Where are databases actually stored? Do we store the database in the web server itself (like NGINX or Apache), or do we have any other kind of server dedicated to only the database, if this is the case, how would we connect to the database from another machine?
For example, I've tinkered with MySQL databases stored in my local machine, which i used to create web applications: how could i store (host) those databases somewhere else in another machine and still use them in the same web application running on a completely different machine?
Where is the database stored?
The database -- the relational database management system -- is a network-accessible hunk of server code. MySQL, for example, is a server software package.
That server software runs on a computer -- in internet parlance a server machine -- somewhere. Maybe it's on your laptop. Maybe it's on a server machine in the next room. Maybe it's on a virtual machine you rent from AWS,Azure, Digital Ocean, or some other cloud vendor.
The machine hosting the database for a web site can be the same machine that hosts the web site's web server, or a different machine. Modestly sized web sites often run the database and the web server on the same machine. Bigger sites often have multiple web server machines all using just one database machine.
As long as the web server code can reach the database server via a TCP/IP connection, you have a working configuration.
Where is the database stored?
The database server software uses the file system (disk, SSD drives, or network-attached storage) of its host machine to store the data in its tables. The structure of the file-system files used by the database server software is a huge topic far beyond the scope of a StackOverflow answer. Suffice it to say that those files are useless without the database server software to read, write, and back them up ( with a few special exceptions).
Related
I have done extensive research, i feel that i have good candidates but i still lack enough knowledge to decide which one i should implement, ideally i would like to hear from someone that actually implemented a solution to a similar problem.
The Problem
Our project consists of a community of distributed nodes (25 nodes). The nods run on Linux computers, and are installed in the typical residential setting (behind a NAT), with wide dispersion geographically and ISP wise.
Our software on the node collects a variety of its own unique data which is logged to MySQL DB on the local host (node) which is not WAN accessible directly. We also have a Web interface for each node that uses the local node DB to allow the local node user to visualize certain data and parameters; this is only accessible on the LAN.
We typically set-up and maintain an open port for SSH from our labs to each node. All remote DB on nodes have the exact same schema but completely different data. We need an automated way to collect all data from all the nodes and get them to our WAN accessible lab servers (Windows 7 servers, but can be Linux if it provide a better solution). We have narrowed the option as follow:
Solutions:
Create a .bat script that sequentially connect to each node over SSH to import data.
Use the web interface that runs on each node to periodically query the local db then save that data to a central MySQL server. I know i can connect to two db in PHP. seems to be doable here.
Use the MySQL supported “slave-master” replication setup which will duplicate all remote databases on the server.
Use the MySQL supported federated engine setup which will link local tables to remote ones.
Questions:
Are all these viable solutions?
Any major cons i should be aware of for the viable ones?
is there better solutions available (paid or otherwise) ?
I am designing the backend of my ios application. The backend has separate database and application server running mysql and django separately in different machines. Till now, I have connected my application server with my database server in simple way: I changed the database host in application server settings to point to remore database server and created a new remote host in database server configuration files allowing remote application server to access the database. All works fine and I have decided to go with this setup for production. Then when I was reading Instagram engineering blog, I saw them mentioning 'Pgbouncer' to pool connection to their postgresql database server. What is the need for something like this? Has this got something to do with only performance, or is this a production friendly approach to use something like this for communication between database and application server. Is my general approach mentioned too amateur?
Your approach is not amateur at all. The purpose of bouncer in your case would be to eliminate connection time that happens on each request django handles. For example, on Heroku, which is hosted on AWS servers, this could eat up 40-50ms of each request.
Now, if you had a master/slave setup or something like that, a connection pool would also provide you a failover functionality (just an example)
Is there any local MySQL database which I can create on my system, just like the localhost we run on our system.
I never thought of this situation since we have our beta servers and live servers with database already set up in our offices.
I am creating an app on my own, that's why I need to setup a local db of mine.
You can use WAMP (or LAMP on linux) which is an integrated web development environment giving you access to your own LOCAL SQL databases accessible through your own machine's localhost. You will have full control to be able to create tables and administrate it. I am currently doing that myself
WAMP
I written a program to work with a MySQL database that powers my website and I have recently bought some reseller hosting however the hosting company has restricted external access on the shared server, so I was going to setup an external mySQL database on another server that can be accessed remotely, however to do this I need a PHP file on my reseller server that can connect to the local database and the remote database and sync them on request from the application via a url.
Does anyone know the best method achieve this?
Try using SQLyog's Database synchronization tool
I have developed several websites on my local host for school. I can program database driven aspects of a webisite such as a blog on my own no problem. At school I used a MySQL DB which was hosted on a dedicated server, so when the server went down I could not have access to my data. I also have a mysql DB on my localhost but...my question is this: If i use the MySQL DB on my localhost, won't I only have access to the data when my computer is running so that my site can make server requests?
How can I set up any kind of DB for my site that is reliable and doesn't depend on my localhost to act as a DB Server?
I am now developing in .NET
Thanks. PS I don't have access to schools' server any more.
PPS I still don't have a site set up through a hosting provider...probalby going to go with godaddy
You'll need a server for that. A server will cost you on a monthly basis, I haven't heard of any free mysql servers, someone else may be able to help you with that.
Regular hosting providers supply PHP and MySQL server. I run my sites on Dreamhost (www.dreamhost.com)
It might also be worthwhile to look into Amazon EC2 : http://aws.amazon.com/ec2/
Also Amazon RDS for pure database only usage : http://aws.amazon.com/rds/
They provide a pay as you use service and the tier 1 service is free for the first year as I understand
There's no magic, you have to host your DB on a server that will run 24/7. Could be on the internet, it depends on the firewalls surrounding you.
The website will always depend on some sort of database server, why so worried that your database will be unreachable? Your webserver can go down also and will have the same consequences as the db.
Why don't you get some paid hosting? It is fairly cheap these days, for around 30dollar/year you will have some reliable hosting. When the DB will break down, it is not your responsibility.
If you don't want te be dependent of MySQL, you will need to use plain-text database that will be maintained by PHP or something.
You might consider running the MYSQL in i.e. a cloud provider, like Amazon EC2. It will certainly cost some money.