Caching - What Is The Default Serialization Used By The HttpRuntime.Cache
Jan 29, 2010
what the default serialization used by the ASP.net HttpRuntime.Cache is? Is it Binary, XML, something else?
I am populating a generic List with multiple objects of the same custom type. The custom type is a POCO, there is nothing special about it. All of its properties are public with { get; set; }, it is public, it has no inheritance, it has no interfaces. In fact it is much less complicated than many other objects which we are caching which work without issue. I have tried adding the [Serializable] attribute to the custom class and it has no effect.
I add the list to the cache with a unique key. The list has been verified as populated before it is inserted into the cache, the objects in the list have been verified as populated as well. But when the list is pulled back out of the cache it is an empty list (NOT NULL), it simply has no items in it. This means that the list is being added to the cache and is retrievable but for some reason the cache is having issues serializing the objects in the list.
I just find this freaky weird since I have another list of custom objects which are much more complicated (consisting of Inheritance, Interfaces, and also containing Properties which are generic lists of other complex objects) and the caching of those lists work without issue.
Both the working and non-working list are being managed in C# classes outside of the ASP.net user controls which consume the cached data. Both of these cache handling classes call the exact same Cache Manager class singleton instance which wraps the HttpRuntime.Cache to provide typed methods for pull and pushing objects into the cache.
we have so many parameters that the cache key is several hundred characters long. is there a limit to the length of these cache keys? Internally, it is using a dictionary, so theoretically the lookup time should be constant. However, I wonder if we have potential to run into some performance/memory problem.
/Web --this is the client facing site /Web/Admin --this is the backend system and is setup as a Virtual Application
I'm using HttpRuntime.Cache for caching calls to the database. What I want to be able to do is clear something that is cached on the /Web site from the /Web/Admin site. It appears though that HttpRuntime.Cache is a single instance per application.
I am new in Asp.net MVC but i really like it. I always prefer flexible authentication systems, on the other hand security is very important issue too. So i looked for some sipmle way to store current loged "user id/user name" in server side. I think that "HttpRuntime.Cache" can be a answer. So i write simple test project Of course this code is is not complete.
We have a web application that is storiing all site data in HttpRuntime.Cache. We now need to deploy the application across 2 load balanced web servers. This being the case, each web server will have its own cache, which is not ideal because if a user requests data from webserver1 it will be cached, but there next request might go to webserver2, and the data that their previous request cached won't be available. Is it possible to use a shared-cache provider to share the HttpRuntime.Cache between the two web servers or to replecate the cache between them, so that the same cache will be available on both web servers?
I've been experimenting with caching objects with HttpRuntime.Cache and I was generally under the impression that if I "added" something to the cache like this:
HttpRuntime.Cache.Insert("Test", "This is a test!", null, Cache.NoAbsoluteExpiration, Cache.NoSlidingExpiration, CacheItemPriority.NotRemovable, new CacheItemRemovedCallback(FileChanged));
that the "NotRemovable" and "NoExpiration" flags would keep the object in-memory for the duration of the application. But was finding that at the end of certain page requests, the HttpRuntime.Cache would be completely empty!
Tracing thru and setting a breakpoint inside my Callback "FileChanged" I could see that indeed something was "removing" my object (and every other object in the cache), but I couldn't figure out why. So eventually, I started disabling other things that I thought might affect this subsystem.
I had been mostly retrieving data from "web.config" in the AppSettings region, but occasionally writing back to AppSettings and saving the changes using the above command. I knew from reading that the "web.config" is cached, but saving my changes back to it shouldn't flush all of HttpRuntime.Cache, right?
EDIT:
I've made this super reproducible if wants to try this on their own machine. (I'm running VS2008 Pro w/ MVC2 targeting .NET 3.5) Just start up a new MVC2 project and paste the following into the HomeController over whatever is already there:
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Configuration; using System.Configuration;........
Start-up the app in debug mode. Click on the "About" link. This loads a string into the Cache. Click on the "Home" link. String is pulled from the Cache and stuck in ViewMessage dictionary. Some key/value pair is written to web.config and saved. String from cache should appear on the Home page. Click on the "Home" link again. String should be pulled from the cache, but it's not. Stop program. Comment out the 3 lines that start with "Config". Restart the program. Try steps 1 thru 4 again. Notice how the HttpRuntime.Cache has not been emptied.
I've got a web application that runs of a state server. It looks like soon it may need to distributed and there will be two web servers behind a load balancer.
This works great for session state but my next challenge is Cache
My application leverages heavily of cache. I understand ASP.Net 4.0 will be offering more here but nothing much has been said about the how too.
There are two challenges that I face
1). Each webserver will have its own copy of cache whereas it would be more efficient to put this to a third server the same as session state is put to state server.
2). The real challenge is keeping cache in sync if a simple dataset derived from the database is changed my code dumps that cache item and reloads the cache. That's all well on one webserver but webserver number two wont know to drop that particular cache item and reload it. This could cause some unexpected problems in the application.
For scenario number 2 I could attempt to do some smart coding so server number two knows to dump the cache and reload it.
My guess is someone else has already been here before and there's probably a better implementation approach rather than writing extra code.
Does anyone know how I could achieve the goal of keeping Cache in sync between multiple webservers or even better farm Cache management to another server?
My servers are behind F5 load balancer, I wanna use HttpRuntime.Cache in my web application but I didn't find out the way for to use that method for those using network load balancing server. Or can we store that HttpRuntime.Cache to sql server like the session we do in web.config file?
I want to put POCO object to Velocity cache. How can I serializable ICollection to Velocity cache, or exclude ICollection from serialization?
I got this exception
Type 'System.Collections.Generic.ICollection`1[Model.Collection]' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. If the type is a collection, consider marking it with the CollectionDataContractAttribute. See the Microsoft .NET Framework documentation for other supported types.
[OutputCache (Duration=20, VaryByParam="None" )] public ActionResult display() {}
This code cache whole page.But, my site has user infomation on top like this ASP.net. The user info "Signed as userid | Edit Profile | ..." section should be changed when user sign in/out. But rest of the page is always same and it's good to Cache.
If the above code is used, the user info on top also cached and give wrong info to user.
I have a List of objects in an asp.net page. when the page loads in the browser for the first time, I fetch data from the database, create objects with those data and populate the list. All these are done inside the page load event handler. Now when the page is posted back to the page, the previous list is gone, since the variables were all freed.
How can I cache that List, so that when this page is posted back, all my objects are available?
Last night I wrote up my first IHttpModule to do some request processing. I'm using a regular expression to inspect the raw url. The IHttpModule will be called on every request, so it seems reasonable to do some sort of caching of the regular expression object to prevent creation of it on every request.
Now my question... what is better: use the HttpContext.Current.Cache to store the instantiated object or to use a private static Regex in my module?I'm looking forward to the reasons why. Just to clarify: the regex will never change and thus always be the same thing.
I am building a web application using asp.net (c#) and lingtosql. When I perform update operations on my db I update my classes. I use gridview to bind to update information. When I relay solely on the database the page's take very long to load. When I relay solely on the cache, I have old data. What workarounds do I have for have asynchronous cache updating, yet not overload the database with endless requests (I'd like to update the cache only if there has been a change in the database itself, and perform the update operation asynchronously).
We display an ASP.NET calendar control and update the color and if the day is enabled with the DayRender event. This process is a bit slow so I'm trying to map out a strategy to cache the results of the all the DayRenders. Basically take a snapshot of the calendar and cache it for X minutes. Where would I hook into the page/control workflow to accomplish this goal?
I would like to use output caching with WCF Data Services and although there's nothing specifically built in to support caching, there is an OnStartProcessingRequest method that allows me to hook in and set the cacheability of the request using normal ASP.NET mechanisms.
But I am worried about the worker process getting recycled due to excessive memory consumption if large responses are cached. Is there a way to specify an upper limit for the ASP.NET output cache so that if this limit is exceeded, items in the cache will be discarded?
I've seen the caching configuration settings but I get the impression from the documentation that this is for explicit caching via the Cache object since there is a separate outputCacheSettings which has no memory-related attributes.
Here's a code snippet from Scott Hanselman's post that shows how I'm setting the cacheability of the request.
How do I setup caching for a Page in ASP.NET and give it a cache key dependency? I am familiar how to do this with a UserControl, I set a Partial Caching attribute and then set
this.CachePolicy = new CacheDependency(..)
How would I do this for a Page? It does not have a CachePolicy object,
I am using this to store my user information for authentication. I'd like to know where this is actually being stored? I know that people suggest to store the Session state in SQL. Is this necessary for the Cache as well?
I'm trying to cache user controls and on some pages i want to cache single objects. There are multiple ways of implementing caching, and my head is breaking over it.
The way I see the caching options now:
You have the PartialCaching option which is set to cache the control for 30 minutes, and after that it clears itself... You have the varyByParam to identity the page by its querystring paramaters... or other vary options
But i just cant find an appropriate way to add caching to a control, and be able to clear the caching programmatically when i update one of the objects used in the control from the backend.
You can do HttpContext.Current.Cache.Insert(), which accepts a key on which you can destroy the caching item later by using remove... This can save objects in cache but can you use options like varyByParam?
My questions are burnt down to two:
Is there a way to clear the caching on specific user controls from the code? If yes, can this be done according to the varyby options? How would the object caching respond to logged in users or anonymous users using Insert()?
EDIT: I'm caching multiple things.... And I'm really flabbergasted in which choice to make referring to caching. Can the Cache.Insert be varied by Parameters?
The main problem is peopling editing things from the backend, which needs to trigger an event that reinstantiates or clears all caching items referring that object.
TL;DR: Which is likely faster: accessing static local variable, accessing variable stored in HttpRuntime.Cache, or accessing variable stored in memcached?At work, we get about 200,000 page views/day. On our homepage, we display a promotion. This promotion is different for different users, based on their country of origin and language.
All the different promotions are defined in an XML file on each web server. We have 12 web servers all serving the same site with the same XML file. There are about 50 different promotion combinations based on country/language. We imagine we'll never have more than 200 or so (if ever) promotions (combinations) total.
The XML file may be changed at any time, out of release cycle. When it's changed, the new definitions of promotions should immediately change on the live site. Implementing the functionality for this requirement is the responsibility of another developer and I.
Originally, I wrote the code so that the contents of the XML file were parsed and then stored in a static member of a class. A FileSystemWatcher monitored changes to the file, and whenever the file was changed, the XML would be reloaded/reparsed and the static member would be updated with the new contents. Seemed like a solid, simple solution to keeping the in-memory dictionary of promotions current with the XML file. (Each server doing this indepedently with its local copy of the XML file; all XML files are the same and change at the same time.)
The other developer I was working holds a Sr. position and decided that this was no good. Instead, we should store all the promotions in each server's HttpContext.Current.Cache with a CacheDependency file dependency that automatically monitored file changes, expunging the cached promotions when the file changed. While I liked that we no longer had to use a FileSystemWatcher, I worried a little that grabbing the promotions from the volitile cache instead of a static class member would be less performant.
(Care to comment on this concern? I already gave up trying to advocate not switching to HttpRuntime.Cache.)
Later, after we began using HttpRuntime.Cache, we adopted memcached with Enyim as our .NET interface for other business problems (e.g. search results). When we did that, this Sr. Developer decided we should be using memcached instead of the HttpRuntime (HttpContext) Cache for storing promotions. Higher-ups said "yeah, sounds good", and gave him a dedicated server with memcached just for these promotions. Now he's currently implementing the changes to use memcached instead.
I'm skeptical that this is a good decision. Instead of staying in-process and grabbing this promotion data from the HttpRuntime.Cache, we're now opening a socket to a network memcached server and transmitting its value to our web server.This has to be less performant, right? Even if the cache is memcached. (I haven't had the chance to compile any performance metrics yet.)On top of that, he's going to have to engineer his own file dependency solution over memcached since it doesn't provide such a facility.
Wouldn't my original design be best? Does this strike you as overengineering? Is HttpRuntime.Cache caching or memcached caching even necessary?
Has anyone been able to cache .aspx pages using the HTML cache manifest? I am porting an html application over to asp.net (and mvc2) and I get a 404 error when trying to cache any *.aspx page. Other files still cache normally (.js, .css, etc). I have changed permissions, handlers, and file names and still no luck. Below is the actual manifest:
CACHE MANIFEST # This file was generated at 2/28/2011 4:03 PM CACHE: /Content/Site.css /Content/Table_style.css /Scripts/jquery-1.5.min.js /Scripts/json.js /Scripts/persist-all.js /Views/Data/Details.aspx /Views/Data/NotFound.aspx /Views/Data/OffLine.aspx /Views/Data/OnLine.aspx /Views/Data/Test.aspx /Views/Home/About.aspx /Views/Home/Index.aspx /Views/Shared/Error.aspx
I'm making use of the new .NET 4.0 Caching namespace: System.Runtime.Caching.Now, i'm just doing some prototype/fiddling with the new API, in order to work out the best fit for the real app.In line with that, i'm trying to create a page (ASP.NET MVC) that basically dumps out everything in the cache, particularly the following info:
