what is the cleanest way to clear cache on ColdFusion 8 server
do i don't have problems with old Stubs when i create
web service client?
ty very much for your response
Adobe Documentation for cfInvoke
Specifically, look at the refreshWSDL argument.
It's not something I'd call every time, since it adds a good bit of overhead to your WS instatniation. However, having a scheduled task to clear and recreate a stub that may change, or using it during development of the webservice might be beneficial.
Related
I don't mean using coherence. I am looking for a way to avoid hitting my application to look something up that I've already looked up. When the client performs a GET on a resource I want it to hit the application the first time only and after that return a cached copy.
I think I can do this with apache and mod_mem_cache, but I was hoping there was a weblogic built in solution that I'm just not able to find.
Thanks.
I don't believe there's inbuilt features to do that across the entire app server, but if you want to do it programmatically, perhaps CacheFilter might work.
I'm using the DataCache API that is part of the Windows Azure Caching Nuget package and I was wondering why there isn't a way to make non-blocking calls against the constituent methods. Am I missing something? I understand that the latencies on these calls are going to be low but it's still a network call - if you're not using the local cache setting.
Suggestions, thoughts?
Thanks!
If you want to understand why the library is this way then I'd have a read of this article on exposing async wrappers for synchronous methods. TL:DR; There are two distinct reasons for wanting to do async, scalability and responsiveness. You really only need an async version of a method if it will help with the former, the latter you can leave to the consumers of your API because it's easy.
EDIT: It seems people have missed my intent in this answer, so I'll try adding some more clarification.
Yes, the cache client may make a network call and MS are trying to get everyone to make all their network calls in a non-blocking manner so that apps remain responsive. However this is a cache and it is designed to be very fast. If you make a request to the cache and the item is not in local cache (according to Scott Guthrie) the response should take 1ms. Given that the response is so quick (and if you are using local cache it will be even quicker), they would have likely added more overhead by creating tasks to run it in the background than they would have gained.
I'm writing a web application using ASP .NET MVC 3. I want to use the MemoryCache object but I'm worried about it causing issues with load balanced web servers. When I google for it looks like that problem is solved on the server ie using AppFabric. If a company has load balanced servers is it on them to make sure they have AppFabric or something similar running? or is there anything I can or should do as a developer for this?
First of all, for ASP.NET you should look at the ASP.NET Cache instead of MemoryCache. MemoryCache is a generic caching API that was introduced in .NET 4.0 to provide an equivalent of the ASP.NET Cache in non-web applications.
You're correct to say that AppFabric resolves the issue of multiple servers having their own instances of cached data, in that it provides a single logical cache accessible from all your web servers. Before you leap on it as the solution to your problem, there's a couple of things to consider:
It does not ship as part of Windows Server - it is, as you say, on
you to install it on your servers if you want to use it. When
AppFabric was released, there was a suggestion that it would ship as
part of the next release of Windows Server, but I haven't seen
anything about Windows Server 2012 that confirms that to be the case.
You need extra servers for it, or at least you're advised to have
them. Microsoft's recommendation for AppFabric is that you run it on
dedicated servers. Which means that whilst AppFabric itself is a free
download, you may be incurring additional Windows Server licence
costs. Speaking of which...
You might need Enterprise Edition licences. If you want to use the
High Availability features of AppFabric, you can only do this with
servers running Enterprise Edition, which is a more expensive licence
than Standard Edition.
You might not need it after all. Some of this will depend on your application and why you want to use a shared caching layer. If your concern is that caches on multiple servers could get out of sync with the database (or indeed each other), some judicious use of SqlCacheDependency objects might get you past the issue.
This CodeProject article Implementing Local MemoryCache Invalidation with Redis suggests an approach for handling the scenario you describe.
You didn't mention the flavor of load balancing that you are using: "sticky" or "stateless". By far the easiest solution is to use sticky sessions.
If you want to use local memory caches and stateless load balancing, you can end up with race conditions the cross-server invalidation messages arrive late. This can be particularly problematic if you use the Post-Redirect-Get pattern so common in ASP.Net MVC. This can be overcome by using cookies to supplement the cache invalidation broadcasts. I detail this in a blog post here.
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.
We are having issues with IIS6 slowdowns when using more than 1.2GB of RAM in a single worker and would like to use more workers. However looks like ASP sessions are made by worker and when the browser accesses some page through another worker it losts the ASP session.
Do you have some tips on how to solve this problem?
We are considering to use some other way to manage session separately from IIS (not database, maybe memcache?). Do you recomend something?
Note.: The application is full of legacy code and we need to avoid big changes in code.
I've had a similar scenario with a legacy app in the past and ended up writing a simple component to serialize the ASP Session object to & from the database.
I have written a central session store for classic ASP in the past using Redis as a storage layer. The code is freely downloadable at https://gitlab.com/erik4/classic-asp-book-examples
It uses a redis ActiveX/COM component, available here.
Using a central session store using Redis will allow you to use as many worker processes as needed.
If you want a detailed explanation of the implemantation, there's an accompanying book, but the example code should work out of the box.