I have the following scenario:
I publish a page which contains multiple binaries which is then received by an HTTP Receiver and Deployed using an in-process Deployer all hosted in IIS in a dedicated application pool running as the Local Service user.
The Page is stored in the Broker Database, and the binaries are published to the local file system using a path like "D:\Binaries\Preview".
The preview folder is shared to a domain user as a read only share at something like \machinename\PreviewBinaries so that the binaries can be displayed using the web application.
Nine time out of ten everything works fine, but occasionally publishing fails, and it seems to be because the binaries can not be overwritten due to them being locked by another process. I have used ProcessMon and other tools to try and establish what might be locking these files (to no avail). Sometimes I can manually delete the images, and then publishing works again. If I restart IIS on the server I can always delete the files and publish.
Does anyone have any suggestions on what processes could be locking these images? Has anyone seen this issue before? Could there be any issues that I am publishing to a share? Or could SiteEdit 2009 possibly be locking these files as it only seems to occur on our preview server and live (no SiteEdit) seems fine.
Thanks in advance
If you're on Windows 2008, you can try and delete the file from disk. It will then tell you what process has locked the file. But given that restarting IIS unlocks the file, it seems quite likely that it is IIS that keeps a lock on them.
I don't see how SiteEdit 2009 could cause a lock on these files. Given that you can have your preview server on another box, SiteEdit only talks to that server through HTTP. It never accesses the files on the preview server directly and not even through a CD API. Just regular requests to your web server, just like a visitor would.
Again, not a direct answer but I wanted to share this anyway:
I've seen a similar situation where I published Pages to the Broker Database and Binaries to the file system. When I changed the Identity of the Application Pool to Network Service this problem disappeared, and I haven't looked into it further.
OK, well it seems the offending code was in the Presentation Framework we are using. The framework used Response.TransmitFile(binaryPath) to asynchronously transmit the binaries to the clients. It seems that this puts a temporary lock handle on the binaries (even when they are on a read only share).
We have removed this line of code, and modified the application to server binaries in another way (we now rewrite the path so that IIS can transmit the files directly). This seems to have solved the issue, and improved site performance.
Thanks for all your suggestions, it helped me rule out all the things that were not causing the issue, so I was able to find the root cause.
Are there any Anti-virus or indexing services running. These tend to take very short-lived locks at just the moment you don't want them to. Particularly with Anti-virus, this is typically just as one process relinquishes its lock and just before your other process tries to take one. If this is the issue, then setting up some exclusion directories should help.
I see you have used Process Monitor, but have you tried Sysinternals Process Explorer? "Find->Find Handle or Dll" is pretty useful for this kind of thing. Or if you prefer a command line tool, Sysinternals aslo make handle.exe, which dumps everything out for you.
Related
A couple of questions:
1) How can I update a Classic ASP website/page without interrupting service (users getting an error or service unavailable message) or shutting the website down temporarily?
2) When updating/restoring a MSSQL DB via SQL Server Management Studio, will the website users get an error message?
Thanks in advance.
A smart practice is to use at least one separate development environment with the same setup as your production environment and debug all changes there to ensure that they work. Once your entire site is running and tested on the other, identical environment to your production environment, you should be able to simply move the files and they should work in production. This model being effective is dependent on actually being able to maintain environments as close to identical to each other as possible.
When updating/restoring a MSSQL DB
Be careful with your terminology; UPDATE and RESTORE are two very different commands.
If the database is locked by the changes being made, then it will be inaccessible to users and may cause error messages depending on your IIS and code setup. Scheduling a maintenance period and blocking user access to any pages that access the database is will help avoid messy errors and revealing any information about your infrastructure while the changes are being made.
It seems like you might want to do some basic research on development and databases both in order to make sure you understand what you're doing and can cover all of your bases. Looking up commands like RESTORE and UPDATE and using them correctly is crucial.
For example, when you rewrite one or more of your website files
via FTP, in that very moment when rewriting is taking place,
users will get a 500 Service Unavailable error. How can I avoid this?
This really shouldn't happen, although you could upload the files to a different folder, avoiding any delay there, and sync the files with a diff tool such as Winmerge (also helping you keep track of changes and revert quickly) when done uploading.
We have an asp.net web site that is deployed on several IIS servers. The site is compile-on-demand as opposed to a pre-compiled web application.
Normally deployments go fine but every now and again we get a 401 for one of the deployed pages on one of the servers. There is nothing special about which page or which server apart from the fact that it's generally the higher traffic pages that it happens to.
The only way to rectify this is to deploy the same page again.
The ACLs look fine on the files themselves so the thought is that there is a file locking issue in the Temporary ASP.NET Files folder when the specific page is re-compiled.
Has anyone seen this before or have any suggestions how to avoid this?
Note: This only seems to have happened since we moved to .net 4.0
As far as I can tell we are getting a 401.3 Denied by resource ACL http://support.microsoft.com/kb/907273
But I have not been able to confirm this.
Those kinds of locks have always been a problem with live site deployment. The reason it's hard to replicate is because you are mid-request when copying/compiling on the server, and this ends up confusing IIS.
We operate a Blue/Green deployment strategy on a 4 tier architecture which has a web site over 4 servers at the top tier. Due to the complexity the architecture introduced for deployments, we needed a way to deploy without disturbing any traffic to the "live" site. Following Fowler's advice, but not quite in the same way, we came up with a solution that means we have 2 sites on each server (a blue and a green, or in our case site A and site B). The live site has the appropriate host header, and once we have deployed and tested to the non-live site, we then flip the headers of the 2 sites so that what was once live is now the non-live site, and vice-versa. The effect is, a robust deployment that can be done in hours and with the highest level of confidence.
This of course complicates your configuration and deployment slightly, but it's worth the effort. I guess it kind of goes without saying that you want to script both the deployment, and the host header swapping.
When i deploy to a server i bring the site down for a minute (or however long the deployment takes) - it may be down anyway during this time as pages are recompiled so it is not too much of a hit. You can do this by creating a file in the root of the app called app_offline.aspx (it needs at least 512 characters in length) once that file is created you can then copy the resources ot the folder knowing there will not be any locking issues. then when the copy is complete remove the app_offline file.
For those that want to achieve a .net website deployment without these issues, one option is to copy the new website files into a new folder first ( not the active website). Then you just change IIS to point to the new folder after all copying is complete.
This can be done in a single server environment for those of us on more limited resources without multiple servers per website.
At my work we write power shell scripts to deploy websites. The powers shell script creates a new directory with a time stamp, copies the new deployment there, then tells IIS to point the website to the new directory (leaving the old directories "orphaned" but still there).
If we really messed something up, we can simply revert by pointing IIS back at the previous date stamp directory. Otherwise if everything tests ok, we can delete the old folder.
This technique works well because you are never writing over a file while it is in use. However it still results in zero downtime. The only effect you will see is the normal .net "warm up" that occurs anytime you change the code behinds or assemblies.
I had several answers suggesting a new environment to deploy. This is something we have been considering for the long term but it's hard to justify the extra work when we regularly deploy only one or two files without a problem. I was really more interested in finding out what is actually happening and why.
In terms of a workaround, and this might sound obvious after the fact, a simple app_pool recycle solves the permissions issue and is much easier than testing for the issue and redeploying the file until the problem goes away.
We are getting frequent errors in the Event Viewer, Application section. The source is ASP.NET 4.0.30319.0, category is File Monitoring. The Event ID is 1185. Text says "Failed to start monitoring changes to "file-path-here" because the network BIOS command limit has been reached." Then there is a reference to Microsoft knowledge base article 810886.
The question is: what process or service is doing this file monitoring, and why? We are not aware of how this is running or how it started. The monitoring seems to look at various folders on our web site, some are .NET folders, some are not.
We are looking for explanation of what is causing this monitoring; then we will try to address the errors.
When a asp.net starts to run a site, is monitoring one basic file (on the root of the web site), this is the app_offline.htm and if he finds it is stop the program showing only this file.
If find that other file change is recompile them if this is nessesary, but still showing the app_offline.htm if exist and not run the site.
Ones you remove the app_offline.htm the web pages starts run again, but asp.net still monitoring for this file - if exist or not.
So this is the monitoring of the asp.net you search for. Of course this is the default behaviour of asp.net. If you have install other software or something else have been on computer and fill it with monitoring, this is something different. I assume that you have too many web sites asp.net on the same server ? 500 or more ? if not then maybe you start searching for other software that make this monitoring of your files.
Analysis
How to find your self whats happends, download the Handle from sysinternals and run it, make the out on a text file like handle.exe >> result.txt and look the results.
http://technet.microsoft.com/en-us/sysinternals/bb896655
Look there if any suspicious program have open huge amount of files and what program is that. Monitoring files and directories are shown like
runningprogram.exe pid: 1352 ServerName\User
AC: File (RW-) D:\Monitor1
E8: File (RW-) D:\Monitor2
F8: File (RW-) D:\Monitor3
408: File (RWD) D:\InetPub\MySite
More
I check on my servers and found that a blog creation program have add a monitoring on every directory blog - I do not know why - but this is the way they have made it, to monitoring every blog for some reason, maybe you have something similar that creates a lot of file/directory monitoring for some reason.
The monitoring is being done by IIS (or the aspnet process with IIS6). It's watching for changes to files so that the site can be recompiled when needed.
You didn't mention your environment, but I used to run into this problem frequently when trying to run websites from Windows XP when the sites were located on a remote file share. I think the error comes up due to a limitation in CIFS (the network stack for file shares). Windows Server didn't seem to have the same limitations.
So, a few possible fixes:
Switch to Windows Server (or possibly Win 7)
Switch to a Web Application (doesn't allow recompiles)
Move your files from a remote share to a local drive
Currently, when we have updates that we want to roll out to our live website, we run a .bat file that copies the entire folder structure up from our development environment to the live servers. This replaces the folder that the virtual directory points to with the new updated new one. This is done while the server and IIS are live and obviously while users are accessing the website.
We occasionally get errors that are caused by files or folders becoming 'locked' immediately after an update, and usually the only option is to stop IIS or reboot the server. We're guessing that this 'locking' is caused by the .bat file attempting to overwrite a file while it is in use by IIS.
Has anybody else experienced this and/or what would you recommend as the best way to update a live website on the fly with minimal downtime (i.e. almost no downtime at all).
Thanks.
Reposted as an answer rather than a comment, was having a stupid moment there!
If you can't have downtime, then the best thing is to have another copy of the server running that you can divert users to when you want to update the primary. Then you divert your users back to the primary after the update.
You can use the State Server sitting on another server to ensure that any session state is maintained when they switch from one to the other.
We are currently experimenting with Microsoft's Web Farm Framework, which seems to do this kind of thing very well.
Our setup involves a front end server, a primary and secondary web server, and a separate state server. WFF keeps copies of web apps in sync on both machines and state server ensures that if a user switches servers between requests (or their current server goes offline), that they should not notice the change.
To upgrade the primary, take it out of load-balancing which will divert all of it's requests to the secondary server. Do your upgrade, put it back in to rotation, and then repeat the process with the second server.
Buy a second webserver, buy a load balancer. Mark 1 server offline, upgrade, bring back online. Mark server 2 offline, upgrade, bring back online.
Another option is to have two folders that you alternate between for every deployment, like in blue-green deployment. So when the blue folder is currently live, you deploy the new codebase to the green folder and then when it is ready you change the IIS settings to point to the green folder.
I am having an ongoing situation where when I try to upload files via FTP that I get an error that the DLL is locked and currently cannot be overwritten. This is only DLLs that this is happeneing to and normal files (aspx, ascx, css etc) can be overwritten fine.
Our Setup
We have 2 webservers that are kept in sync via DFS which is managed from a separate server.
They all belong to the same domain.
They all do internal transfers on 1GB ethernet cards on a private network.
Our Problem
We develop in VS2010 and build the site we are working on, when it gets to a level where it needs to be checked on the server then its hit and miss whether we can overwrite the DLL's in the BIN folder. I only started experiencing this issue when we migrated from our old, unreliable sync tool to the super Windows 2008 DFS tool. Its a good tool and works well but this is the only thing I can think thats causing this issue.
To actually overwrite the file I need to take down all the sites that are using this base level code which then releases the lock on the DLL and I can upload it.
I come today in desperation, I am fed up and bored of having to take sites down every so often just so I can upload a DLL.
It is my understanding that ASP.Net caches the DLLs into a temporary folder, so god knows why the lock remains on the DLL itself in the BIN folder.
The weird thing is, this does not always happen, it can go for weeks and not do it. Or like recently, its around every day I have to take the IIS sites down so I can upload.
As of writing this, I cannot upload to FTP even though I have taken the sites down.
Could anyone please shed any light on this so I can actually just get on with my work rather than messing with this every ten mins. It's bad enough that VS2010 is so unstable and visual source safe only checks in what it wants without this being an issue as well!
Trying using UnLocker to free the handles.