Is it possible to create multiple backplanes within Signal-R?
We're working on an ASP.net WebAPI Sass application and are looking to implement Signal-R for "real-time" web functionality. Since we'll be hosting the application a web farm, client-connection state will be managed through a SQL Server backplane.
The application is multi-tenant - but database is not. The application determines which connection string to use and all client requests talk to their appropriate database. Now the code for configuring the Signal-R SQL Server backplane within Application_Start() is:
GlobalHost.DependencyResolver.UseSqlServer(connectionString);
Does anyone know if it's possible to create multiple backplanes with Signal-R, basically loop through each connection string and call the above code?
Thanks for checking this out!
If you need to eliminate the single point of failure, I suggest setting up a failover server in case the primary SQL Server machine goes down. Reference: http://technet.microsoft.com/en-us/library/hh231721.aspx
If you simply need more performance than a single SQL Server instance can provide, I suggest using Redis as the backplane.
In either case, I doubt attempting to use "multiple backplanes" will be helpful, unless you intend to map certain hubs to certain backplanes for load distribution.
Related
The SQL Server is a given.
I need to create a web UI that accesses the DB and refreshes itself automatically when the DB data changed, regardless of how it changed. This should be done without constant DB polling on the side of the UI.
I saw such a UI done in Java. Nevertheless it reacts only to changes originating from this particular Java UI. Data changes done in some external DB client, like SQL Server Management Studio, for instance, do not appear in the said Java solution.
Is it possible for a web UI to react to all changes, irrespective of their origin?
Ideally the UI should reside on a Linux server and should use Bootstrap. The SQL Server runs in a Windows environment in the same LAN.
If it's possible, what technology stacks would you recommend?
Thank you.
I want to know how to connect Xamarin.Forms PCL with SQL Server directly. I know accessing the database directly will not be secured. But that's not problem in my situation. I need to access database directly from Xamarin.Forms. I am using Visual Studio 2017. I have developed an app with Xamarin.Forms PCL.
In answer to your question, use Entity Framework Core and a connection string, directly to your database. That will enable you to connect directly to it.
Now, I'm going to spend the rest of this answer, why you shouldn't do this
You are giving a remote, unknown, complete stranger, complete, direct access to your database. Even if it's in a separated network, with completely trusted users, and not on the app store, you are still opening your database up to potential security breaches.
It is likely over an unreliable mobile connection or wifi. It will fail and drop out, a lot.
It will be incredibly slow
If you want to move that SQL server later or update, you will break every single client out there, while you send an update for your app.
You won't be able to easily add any logic, in between, to improve performance, or add business logic as needed.
Database corruption, another important and likely to occur scenario, as mentioned by Brandon above.
What you need to do.
Create a web api. It's easy to setup one with WebAPI with dotnetcore
The API connects to the database, the mobile client connects to the API.
Add authentication to your API.
And I go into some more detail in Connecting to a remote database here.
I got VPS with limited memory and my WCF service is hosted using AppFabric.
Since memory is limited and I am not using SQL server for anything other than AppFabric prerequisite im thinking about uninstalling SQL Server. (instance can eat up to 200mb memory at times). I am not using any DB related features of AppFabric like dashboard or caching. I like IIS extensions and simplicity for WCF service manipulations however, and I am thinking those do not require Sql Server actually.
I am unable to just try it out so wonder if someone has such experience, or can predict result of uninstalling SQL server on appfabric behaviour.
Instead of uninstalling SQL Server you could just stop the SQL Server process. Set the process to manual startup.
That way if you need SQL Server in the future you can just start the process.
As #Shiraz Bhajiji illudes to if you are using SQLServer as the configuration store, you will need to reconfigure it to use file based configuration instead, it sounds like you are only using a single AppFabric instance, but if you are or needed to use multiple instances the config file would need to be accessible to all instances.
Again it isn't necessarily relevant to you, but if you have multiple app fabric instances, the sql server configuration option is a much more robust approach. With the file based approach, if you configure things incorrectly one app fabric node going down can take down the entire cluster. The SQLServer approach does represent a single point of failure however, if you are using clustering etc you can easily mitigate this. Again I appreciate I'm getting a little off topic here.
So I'm inexperienced in hosting DB's and I've always had the luxury of someone else getting the db setup.
I was going to help a friend out with getting a webpage setup, I've got experience in Asp.Net MVC so I'm going with that. They want to setup a search page to query a db and display the results. My question I have is in getting the DB setup and hosted. They currently just have the Access DB on a local computer. There is basically only one table that would need to be queried for the search.
What is the best approach to getting this table/db accessible? They would like to keep the main copy of the db on the local machine, so copying the entire db over to the hosted site would be time consuming, could the lone table needed be solely copied to the host? Should I try to convince them to make changes on the hosted db and just make copies of that for their local machines? Any suggestions are welcome, Again I'm a total noob when it comes to hosting databases.
Thanks
Added: They are using a MS Access 2000, and the page will have access restrictions. Thanks for the responses.
How about SQL Server Express? I think you can do a remote connect from Access and just push the data over from Access.
I wouldn't use Access on a web server in any case.
I would strongly recommend against access from web work, its just not designed for it and given that SQL server express is free there is no reason not to give it a go.
You can migrate the data over by using the SQL server upsizing wizard, here is a link for help on using that feature
http://support.microsoft.com/kb/237980
It depends on what you mean by web work? Access 2010 can build scalable browser neutral web applications. They can scale to 1000's to users. In fact, you can even park the web sites on Microsoft's new cloud hosting options, and scale out to as many users as you need.
Here is a video of an application I wrote in access 2010. Note how at the half way I run the same application including the Access forms in a standard web browser. This application was built 100% inside of the Access client. The end result needs no ActiveX or Silverlight to run.
http://www.youtube.com/watch?v=AU4mH0jPntI
So, the above shows that access can now be used to build scale web sites (you can ignore the confusing answers by the other two posters here they are not quite up to speed on how access works or functions).
However, for your case, I would continue to have the access database on the desktop. You can simply link to tables that are hosted on the web server. Those tables can exist in MySql, or sql server. As long as the web site supports external ODBC connections (many do), then you can thus have the desktop application use the live data from the web server. If connections to the live data at all times is a issue, then you could certainly setup something to send up new records (or the whole table) on some kind of interval or perhaps the reverse, and pull down new records on a interval from the web site (depends which way you need to go). So, connecting to MySql or sql server is quite easy as long as the web hosting and site permits external ODBC connections. I do this all the time, and it works quite well.
As mentioned, new for access 2010 is web site building ability but that does requite Access Web services running on SharePoint.
You don't need to upgrade to Access 2010. One option is to use the EQL Data plugin to sync the database up to the server. Then you can write an asp.net, php, or whatever application that queries the table using the EQL API and prints the results however you want. This kb article describes how to use the EQL API from a web app.
The nice thing is that the database is still totally usable (and at full speed) even when you're not online, and then you can sync the new data up to the web occasionally. It only uploads the changes, not the entire database every time, so it's fast.
Disclaimer: I work at EQL Data so I'm a bit biased. But this kind of use case is the whole reason the company exists.
Scenarion:
I am having a web application which is going to use SqlServerReport(SSRS) sitting on ReportingServer which is on my DatabaseServer.
There is a firewall between webapplication & SqlserverReport server.
Now how safe is it to use reports directly from webserver (ie accessing something there on database server.)
We use a appserver to interact with the database data.
All basic calls are
UI ==> AppServer ==> DatabaseServer (general cases) :) happy
UI ==> DatabaseServerReports (to access Sqlserver reports) :(
So my concern is how safe is to access reports directly from Databaseservers.
Yo need to open the ports 80(http)/443(https) in the firewall to using the SSRS server from the AppServer.
Please, contact your Network Admin.
Our security folks made us install IIS on a separate partition.
Why not use your app to display the reports? With ASP.NET you can use a report viewer control to display the report so the user has no idea where the report is coming from except that it is within the application.
How safe depends on where the user is located. SQL Server Reporting Services was not intended to be opened up to the Internet, for instance. Neither was the SQL Server database engine, for that matter. You said there's a firewall between the web server and the SQL Server, but that's not an unusual configuration in internal networks nowadays.
The concern that might come up is one from the performance side, more than any other. By viewing the reports using SSRS, the report rendering will occur on the same server as your database engine. If the hardware isn't enough for both roles, you'll see performance issues.