I was thinking to use opcode caching for performance profit
what is the easiest way for opcode caching with PHP/Apache ?
and what are the performance improvements ?
I have read about xDebug but I was wondering if there are more options ?
I use the APC extension as an opcode cache on both my personnal server, and on the servers we are using at work -- and I've almost never run into any kind of trouble with it.
Installation is pretty easy : depending on your Linux distribution, you might want to use something like :
sudo aptitude install php5-apc
But you'd not necessarily have the last stable version... And I generally prefer using :
sudo pecl install apc
Which will fetch the last version from PECL and compile it (Note : you'll probably need to installed a package called php5-dev).
You'll then have to configure it ; see Runtime Configuration for the directives you can configure.
The performance improvements can vary depending on your server/application, but, on a server that only serves PHP pages (i.e. if your DB is on another machine) you might see a drop in CPU load that's quite important (I've seen CPU load go from 80% to 40-50% on a server, once)
Xdebug is not related to opcode caching nor performance : as its name indicates, it's useful for debugging.
And Xdebug should not be installed on a production server : it can be a pain, when it comes to performances -- I suppose it's because it "hooks" into PHP and add lots of stuff, like logging many informations useful for debugging ; which means more calculations to do -- which takes time and CPU.
Try APC : been using it with Mediawiki and the results are significant.
Other popular options are eAccelerator and APC.
Performance improvements will depend on the web app you're caching. Here are some benchmarks for the Drupal CMS using APC and eAccelerator, and here's the same site's tutorial on installing APC (nice and easy).
On Debian/Ubuntu, try:
sudo aptitude install php5-xcache
A commercial solution is from Zend, http://www.zend.com
Related
I am running a web server with Debian and I'm hosting a ZF1 project.
The PHP process crashes from time to time without any reason, so my hosting provider suggests that I should switch from APC to APCu caching. I'm not very familiar with PHP caching and I can't really find any documentation on the topic, but I read a few similar questions here.
As far as I understand the APCu caches only user data (whatever that means) and it's not the full features of the APC. Considering this, my question is will APCu increase the load of the server and will the PHP extension work out of the box without touching the ZF1 code?
http://zend-framework-community.634137.n4.nabble.com/Does-ZF-1-12-support-PHP-5-5-td4661902.html
You should upgrade to the latest PHP on a test environment, if it works well (most likely scenario), you can switch. PHP 5.5 has built-in opcode cache (http://php.net/manual/en/intro.opcache.php), so you won't lose performance. Very little difference can be between the performance of APCu and APC.
Also, function names are not identical (apcu_fetch for instance), so you have to modify the code to reflect this.
I have been compiling PHP for years with the configuration options I want. I compile extensions I use from source. Is there an advantage to doing this versus installing it from a package manager like apt-get or yum. I assumed it would also give me a leaner binary. I noticed that their are PHP modules in the repos such as "php53-gd". What if there wasn't a package available for something I wanted such as cURL for PHP?
I understand the disadvantages of compiling such as needing to download/install dependencies based on my configuration options. I'm not really concerned with that.
So the question is:
Compile PHP on Linux or just use apt-get / yum? Can I get all the things I need from the repos? Does anyone out there still compile it from source?
Any insight is appreciated! Thanks.
I compile from source every time. It's not hard to corral the mentioned issues with regards to compiling manually. For example, my ./configure settings are saved to a file which is version controlled, so when a new version of PHP is stable and I am ready to make the switch, I download and extract the file, then run this command:
./configure `sh /path/to/my/configure/php.sh`
Not too difficult. And because it's in version control, I can add notes as to why a module was added or removed.
Another benefit of manual compilation is it allows me to keep the PHP footprint as minimal as possible. I pass the --disable-all flag, then add the modules I need. However, there is a downside to this minimalist approach, recently I needed to install Magento, so I had to recompile with --enable-hash and --with-mcyrpt flags. Even though I needed to add new flags, it wasn't difficult to add to the configure file and recompile.
Compiling from source has a few quirks:
There are hundreds of config parameters and flags. And you might not know the optimal ones that need to be used.
if you rely on apt-get's PHP, then you can be assured that you will get the latest patches and security updates if you set up auto-upgrade on your server.
the configuration of php.ini varies a lot. Sometimes your OS may decide some defaults for you which may work better with the rest of the system.
installing extensions like xdebug or other packages are a lot easier with apt.
However, it's worth compiling php from scratch if you want to learn. Also if you don't use some portions of it, you can always disable them in configuration - but then again it might not make much difference to performance.
I compiled php for specific needs only, like :
very small hard disk space so required a minimalist php version
and/or
need only a few specific modules or extensions
and/or
needed for a specific application
and/or
needed to optimize performances: when compiling on the machine where it's used, this allows some performance improvements, if using compile options to get a real tuned version for your system,
and/or
needed multiple and different php versions on the same machine.
and/or
I had a specific nux distro like only a busybox, so no other options than compiling.
But for common usage, e.g. in 80% of the cases, it's not worth spending time to compile and better using the repository version. But I learned a lot by compiling.
Personally, it's a matter of opinion. If you are in a hurry, apt-get it, if you have time to learn and possibly need to reinstall 20 times...compile it.
There are tons of guides out there for PHP compiling. It has a ton of flags for configuration, especially for GD and other libraries. Personally if this is for learning and development, just get LAMP or use apt-get...especially if you need to use Apache
I feel the primary reason for compiling is to have latest version binary (stable or nightly). package managers (most distors) are often annoyingly slow in this respect.
The other reason is that its very common problem that production systems are not wholesale upgraded using package managers. Even if that can be easy. Since package managers create dependency chains and you may not want to upgrade those items. So just to pick one item, compiling is an option. It keeps everything else as it is. You ofcourse have to always study the upgrade issues and make sure nothing else will fail.
I have installed PHP5 - PHP5-MEMCACHE - PHP-APC.
Can they work like that together? Will the loading be fast with these modules ?
I tried to use them, I don't "see" particular differences, maybe the CPU is used less with these modules. My website doesn't have high traffic, but If i can save resources is better!
Thank you
APC keeps cache of PHP bytecode. Memcache keeps cache of your vars, that you set.
So answer is Yes, they can. They're made for different things.
They work together very well, you just need to use them properly :
Memcached is a distributed cache system. What that means in a nutshell is that if you have a cluster of servers all of them can access the same cache pool
APC is an opcache and local cache system. Meaning it optimizes the php scripts so when going through the compiler less operations are made and the code is executed way faster. Another use of APC is local cache, which means you can store values in the cache and access them from the machine running the code.
Yes, they can work together. Whether they will on a production system is another story...
Personally, I had to give up trying to get the following to work for any extended period of time:
Ubuntu 10.04
NGINX 0.7.65
PHP 5.3.2
php-apc
php5-memcache
It will run for awhile, but after stress testing php errors out. I can restart php-fastcgi via /etc/init.d/php-fastcgi and things will role along for some time more, but it always crashes again sooner than later.
I can run either/or without issue, but the two together won't cooperate for me. FYI I tried using binaries (apt-get packages), installing as PECL extensions, downloading source, but all roads lead me to the same sad fate. I also tried running the memache daemon local & remotely on my web host, but same outcome.
I'm working on mmo game based on JavaScript and PHP. We are using both of them. I can't tell you more, beacause I am only frontend developer, however I think if APC and memcache were bad we were not using it.
I am working on a website which is hosted on a VPS with CENTOS 5.4 i686 virtuozzo installed. I have a drupal installation on the server which gets around 100s of authenticated users at the same time.But at a certain point of time the server stopped responding and the site went offline. So, I tried installing the opcode cache - Alternative PHP Cache.
While the rest parts of the server work fine, the Drupal installation crashes as soon as I install PECL APC with the following message
Fatal error:Cannot run code from this file in conjunction with non encoded files in /home/apogee/public_html/2010/themes/zen/zen/block.tpl.php.
Could you please tell me a way to properly configure Drupal to use APC ?
Thanks
niting
I think the error comes from Zend Encoder...if you don't need it installed then uninstall it and see if that fixes things. If you do need it (closed-source module?), then not sure if that and APC can play nicely together...
you must be disable APC on php.ini
apc.enabled=0
APC and Zend Optimizer can't work with together
David Strauss at four kitchens has done some work on getting Pressflow (Performance tuned Drupal distribution) to work well with APC https://wiki.fourkitchens.com/display/PF/Tuning+APC.
With that much concurrent usage it may be worth your while to look into pressflow.
I have a couple of websites using APC and I've never seen that kind of error -- even with the Drupal-based ones.
After a bit of searching, it seems related to Zend Optimizer and/or Encoder (see the last answer on this thread, for instance), and not to Drupal itself.
I suppose you should use either Zend products, or APC, but not a combinaison of both.
What is the simplest way to install memcached on CentOS for someone new to the world of Linux? What is the best way to enable it for Apache and PHP
Unless Apache and PHP have some option to utilize memcached for internal workings (of which I am unaware of), you typically don't "enable" it for such apps. Instead, you would get a client library to use memcached from within your application, then start up memcached on whatever servers you want to provide memory with, then just use the client library API to store and retrieve cached data across multiple servers.
The easiest way is to find a reilable source of the RPM's needed to install memcached and memcached for PHP. There is a blog post which addresses this concern:
http://blog.gahooa.com/2009/02/08/update-on-fedora-vs-redhat-enterprise-linux/
We have been using EPEL (Extra Packages for Enterprise Linux) for exactly that on RedHat Enterprise 5.3. I believe it is a stated goal of EPEL to support Centos.
http://fedoraproject.org/wiki/EPEL
Essentially, it is a YUM repository which contains lots of extra packages from Fedora that were compiled for RHEL. Super easy to use.