I've been struggling with the following challenge for quite long and couldn't find a proper solution.
I need to send a unique ID to the server when my service worker handles the pushsubscriptionchange event.
I have a unique ID stored in a cookie but SW can't access cookies, I was trying to use the Cache API to pass that info to the SW but it doesn't seem like the right way.
I'm open to hear new ideas/solutions to tackle this challenge.
Thanks
One way to solve this problem is using IndexedDB. It is available in the Service Worker context.
You can use localForage, which makes using IndexedDB really simple.
Related
For client security and privacy reasons, we want to deploy a unique database for each client while using the same website.
I envision that during the session_start event, we would determine which database to use for them (by looking at the subdomain they come in on) and set the connection string in a session variable. Then on every page_init, we'd dynamically set any object's connection string. In code behind, we'd do the same thing with the connection string.
Is there a better approach to doing this and will setting the connection string in page_init work? Is using a session variable wise? I've tended not to ever use them except when no other solution was possible.
The problem with the model itself it is really complex and can let you with some errors specially when we are talking about changes in the database. Imagine that you need to add an extra field on the interface. if you have 100 clients this will mean updating 100 different databases. when we talk about dealing with downtime them things get even worst.
I would do with that in a light different abstract your database layer create one api that will call the database. And from the website you always call the api passing the domain that you want the data to come from.
You can ask me what advantage this will give to you. The biggest one that you will see it is when doing upgrades and maintenance. Having one api per client it is a lot better to think them having one database per client. and if you really want to have just one (I would really recommend having one per client and deploying automatically) you can have a switch on the call and base with some parameters that you pass to the api ( can be on the header like the subdomain on the header) you can chose what database to connect.
Let me give you a sample scenario and how I would suggest to approach this scenario (that is true for database or api)
I want to include a new data field. So first thing it is to add this field on the backend (api or database) deploy this new field if it is one api you can even test that calling the api and see that the new field it is now returned that is not a problem for your ui because it is just a field that it does not use. after that you change the ui to actually use this field and deploy that to production.
I need to share session in order to pass data from asp page to aspx. The solutions I've found:
• Pass data through hidden form (link)
• Pass data through database (link)
I've tried method with form and it worked fine (after some modification). Now I'm trying method with database. First method is easier imho, so I wonder if the second method is more secure (and preferable) than the first one?
And what potential problems exist with these methods?
The first solution is definitely less secure since you're sending session data to the client and then receiving it back. That means that it's possible for someone on the client side to modify the data they post back to your page. This removes one of the best things about sessions, that only the programmer controls what's in them. In a way, the first method is similar to using cookies. As for the second method, it may be more difficult but I would definitely recommend it over the first.
If the session is encrypted I think you will fine. ASP.NET has the option of storing the session in a database and URL querystring to get around users not having cookies enabled. Your solutions sound similiar.
Microsoft outlines a method to share session state between ASP classic and ASP.NET using SQL Server to store the session here: http://msdn.microsoft.com/en-us/library/aa479313.aspx
I know that similar questions have been asked all over the place, but I'm having trouble finding one that relates directly to what I'm after.
I have a website where a user uploads a data file, then that file is transformed and imported into SQL. The file could be up to 50mb in size, and some times this process can take 30 minutes or sometimes even longer.
I realise I need to palm off the actual work to another process, and poll that process on the web page. I'm wondering what the best approach would be though? Being a web developer by trade, I'm finding all this new Windows Service stuff a bit confusing, and I just wanted somewhere to start.
So:
Can I do / should I being doing this with a windows service? if so, how?
Should I use WCF? If this runs under IIS, will I have problems with aspnet_wp.exe recycling and timing out my process?
clarifications
The data is imported into sql, there's no file distribution taking place.
If there is a failure, it absolutely MUST be reported to the user. The web page will poll every, lets say, 5 seconds, from the time the async task begins, to get the 'status' of the import. Once it's finished another response will tell the page to stop polling for status updates.
queries on final decision
ok, so as I thought, it seems that a windows service is the best idea. So as to HOW to get it to work, it seems the 'put the file there and wait for the service to pick it up' idea is the generally accepted way, is there a way I can start a process run by the service, without it having to constantly be checking a database table / folder? As I said earlier, I don't have any experience with Windows Services - I wondered if I put a public method in the service, can I call it somehow?
well ...
var thread = new Thread(() => {
// your action
});
thread.Start();
but you will have problems with that:
what if the import to sql fails? should there be any response to the client
if it fails, how do you ensure the file on a later request
what if the applications shuts down ... this newly created and started thread will be killed either
...
it's not always a good idea to store everything in sql (especially files...). if you want to make the file available to several servers why not distribute them via ftp ...?
i believe that your whole concept is a bit messed up (sry assuming this), and it might be helpful if you elaborate and give us more information about your intentions!
edit:
Can I do / should I being doing this
with a windows service? if so, how?
you can :) i advise you to create a simple console-program and convert this with srvany and sc. you can get a rough overview howto here (note: insert blanks after =... that's a silly pitfall)
the term should is relative, because you did not answer the most important question
what if a record is persisted to the database, telling a consumer that file test.img should be persisted, but your service hasn't captured it or did not transform it yet?
so ... next on
Should I use WCF? If this runs under IIS, will I have problems with aspnet_wp.exe recycling and timing out my process?
you probably could create a WCF-service which recieves some binary-data and then stores this to a database. this request could be async. yes. but what for?
once again:
please give us more insight to your workflow: what are you exactly trying to achieve? which "environmental-conditions" to you have (eg. app A polls db and expects file-records which are referenced in table x to be persisted) ...
edit:
so you want to import a .csv-file. well that changes everything :)
but i won't advise you to use a wcf-service (there could be a usage: eg. a wcf-service which has a method to insert a single row, then your iteration through the file would be implemented in another app... not that good, though).
i would suggest following:
at first do everything in your webapp (as you've already done), but rather use some sort of bulk-insert and do your transformation/logic on the database.
if you have some sort of bottle-neck then, i would suggest you something like a minor job-service, eg:
webapp will upload the file and insert a row to a job-table. the job-service is continiously polling the table/or gets informed via wcf by the webapp (hey, hey, finally some sort of usage for WCF in your scenario... :) ) and then does the import-job, writing a finish-note to a table/or set the state of the job to finished ...
but this is a bit overkill :)
Please see if my below comments helps you to resolve your issue:
•Can I do / should I being doing this with a windows service? if so, how?
Yes you can do this with a windows service. And I think that is the way you should be doing it. You can implement your own service to process your request or you can use the open source code Job Proccessor
Basically the idea is..
You submit a request for processing
the csv file in database table with
some status as not started.
Then your windows service picks up
the request from database table which
are not started and update them as in
progress status.
Once the processing is complete
succesfully /unsuccesfuly your
service updated the database table
with status as Completed / Failed.
And your asp.net page can poll to
database table for the current status
every 5 sec or so.
•Should I use WCF? If this runs under IIS, will I have problems with aspnet_wp.exe recycling and timing out my process?
you should not be using WCF for this purpose.
I am searching to find a way to read and write on session data but with out having the HttpContext. Current.
Why I won to do that ? because I wish to make some action with the user Session after the page have been close and unloaded.
For example, a user load and see a page, then I create a thread to make some action and let user go. Inside this thread I like to read the session data, but in this case HttpContext . Current is not exist any more.
So is there a way to read Session Data knowing just the session id.
I store my session inside an SQL server, and I see them. its there on table ASPStateTempSessions :)
How can I read them "offline" and manipulate them ?
Thank you in advanced.,
Still not quite clear why you might want to do that but you might not actually need to do it on Session_End(). At that point, it may be too late for you to work with the session data anyway (I've read some articles before about this). What might be a better solution is to actually attempt to work on the session data when your application actually has the context.
For example:
There's nothing to stop your application creating an asynchronous request on a new thread in the background (or even a different application, such as a Windows Service, for instance) when the specific session variable that you want is updated or has been set. This way, your application will be able to access the current HttpContext as well as all of the session data.
Not sure if this helps, but it was worth a shot ;)
Richard.
I may be a little late but...
Today I found about the:
System.Web.HttpRuntime.Cache
I know is not the same that a session but I think it's much better alternative that db.
Regards.
In an asp.net application, i would like to use a webservice to return the username associated with the session id passed as a parameter. We're currently using InProc session store.
Is it possible to do this ?
Edit: what i'm trying to do is get information about another session than the current one. I'm not trying to get the SessionID, i've already got it. I'm trying to get the user information associated with a given SessionID.
Thanks,
Mathieu G.
You could possibly create a "fake"cookie with the session ID and make a request to your web service using it, so that the web service was fooled into thinking you were part of the session, enabling you to read any info from it. Sounds like quite the hack, though :)
Something like:
HttpSessionState ss = HttpContext.Current.Session;
HttpContext.Current.Response.Write(ss.SessionID);
That will get the current sessionID.