I've searched the stack but didn't find an answer that helps my situation. We have two web apps on different sets of servers. Both do Active Directory authentication using the exact same standard code. And the target LDAP server is the same in all cases.
Using ctx As New PrincipalContext(ContextType.Domain) If ctx.ValidateCredentials(un_in, pw_in) Then...
However, in one case those two lines execute instantaneously, and the other there's a consistent 21 second delay (there's logging directly before and after these lines). And for the slow one, it's slow regardless of environment, i.e. on our dev/test/stage/prod servers.
We're at a loss as to what to check. Basic network connectivity checks show no delays, and plus this happens on 4 different servers. Connectivity to the domain controller, which as I understand it is how IIS would know which LDAP server to check possibly?. Thoughts?
In case anyone comes across this. The solution was to add a parameter,ContextOptions.Negotiate, to the code:
Using ctx As New PrincipalContext(ContextType.Domain)
If ctx.ValidateCredentials(un_in, pw_in, **ContextOptions.Negotiate**) Then
Something in the network environment changed that no one could identify. But adding this param removed the delay.
Related
I've built an application that does a lot of processing of user data (they can load in their data, map the variables, run analyses, review a dashboard, and download the results/report). It's a pretty heavy application, and I'm running into an issue that I'm not sure how to best solve for.
The problem is that sometimes the session will unexpectedly disconnect from the psql database. This causes problems because just about every corner of the application depends on retrieving or sending information. Basically, the app doesn't work at all without the connection. What's even worse, is the UI doesn't really inform the user of the problem, it kindof sits all lazy-like.
The application exists on an EC2 instance within a docker container, served through an HTTPS proxy (Caddy) to the public via a registered domain name. Each new session searches for a global pool connection, and if one does not exist, it creates one, then checks out a local connection and passes that into all the downstream modules.
I'm wondering how others have addressed this problem. Should I,
use a global pool, then check out a single connection and test for a severed connection at the start of each function? This is my current (unfinished) approach and seems not great.
search for a pool connection and checkout a connection at the start of each function, then return at the end? This would take a bit of time to implement (and test), but seems like a reasonable solution.
check for a connection every minute and if one doesn't exist, create one. I'm guessing this would need to happen in each module independently.
Any direction will be greatly appreciated.
Thanks,
I'm having a problem on my application. It's an ASP.NET application set up on IIS 10.
Let's say one system page is accessible by 20 users. The page works perfectly (no logical error on coding) every action works and delivers the expected values requested by users.
The problem is, whenever someone requests let's say, the same method as another user at the same time (with different values), the application randomly throws an error to one of these users. We've checked for log errors and all of them are system index out of range errors, which never happened in our QA server.
I randomly thought about testing that exact scenario (adding different values with another user at the same time) and I saw it happen for the first time on the QA server. We've managed to reproduce the error multiple times.
While we don't discard the possibility that this could be another issue, did anyone else experience something like that?
The question is: Can IIS manage the same requests, multiple times at the same time within the same instance without any trouble? Does it run on multiple threads or something like that?
Thanks for taking time for answering this, if you need any info
Stick to your question
Yes IIS can handle very easily (more efficient as well)
As per your application concern without code I can't point out but you may consider few points
Is it happening for just one method or for all. If it happening for just one that means you are trying to use such a code that may used by another user
You are using such a array or list which is null or empty for other user. Like a user has First Name Followed by Last Name But other user don't fill last name and you are using that last name property
May be u r using HttpContext and trying to use same as for different users
May be You are using types which are not Thread safe
So these can be possible cases but without code we can't assume.
About your problem, for multiple requests from different user, iis will create a thread in the application pool for each request. For multiple requests from the same user, it will only run in one thread and affect only the user's instance. Unless the instance or resource is a shared resource and your code does not perform any lock operations.
IIS, including most web servers, use threads to process requests, so multiple requests will be executed in parallel unless you place a lock. A web server usually has a minimum and a maximum number of work programs. These work programs are adjusted according to the CPU or memory of the current hardware. If resources are exhausted, new requests will be queued until new resources are available.
So what you need to do may be to modify the application code to take multi-threading and synchronization into consideration.
I'm searching for a way to change the way Meteor loads the Mongo database. Right now, I know I can set an environment variable when I launch Meteor (or export it), but I was hoping there was a way to do this in code. This way, I could dynamically connect to different instances based on conditions.
An example test case would be for the code to parse the url 'testxx.site.com' and then look up a URL based on the 'textxx' subdomain and then connect to that particular instance.
I've tried setting the process.env.MONGO_URL in the server code, but when things execute on the client, it's not picking up the new values.
Any help would be greatly appreciated.
Meteor connects to Mongo right when it starts (using this code), so any changes to process.env.MONGO_URL won't affect the database connection.
It sounds like you are trying to run one Meteor server on several domains and have it connect to several databases at the same time depending on the client's request. This might be possible with traditional server-side scripting languages, but it's not possible with Meteor because the server and database are pretty tightly tied together, and the server basically attaches to one main database when it starts up.
The *.meteor.com hosting is doing something similar to this right now, and in the future Meteor's Galaxy commercial product will allow you to do this - all by starting up separate Meteor servers per subdomain.
Hi, We are developing a multi-tenant application in Asp.Net with separate Database for each tenant, in which one of the requirement is to monitor the bandwidth usage for each tenant,
i have tried to search but not found much help on the topic,we want to monitor exactly how much bandwidth is being used for each tenant while each tenant can have its own top level domain or a sub domain or a combination of both.
so what are the available options, the ones which i can think of can be
IIS Log Monitoring means a separate application which will calculate the bandwidth for each tenant.
Log Each Request and Response for a tenant from within the application and then calculate the total bandwidth usage based on that.
Use some third part components if available
So what do you think will be the best approach, also if there is any other way to do this.
Ok, here is an idea (that I have not test, leave that to you)
On global.asax
use one of this function (find the one that have a valid final size)
Application_PostRequestHandlerExecute
Application_ReleaseRequestState
and get the size that you have send with
Response.Filter.Length
No need to metion, that you get the filename of the call using the
HttpContext.Current.Request.Path
This functions called with every single request, so you can get your size and you do the rest.
Here must note, that you need first to test this idea to see if its work, and maybe improve it, and have in mine that if you have compress the pages on server the length is not the correct and maybe you need to compress it on Global.asax to have the actually lenght.
Hope this help.
Well, since the IIS logs already contain the request size and response size, it doesn't seem like too much trouble to develop a small tool to parse them and calculate the total per day/week/month/whatever.
Trying to segment traffic based on host is difficult in my experience. Instead, if you give each tenant their own IP(s) for the applications you should be able to find programs that will monitor bandwidth based on IP.
ADDITION Is the structure of IIS that you have one website to rule them all for all tenants and on login the system forks to the proper database? If so, this may create problems with respect to versioning in that all tenant's sites will all have to have exactly the same schema and would all need to be updated simultaneously when you update the application such that a schema change is required.
Another structure, which sounds like what you may have, is that each tenant has their own website like so:
tenant1_site/appvirtualdir
tenant2_site/appvirtualdir
...
Where the appvirtualdir points to the same physical path for all tenant's sites. When all clients have the same application version, they are all using literally the same code. If you have this scenario and some sort of authentication, then you will need one IP per tenant anyway because of SSL. SSL will only bind to IP and port unlike non-SSL which will bind to IP, port and host. If that were the case, then monitoring traffic based on IP will still be simpler and more accurate as it could be done at the router or via a network monitor.
I have a web service that is on an internal server. It can be called from any website on our network.
More and more developers are starting to use it. Current probably 20+ pages use this service, and the number is growing fast. I can see a year from now, someone asking what pages are using this service and what methods.
I would like to log the url of the pages that use my web service as the request come in.
It would also be nice to know the method they are calling.I need to do something in such a way, that it does not affect the client web sites.My first thought was that I could write some code in the global.asax.
I have added some code to the Application_BeginRequest to log the request object details, but there does not appear to be anything about the requesting url.
What am I missing? Should I be looking at a different object?
Thanks.
Without disrupting existing users this is going to be difficult. The httpContect.Current.RequestUrl will just return the URL used to call your web service, not which web page called it.
The closest you can do without disrupting existing apps and forcing developers to change them is to grab the HttpContext.Current.Request.UserHostAddress, so you can at least get the IP of the machine calling your service.
Beyond this, what you might want to consider is adding a parameter to your functions for "CallingApp" and then log that in your code. That's pretty much what we did once re realized that we needed to know which apps are calling our service. We actually have an application monitoring service that uses a GUID for every new app we develop, and we pass that GUID to any web service. It[s extra work but to us it was critical because it allows us to know which apps will be affected when we need to perform updates or take the app server down for maintenance.
Edit - added
As a side note, at the point we realized we needed to track this, we had already been using web services for about a year. When faced with the same problem, we created a new set of web services, and included the extra field for the calling app in all of the new services, and then slowly went back and changed the older programs to point to the new services.
IN retrospect, we wish we had known we would need to do this up front because it created a lot of extra work. I'm guessing you'll be facing something similar if you really want to know exactly who is calling your services.
The only thing you can probably retrieve from the consumer is the IP address without changing your interface.
If you can change this you could do this e.g. by adding authentication and logging who is calling what, or by having some simple "token" principle.
However both methods require you to change the interface and therefore break backwards compatibility - which you should never do.
By always ensuring both back and forward compatibility you should not need to know exactly who is calling your service, but only that it is actually used.
#David Stratton
Thanks for your help. I think your suggestions were great. I accually did something very different, after your answer gave me some new ideas.
I should have mentioned that I was generating the web proxy that most of my users were using to make calls against my web service. My client in general do NOT use the proxy that Visual Studio creates.
Here is what did:
I generated my web proxy client again, and added calls to log the httpcontext of the client before every call. Because the proxy is running on the client, he had access to everything I needed. That allowed me to record everything about the client and the specific call they were making. I realize this would not work for most cases. But all of my clients are internal web sites.
It also had the advantage in that the clients did not have to modify their code at all. I just gave them all a new DLL. Problem solved. I get all the tracking data I want, and they did not have to modify their code.
I was stuck trying to solve the problem from the web service's point of view.
I realize that there is still a whole in this implementation, because someone does not have to use my client proxy to call my service. I guess I could force that at some point in the future. For now, they could let Visual Studio genereate a web proxy for my service. However, if they do that I guess I don't care. That is not the recommened way to call my service. I think the only one doing that is an ASP.NET 1.1 web site. When they upgrade, they will probably switch to my generated proxy.
Without implementing some sort of authentication, there isn't a guraenteeted way of knowing exactly who is calling your service - web metrics are the only way you can gauge what volume of traffic is hitting your service.
I'm sure you already know this but the whole point of a web service isn't to know or care who is calling it.
I have successfully used ...
Dim strReferrer As String = HttpContext.Current.Request.UrlReferrer.AbsoluteUri
to get the calling page that called my WEB API 2 Web Service.