Related
I don't have any experience regarding server hosting performance and how slow it gets so I wanted to ask this question.
My situation is, I want to host a ~1MB data file that needs to be downloaded by clients occasionally (once every 2-3 days). Of course I would like to minimize costs as long as it does not hurt user experience too much. I have data to indicate that I have clients globally.
I wanted to ask what the ballpark figure would be for the amount of time it would take to download a file of this size from other parts of the world (data is hosted in the US). Does anyone have any idea, for instance, how long it would take to download a 1MB file from locations such as Japan?
In case people are wondering, I personally would consider it OK if it takes under 10s to download in most parts of the world.
The first thing to do when you don't know how well something works... is to try it. Create buckets in all of the regions, store a file, and then download it and see.
The official AWS-centric answer for global content distribution is to connect a CloudFront distribution to an S3 bucket, and set things up so that your content is downloaded from S3 via CloudFront. This will tend to improve download speeds more when the user is distant from the bucket, even if the content isn't cached at a CloudFront edge, because most of the distance the download has to travel, it will be traveling on the AWS "Edge Network," a global network connecting CloudFront to the AWS regions, with fewer unknowns than the Internet at large between here and wherever.
I have a global client base, but -- for example -- my shopping pages' catalog images are stored in S3 in Oregon (us-west-2), but with links pointing to CloudFront.
Interestingly, the pricing for using both services together sometimes works out a little bit less expensive than using only S3. A possible explanation for this is that edge network egress traffic represents a lower cost to AWS and the rates are set accordingly. It's not a major difference, but once you understand the pricing tables, you'll see it.
1MB in 10s equals 800kbps. I'd be very surprised if any reputable hosting provider couldn't keep up with that speed of delivery. Looking at Akamai rankings (2015)*, in Japan (as in your example) the average user's speed is 15Mbps: your file would then be downloaded in 0.53 seconds.
( *Looking at the rankings, keep in mind that in countries where fast internet infra is yet to be ubiquitous, the "average speed" will be an average of fast corporate pipes and other premium links, with actual mainstream users having substantially slower speeds.)
Then in most cases, this will be up to the user's connection speed, and further, their ISP's international links, which can be much slower than their national or regional pipes. More so in countries with less developed internet infrastructure, where operators are cutting costs and corners.
In deciding if you need to deploy S3 or other CDN solutions, or no extra solutions at at all, you'll have to start with mapping up your user demographics. If there's a substantial sector from far-away countries with weak net infra, it makes sense. Otherwise, it doesn't seem likely that your target speed of 1MB/10s wouldn't be matched even without a special means of delivery.
If you have some but not substantial traffic from countries/regions where you reckon int'l traffic might be slower, and if you want to eliminate extra costs, I figure your users will survive even if it takes 15-20 seconds once in a blue moon as their speeds fluctuate. (This is opinion-based relative to how picky your users are!) In such a case, I'd only bother with a CDN if I wanted to improve speeds across the board, e.g. for all requests for static resources, not just a single file requested every couple of days. Would make a more substantial contribution towards the general user experience.
What if you had one large database to server all your apps. So your website that needs to store customer orders can use the same database that your game uses to store registered users. Different applications could have tables only for them to use. Some may say that this could be a security issue, because if someone cracks your database, they could attack all your applications. But in a lot of databases you could use a line like the following to restrict access:
deny select on aTable to aUser;
I am wondering if this central database would be considered a poor practice, and if so why?
They way I look at it, a web application is nothing more than a collection of web pages. Because of this, it really doesn't matter if one page is about, say, cooking, while the other page is about computer programming.
If you also consider it, this is very similar to Openid, which I use to log into my SO account!
If you have your fundamental security implemented correctly, it doesn't matter how the user is interacting with your website. Where I would make this distinction is in two cases:
Don't mix http with https. On a shared host, this isn't going to be an issue anyway; if you buy the certificate for https, make everything that way (excluding the rare case where this might affect performance).
E-commerce or financial data should be handled fundamentally in a different way. If you look at your typical bank, they have multiple log-in protocols, picture verification and short log-in times. This builds confidence in user's securities. It would be a pain in the butt for a game site, or most other non-mission critical applications.
Regarding structure, if you do mix applications into one large database, you should consider the other maintenance issues, such as:
Keep tables separate; consider a prefix for every table unique to each application. Following my example above, you would then start the cooking DB table names with 'ck', and the computer programming DB table names with 'pg'. This would allow you to easily separate the applications if you need to in the future.
Use a matching table to identify which ID goes to which web application.
Consider what you would do and how to handle it if a user decided to register for both applications. Do you want to offer transparency that they can share the same username?
Keep an eye on both your data storage limit AND your bandwidth limit.
If you are counting on these applications to drive revenue, you are putting "all your eggs in one basket". Make sure if it goes down, you have options to restore or move to another host.
These are just a few of the things to consider. But fundamentally, outside of huge (big data) applications there is nothing wrong with sharing resources/databases/hardware between applications.
Conceptually, it could be done.
Implementation-wise, to make the various parts distinct from one another, you could use both naming conventions (as per #Sable Foste) and/or separate database schemas (table Finance.Users, GameApp.Users, etc.)
Management-wise, things could get tricky. Repeating some points, adding others:
One application could use a disproportionally large share of resources (disk space, I/O, CPU)
Tracking versions could be tricky (App is v4, finance is v7) -- depends on how many application instances you have to support.
Disaster recovery-wise, everything is lumped together. It all gets backed up as one set, it all gets restored as one set. Finance corrupt? Restore from backup... and lose your more recent game data.
Single point of failure. One database goes down, all your applications are down.
These (and other similar issues) are trade-offs you'll want to consider. Plan ahead, to lessen the chance that what's reasonable and economic today becomes a major headache tomorrow.
I've seen "The Coolest Server Names," and I've seen another smaller-ish question related to mine, which was unfortunately closed.
It's a serious question though, as I'm on an internal applications dev team that manages the apps on a couple dozen servers. The networking folks typically don't care what we call the servers as long as they know about 'em, so we can come up with whatever conventions.
The apps the servers deal with can be home-grown custom apps, or they can be larger vendor ones like SharePoint. They can be:
In multiple networking environments that can't speak to each other (think firewalled-off external servers versus intranet-esque servers)
In different physical locations (California office versus New York, etc.)
In multiple deployment tiers (production, staging, testing, dev)
Have one or many functions (web server, DB server, mail server, app server)
Load-balanced or not
Standby (for disaster recovery purposes) or primary
Whew! Think it's even possible to come up with a convention that can address all of these aspects, or significant ones? It'd be nice to hear a server name (or DNS entry for it) and be able to immediately know what it does, and it works for getting new guys up to speed as well. "sharepoint-IPC-1 is down" could be parsed into "the internal production SharePoint web server in the California datacenter that's the first node in the load balancing is down!"...but that seems overly complicated at first glance.
Another thing in the back of my mind is that an old mail relay server is getting decommissioned, which means we have to scour through a lot of old apps to repoint hardcoded server values (I know... :).
Here are some general guidelines I try to abide by, based on mistakes I've made in the past.
Never base your machine names on...
Hardware Machines get swapped out all the time, and you don't want to have to do too much work if you change from an IBM server, to a Sun server, to a Dell server.
Location Equipment and even entire server rooms can be moved based on business requirements or technical issues.
Intended Use As your product evolves, so too may the intended use of each server. Having a machine named "dbsrv" but eventually acts as a file server too, is confusing.
Owner The person who "owns" the equipment (an employee) can change, due to firings, layoffs, and moves within the company.
Subnet As I said before, labs can move, and so can subnets. One of the main goals of DNS is to free you from being tied to a specific IP address, so why tie yourself down needlessly?
Now, some suggestions for the situation you described...
Machines spread across a region This is what subdomains are for in DNS. You could have "west.company.com" and "east.company.com".
Have one or many functions Don't name them based on intended use. If you name them based on some large collection of names--Greek gods, for example--you will eventually intuitively know that zeus.east means your master database server and apollo.west is your backup database server. Worst case, look it up in a spreadsheet.
Load-balanced or not You can take two approaches. You could have a unique name per node behind the load balancer, or you could do something like athena-1.east, athena-2.east, etc. Either way, a load balancer will (hopefully) free you from worrying too much about what each node is named.
Standby or not This doesn't sound like a criterion that should have an impact on the machine name.
What I'm essentially saying is:
Separate your equipment into different regional subdomains
Choose a naming scheme with plenty of names (Greek gods in this example)
Don't base the names on any of the criteria I mentioned above (intended use, location, etc.)
Trying to do anything more than that will be more trouble than it's worth.
I know that it's tempting to assign names to servers that describe their functions and other similar attributes and in a perfect world that will work but in practice I have found that after a while these things get messed up as functions and other parameters of the servers change (as the requirements of the business change) so the names no longer reflect the reality.
I think you should assign unique names to the servers that do not tell anything about the function or other parameters and have some sort of (up to date) list detailing those things so that your people can look it up. That's what we do here.
The other extreme is using IP addresses only or having names based on IP addresses which can lead to a disaster too if you ever have to change your IP addresses.
Closed. This question is off-topic. It is not currently accepting answers.
Want to improve this question? Update the question so it's on-topic for Stack Overflow.
Closed 10 years ago.
Improve this question
So, I have a dedicated server. I host about dozen or so small sites.
Is there a real benefit in using S3(or Mosso) for my image and static file hosting? My server has more than enough disk space, or am I completely missing the point of S3?
I keep reading about how wonderful and cheap it is, and I ask myself "self, why aren't you using this" and the reply is always "why?"
if you're running within the included storage and bandwidth of your server and your needs are being served well, you are already doing the simplest thing that is working for you and that is where you should always start. Off the top of my head I can think of a couple reasons why you may want to move some storage to S3 in the future:
Your storage or bandwidth needs grow beyond what you have and S3 is cheaper than upgrading your current solution
You move to a multiple-dedicated-server solution for failover/performance reasons and want to be able to store your assets in a single shared location
Your bandwidth needs are highly
variable (so you can avoid a monthly
fee when you're not getting traffic) [Thanks Jim, from the comments]
If you run an entire website off of a single machine, and that machine is more than enough to handle your site, then kudos, images are not a bottleneck that needs solving right now. Forget about S3 for now.
However, as your server gets busier, you will want your server to be spending all of its time doing server things. Transferring static content like flat HTML files and images is an easy, dumb job, and wasting precious active connections, bandwidth, and CPU cycles on them is no good. By switching to S3, your server can concentrate on doing what's important, which is whatever your program actually DOES.
S3 also has benefits of being distributed around and attached to what's probably a fatter pipe than your server, which means the images will show up slightly more quickly on your client's machines, so that's an added bonus.
S3 is also backed up, which means that it makes for a pretty nice place to store pretty much any private data under the sun, in addition to stuff that you want to serve to others (although don't confuse the permissions settings between those two things -- in fact, you may want to use separate accounts entirely).
S3 is also nigh-infinite, which means that if you want to let users upload files to your site (profile images, attachments, etc), S3 is a great choice so that you don't have to constantly worry if your server is going to run out of disk space (obligatory $$$ warning here).
But like I said at the top, if you're a one-server setup with a handful of users, none of this really matters. It's a tool like any other, and it may not be something you need yet.
It's simply a matter of doing the numbers: given a certain amount of traffic for a set of files, you can calculate exactly how much hosting those file on S3 would cost you, and you should be able to do the same for your current provider. If the number is lower for S3, there you have your reason.
An added benefit is that S3 scales pretty much linearly with traffic and you pay only for what you actually use, whereas most providers charge you a flat fee no matter how little traffic you actially have, and some will gouge you badly if you ever exceed the maximum traffic included in the flat fee.
Better speed and availability could be an additional benefit.
Basically, if you have a site that could potentially incur wildly disparate traffic, then using S3 for its images and other static files means that if you're hit by the Slashdot effect, the site has a much better chance of staying reachable, and you have a much better chance of avoiding nasty surprises concerning excess traffic fees.
The advantages of Amazon S3 are reliability, scalability, speed and cost. Here is some info on each.
Reliability: Amazon stores your data in multiple data centers. If there was a disaster and one data center was destroyed your content would continue to be served from the second data center. It’s very unlikely that data you upload to Amazon would ever be lost.
Scalability: If one of your web sites becomes popular and millions of people visit the site, your web server will not be able to handle the load. In comparison when you upload your files to Amazon they are stored in multiple locations. If the load on your content grows your files are automatically replicated to more servers so your files will always be available.
Speed: Amazon has a service called CloudFront that works in conjunction with Amazon S3. When you activate CloudFront on your S3 content your content is moved to edge locations. These are servers that make your content available for high speed transfer.
Cost: With Amazon S3 you only pay for what you use. If you have a few files that get little traffic you will only pay a few cents a month.
SprightlySoft has a blog post which gives even more reasons why Amazon S3 is great. Read it at http://sprightlysoft.com/blog/?p=8
If you're hosting a high-traffic site, the bandwidth cost (and latency issues) of hosting images yourself makes S3 and other services like Akami attractive. For a low-traffic site, it probably isn't an issue.
I'd say that there's no reason if your base hosting plan provides enough space/bandwidth. Where I think it's useful is when your file transfers become enough that you have to look at buying an add-on of storage/bandwidth from the provider -- in that case, S3 may be a viable alternative. But if I'm paying $X/month and not using all of the storage, there's no upside to it.
On the other hand, if your capacity planning calls for you to someday exceed the provider's limits, S3 may be a good solution from the start so you don't have files being served from multiple places.
I would second the mention of "redundancy" -- you can count on any content that's in S3 to be distributed to multiple data centers, and effectively been very much always accessible for anyone with functioning network connection.
Cost may be another factor: data transfer rates for S3 are quite competitive.
And speed is the last one: you can access data VERY fast from S3. But that's more of an issue for data other than browser-viewable images.
For small sites, S3 or Mosso may not be that reasonable for image hosting, but if you have any video files (.wmv, .flv, etc...) or large downloads (app distributions, etc..), I'd still put them on S3 or Mosso to save potential bandwidth spikes if for some odd reason, your content becomes wildly popular.
You write:
My server has more than enough disk space, or am I completely missing the point of S3?
You are not missing the point if what you have on you server is write-once read-less-than-once stuff, such as disaster-recovery backups (which you hope will be read-never), because transfer times will not matter. The point of S3 is delivery speed.
First, S3 distributes your content geographically. End users benefit from shorter paths.
Second, S3 can act as a BitTorrent seed, which not only conserves your bandwidth, it means your most popular content will be distributed faster because it can take advantage of the ad-hoc swarm. There are reports on the AWS Discussion Forums that S3 support of the BitTorrent protocol is "very, very spotty." I have not tested it myself.
Many of you won't have this problem, but if you (and your web server) are located in Australia (read: the 3rd world of the Internet), you run into the issue that S3 does not have geographically close locations, which means there will be a higher latency on your images and other static content. Scalable: yes. Fast: no.
From what I hear, besides low cost, the main advantage is the ease of backup from an EC2 setup.
Link..
http://groups.drupal.org/node/2383
Speed might be the only benefit. If your dedicated server is simply networked through your ISP (which may well throttle upstream speeds even if downstream speeds are high) then you might find that your sites are often slow to load. If so, then S3 or another dedicated server provider can help. Other than that, I can think of absolutely no reason why Amazon's service would be more appropriate for you - especially with simple, static sites.
It's not really directly related to your actual hosting of web sites, but it's certainly an important part of it, especially if the sites don't belong to you alone -- S3 is a great backup solution. There are tools such as duplicity that can automatically and efficiently back things up onto S3 for you, and it's extremely cheap for this purpose. I back up a fairly large amount of data for less than $1/month.
Besides the Fat Pipe and Local Delivery arguments for S3 there is also the manner of a single server does not function optimally when its functioning both as a db server and as a file server. If your running any sort of db I would suggest offloading all your static files to s3. The cost is trivial and you will see pretty big performance gains on page load.
There's alot of information out there on setting up LAMP stacks on a single box, or perhaps moving MySQL onto it's own box, but growing beyond that doesn't seem to be very well documented.
My current web environment is having capacity issues, and so I'm looking for best-practices regarding configuration tuning, determining bottlenecks, security, etc.
I presently host around 400 sites, with a fair need for redundany and security, and so I've grown beyond the single-box solution - but am not at the level of a full ISP or dedicated web-hosting company.
Can anyone point me in the direction of some good expertise on setting up a great apache web-farm with a view to security and future expansion?
My web environment consists of 2 redundant MySQL servers, 2 redundant web-content servers, 2 load balancing front-end apache servers that mount the content via nfs and share apache config and sessions directories between them, and a single "developer's" server which also mounts the web-content via nfs, and contains all the developer accounts.
I'm pretty happy with alot of this setup, but it seems to be choking on the load prematurely.
Thanks!!
--UPDATE--
Turns out the "choking on the load" is related to mod_log_sql, which I use to send my apache logs to a mysql database. By re-configuring the webservers to write their sql statements to a disk file, and then creating a separate process to submit those to the database it allows the webservers to free up their threads much quicker, and handle a much greater load.
You need to be able to identify bottlenecks and test improvements.
To identify bottlenecks, you need to use your system's reporting tools. Some examples:
MySQL has a slow query log.
Linux provides stats like load average, iostat, vmstat, netstat, etc.
Apache has the access log and the server-status page.
Programming languages have profilers, like Pear Benchmark.
Use these tools to identifyy the slowest/biggest offenders and concentrate on them. Try an improvement and measure to see if it actually improves performance.
This becomes a never ending loop for two reasons: there's always something in a complex system that can be faster and as your system grows, different functions will start slowing down.
Based on the description of your system, my first hunch would be disk io and network io on the NFS servers, then I'd look at MySQL query times. I'd also check the performance of the shared sessions.
The schoolbook way of doing it would be to identify the bottlenecks with real empirical data.
Is it the database, apache, network, cpu, memory,io? Do you need more ram, sharding(+), is the DiskIO, the NFS network load, cpu for doing full table scans?
When you find out where the problem is you might run into the problem that its not enough to scale the infrastructure, because of the way the code works, and you end up with the need to either just create more instances of you current setup or make the code different.
I would also recommend as a first step in terms of scalability, off-load your content to a CDN like Edgecast. Use your current two content servers as additional web servers.