Our application uses multitenant model by implementing one database for each customer. The application is live now and is working fine and there are around 600 databases spread across two database servers. The databases are connected using a master database called admin which stores the details of all other databases. One of the requirement is to check the admin database and find all the databases, check specific tables in the databases and send email notifications. This is a backend process. Currently we use a windows service to do the same but we see that there are delays in sending the mails due to the looping of 600 databases. Is there any other way to handle this?
Thanks,
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Im developing a database application using MariaDB where I have a table for clients registers. I want them to be able to query the database, but I don't know if I have to create a database user account for each one in order to allow simultanious connections without collitions(same user trying to query at the same time) or can I use the same user account for simultanieous queries.
I'm kind of new to MariaDB.
Thanks in advise.
Databases are good at handling 'simultaneous' accesses by multiple connections to the same table.
The question of "one" versus "many" user accounts is independent of simultaneous access.
Most accesses work just fine without any problem. In the extreme, I suggest you read about "deadlocks".
My organisation (a small non-profit) currently has an internal production .NET system with SQL Server database. The customers (all local to our area) submit requests manually that our office staff then input into the system.
We are now gearing up towards online public access, so that the customers will be able to see the status of their existing requests online, and in future also be able to create new requests online. A new asp.net application will be developed for the same.
We are trying to decide whether to host this application on-site on our servers(with direct access to the existing database) or use an external hosting service provider.
Hosting externally would mean keeping a copy of Requests database on the hosting provider's server. What would be the recommended way to then keep the requests data synced real-time between the hosted database and our existing production database?
Trying to sync back and forth between two in-use databases will be a constant headache. The question that I would have to ask you is if you have the means to host the application on-site, why wouldn't you go that route?
If you have a good reason not to host on site but you do have some web infrastructure available to you, you may want to consider creating a web service which provides access to your database via a set of well-defined methods. Or, on the flip side, you could make the database hosted remotely with your website your production database and use a webservice to access it from your office system.
In either case, providing access to a single database will be much easier than trying to keep two different ones constantly and flawlessly in sync.
If a webservice is not practical (or you have concerns about availability) you may want to consider a queuing system for synchronization. Any change to the db (local or hosted) is also added to a messaging queue. Each side monitors the queue for changes that need to be made and then apply the changes. This would account for one of the databases not being available at any given time.
That being said, I agree with #LeviBotelho, syncing two db's is a nightmare and should probably be avoided if you can. If you must, you can also look into SQL Server replication.
Ultimately the data is the same, customer submitted data. Currently it is being entered by them through you, ultimately it will be entered directly by them, I see no need in having two different databases with the same data. The replication errors alone when they will pop-up (and they will), will be a headache for your team for nothing.
i m having two databases in different environments but both are having same data.Presently my application connecting one database .I need to disconnect that database and i want to connect another database .Is it possible to connect to another database? If Its possible then what are things i have to modify in the application code.
Is it possible to connect to another database?
Yes.
If it is possible then what are things I have to modify in the application code.
You need to change the Data provider APIs especially if you are working with the database specific API e.g Ms-Sql server (SqlClient) or ODP.net (oracle).
For further, read - Data Access Application Block and .NET Data Access Architecture Guide.
I am planning to develop a fairly small SaaS service. Every business client will have an associated database (same schema among clients' databases, different data). In addition, they will have a unique domain pointing to the web app, and here I see these 2 options:
The domains will point to a unique web app, which will change the
connection string to the proper client's database depending on the
domain. (That is, I will need to deploy one web app only.)
The domains will point to their own web app, which is really the
same web app replicated for every client but with the proper
connection string to the client's database. (That is, I will need to
deploy many web apps.)
This is for an ASP.NET 4.0 MVC 3.0 web app that will run on IIS 7.0. It will be fairly small, but I do require to be scalable. Should I go with 1 or 2?
This MSDN article is a great resource that goes into detail about the advantages of three patterns:
Separated DB. Each app instance has its own DB instance. Easier, but can be difficult to administer from a database infrastructure standpoint.
Separated schema. Each app instance shares a DB but is partitioned via schemas. Requires a little more coding work, and mitigates some of the challenges of a totally separate schema, but still has difficulties if you need individual site backup/restore and things like that.
Shared schema. Your app is responsible for partitioning the data based on the app instance. This requires the most work, but is most flexible in terms of management of the data.
In terms of how your app handles it, the DB design will probably determine that. I have in the past done both shared DB and shared schema. In the separated DB approach, I usually separate the app instances as well. In the shared schema approach, it's the same app with logic to modify what data is available based on login and/or hostname.
I'm not sure this is the answer you're looking for, but there is a third option:
Using a multi-tenant database design. A single database which supports all clients. Your tables would contain composite primary keys.
Scale out when you need. If your service is small, I wouldn't see any benefit to multiple databases except for assured data security - meaning, you'll only bring back query results for the correct client. The costs will be much higher running multiple databases if you're planning on hosting with a cloud service.
If SalesForce can host their SaaS using a multitenant design, I would at least consider this as a viable option for a small service.
Scenario
Web server running an ASP.NET site that's connected to a sql server instance for all the web related DB needs (products, pricing, users, etc.)...
The companies accounting, inventory control(FIFO, etc.) and whatnot are mainly done on another system which uses a different SQL server...much more complex, for obvious reasons.
What I Need
What I need is to retrieve the current quantity on hand for every product that's on the web by connecting to the internal accounting sql server, even though the website uses a different sql server for it's own requirements.
The reason I can't have the information that is required to calculate the quantity on hand for every product on the web to be on the same sql server is because there are way too many tables that are needed to calculated that information...what's on purchase order, what's on sales order, and the physical inventory.
What is the best way to accomplish this without altering either database?
You can achieve this in two ways.
If you can connect directly to the SQL server from the website. Do that.
Create a Service (Web/Windows Hosted) which will be able to access internal complex SQL Server and be exposed to your web site so that it can access the information you need there.
Hope this helps.