I have certain goods for consumers to buy, let's say there are 10 limited books. Users have to submit their info forms asap to get the book.
What concerns me is, if there are say 30 people submit the form, there can only be 10 people who got the book, and the other 20s will waste there time, this harms user experience.
What I want is, I store the page open count in db, if 10 people has open the page, I will stop that view. However, what if someone just close that window and don't buy? Then the remaining books will never be sold.
How can I solve this? I am wondering if I can enable the view again if someone who opened the page didn't answer for a specific time?
You might want to implement a 2-tier system.
The first tier is the count of sold books. As soon as you have sold 10 books. The action is finished and you can deactivate the view.
To prevent more users calling the url for the offer i'd recommend you some kind if AJAX Heartbeat:
User requests url
session is set for this user and comes with a timeout, in case this user doesn't to anything for X Minutes/hours/etc. If timeout is reached: session will be deleted
offer counter is incremented by 1
javascript sends a keep alive heartbeat via ajax, so your system knows that user is still using that url and hasn't moved anywhere else.
if the heartbeat stops: delete session and decrement offer counter by 1.
this ensures that only 10 people can look at your view at a time, but you will be able to sell all 10 books.
You might want a redirect to a different page when your counter is full?
You can add some cookies to each user and save in database cookies values with page views information. And you can save user IP address to improve your system.
Related
I am setting up Sitecore xDB and am trying to test exactly what info gets through the system for authenticated and non-authenticated users. I would like to be able to make a change and see the results quickly in Sitecore. I found the setting to lower session lifetime to 1 minute rather than 20. I have not found a way to just force Sitecore to sync with Mongo on demand or at least within 1-5 minutes rather than, what also appears to be about 20 minutes at the moment. Does it exist or is "rebuilding" the database explained here the only existing process?
See this blog post by Martina Welander for this and more good info about xDB sessions: https://mhwelander.net/2016/08/24/whats-in-a-session-what-exactly-happens-during-a-session-and-how-does-the-xdb-know-who-you-are/
You just need a utility page that calls System.Web.HttpContext.Current.Session.Abandon(). You may also want to redirect the user to a page that doesn't exist.
Update to address comment
My understanding is that once an xDB session has expired, processing should take place quickly. In the Sitecore.Analytics.Processing.Services.config file, the BackgroundService agent is set to run on an interval of 15 seconds by default.
You may just be seeing cached reporting data. Try clearing the cache using the /sitecore/admin/cache.aspx page. You could also decrease the defaultCacheExpiration setting for the reporting cacheProvider in the Sitecore.Analytics.Reporting.config file. The default is 10 minutes.
I'm planning to build a cashback site, but I'm confused on how the system work.
After googling i found this answer on Quora:
There is a tracking mechanism into the process. When you sign up to cash back site like fatwallet, the site create for you an ID, this ID is passed through your cookies, when you click on the link of the cash back site to the retailer. When a sale take place, the tracking mechanism send the transaction summary to the rebate website with your id so the store can link it back to you.
Is it possible to track such information? If possible, how can I achieve this?
I need to push changes to my app's session scopes in real time. Each user in session in my app has a similar struct to this:
session.user =
{
name = "Foo",
mojo = "100"
};
Users can modify each others' "mojo." For example, if user Foo received 10 mojo points, and he now has 110, I need to update his session.user.mojo to reflect the additional "mojo" received. I need to modify his session struct, in other words.
Example 2: User in session 1 does something where user in session 2 receives "mojo." The session.user.mojo in session 2 needs to be updated to reflect this change.
Some info:
The inital mojo value is pulled from the database and stored in the session when a user logs in.
"Mojo" updates always take place in the database. "Mojo" stored in the session is used to govern user privileges.
What are my options? Is this even possible? I have absolutely no idea on how to do something like that.
UPDATE I don't want pass the updated values back to the user (the data will refresh when the user navigates between pages). I only want to change them in the appropriate user's session scope.
This answer is ColdFusion 9 specific.
Cache user data (e.g. cachePut()) by user ID, and keep track of their user ID in session. Every update to mojo should retrieve the user data in cache - if present - and update it there as well. Finally, if this is a multi-server environment, setup messaging between the machines that broadcasts the user ID of any change to mojo, servers receiving the message then update their own cached user data.
What this buys you is limiting the amount of database activity that goes on, pretty good liveness, and makes the mojo value available globally, which has the added benefit of being available for purposes other than the user session (e.g. another user can review their profile to see the mojo score).
If you really need to change vars in a particular Session, there's no built-in way to do that. Maybe you can abstract out the logic, instead of accessing the mojo from Session, always access mojo from DB?
update: Why session? How about a big struct in Application scope, and use userID or sessionID as key, and mojo as value? You can also store a timestape like lastUpdated and delete the ones that has not been updated to reclaim your memory. Then from time to time, update your DB? Or... update your DB async if u're worry about performance.
I need to track some information on users, but would like to retain it for a fixed time period, say a week.
If I set this value via request.sessions, and the user logs out, can I retrieve it if they log back in later? This all assumes that my sessions are normally set to expire in 30 days, if the user neVer logs out.
While thinking about the above problem, I decided to store the data in a table, but I would still like to know the answer to above for referenCe. I also decided not to use cookies due to unreliability.
It would depend on your session backend. But the default backend (backends.db) does delete the row from the sessions table when you log out.
I would recommend adding the data to a field in the user profile. Using the session will give problems even if you don't delete the data. The next time the user logs in you won't know which session id he/she used the last time and normally you only have the session id to look up. Not a user id so you can get all sessions owned by a specific user.
What is a good approach to keeping accurate counts of how many times a page has been viewed?
I'm using Django. Specifically, I don't want refreshing the page to up the count.
As far as I'm aware, no browsers out there at the moment send any kind of message/header to the server saying whether the request was from a refresh or not.
The only way I can see to not count a user refreshing the page is to track the IPs and times that a user views a page, and then if the user last viewed the page less than 30 minutes ago, say, you would dismiss it as a refresh and not increment the page view count.
IMO most page refreshes should be counted as a page view anyway, as the only reason I have for refreshing is to see new data that might have been added, or the occasional accidental refresh/reloading after a browser crash (which the above method would dismiss).
You could give each user cookie, that expires at the end of the day, containing a unique number. If he reloads a page you can check wether she has been counted already that day.
You could create a table with unique visitors of the pages, e.g. VisitorIP + X-Forwarded-For content, User-Agent string along with a PageID of some sorts. If the data itself is irrelevant, you can create a md5/sha1 hash from these values (besides the PageID of course). Be warned however that this table will grow really fast.
I'd advise against setting cookies for that purpose. They have a limited size and with many visited pages by the user, you could reach that limit and make the solution unreliable. Also it makes it harder to cache such page on client-side (see Cacheability), since it becomes interactive content.
You can write a django middleware and catch request.url, then setup a table with url / accesses columns. Beware of transactions for concurrent update.
If you have load problems, you can use memcached with incr or add function and periodicaly update the database table to avoid transaction locks.