How To Manage Cache Stored On The Web Server When Using 3 Web Servers
Jul 23, 2010
We are working on a web application that is distributed across 3 load-balanced web servers. A lot of the data we retreive via NHibernate is stored in System.Web.Caching.Cache.
System.Web.Caching.Cache does a lot to increase the responsiveness of an application, but there are a few issues that we don't exactly know how to resolve, such as
when a user requests data on server1 that data is cached on server1, but for their next request, the load balancer might direct them to server2. That data they requested on server1 is no longer available, and server2 will have to request it from the database again. If the user does something on server1 to invalidate the cached data, the cache is flushed on server1. However the original cache is still available on server2 & server3, so when the user submits a subsequent request and they're directed to either of the other servers, they are going to be presented with invalid data.We have applications that update data (such as performance data) on a regular basis. When the performance data is updated we want to flush this from the cache so when a user requests the data again, they're presented with the latest data. How can we get these applications to flush the cache on 3 web servers?
What are the best ways to resolve these issues?
Should we have cache stored on a separate server such as we could to for HttpContext.Session with a SessionState server?
Is there a way for us to set a Cache Dependency on the Cache in the other 2 servers?
Is it possible for us to implement a Cache Dependency on the actual database tables or rows? When these change the cache is flushed? -- or could we set up a database trigger to flush the cache somehow?
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?
We have a CMS system and in the production mode a number of servers only have read-only access to the content (with a few exceptions) and the editors for the site work on the content on servers behind it (which are not available to the public).
We're caching the content quite a long time on the front servers, but sometimes we want the content the editors publish to be available for visitors instantly. What is best practice for invalidating the cache in those cases?
I need to enable caching in my asp.net application, but I do not want to use the webserver's memory for holding cache objects. If I add the page directive for output caching will the page be stored in the asp.net cache object?
I have a server control that I developed which generates navigation based on a third party CMS API. Currently I am caching this control using the PartialCaching attribute. The CMS uses cache key dependencies to invalidate the cache when a user makes an edit, however in the case of my server control it does not get invalidated and the updated navigation will not show up until the cache expiration set by the PartialCaching attribute.Here is my two part question:
What is the proper way to programmatically cache a server control, without using the PartialCaching attribute, and adding a cache key dependency?
Is it possible to continue to use the PartialCaching attribute and add a cache key dependency?
I'm looking for a steer on how to go about running stored procs efficiently.
I have a current requirement to populate a control, so I have all the specific data i.e the parameter value I need to pass and the control I want to populate, plus generic data such as SqlConnection etc.
I'd like to be able to call, say, "MyStoredProc". MyStoredProc would contain all the necessary information to run the proc, but then pass onto a method, say, GetSpData, which contained all the generic stuff about running stored procs.
Then when setting up MyStoredProc2 I could do without repeating a lot of the original function
Im I barking up the wrong tree or is there an efficient way of managing this kind of situation.
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?
I am trying to set up my web site on a stand alone server using Windows Server 2003 with IIS 6 which will access SQL server database (2008) on windows 2008 R2 server (also not in the domain) I am using form authentication and I have configured a custom identity account in IIS6. The local account is on both servers with same password and I have registered the account using aspnet_regiis.exe -ga The application pool in my iis6 has the custom local account set as the identity and my web.config file has the appropriate tags in the system.web element <identity impersonate="true" />
The problem is the local account does not seem to get passed to the sql server. Right now my iis settings are anonymous access (using the local acct vs isr) and no authentication specified under that - I did try Integrated and basic but it prompts for the username and password which I do not want. One article I read stated this: windows authentication does not support delegation (passing credentials from one server to another) and is limited to the one hop rule, only a primary token can be passed to a second server. windows authentication on iis (all versions) gives the thread a secondary(impersonation) token which can not be used to access any network resouce
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?
If i wanted to communucate from two application server to one SqlServer,what are the drawbacks if i implemented a senario like this, at the same time wat are the advantages.
I have a mdf database in my computer. And I have sql management studio 2005 installed. I would like to mange the mdf database with this program and I do not know how.
I am developing a web application and need to continue development while travelling. I have SQL Server express installed on my desktop and my laptop but (obviously) the server names differ on each machine. eg "MydesktopSQLSERVEREXPRESS" and "MyLaptopSQLSERVEREXPRESS".
Anyone know of a way I can use a generic connection string or something so I can simply transfer the solution file from my desktop to my laptop and continue development on the road?
I'm hosting a few .net sites, some collapse with this error on an almost daily basis. I've moved the sites between servers, but sites on all the servers seem to be affected, so it is not just a bad install.This problem is acknowledged by MS and they have a fix here:http://support.microsoft.com/kb/975410But they don't provide the fix they talk about.Does anyone have any way to resolve this that does not need Microsoft (since Microsoft clearly aren't bothered to fix it)?
I'm somewhat new to aps.net and am not sure how to come up with a technique for acheiving the following results.I think a GridView might do the trick, but am unsure how to manage the sorting/grouping aspect. Here's what I need to do:
I have created stored procedure and student database and also asp.net application for asp.net page but it could not found stored procedure what is the mistake actually I don't no
The question: Is it possible to configure multiple SMTP servers or update the SMTP object server information at runtime?
Description of problem: The site I'm working on has a few pages which send emails. Our site is using Gmail so even though it's a custom domain our email is sent out though Gmail SMTP servers.
Some emails come from the system and some emails come from users in certain groups. I have an SMTP server configured with the admin email for the system e.g. admin@mysite.com This works fine and when I get the email it shows from admin@mysite.comOne of our user groups let's call it "groupA" has an email configured on our domain i.e. groupA@mysite.com When I send the email and specify a from address for the MailMessage object as groupA@mysite.com it still shows up in my outlook as coming from admin@mysite.com I did a little further testing and if I specify both the from address and the ReplyTo as groupA@mysite.com it will show as From=admin@mysite.com but when I choose reply in outlook it shows groupA@mysite.com My best guess is that Gmail is overwriting the From address with the SMTP user to prevent email spoofing.
I found this: http://www.systemnetmail.com/faq/4.1.aspx but it won't work for me since group A, B, and C all need to send emails from the same page.
We have a wfc layer that wraps the business classes and database access and use a client that lives on the database layer. Amongst our group we are attempting to form standards. Some want to have the client call the web method and pass the page they are requesting and the page size. Pass that to the database and then page in SQL Server use RowNum.Some want to cache the full list of objects in http cache on the service tier and page in memory. They concern here is memory use on the server.
Which would be best for a medium number of users with potentially large number of records to manage (say 30K) Is it better to cache them all in memory and work from there or page at the database as the application scales?
