Mark Williams

Using IIS. New to FTP. Can anyone please give me a steer as to how to programmatically add and configure virtual FTP directories in IIS via Delphi?

@Remy LebeauThanks for the detailed response. Are there any problems running an Indy FTP server alongside IIS? Also, do you know of any good sample FTP server projects anywhere?

I would like to shellexecute one app from another. Both apps require username and password. I would like to be able to pass the password securely from one app to the other. Obviously, command-line parameters are out and I would imaging a memory mapped file will also not be secure. Is there any relatively simple and secure way of achieving this.

Is it not possible to also password protect the folder? My intention is to maintain a record of the virtual folders in a database and require the user to signal continued use of the folder and as soon as there is a failure to do so the folder would be deleted. Is this the Overbyte stuff? I will have a look. So if I wanted to run IIS and ICS on the same server I would need a second static ip?

Thanks. I'll have a look at WMI. Which type library do you use? I've got a couple on my registered libraries.

Yes it's pretty easy to set up via IIS, but the security angle is precisely why I don't wish to do it this way. I want to check the user's credentials against database and then issue that user a one-off password for a single transaction and add a temporary ftp folder, which then gets removed as soon as the user has completed the transaction. There may be better ways of doing this. As I said I'm a FTP novice!

The default MaxConnections is set at 32 for TISAPIApplication. I have no idea how many people may be calling my dll at any given time. 32 seems to me to be too low a number. I have set it to 200. I cannot find any advice as to best policy on setting this value. The help file simply says to test the ActiveCount and InactiveCount and adjust accordingly. That is going to be a little difficult to test. I don't want to have exceptions flying off because of MaxConnection exceeded and likewise I don't want to degrade performance. If, for example, I set MaxConnection to 1000 I assume that will not of itself degrade performance and that there will only be issues when actual connections are that high, If that is right then it seems to me that slightly deteriorated performance is preferable to exceptions due to exceeding max connections. Or am I missing something?

Thanks. I'll look into this at some point. However, my ISAPI dll isn't really designed to do heavy lifting. Just user validation, configuration settings and downloading of smallish files. There is occasionally a need to upload/download largish files and this is something I am planning to move to FTP or maybe there is a better/faster solution?

I wouldn't have thought it was possible to do this, but when my kids sign in to my Netflix account from various locations I get an email from Netflix to let me know what country and region they have signed in from. Does anyone have any idea how Netflix gets this info?

Must be a European thing. As of last Friday it is now unlawful for me to get such jokes!

I'm not sure what you're referring to. Can't see anything on the page/website which helps.

I found an example of how to do it (although not tried it) here: https://www.example-code.com/delphiDll/geolocation_ip_address.asp

I'll give that a try and see how it pans out. I thought this was more or less what iis does with the dll.

Modern scanners on auto color detection mode seem to be very efficient in detecting whether a document is a text document and whether to scan it as monochrome even though the image contains some degree of color. It has to be more than a pixel by pixel analysis to analyse the extent of the color in any image. Does anyone have any idea how this is done or even better if they can point me o some example code? I have searched on Google and the only example I can find is written in Python and I have no idea how to adapt for Delphi (Python example).

Ok. Thanks. I'll have a look at that and report back if I can improve on what I have already got.

Scanlines is fast enough for my purposes even when it scans every pixel. I would be reluctant to rely on random sampling.

Thanks. I've sort of come up with something along those lines using Scanlines. It seems to be tolerably effective and sufficiently fast.

I have written an ISAPI DLL (Delphi 10.3) for IIS to carry out various functions (download/upload of documents, query tables etc). It was working fine until I started firing more than one request at a time then the DLL simply crashed and I had to restart WWW service. The DLL is being used to request smallish files (20-30KB) over a local network. These are being requested one at a time. If I make these requests the same time as one or two Head requests that all goes Kaput. I though it may be the TWebRequestHandler's maxConnections so I set that to 200. It made no difference. After a bit of digging around I noticed that the IIS ApplicationPool that I created for the DLL has a "Maximum Worker Processes" property and that this was set to 1. I have set this to 20 and now the DLL seems to be able to handle more than one concurrent request. However, I noticed from my DLL's log file that it was now creating a new instance of the DLL for every request. I had a dig around on the web and from the information I found I have come to the conclusion that Maximum Worker Processes is probably not what I need. It seems to be designed for long-running processes, which is not what my DLL is designed for. If not Maximum Worker Processes and increasing MaxConnections doesn't work how do I get my DLL to deal with concurrent requests.

Solved at last. The DLL was hanging due to the call to AddToLog in CloseServer due to the Log thread being terminated at the same time as the call. In the meantime, I had added a TFDMoniFlatFileClientLink component to provide a FireDAC trace to see what was happening with the FDManager as I thought that was causing the problem. Once I'd fixed the problem with the thread log, I still had issues. By a process of starting from scratch (as you suggested) and adding units/components as I went along, I eventually managed to narrow it down to the FlatFile component. Once I removed it, all was well. Must be a threading problem or some such. Many thanks for your help

I've been through all my code. As far as I can see, I am destroying everything I create in an action event within the same action event. I have tried calling the DefaultHandlerAction and nothing else. procedure TWebModule1.WebModule1DefaultHandlerAction(Sender: TObject; Request: TWebRequest; Response: TWebResponse; var Handled: Boolean); begin Handled:=true; try SetResponse(Response, 400, 'Bad Request', 'Default Handler - if you are getting this message it either means that your are providing the wrong PathInfo or the action has been deleted.'); except end; end; And SetResponse: Procedure SetResponse(var Response:TWebResponse; code:integer; statusText:String; debug:string=''); begin Response.StatusCode:=code; Response.ReasonString:=code.ToString+' '+StatusText; if debug<>'' then AddToLog('Response set: '+Response.StatusCode.ToString+' '+StatusText+' Debug Info: '+debug, leMinorError) else AddToLog('Response set: '+Response.StatusCode.ToString+' '+StatusText, leDevelopment); end; It still hangs on shutdown. So I tried removing my calls to StartServer and CloseServer. Edited my DefaulHandlerAction so it didn't call SetResponse. It just sets the statuscode to 400 and still a huge delay in shutdown. My project file now looks like this: library MWCWebServer; uses Winapi.ActiveX, System.Win.ComObj, System.SysUtils, Web.WebBroker, Web.Win.ISAPIApp, Web.Win.ISAPIThreadPool, WinAPI.Isapi2, WinAPI.Windows, System.SyncObjs, system.classes, WebModule in 'WebModule.pas' {WebModule1: TWebModule}; {$R *.res} exports GetExtensionVersion, HttpExtensionProc, TerminateExtension; begin CoInitFlags := COINIT_MULTITHREADED; Application.Initialize; Application.WebModuleClass := WebModuleClass; Application.MaxConnections:=200; //MaxConnection=32 by default; IsMultiThread:=true; Application.Run; end. I'm not creating anything over and above the webapplication itself and still it won't shut down properly.

Yes. I'm sure that freeing of FDManager is not the issue. Yes. Will do.

See post two up. I don't think the problem is anything to do with FDManager. The reason it was hanging at the point of freeing was due to the call to the threadlog and my freeing of the threadlog before the threaded call had been made. My CloseServer now executes fully and appears to free all resources its requested to free. There has to be something else I am missing. Something I am creating somewhere and not freeing. No idea what though! Checking now.

Terminate WWW via services. I can see my logfile is updated almost immediately with message "Server Closed" and then the progress bar from Services takes well over a minute from this point to complete the shutdown.

Further process of elimination. It was nothing to do with the call to free FDManager. It was the AddToLog calls that were causing the problem. These are threaded using the FThreadFileLog, which I free in the final part of CloseServer and before the threads called in CloseServer had terminated. I have changed these calls so that they are now not threaded and also as a double precaution added a check in ThreadFileLog's destroy event to make sure no threads are running before it is shut down. My CloseServer procedure now frees all the resources as expected, but the application pool is still taking an age to close down. There must be some resource I am creating and not freeing. I will check all my code and if I can pinpoint what it is I will update.

A good question! There is no need. Removed. But that's not the cause of the problem on shutdown. Any ideas why it would be hanging at this point?