I am working on a website where right rail and menu components will be using an external data source exclusively. The external source is a Lucene based index which sits on a different server.
I want to implement Sitecore caching on these components but I want the cache to refresh when new data is available for the component in the index. New data will be available very frequently. I am talking in terms of seconds not minutes or hours in some cases. How can I achieve Sitecore caching in this instance?
I am using Sitecore 6.5 for this website.
Aside from the duplicate post I mentioned above, if your content is updating so frequently (in seconds) it might not even be worth the caching overhead if you will have an infrequent number of hits per each cache instance. You'll end up using memory for the caches and barely use them. Instead use Lucene.NET to deliver your component a collection of SkinnyItem (a very fast operation) and convert them to Item at the last moment when binding to the front-end (e.g. an ItemDataBound event in a Repeater)
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I want to Load Dropdown data from Database at once and set inside java object and tie to my view (JSP page ) and available all the time for that particular controller or functionality using spring mvc AND jsp pages.
I dont want to load on application start up as ours is big one and and each functionality is independent.
It takes a lot of time to start the application if i load on application start up
Is there a way to it using spring mvc pattern and using JSP
Could someone please let me know how to do it
As you have not mentioned how frequently you are doing the database operation or how frequently you are fetching the data. Considering the average user.
Approach: Create your own local cache/ program cache implementation.
Instead of loading all the data from the database during startup, load only master data which will be common for all. If master data is also high then you can perform the lazy loading approach.
Load the data of a specific feature when it is requested for the first time. Keep the data in the local cache.
Whenever someone is making the changes then add the data in the cache and save the same to the database. so you will always have latest data in the cache.
Advantage:
Very useful for common or static master data
-If you need good business logic for some common data. This way only once you are processing the data and keeping cache.
-Fetching the data is very fast as it doesn't involve database request except for the first time
Disadvantage:
If you have a very high number of users and a very high update operation then the updating cache will delay the update process as you need to update it sequentially.
I suggest you can use a combination of approaches to improve the code quality and processing.
This sounds like a typical cache functionality.
Spring supports caching out of the box by #EnableCaching on application level and #Cacheable(“cachename”) on the repository method retrieving your dropdown data. In your simple use case you not even need an additional framework as there is a CacheManager based on ConcurrentHashMap which simply caches for ever.
With caching in place your controller can simply fetch the dropdown data from the repository. Caching will ensure only the first call will really fetch from database and keeps the result in memory for all upcoming calls.
If you ever need more sophisticated caching you only have to exchange the cache manager and configure the cache for your needs.
I'm trying to work out of I can take advantage of a caching layer in my web application or not (and if so which technology).
Our web app has and internal and external component and I would like if possible to add an in-memory cache tier between the Web App and DB Tier for the public external component. We are suffering DB performance issues and I want to alleviate stress on the DB as much as possible (plus make our public facing site of the component lightening fast).
The external component offers a location search facility based on a post code. E.g enter post code for an area and you get 50 results back each time (the data is relatively stale) the DB might change (new record added 1 per day) so I was thinking if a cache tier was possible then I could invalidate the cache nightly and then load it again (as opposed to the cache aside pattern).
Question:
Based on my overview above e.g. postcode mapping to multiple records (JSON or serializable objects) can I use a cache tier to store the data in-memory (total size of data ~100 MG, heaps of RAM free) and retrieve multiple records back per post code based on a caching technology "key-value data stores"?
If number 1 above is feasible, what caching technology, we are using a PHP front end, Zend server has an im-memory cache but it doesn't look mature, I would prefer Redis over Memcached for caching, thoughts?
If pre-loading the cache nightly is not achievable, thoughts on a better approach to utilise the cache?
If in-memory caching is not achievable at all (based on my requirement) then should I look at opmtiising the DB (it's SQL Server), e.g. loading the search table into SQL cache on SQL Server start-up?
Other, something I'm missing?
Thanks in advance, all comments welcome!
Cheers,
Okay, so I have an old ASP Classic website. I've determined I can reduce a huge number of DB calls by caching the data daily. Our site data is read only, and changes very slowly. I think based on our site usage, I would be able to cache pages by query string for every visit each day, without a hit to our server.
My first thought was to use Output Caching, but the problem I discovered right away was that it wasn't until the third page request was generated that I gained any performance. I verified this using SQL profiler, but I'm not sure why.
My second thought was to add this ObjPageCache include file from https://web.archive.org/web/20211020131054/https://www.4guysfromrolla.com/webtech/032002-1.shtml After some research I discovered that this could cause more issues than it may solve http://support.microsoft.com/kb/316451
I'm hoping someone on here will tell me that since 2002 the issue with Sending ServerXMLHTTP or WinHTTP Requests to the Same Server has been resolved with Microsoft.
Depending on how your data is maintained you could choose from a number of ways to cache it.
If your data is changed and saved in one single place you could choose to generate an html-file which you save to the serverdisk and refer to in your linking. This will require write access for the process running your site though (e.g. NETWORK SERVICE). This will produce fast pages as the server serves these pages without any scriptingengine getting involved.
Another option is reading the data into an DomDocument which you store in the Application object and refer to on the page that needs it (hence saving the roundtrip to the database). You could keep two timestamps together with the cached data (one for the cachingtime and one for the time of change of data in the database). Timestamps will allow for fast check for staleness of the cached data: cached timestamp <> database timestamp => refresh data; otherwise use cached data. One thing to note about this approach is that Application does not accept objects other than multithreaded object so you will have to use the MSXML2.FreeThreadedDomDocument.6.0
Personally I prefer the last one as it allows for a more dynamic usage and I don't have to worry about write access permissions for the process running my site (which would probably pose security risks anyways).
I have developed application using ZF.The app is little big with a lots of features.
I use Zend_Application(already using autoloader in constructor),Zend_Layout,Zend_view,Zend_form,etc. My current issue is, the page loading is very slow and that too in localhost with XAMP.
I have enabled xdebug, to investigate the issue, got a cachegrind file in "tmp" folder and tried to view it with WinCachegrind software. There i can a see a lot of processes and functions being run for each and every request or page load.
Also, i have installed YSlow add-on for firefox and observed the speed of page loads in seconds...I have compare the speed with ZF and non ZF applications. And from the comparison, the pages for non zf app takes less than 1 sec to load and for the ZF app, it takes atleast 6-7 seconds. What a huge difference.
Main Things happen in the app are :
1) Database connection happens for each request.
2) Im not adding the view to layout explicitly,ZF just appends it automatically, to layout.phtml, based on the action name.
3) Some windows have forms with few drop down boxes which fetches data from the database.
4) Have menus with ACL implimented, before it was loading the privilges from DB for each and every request, but now i have optimized it, so that it will work only duiring the login and rest of the time it will take from the Zend_Registry.
I would like to attach the cachegrind file so that some one can see whats happening in the background, but i cant see an option here for attaching.
Someone please help me to find a solution for this. Any kind of help is really appreciated. Thanks a lot
Let's try to give some hints.
First database connection should happen only once (except if you use several privileges access on the database or several databases). So check that you use Singleton patterns with you Zend_Db_Tables object
Then you do not use Zend_Cache. You should really start to use Zend_Cache and build several cache objects. Let's say for example a File cach, with long term storage, and a memcache or Apc Cache, storing objects. Then use these cache in several layers:
gives the FileCache to Zend_Db_Table (defaultMetaDataCache), this way you will avoid a loot of metadata queries, queries that ask for description of each columns of the tables you use.
Store one or more Acl object (depends on how you use Acl, if you have one big Acl with all rules or several with subsets). And store them in mid-duration caches when they are built.
Think of other usages, detect heavy loops, semi-static contents (like you select lists, how many time should they be considered static?)
Finally, get a whole mental image of how your application engine works, and how your data will grow and be used.You will need that step to use application levels caches in the very best way (for example should some elements be cached for groups of users?, should Acl objects be build for groups, for each user, for everybody, is ther some blocks in the layout that should be rendered the same for everybody?).
We have 3 front-end servers each running multiple web applications. Each web application has an in memory cache.
Recreating the cache is very expensive (>1 min). Therefore we repopulate it using a web service call to each web application on each front-end server every 5 minutes.
The main problem with this setup is maintaining the target list for updating and the cost of creating the cache several times every few minutes.
We are considering using AppFabric or something similar but I am unsure how time consuming it is to get up and running. Also we really need the easiest solution.
How would you update an expensive in memory cache across multiple front-end servers?
The problem with memory caching is that it's unique to the server. I'm going with the idea that this is why you want to use AppFabric. I'm also assuming that you're re-creating the cache every few minutes to keep the in memory caches in sync across all servers. With all this work, I can well appreciate that caching is expensive for you.
It sounds like you're doing a lot of work that probably isn't necessary. This article has some detail about the caching mechanisms available within SharePoint. You may be interested in the output cache discussed near the top of the article. You may also want to read the linked TechNet article and the linked article called "Custom Caching Overview".
The only SharePoint way to do that is to use Service Application infrastructure. The only problem is that it requires some time to understand how it works. Also it's too complicated to do it from scratch. You might consider downloading one of existing applications and rename classes/GUIDs to match your naming conventions. I used this one: http://www.parago.de/2011/09/paragoservices-a-sharepoint-2010-service-application-sample/. In this case you can have single cache per N front-end servers.