Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
6k to 12k users connected for around 1.5 to 2 hrs. It is kind of an online examination.

You're asking the wrong questions; or at least, providing the wrong information; and of the wrong people.

It's simple to demonstrate that a single commodity box with an average amount of memory (say 4GB to 8GB) with suitable server software can sustain 12000 concurrent connections with ease. If they are doing nothing or very little.

Whether those 12000 users would be serviced in a timely manner if they all attempted to connect at the exact same moment is a different matter; but that's normally not a concern as it is rare for 12000 people to coordinate their actions in that way.

Of course, for an exam, you might stipulate that they must start at exactly the same time. Even then, you would normally tell them that they must be logged on a least 5 minutes before the start time, and give them a 15 or 20 minute window before that during which to get logged in etc.

Assuming that you do require them all to see that first page of the questions at "exactly the same time", then the concern is, can your server deliver that first page to 12000 users within some specified period of time. Assuming sufficient bandwidth and ignoring net latency, that equates to can your server/software deliver that first page to all 12000 within that specified period.

Given the first page will be the same (or substantially the same) for all of them, that means a 'static page' delivery. Even if the first page is customised -- with the user name/ID etc.; as you have this information for 5 minutes before the off; those customisations can be done before the off, thus avoiding active content generation at that peak period.

After that, each user will move through the pages of the exam at different speeds, which will have a natural tendency to spread the load out.

So the headline number you need to look at is how much content (kbytes) needs to be delivered to each user over that 1.5 or 2 hour period; and how much resource -- CPU; DB; etc. -- does your software need to generate that content.

Once you have those figures -- easily measured from your existing or test system setup -- then you have what you need to perform your capacity planning for the numbers involved.

Bottom line: asking random strangers on the net to guess how to do your job; when only you have the information required to do it; is likely to lead you in completely the wrong direction.


With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". I knew I was on the right track :)
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: Scalable application with perl by BrowserUk
in thread Scalable application with perl by jasz

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others admiring the Monastery: (6)
As of 2024-03-28 13:45 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found