending designs that flatter every skin tone. Pick out the best kurta set design that reflects your personality. At Meena Bazaar, you get to choose from Designer Kurtas to basic Regular Kurta Sets.

    Shop Now: Womens Ethnic Wear | Cotton Kurta Set for Women | Designer Gown Dress |Lehenga Online

    ReplyDelete

  101. am truly pleased to read this weblog posts which contains lots of helpful information

    ReplyDelete
  102. Its very well written; I love what youve got to say.

    ReplyDelete
  103. Beneath are some webpages really worth checking out

    ReplyDelete
  104. well I’m not writing all that over again. Regardless, just wanted to say fantastic blog!

    ReplyDelete
  105. please visit the internet sites we comply with, such as this one.

    ReplyDelete
  106. Your means of describing the whole thing in this piece of writing is truly good.

    ReplyDelete
  107. I am reading articles online and this one of the best, Thankyou!

    ReplyDelete
  108. Hello there, You have performed an excellent article..Goodjob!

    ReplyDelete
  109. Really nice post. Thank you for posting something like this. Keep it up!

    ReplyDelete
  110. Excellent post. I was checking constantly this blog and I am impressed!

    ReplyDelete
  111. this content is valuable and simple, I’ve learned a lot here.

    ReplyDelete
  112. I’ve got you saved as a favorite to look at new stuff you post…

    ReplyDelete
  113. Great blog article. Really looking forward to read more.

    ReplyDelete
  114. Great Post! I look forward to seeing more from this blog here.

    ReplyDelete
  115. Thank you for sharing this amazing idea, really appreciates your post.

    ReplyDelete
  116. Thanks for sharing this piece of information.

    ReplyDelete