I have some doubts about Application pool
Multiple application in One Application pool running under the only worker process by default
Multiple application in One Application pool We can assign different worker processes for different applications.
Above is my Understanding about Application pool and worker process
I want to clarity in these concepts, If anybody have please explain me.
Thanks,
Dnyaneshwar
I think your understanding is almost correct.
When you create a new web site in IIS it creates an application pool
for you with the same name as the web site, so in fact the default is
every web app gets its own application pool.
You can set single application pool to host multiple IIS web sites. The
effect is that all the sites sharing the app pool are hosted in the
same exe. If you restart/recycle this app pool, it will restart all the web
sites it is being used in.
You can isolate different web sites by assigning different
application pools to each web app (as mentioned IIS does this by default)
One application pool has a single worker process (w3wp.exe) by
default but but you can increase this.
Related
I have main website hosted in my IIS and under that I have multiple applications (another web apps) that run on a separate application pool. I know that if you will change some files of site that is hosted in IIS it will result into application pool recycling. However I am not sure what will happen in my scenario, from one hand they have different app pools, but from another hand application is hosted under main website.
Is it possible to deploy application that is hosted under web site without disrupting main site operation?
Thanks in advance.
No it wont. If you have your main site and applications running under different application pool, you should be fine.
Application Domains and application pool ensure isolation with respect to applications on IIS. Changes made to application will cause specific application domain to refresh and will not have an impact on other applications.
We've recently migrated our site from Azure Cloud Services to use Web Apps.
Previously we had one main website application, which has a virtual application at /forums - in cloud services we configured this to use a separate app pool to the main website.
Whilst we've had no issues adding a virtual directory and deploying to it, we seem to be unable to configure a separate app pool, is there anyway to achieve this?
Here is a description on the Azure site, Migrate an enterprise web app to Azure App Service
Application Pools – In Web Apps, each site and its child applications run in the same application pool. If your site has multiple child applications utilizing multiple application pools, consolidate them to a single application pool with common settings or migrate each application to a separate web app.
So it seems that currently, we cannot achieve this.
If Azure App Service plans are virtual machines dedicated to the Web, API, Logic, and Mobile apps defined within them, does that mean that a web app in an app service plan is an instance of a virtual web server in IIS on that virtual machine?
Assuming this is the case and that each virtual web site gets it's own application pool, is there an Azure scaling strategy or scenario where more than one worker process in that app pool will run, creating a web garden? My understanding of web app scale out is that it results in additional VMs being allocated and not additional worker processes.
The scaling strategy will depend upon the pricing tier you have opted for.
Basically each Service Plan will contain a collection of Web, API, Logic, Mobile apps. These will form a web garden within the Service Plan server you choose.
If you initially choose a single B1 Basic Service Plan, you will get a single virtual machine with all of your applications running on that. As the load on that server increases, you can scale it up to larger servers, but it will still be running on a single server.
If you then choose to create a second instance (and a 3rd, 4th, 5th...) that second server will be a replica of the first server, with the load being balanced between the two. (3,4...)
While I've not seen documentation for this, I would imagine that each Web, API, etc app is run under its own application pool / worker process, and scale out is simply duplicated instances.
I'm not sure what a Virtual Server is, but each app runs in its own dedicated application pool and w3wp.exe process. There is only a single w3wp.exe process per application pool, so no web gardens.
Is there a specific reason you think you need these to scale your apps? In most cases, using web gardens is the wrong way to scale, as adding more processes can cause unnecessary overhead (amongst other problems - you can find some useful resources on the web). You almost always want to prefer threads over processes for improving concurrency. If you're running out of physical resources (CPU, memory, etc), then the correct way to scale is to add additional VMs.
I just read something that said it's much better to use integrated security here on SO, so I've switched all my connection strings over.
The error I get is "Login failed for user 'IIS APPPOOL\DefaultAppPool'."
Before I go ahead and grant this user permission, I wanted to ensure that it was the correct thing to do and I wasn't inadvertently opening the floodgates of hacker hell.
Should I grant this app pool permission to access my SQL or should I create a new app pool?
I'm writing WCF services in .NET 4.5
Do you have other sites or services on the server that use this app pool and could potentially provide a security risk for database access? If yes, create a new app pool. Do you have another site that might cause the app pool process to crash, or might have a memory leak (thus affecting other sites in the same app pool)? If yes, create a new app pool.
Other than slightly more memory usage, app pool isolation really doesn't have any serious downsides. Microsoft "generally" recommends it (although this article is about SharePoint setup, the app pool / database access concept is the same):
You need to establish which Application Pool in IIS is going to be used by the IIS Web Site. Application Pools in IIS access resources on behalf of the Web Site using an account identity that you specify. This Application Pool will be used by the web application to access its content database. Generally, you’ll want to create a new one to keep it separate from the existing Application Pools.
See this thread for some additional discussion of the pros and cons of separate app pools per site.
I am learning IIS. So when ever the application pool is created the id of that will be registered with HTTP.sys. So when the request come from client how it will found that request is belong to that particular id?
Then What is the use of Web Admin Services (WAS) ?
Obviously from IIS configuration (metabase or applicationHost.config) you can see a mapping for request path (such as /vdir1/file1.aspx) to an application pool. Such mappings are also loaded into http.sys, so that it can map incoming requests to the expected application pool.
WAS is a service that create/dispose w3wp.exe instances. It also reads IIS configuration to know how many application pools are there, and how to create worker processes based on the setting. BTW, its official name is Windows Process Activation Service.