I am very new to Redis. I've implemented caching in our application and it works nicely. I want to store two main data types: a directory listing and file content. It's not really relevant, but this will cache files served up via WebDAV.
I want the file structure to remain almost forever. The file content needs to be cached for a short time only. I have set up my expiry/TTL to reflect this.
When the server reaches memory capacity is it possible to priorities certain cached items over others? i.e. flush a key, flush a whole database or flush a whole instance of Redis.
I want to keep my directory listing and flush the file content when memory begins to be an issue.
EDIT: Reading this article seems to be what I need. I think I will need to use volatile-ttl. My file content will have a much shorter TTL set, so this should in theory clear that first. If anyone has any other helpful advice I would love to hear it, but for now I am going to implement this.
Reading this article describes what I needed. I have implemented volatile-ttl as my memory management type.
By default, the Symfony2 profiler only saves a few* of the last requests (Don't know how many excactly - something between 25 and 40). I think the list removes the older ones after a cupple of minutes..
I'd like to do a long-time profiling and measuring of some data. Is it possible to configure the max profiling amount? Or maybe store all the data in my (MongoDB) Database? (I'm currently using Symfony 2.2)
Update: I found out, that clearing the cache, also clears the profiler data - so I guess the key issue here is, to save the profiler data somewhere else..
Check this out.
You can override the default profiler.storage service, which is defined here.
You could either define your own class (implementing the ProfilerStorageInterface) or use one of the provided implementations (check here for the whole list).
For example if you want to use the MongoDbProfilerStorage you can redefine the service as follows:
<service id="profiler.storage" class="Symfony\Component\HttpKernel\Profiler\MongoDbProfilerStorage" public="false">
<argument>mongodb://[USER:PWD#]HOST/DATABASE/COLLECTION</argument>
<argument></argument>
<argument></argument>
<argument>86400</argument>
</service>
This way you wouldn't delete profiler data whenever you clear the cache.
I'm using Docpad and want to do increment a counter (for cachebusting of assets) every time a static site is generated.
I figured the easiest way would be t:
hook into docpad.coffee.writeBefore
increment a counter templateData.assetCounter
persist docpad.coffee.
Still figuring out the functionality that comes out-of-the-box with Docpad, so looking for a way to persist docpad.coffee to disk. Would that be a good idea at all?
Of course I could read/ write to disk using require('fs') but that may conflict/race with what docpad may internally be already doing (just guessing)
ideas?
That's a really cool idea! A plugin would be great for this, it could:
hook into docpadReady to load the persisting file
hook into extendTemplateData to add the current counter value to the template data
hook into writeAfter to increment the counter and save it to the persisting file
the persisting file could just be my-website/generateCounter.json
This way you don't have to modify your docpad.coffee file after each generation :)
I realize that this might be a vague question the bequests a vague answer, but I'm in need of some real world examples, thoughts, &/or best practices for caching data for a web app. All of the examples I've read are more technical in nature (how to add or remove cache data from the respective cache store), but I've not been able to find a higher level strategy for caching.
For example, my web app has an inbox/mail feature for each user. What I've been doing to date is storing typical session data in the cache. In this example, when the user logs in I go to the database and retrieve the user's mail messages and store them in cache. I'm beginning to wonder if I should just maintain a copy of all users' messages in the cache, all the time, and just retrieve them from cache when needed, instead of loading from the database upon login. I have a bunch of other data that's loaded on login (product catalogs and related entities) and login is starting to slow down.
So I guess my question to the community, is what would you do/recommend as an approach in this scenario?
Thanks.
This might be better suited to https://softwareengineering.stackexchange.com/, but generally you want to cache:
Metadata/configuration data that does not change frequently. E.g. country/state lists, external resource addresses, logic/branching settings, product/price/tax definitions, etc.
Data that is costly to retrieve or generate and that does not need to frequently change. E.g. historical data sets for reports.
Data that is unique to the current user's session.
The last item above is where you need to be careful as you can drastically increase your app's memory usage, by adding a few megabytes to the data for every active session. It also implies different levels of caching -- application wide, user session, etc.
Generally you should NOT cache data that is under active change.
In larger systems you also need to think about where the cache(s) will sit. Is it possible to have one central cache server, or is it good enough for each server/process to handle its own caching?
Also: you should have some method to quickly reset/invalidate the cached data. For a smaller or less mission-critical app, this could be as simple as restarting the web server. For the large system that I work on, we use a 12 hour absolute expiration window for most cached data, but we have a way of forcing immediate expiration if we need it.
This is a really broad question, and the answer depends heavily on the specific application/system you are building. I don't know enough about your specific scenario to say if you should cache all the users' messages, but instinctively it seems like a bad idea since you would seem to be effectively caching your entire data set. This could lead to problems if new messages come in or get deleted. Would you then update them in the cache? Would that not simply duplicate the backing store?
Caching is only a performance optimization technique, and as with any optimization, measure first before making substantial changes, to avoid wasting time optimizing the wrong thing. Maybe you don't need much caching, and it would only complicate your app. Maybe the data you are thinking of caching can be retrieved in a faster way, or less of it can be retrieved at once.
Cache anything that causes duplicate database queries.
Client side file caching is important as well. Assuming files are marked with an id in your database, cache them on every network request to avoid many network requests for the same file. A resource to do this can be found here (https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API). If you don't need to cache files, web storage, local storage and cookies are good for smaller pieces of data.
//if file is in cache
//refer to cache
//else
//make network request and push file to cache
i'm looking on performance (server load time) of magento site and i'm trying to tune search result pages. I realized that when I disabled all heavy things like top navigation, lev layered navigation and product listing and I cleared all cache then after this magento core does like 60 SQL queries agains a database. Does anyone have any procedure how to rid of them or how to reduce them to some acceptable amount?
Also can I somehow reduce a time spent during creating of blocks?
Thank you very much,
Jaro.
Magento is a extremely flexible ecommerce framework, but that flexibility comes with a price: performance. This answer is a collection of pointers and some details on caching (especially for blocks).
One thing to consider is the Magento environment, e.g. tuning the php, the web server (favor nginx over Apache), and MySQL. Also, set up a good caching backend for Magento. All these are covered e.g. in the Magento Performance Whitepaper that applies also to the CE.
After the environment is set up, the other side of things is the code.
Reducing the number of queries is possible for some pages by enabling the flat table catalog (System > Configuration > Catalog > Frontend), but you will always have a high number of queries.
You also can't really reduce the time spent creating the blocks except by tuning the environment (APC, memory, CPU). So as the other commenters said, your best choice is utilizing the caching functionality that Magento has built in.
Magento Block Caching
Because you specifically mentioned blocks in the question, I'll elaborate a bit more on block caching. Block caching is governed by three properties:
cache_lifetime
cache_key
cache_tags
All these properties can be set in the _construct() method of a block using setData() or magic setters, or by implementing the associated getter methods (getCacheLifetime(), getCacheKey(), getCacheTags()).
The cache_lifetime is specified in (integer) seconds. If it is set to false(boolean), the block will be cached for ever (no expiry). If it is set to nullthe block will not be cached (this is the default in Mage_Core_Block_Abstract).
The cache_key is the unique string that is used to identify the cache record in the cache pool. By default it is constructed from the array returned by the method getCacheKeyInfo().
// Mage_Core_Block_Abstract
public function getCacheKeyInfo()
{
return array(
$this->getNameInLayout()
);
}
public function getCacheKey()
{
if ($this->hasData('cache_key')) {
return $this->getData('cache_key');
}
/**
* don't prevent recalculation by saving generated cache key
* because of ability to render single block instance with different data
*/
$key = $this->getCacheKeyInfo();
//ksort($key); // ignore order
$key = array_values($key); // ignore array keys
$key = implode('|', $key);
$key = sha1($key);
return $key;
}
The best way to customize the cache key in custom blocks is to override the getCacheKeyInfo() method and add the data that you need to uniquely identify the cached block as needed.
For example, in order to cache a different version of a block depending on the customer group you could do:
public function getCacheKeyInfo()
{
$info = parent::getCacheKeyInfo();
$info[] = Mage::getSingleton('customer/session')->getCustomerGroupId()
return $info;
}
The cache_tags are an array that enable cache segmentation. You can delete sections of the cache matching one or more tags only.
In the admin interface under System > Cache Management you can see a couple of the default cache tags that are available (e.g. BLOCK_HTML, CONFIG, ...). You can use custom cache tags, too, simply by specifying them.
This is part of the Zend_Cache implementation, and needs to be customized far less frequently compared to the cache_lifetime and the cache_key.
Other Caching
Besides blocks Magento caches many other things (collection data, configuration, ...).
You can cache your own data using Mage::app()->saveCache(), Mage::app()->loadCache(), Mage::app()->cleanCache() and Mage::app()->removeCache(). Please look in Mage_Core_Model_App for details on these methods, they are rather straight forward.
You will also want to use a full page cache module. If you are using the Magento EE, you already have one. Otherwise search Magento Connect - there are many options (commercial).
Some of those modules also tune various parts of Magento for you beyond the full page caching aspect, e.g. Nitrogento (commercial).
Using a reverse proxy like Varnish is also very beneficial.
There are quite a number of blog posts on this subject. Here is one post by the publishers of the Nitrogento extension.
If you are running Magento on a more low-scale environment, check out my post on the optimization of the file cache backend on magebase.com.
I am adding additional comments for speed:
Instead of using Apache use nginx or litespeed.
Make sure flat catalog is used.
If possible use FPC.
compiler mode to be set on.
Merge css and js(Fooman Speedster ).
Use image sprites to reduce number of request.
Use query cache but avoid size greater then 64 MB.
Remove all modules not in use by removing there xml.Just disabling will not do.
Session to be on Ram.
Use of APC recommended.
Your cron should be run in offpeak hours.
Delete additional stores if not in use.
Delete cart rules if not in use.
optimize image for size.
Use Ajax where ever possible.
CMS blocks take more time then a magento block so unless you want a block to be modified do not use CMS blocks.
Do not use collection count use collection getSize to get what is the collection size.
Minimize number of searchable attributes as these result in columns in flat catalog table and will slow down your search.
Use of Solr search is recommended. It comes with EE version but it can be installed with CE as well.
Minimize customer group as suggested in comment.
Enable compression in .htaccess (mod_gzip for Apache 1.3, mod_deflate for Apache 2)
Remove staging stores if on EE.
Use Apache mod_expires and be sure to set how long files should be cached.In case you are on Apache server.
Use a Content Delivery Network (CDN).
Enable Apache KeepAlives.
Make your output W3C compliant
Use of getChildHtml('childName') is recommended as this will cache block against direct use of block code in .phtml file.
Make sure cron is run so as to clean logs stored in data base.
Number of days log should be minimized as per requirement.
Load cache on RAM if memory permits.
Reduce hard disc file reads and try reads from ram as this is faster.
Upgrade PHP version to above 5.3
If on EE make sure that most pages are delivered without application initialization.Even if one container needs application initialization its going to effect execution speed as apart form URL rewrites most of the other code will get executed.
Check XML for blocks placed in default handle and if those blocks not on specific page then move those XML values from default handle to specific handles.It has been observed that lots of blocks are executed that are not displayed.
If using FPC make sure your containers are cached and repeat request for container is delivered via cache.Improper placeholder definition results in container cache not being used but each time new container content getting generated.
Analyze page blocks and variables and if possible add those variables/blocks to cache.
Switch off Logs writing in Magento.
Remove Admin notification module.
Use of image sprites.
Use some web test tool to analyse number of requests and other html related parameters responsible for download time and act accordingly.
Remove attributes if not needed.With proper care we can even remove system attributes if not in use.
42: If on enterprise make sure partial indexing is effectively used.
Write your own solr search populate to bypass Magento search indexing.
Clean _cl tables or reduce _cl table rows.
I would add into list: try to avoid file cache if possible, replace it by apc / redis / memcache( As suggested by Jaro)
Remove system attributes not in use( Be careful,do a thorough check before removing).
There are some cron tab jobs that are not applicable to all stores so depending on your store features those can be removed.
Optimization by proper attribute management like setting required attribute to yes or is searchable or required in listing etc.
Some observers are not required for all stores so in case those observers are not applicable to a specific Magento site then they should be removed.
Make sure FPC is applicable to most of the site pages. Specially when you added some new controllers to delivering a page.
Magento has lots of features.For this it has many events and associated observers.There are few features that are not used by a store so any observer related to that feature should be removed.e.g : If you check enterprise version there is category permission concept which if not used, then its recommended that on save after events permission related observers to be removed.
If a specific attribute is to be save for a product then instead of call $product->save call a function that will save specific attribute.
In EE version that has partial indexing and triggers modify triggers to avoid multiple entries to_cl tables.
No.phtml files bypasses blocks and use modules or resources directly.As this will result in no caching which in-turn means more work for Magento.
Delivering images depending on device in use.
Some of the FPC recommended for community : Lesti( Free as on date ),Amasty( commercial),extender(commercial ) and Bolt(commercial).
Warming Cache.
Controlling bots by .htaccess during peak hrs.
Pre-populating values in a custom table for Layered Navigation via a custom script that executes daily by cron.
Making sure to avoid unwanted Keys to reduce cache size.
Using a higher PHP version 5.4+
Using a higher Mysql version( 5.5 +)
Reduce number of Dom elements.
Move all js out from html pages.
Remove commented html.
Modify triggers if on enterprise version(1.13 or higher) so as to reduct _cl table entries.As these entries results in cache flushing which in turn results in lower cache hit,hence more TTFB time.
Use Magmi to import products.
As Vinai said, Magento is all about extensibility and raw performance is secondary but remedied by things like indexing and caching. Significantly improving performance without caching is going to be very difficult. Short of full-page caching, enabling block caching is a good method of improving performance but proper cache invalidation is key. Many blocks are cacheable but not already configured to be cached by default so identify the slowest ones using profiling use Vinai's guide for enabling caching. Here are a few additional things to keep in mind with block caching:
Any block that lists product info should have the product's tag which is 'catalog_product_'.$productId. Similarly, use 'catalog_category_'.$categoryId for categories. This will ensure the cache is invalidated when the product or category is saved (edited in backend). Don't set these in the constructor, set them in an overridden getCacheTags() so that they are only collected when the block is saved and not when it is loaded from cache (since that would defeat the purpose of caching it).
If you use https and the block can appear on an https page and includes static resources, make sure the cache key includes Mage::app()->getRequest()->isSecure() or else you'll end up with http urls on https pages and vice versa.
Make sure your cache backend has plenty of capacity and avoid needless cache flushes.
Don't cache child blocks of a block that is itself cached unless the parent changes much more frequently than the child blocks or else you're just cluttering your cache backend.
If you do cache tagging properly you should be able to use a very long default cache lifetime safely. I believe setting "false" as the lifetime actually uses the default, not infinite. The default is 7200 seconds but can be configured in local.xml.
Using the redis backend in most cases will give you the best and most consistent performance. When using Redis you can monitor used memory size using this munin plugin.
Just to follow on from Mark... most of the tables in the Magento database are InnoDB. Whilst the query cache can be used in a few specific places, the following are more directly relevant...
innodb_buffer_pool_size
innodb_thread_concurrency
innodb_flush_method
innodb_flush_log_at_trx_commit
I also use
innodb_file_per_table
as this can be beneficial in reorganising specific tables.
If you give the database enough resource, (within reason) the amount of traffic really doesn't load the server up at all as the majority of queries are repeats anyway, and are delivered out of database cache.
In other words, you're probably worrying about nothing...
Make sure mysql query cache is turned on. And set these variables in mysql (maybe need tweaking depending on your setup).
query_cache_type=1
query_cache_size=64M
i found a very interesting blog post about Magento Performance optimization, there are many configuration settings for your server and your magento store, was very helpful for me.
http://www.mgt-commerce.com/blog/magento-on-steroids-best-practice-for-highest-performance/
First you need to audit and optimize time to first byte (TTFB).
Magento has profiler built-in that will help you identify unoptimized code blocks.
Examine your template files and make sure you DO NOT load product models inside a loop (common performance hog):
foreach($collection as $_product){
$_product = Mage::getModel('catalog/product')->load($_product->getId()
I see this code often in product/list.phtml
I wrote a step-by-step article on how to optimize TTFB
Disclaimer: the link points to my own website