Given: Each call to a BE module takes several seconds even with a SSD drive. (A well configured setup runs below 1 second for general BE tasks.)
What are likely bottlenecks?
How to check for them?
What options to speed up?
On purpose I don't give a special configuration, but ask for a general checklist, so that the answer is suitable for many people as first entry point.
General tips on performance tuning for TYPO3 can be found here: https://wiki.typo3.org/Performance_tuning
However, in my experience most general performance problems are due to one of a few reasons:
Bad/no caching. Usually this is a problem with one or more extensions (partly) disabling cache. Try disabling all third party extensions and enabling them one by one to see which causes the site to slow down the most. $GLOBALS['TSFE']->set_no_cache() will disable all cache, so you could search for that. USER_INT and COA_INT in TypoScript also disable cache for anything that's configured inside there.
A lot of data. Check the database for any tables containing a lot of data. How many constitutes "a lot", depends on a lot of factors, but generally anything below a million records shouldn't be too much of a problem unless for example you do queries with things like LIKE '%...%' on fields containing a lot of data.
Not enough resources on the server. To fix this, add more memory and/or CPU cores to the server. Or if it's a shared server, reduce the number of sites running on it.
Heavy traffic. No matter how many resources a server has, it will always have a limit to the number of requests it can process in a given time. If this is your problem you will have to look into load balancing and caching servers. If you don't (normally) have a lot of visitors, high traffic can still be caused by robots crawling your site too quickly. These are usually easy to block on IP address in your firewall or webserver configuration.
A slow backend on a server without any other traffic (you're the only one who can access it) rules out 1 (can only cause a slow backend if users are accessing the frontend and causing a high server load) and 4 (no other traffic).
one further aspect you could inspect: in the user record a lot of things are stored, for example the settings you used in the log module.
one setting which could consume a lot of memory (and time to serialize and deserialize) is the state of the pagetree (which pages are expanded/ which are not).
Cleaning the user settings could make the backend faster for this user.
If you have a large page tree and the user has to navigate through many pages the effect will stall. another draw back: you loose all settings as there still is no selective cleaning.
Cannot comment here but need to say: The TSFE-Object does absolutely nothing in the TYPO3 Backend. The Backend is always uncached. The TYPO3-Backend is a standalone module to edit and maintenance the frontend output. There are tons of Google search results that will ignore this fact.
Possible performance bottlenecks are poor written extensions that do rendering or data processing. Hooks to core functions are usually no big deal but rendering of many elements for edit forms (especially in TYPO3s Fluid Template Engine) can cause performance problems.
The Extbase-DBAL-Layer can also cause massive performance problems. The reason is the database model does not know indexes. It' simple but stupid. A SQL-Join on a big table of 2000 records+ will delay the output perceptibly, depending on the data model.
Also TYPO3 Backend does not really depend on the Typoscript-Configuration but in effect to control some output or loaded by extensions, the full parsing of the *.ts files is needed. And this parser is very slow.
If you want to speed things up you need to know what goes wrong. The only way to debug this behaviour is to inspect the runtime with a PHP profiling tool like xdebug because the TYPO3 Framework is very complex. It's using some kind of Doctrine Framework and will load tons of files, by every request. Thus a good configured OpCache is a must.
Most reason the whole thing is slow is because it is poor written. You can confirm that fact by inspecting the runtime.
In addition to what already has been said, put the runtime environment onto your checklist:
Memory:
If heavy IDE and other tools are open at the same time, available memory can become an issue. To check the memory profile, you may start a tool that monitors the memory usage of the machine.
If virtualization is used, check the memory assigned to the box. Try if assigning more memory improves behaviour.
If required and possible spend more memory to your machine. This should not be a bugfix to poorly written code. Bad code can blow up any size of memory.
File access:
TYPO3 reads and writes thousands of files. If you work with a contemporary SSD, this is surprisingly fast. I did measure this. Loading all class files of TYPO3 takes just a fraction of a second.
However this may look different if you do not work with a standard setup. Many factors may slow you down:
USB-Sticks as storage.
Memory cards as storage.
All kind of external storage may be limited due to slow drivers.
Virtualization can become an issue. Again it's a question of drivers.
In doubt test and store your files and DB on a different drive to compere the behaviour.
Routing
The database itself may be fast. A bad routing of your request may still slow you down. Think of firewalls, proxies etc. even on your local machine and specially if virtualisation is used.
Database connection:
I fast database connection is crucial. If the database access is slow TYPO3 can't be fast.
Especially due to Extbase TYPO3 often queries much more data than really required and more often than really required, because a lot of relations are resolved in the PHP layer instead of the DB layer itself. Loading data structures like the root line may cause a lot of ping-pong between the PHP and the DB layer.
I can't give advice, how to measure your DB-connection. You have to as your admin for that. What you always can do is to test and compare with another DB from a completely different environment.
The speed of the database may depend on the type of the database itself. Typically you use MySQL/Maria-DB which should be fast. It also depends on the factors mentioned above, memory, file access and routing.
Strategy:
Even without being and admin and knowing all performance tools, you can always exchange parts of your system and check if matters improve. By this approach you can localise the culprit without being an expert. Once having spotted the culprit, Google may help you to get more information.
When it comes to a clean and performant setup of routing or virtualisation it's still the best idea to ask an experienced admin.
Summary
This is all in addition to what others have already pointed to.
What would be really helpful would be a BE-Plugin, that analyses and measures the environment. May there are some out there I don't know.
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I was asked this question once at an interview:
"Suppose you own a website where the server is at some remote location. One day, some user calls/emails you saying the site is abominably slow. How would you identify why the site is slow? Also, when you check the website yourself as any user would (using your browser), the site behaves just fine."
I could think of only one thing (which was shot down):
Check the server logs to analyse incoming traffic. Maybe a DoS attack or exceptionally high traffic. Interviewer told me to assume the server has normal traffic and no DoS.
I was kind of lost because I had never thought of this problem. I have almost no idea how running a server/website works. So if someone could highlight a few approaches, it would be nice.
While googling around, I could find only this relevant, wonderful article. That article is kind of too technical for me now, but I'm slowly breaking it down and understanding it.
Since you already said when you check the site yourself the speed is fine, this means that (at least for the pages you checked) there is nothing wrong with the server and it can serve those pages at a good speed. What you should be figuring out at this point is what the difference is between you and the user that reports your site is slow. It might be a lot of different things:
Is the user using a slow network connection (mobile for example)?
Does the user experience the same problems with other websites hosted at the same webhoster? If so, this could indicate a network problem. Normally this could also indicate a resource problem at the webserver, but in that case the site would also be slow for you.
If neither of the above leads to an answer, you could assume that the connection to the server and the server itself are fine. This means the problem must be in the users device. Find out which browser/OS he uses and try to replicate the problem. If that fails find out if he uses any antivirus or similar software that might cause problems.
This is a great tool to find the speed of web pages and tells you what makes it slow: https://developers.google.com/speed/pagespeed/insights
I think one of the important thing that is missing from above answers is the server location, which can play a vital in web performance.
When someone is saying that it is taking a longer time to open a web page that means high latency. High latency can be caused due to server location.
Let's assume as you are the owner of the web page then the server and client are co-located, so it will have a low latency.
But, now if client is across the border, then latency time will increase drastically. And hence a slow perfomance.
Another factor is caching which drastically affects the latency time.
Taking the example of facebook, they have server all over the world to reduce the latency time (and also to provide several other advantages) and they use huge caching system to cache their hot data (trending topics) whereas cold data (old data) are stored in hard disk so it takes a longer time to load an older photo or post.
So, a user might would have complained about this as they were trying load up some cold data.
I can think of these few reasons (first two are already mentioned above):
High Latency due to location of client
Server memory might need to be increased
Number of service calls from the page.
If a service could be down at the time of complaint, it could prevent page from loading.
The server load might be too high at the time of the poor experience. The server might need to increase the resources (e.g. adding another server/web server to the cluster).
Check if there was any background job running on the server at that time.
It is important to check the logs and schedules of the batch jobs to determine what all was running at that time.
Hope this help.
Normally the user takes the page loading time as a measure to find out that the site is slow. But if you really want to know that what is taking the maximum time the you can open the browser debugger by pressing f12. if your browser is chrome the click on network and see what calls your application is making and which are taking maximum time. If you are using Firefox the you need to install firebug. If you have that, then again press f12 and click on Net.
One reason could be the role of the user is different of your role. You might be having suppose an administrator privilege (some thing like super user role) and the code might be just allowing everything for such role that means it does not really do much of conditional checking to see what is allowed or not. Some times, it's a considerable over ahead to get all the privileges of the user and have the conditions checking, how course depends how how the authorization is implemented. That means, the page might be really slow for specific roles. Hence, you should find out the roles of the user and see if that is a reason.
Obviously an issue with the connection of the person connecting to your site OR it's possible it was a temporary issue and by the time you checked your site, everything was dandy. You could check your logs or ask your host if there was an issue at the time the slow down occured.
This is usually a memory issue and it can be resolved by increasing the Heap Size of the Web Server hosting the application. In case the application is running on Weblogic Server. Heap size can be increased in "setEnv" file located in Application Home.
Goodluck!
Michael Orebe
Though your question is quite clear, web site optimisation is a very extensive subject.
The majority of the popular web developing frameworks are for some reason, extremely processor inefficient.
The old fashioned way of developing n-tier web applications is still very relevant and is still considered to be best practice according the W3C. If you take a little time to read the source code structure of the most popular web developing frameworks you will see that they run much more code at the server than is necessary.
This may seem a bit of a simple answer but, the less code you run at the server and the more code you run at the client the faster your servers will work.
Sometimes contrasting framework code against the old fashioned way is the best way to get an understanding of this. Here is a link to a fully working mini web application which represents W3C best practices and runs the minimum amount of code at the server and the maximum amount of code at the client: http://developersfound.com/W3C_MVC_EX.zip this codebases is also MVC compliant.
This codebase comes with a MySQL database dump, php and client side code. To see this code in action you will need to restore the SQL dump to a MySQL instance (sql dump came from MySQL 8 Community) and add the user and schema permissions that are found in the php file (conn_include.php); setting the user to have execute permissions on the schema.
If you contrast this code base against all of the most popular web frameworks, it will really open your eyes to just how inefficient these frameworks are. The popular PHP frameworks that claim to be MVC frameworks aren’t actually MVC compliant at all. This is because they rely on embedding PHP tags inside HTML tags or visa-versa (considered very bad practice according the W3C). Also most popular node frameworks run way more code at the server than is necessary. Embedded tags also stop asynchronous calls from working properly unless the framework supports AJAX dumps such as Yii 2.
Two of the most important rules to follow with MVC compliance is: never embed server side tags (such as PHP tags) in HTML tags or visa-versa (unless there is a very good excuse such as SEO) and religiously never write code to run at the server if it can be run at the client. Also true MVC is based on tier separation, where as the MVC frameworks are based on code separation. True MVC compliance is very processor efficient. Don’t get me wrong MVC frameworks are very useful for a lot of things, but if you’re developing a site that is going to get millions of hits, they are quite useless, or at least they will drive your cloud bills so high that it will really eat into your company’s profits.
In summary frameworks don’t give much control over what code runs at the client or server and are very inefficient but you can get prototypes up and running quicker with less code.
In contrast the old fashioned way takes a bit more elbow grease but you have complete control over what runs at the server and what runs at the client.
As an additional bit of advice for optimisation avoid using pass-through queries and triggers and instead opt for stored procedures. Historically stored procedures weren’t invented at the time MVC was present as a paradigm but it definitely increases separation of concerns between the tiers and is much more processor efficient.
Hope this advice helps.
Is there an advantage of some sort (speed or performance wise) to embed your CSS and JS into your web page, as opposed to keeping the code in sparate files? I was raised to believe that keeping code separate in separate files makes things easier to maintain. However, on high profile websites like amazon or google even facebook, I see a lot of embed code. Is there a performance reason they choose to do so or is it just an old/new way of doing things. I suppose my question is similar to this one: Should I inline CSS & JS in mobile sites to save bandwidth?
But I would like to hear form experts, most notably from people who worked on high profile web sties and have done so, if any.
P.S.
Bonus Question: Last html comment on amazon web pages is <!-- MEOW --> does it mean anything or is it just a funny prank?
There are good reasons to inline resources, but as with most things, it also has its tradeoffs. The simplest case for inlining is cases where the cost of an HTTP connection is much more than the resource itself, ex: if you have a 10x10 icon you need to show, a dedicated request for that may not be worth it vs. inlining the data via a data URI.
This is especially true when and if you have many small resources that need to be fetchd. Most browsers limit themselves to a max of 6 connections per host, so if you have 60 resources which need to be fetched, then you'll be blocked for a significant chunk of time.
To work around these case we've invented other workarounds: domain sharding to go over the 6 connection limit, and "spriting" to fetch one resource vs multiple.
If you take a look at mod_pagespeed (Apache module), which does many of these optimizations on the fly for you, then the recommended setting we provide is to inline any resource that's below 2kb. That's a pretty good rule of thumb for today's stack.
Once SPDY is more widely deployed, many of these workarounds can be eliminated: no need to do domain sharding, cost of extra requests is much less, etc.
Stoyan did an experiment that you might find interesting http://www.phpied.com/style-tag-to-inline-style-attrrib/
CSS/JS external files typically get cached on the user's hard drive under that users browser's profile. So unless you change the code frequently, you won't really be doing yourself a favor by putting it inline.
Definitely saves you time from maintenance, but you can easily call in a javascript/css file and embed the code on the page you're populating on the server side, but that also means you're making your server do additional work.
As for the MEOW - yeah, them trying to be funny, or it's code... for... cat...
We have a new project for a web app that will display banners ads on websites (as a network) and our estimate is for it to handle 20 to 40 billion impressions a month.
Our current language is in ASP...but are moving to PHP. Does PHP 5 has its limit with scaling web application? Or, should I have our team invest in picking up JSP?
Or, is it a matter of the app server and/or DB? We plan to use Oracle 10g as the database.
No offense, but I strongly suspect you're vastly overestimating how many impressions you'll serve.
That said:
PHP or other languages used in the application tier really have little to do with scalability. Since the application tier delegates it's state to the database or equivalent, it's straightforward to add as much capacity as you need behind appropriate load balancing. Choice of language does influence per server efficiency and hence costs, but that's different than scalability.
It's scaling the state/data storage that gets more complicated.
For your app, you have three basic jobs:
what ad do we show?
serving the add
logging the impression
Each of these will require thought and likely different tools.
The second, serving the add, is most simple: use a CDN. If you actually serve the volume you claim, you should be able to negotiate favorable rates.
Deciding which ad to show is going to be very specific to your network. It may be as simple as reading a few rows from a database that give ad placements for a given property for a given calendar period. Or it may be complex contextual advertising like google. Assuming it's more the former, and that the database of placements is small, then this is the simple task of scaling database reads. You can use replication trees or alternately a caching layer like memcached.
The last will ultimately be the most difficult: how to scale the writes. A common approach would be to still use databases, but to adopt a sharding scaling strategy. More exotic options might be to use a key/value store supporting counter instructions, such as Redis, or a scalable OLAP database such as Vertica.
All of the above assumes that you're able to secure data center space and network provisioning capable of serving this load, which is not trivial at the numbers you're talking.
You do realize that 40 billion per month is roughly 15,500 per second, right?
Scaling isn't going to be your problem - infrastructure period is going to be your problem. No matter what technology stack you choose, you are going to need an enormous amount of hardware - as others have said in the form of a farm or cloud.
This question (and the entire subject) is a bit subjective. You can write a dog slow program in any language, and host it on anything.
I think your best bet is to see how your current implementation works under load. Maybe just a few tweaks will make things work for you - but changing your underlying framework seems a bit much.
That being said - your infrastructure team will also have to be involved as it seems you have some serious load requirements.
Good luck!
I think that it is not matter of language, but it can be be a matter of database speed as CPU processing speed. Have you considered a web farm? In this way you can have more than one machine serving your application. There are some ways to implement this solution. You can start with two server and add more server as the app request more processing volume.
In other point, Oracle 10g is a very good database server, in my humble opinion you only need a stand alone Oracle server to commit the volume of request. Remember that a SQL server is faster as the people request more or less the same things each time and it happens in web application if you plan your database schema carefully.
You also have to check all the Ad Server application solutions and there are a very good ones, just try Google with "Open Source AD servers".
PHP will be capable of serving your needs. However, as others have said, your first limits will be your network infrastructure.
But your second limits will be writing scalable code. You will need good abstraction and isolation so that resources can easily be added at any level. Things like a fast data-object mapper, multiple data caching mechanisms, separate configuration files, and so on.
What various methods and technologies have you used to successfully address scalability and performance concerns of a website? I am an ASP.NET web developer exploring .NET remoting with WCF with SQL clustering and am curious as to what other approaches exist (such as the ‘cloud’). In which cases would you apply various approaches (for example method a for roughly x many ‘active’ users).
An example of what I mean, a myspace case study: http://highscalability.com/myspace-architecture
This is a very broad question making it difficult to answer, but I'll try and provide a few general suggestions.
1 - Unless you are doing some things seriously wrong then you'll likely not need to worry about perf or scale until you hit a significant amount of traffic (over 1 million page views a month).
2 - Your biggest performance problems initially are likely to be the page load times from other countries. Try the Gomez Instance Site Test to see the page load times from around the world, and use YSlow as a guide for optimizing.
3 - When you do start hitting performance problems it will first most likely be due to the database work. Use the SQL Server Profiler to examine your SQL traffic looking for long running queries to try optimizing, and also use dm_db_missing_index_details to look for indexes you should add.
4 - If your web servers start becoming the performance bottleneck, use a profiler to (such as the ANTS Profiler) to look for ways to optimize your web pages code.
5 - If your web servers are well optimized and still running too hot, look for more caching opportunities, but you're probably going to need to simply add more web servers.
6 - If your database is well optimized and still running too hot, then look at adding a distributed caching system. This probably won't happen until you're over 10 million page views a month.
7 - If your database is starting to get overwhelmed even with distributed caching, then look at a sharding architecture. This probably won't happen until you're over 100 million page views a month.
I've worked on a few sites that get millions/hits/month. Here are some basics:
Cache, cache, cache. Caching is one of the simplest and most effective ways to reduce load on your webserver and database. Cache page content, queries, expensive computation, anything that is I/O bound. Memcache is dead simple and effective.
Use multiple servers once you are maxed out. You can have multiple web servers and multiple database servers (with replication).
Reduce overall # of request to your webservers. This entails caching JS, CSS and images using expires headers. You can also move your static content to a CDN, which will speed up your user's experience.
Measure & benchmark. Run Nagios on your production machines and load test on your dev/qa server. You need to know when your server will catch on fire so you can prevent it.
I'd recommend reading Building Scalable Websites, it was written by one of the Flickr engineers and is a great reference.
Check out my blog post about scalability too, it has a lot of links to presentations about scaling with multiple languages and platforms:
http://www.ryandoherty.net/2008/07/13/unicorns-and-scalability/
There is velocity from MS as well as MEMCache has a port to .NET now and also indeXus.Net
Sharepoint isn't the speediest of server applications, and I've read about a few tips to speed it up. What steps do you think are necessary to increase performance so it can be used to host a high traffic site?
At the end of the day SharePoint is just a complicated web site with all the standard components.
In order to optimize performance you need to analyze each component and determine which one is a problem, and then adjust it accordingly.
We're in the process of implementing a 1000 concurrent user sharepoint website, which may or may not be large, however some steps we are taking are:
Implementing a detailed caching strategy, to cache webpart content intelligently.
Use load balanced servers to ensure all our hardware is utilised rather then lying idle.
We've undertaken capacity planning given the existing solution, so we have a good idea which component is the bottleneck for us. (The SQL Server), so we will ensure the server can cope with expected load and future growth of the site.
We're also using hardware load balancers which will ensure our network and the related servers operate as expected, and again this is something to investigate before you implement a sharepoint website.
We're also ensuring our webparts don't generate unnecessary html, and don't return unnecesary data, as this will slow down loading times.
Something which I definately think is a good idea is to have a goal to work towards, as you can spend a huge amount of money and time optimizing SharePoint, which may prove unnecessary.
My additional best bets are:
use x64 to allow more RAM on your server
Make the best use of your application pool recycling http://blogs.msdn.com/joelo/archive/2007/10/29/sharepoint-app-pool-settings.aspx
Make sure all custom code properly disposes SPWeb and SPSite objects using this http://blogs.msdn.com/rogerla/archive/2008/02/12/sharepoint-2007-and-wss-3-0-dispose-patterns-by-example.aspx
utilize MS Capacity Planning Tool http://technet.microsoft.com/en-us/library/bb961988.aspx
Plan your site collection and database sizes. Keeping your databases and site collections under control will be key
GOVERNANCE GOVERNANCE GOVERNANCE - Plan for site size limits and expiration strategy. Old data should be deleted or archived for better performance. http://technet.microsoft.com/en-us/office/sharepointserver/bb507202.aspx
I cannot emphasize enough that proper early planning is essential for a successful SharePoint implementation.
In addition to caching and hardware, try to make sure that your masterpages and page layouts are not ghosted in the database (requiring a database call to retrieve).
Do this by ensuring the files get released to the 12 hive in your solution.
Don't forget careful selection of the built-in cache settings (choose the right one for your situation).
Use the BLOBCache.
Use IIS Compression/caching (the defaults are not enough BTW).
Ensure your SQL box can keep up, especially during indexing/crawling. Splitting the Application roles (indexing vs search query and dedicated WFE for indexing/crawling) helps.
BTW if you're running VMWare VMs for your WFEs, Windows NLB breaks (though not consistently), so use hardware NLBs or DNS round-robin, etc.
If you don't need > 2gig RAM for the IIS Application Pool on a WFE, don't bother with 64bit on the WFE.
Just my 2c.