My question is about displaying thumbnails and storage.
Let's say I have a website where users can upload photos and view them in albums.
How are the photos usually stored in this scenario? Are the images themselves or are the file paths usually stored in the database?
If the photos are large and you want to display thumbnails, is it better to:
save a copy of the image and a reduced size image, only displaying the larger if requested?
use HTML to reduce the size?
It's almost always a bad idea to store images in a database. BLOBs can really slow down a database something fierce. It also limits your ability to spread storage around different drives. When the files are separate, you can even have one or more separate image servers to reduce the load on the main dynamic server. My recommendations are:
In your database table, have columns for both the directory the image resides in and the image name. That way you are free to change where images are stored, round-robin drives, add more storage later and put new images in the new storage, or whatever you want. Storing the path and the filename in separate fields makes it trivial to move images from one directory to another.
You definitely want to generate thumbnail images to reduce your network bandwidth and make your application run faster. However, you can generate the thumbnails on demand, or when the system load is low. If you're on Linux, ImageMagick is wonderful at automated batch resizing of images. It can even resize by a percentage instead of an absolute amount.
Some software such as TikiWiki stores the photos in a database. It then also caches thumbnail sized photos in the database.
Other software stores it in a directory. This is the way Gallery2 operates. I find the directory approach more scaleable. If a different size than the original is requested, typically the app will use ImageMagick to resize the photo, and then store a copy of the resized photo.
Another alternative is to re-upload the photo to a service like S3, and not store the photo locally at all.
This is common question and the basic answer is that it depends. You need to give more information. What database are you planning on using? SQL Server 2008 has some good new features for handling this scenario with FILESTREAM function. Generally I prefer to put them in the database, but if you just stuff them in their without thinking about design and access requirements you could have poor performance as the number of photos increases.
IF you are absolutely positively sure that your web server will always have access to the file system hosting the images, then go that route. Maybe.
However, if at any time you think you might need to, i don't know, create an image server because the hard drive on your web server is running out of space OR that you need to run multiple web servers, then save yourself the trouble and store them in a database. The hard part in storing on a file system is the security requirements of crossing the network.
Also, bear in mind that not all database servers are created equal in this regard. SQL 2008 introduced a FILESTREAM data type which actually stores the images on the local file system while allowing all read / write access through the db server. This has the added benefit of allowing you to run virus scanners on the incoming files while in storage.
Oracle has had some nice file storage facilities for awhile now. MySQL? I don't think I'd want to try, but you might be okay.
As to the second question: save a thumbnail along with the image. This process occurs only once per image and saves on presentation bandwidth. Using HTML to size an image down really does nothing for the client.
Related
I have read many questions/comments regarding saving the image in DB or file system on server side. However i'm still confused. For now I allow user to upload image (limit to 10MB) and I save the image in the server folder and serve the image via apache context path configuration pointed to that location. However, due to the numbers of image and high load. We want to provide load balancing and fail over functionality. So I have 2 options.
Add code to replicate the uploaded image to all servers or using rsync to do that.
Using CouchDB or MongoDB and save the image as attachment of an document. So I have out of the box replicate functionality.
Can anyone show me the pros/cons of these approach. Can CouchDB/MongoDB have the same read performance compared to file system ?
You can also store files in distributed file system. The benefit over DB supported image server is you do not have to alter the application. Obviously, storing all the data the same way, including images, may be a benefit for you, but changing architecture for already working system may also be problematic.
For example, GlusterFS may be installed on top of "normal" file system to give you distributed features minimizing changes to the system itself. It is supposed to support via its plugins (translators) all the feature you would potentially expect from cloud system: replication, load balancing, stripping of files into relocated parts and fail-over.
Can CouchDB/MongoDB have the same read performance compared to file system ?
No, there will be lag between file system timers and database timers, this is an unfortunately reality.
I have no idea of your current setup, load and performance so I cannot really advise on what to do, however, Apache isn't really a good image server anyway.
Your best bet might be to look into a CDN cache for your images.
I got a page, with not that much bandwidth, therefore I want to store the images externally on another server, that offers unlimited bandwidth. Any suggestions on how to do this, or maybe a better solution?
Image storage on different server
Check out this similar post, Facebook does it, Google does it, so it's a preferred solution to store images on another server. You can assign links to the images dynamically or statically from the external server and that's all you need to do! You need to take care of the hierarchy how the images are to be stored in the external server.
I'm programming a application with mvc2. Users should be able to upload images to their profile.
The best way to save the images is to save them in a database, but I think it is the most expensive one too. (I'm using MSSql)
I thought the best way would be to save them on the server. I thought about: a User uploads images, the server resize them and save the Image on the server and the image-path in a database.
But what about if I do not have any more capacities on my server an I have to use a second one or third one?
My question: what is the best way to handle images on a server? What is the best way to be flexible?
Thanks for your answers!!!
There are a number of factors to consider.
The best way isn't necessarily storing images in a database. That can be a good choice, especially if you want to implement access control on the images. However, this comes at the cost of having to pull the image from the database and loading it into memory so that it can be streamed out by a server.
However, as these are profile images, and presumably visible by anyone who visits that user's profile, I'd advocate storing the file as a file on the server and storing a reference to that file in your database.
When it comes down to it, web servers are very good at serving files efficiently. If you can make use of that, you should.
Finally, you have concerns about space. In the first instance, you can prevent images of a certain size from being uploaded in the first place. You can also, as you suggest, auto-crop to a selected size.
If sheer volume of users becomes a problem, you can always store your media on a separate server, storing a fully qualified link to each resource, eg :-
<img src="http://images2.mydomain.com/image/profile_123.png" alt="A profile pic" />
I am developing a eCommerce website in ASP.NET MVC 3 in C#. Using SQL Server 2008R2. My question is if I have 5 images that I want to show in gridView with thumbnails (e.g. something like Amazon website that gives customers couple of pictures to show) would it be advisory if the images are coming from the database or should I reside in the Content\Images folder? There are quite a few sub-categories in sub-category in my db design. What is the most common suit for a professional developer to follow? Thanks. I know there are few options for third party tools like jquery & Telerik Extensions. So I will use them.
Thanks
From my experience and research it is better to put it in a folder/content structure. Yes, there are security things with opening directories to the public but if you instead upload a file via ftp dynamically the problems are solved. I have heard of horror stories about storing files in database and have seen the issues come up but have resolved them. Basically, it is easier to write to database and there are not the security issues of opening up a directory to public but just make sure to regularly check backups that the files are not corrupt or make sure the data is on a fail over cluster where that will never be a problem.
So summary: Database is fine just regularly check backups by restoring them that they are not corrupt or run as a fail over cluster. Otherwise just go with the typical folder/content structure but use ftp to upload the file so there are no open directories to the public.
For me, the best anwser to this question is this: To BLOB or Not To BLOB: Large Object Storage in a Database or a Filesystem
Sumary: Application designers often face the question of whether to store large objects in a filesystem or in a database. Often this decision is made for application design simplicity. Sometimes, performance measurements are also used. This paper looks at the question of fragmentation – one of the operational issues that can affect the performance and/or manageability of the system as deployed long term. As expected from the common wisdom, objects smaller than 256K are best stored in a database while objects larger than 1M are best stored in the filesystem. Between 256K and 1M, the read:write ratio and rate of object overwrite or replacement are important factors. We used the notion of “storage age” or number of object overwrites as way of normalizing wall clock time. Storage age allows our results or similar such results to be applied across a number of read:write ratios and object replacement rates.
What techniques do people commonly use for uploading, storing and presenting images with a CMS?
Do you store them in the database or on the file system?
Do you generate thumbnails on upload? Or on the fly, then maybe cache them for reuse? Or rely on browser scaling?
Typically, most content management systems will store images the actual data of image uploads to the file systems and then add a link to the file within the database. Thumbnails can either be generated on upload or on first request (on the fly is considered inefficient, especially given the cheap cost of storage). Browser scaling is a bad idea (images may be uploaded as multi megabyte uncompressed files) but is done by some systems.
i agree with kevin. i can't think of any cms that doesn't store in the file system. then only issue that comes up with that technique is if you are planning on clustering multiple web servers to run your cms. if thats the case then you have to plan on it and have the ability to point all the web servers to the same file storage location.
the technique ive used for years is on upload, resize the image to something practical for the web, then generate the thumbnail, then write them to the file system and record the pointer in the database.
if the site is a huge site then you need serve the images from cache servers because file systems are very slow in comparison to network IO. take facebook for example, they have billions of images on their site and last i heard 80% were held in cache servers around the world in ram. the file storage array they have is more or less a backup to the cache servers.