I'm writing my first application using MSMQ and everything works well with local queues on my development machine. I cannot seem to connect to a remote queue when I tested it.
I have 10 Windows 10 Pro installation (not domain joined, but I have also tried this on two domain joined machines), both with MSMQ installed. I have disabled the firewall on both machines, unchecked the 'Disable un-authenticated RPC calls" on both machines. Changed the permissions on the queue to full control for everyone and anonymous.
I'm using .NET and the system.messaging namespace. When I call the messagequeue constructor, I can see that most of the properties are in a exception state.
VB code New MessageQueue("FormatName:Direct=TCP:x.x.x.x\private$\test")
I found an article detailing a registry entry NewRemoteReadServerAllowNoneSecurityClient I thought might work but got the same result. I'm sure this is some sort of security issue but I have no idea what I'm doing wrong.
Anyone have any ideas? Seems like this should be much easier than I am experiencing.
Related
I want to use Postgresql in Windows Server 2012 R2 for one our project where it can be 24/7 uptime.
I would like to ask the community if I can have 2 master instances in 2 different servers A&B and they will 'work' on the same DB located in a shared file storage in lan. Always one master instance on server A will be online and when it goes offline for some reason (I suppose) a powershell script will recognize that the postgresql service stopped and will start the service in server B. The same script will continuous check that only one service in servers A & B is working to avoid conflicts.
I'd like to ask if this is possible or a better approach for my configuration.
(I can't use replication because when server A shuts down the server B is in read-only mode thing that I don't want)
If you manage to start two instances of PostgreSQL on the same data directory, serious data corruption will happen.
Normally there is a postmaster.pid file that prevents that, but a PostgreSQL server process on a different machine that accesses the same file system will happily unlink that after spewing some log messages, thinking it was left behind from a crash.
So you are really walking on thin ice with a solution like that.
One other issue that you didn't think of is that script that is supposed to check if the server is still running. What if that script fails, because for example the network connection between the two servers is down, but the server is still up an running happily? Such a “split brain” scenario will cause data corruption with your setup.
Another word of caution: since you seem to be using Windows (Powershell?), you probably envision a CIFS file system when you are talking of shared storage. A Windows “network share” is not a reliable file system — last time I checked, it did not honor _commit.
Creating a reliable failover cluster is harder than you think, and I'd recommend that you check existing solutions before you try to roll your own.
I'm trying to get the list of available queues on the remote machine. The machine is a Win2003R2 in Workgroup mode, and the client machine that runs the code is a Windows 8 machine both using the same Workgroup name. I get an exception when running the following code:
var messages = MessageQueue.GetPrivateQueuesByMachine("Win2003SRV");
And the error message is:
base {System.Runtime.InteropServices.ExternalException}: {"Access to Message Queuing system is denied."}
Message: "Access to Message Queuing system is denied."
MessageQueueErrorCode: AccessDenied
I'm pretty sure it has something to do with permissions on Windows 2003 but couldn't find much. The code works fine with another Win Server 2008 (but in workgroup mode) and works with local MSMQ as well. According to the MSDN page, this function is supported on Workgroup mode, so what's the catch?
SOLVED:
My issue turned out to be that I didn't have MSMQ installed on my Client machine! The help on the link pointed me to the right direction, so all I had to do was to install MSMQ on client machine as well. If you look at the implementation of GetPrivateQueuesByMachine, the native call can throw a DllNotFoundException and it is that exception that translates into that specific message, so it should give you a hint on what is wrong
John Breakwell who is/was a msmq MVP has a few posts which may help. The problem seems to be caused because the GetPrivateQueuesByMachine() method uses RPC under the hood to communicate between queue managers on different machines.
http://blogs.msdn.com/b/johnbreakwell/archive/2010/03/24/understanding-how-msmq-security-blocks-rpc-traffic.aspx
I am DBA. I am trying to write bunch of scripts that I could execute from one central server. Ideal would be to send all the scripts from central server to say 50+ servers across multiple win domains (for databases management purposes).
The problem I am running into is - security. Seems like PowerShell Remoting is the way to go. But when I send a script to another server, I get 'not digitally signed' error.
I could 'self sign'. But that cert if only trusted on local machine. So that option is out.
Maybe Certificate Authority is a way to go. Or adding trusted hosts. I just have no clue on this one, so if you know any blog posts or how to do this - it would be big help.
Well, it's a security risk, but there's always the possibility of setting the execution policy to RemoteSigned, keeping a local repository on each server and calling those as needed via PS-Remoting. I don't like that idea one bit though.
If you are doing remote execution, you will need to sign your scripts. A detailed step by step can be found here. It even covers deploying the cert via GPO so that it's domain trusted.
I would use PowerShell remoting. This would allow you to run it as remote commands instead of remote scripts. If you catch the bottom of this SimpleTalk article, after "Persistent Sessions". It shows the option of executing a set of commands against each server instead of the script. This should prevent having to deal with the remote signed issue and provide a little more control.
The only thing to deal with on remote sessions is your credentials. I have not tried this on multiple domains but a few stand-alone servers.
I have an agent and a server in different domains. The server acts as an MSMQ server and the agent acts as an MSMQ client. I am using the mqsender utility, which is part of the MSMQ tools.
My problem is that a message is not delivered when using the HTTP:// format string (the MSMQ is installed with HTTP support). Using the OS: format string works fine.
When using HTTP the messages are immediately moved to the Dead Letter queue and the Class is set to Unknown, so I do not know the reasons for this behaviour.
So, this works:
mqsender.exe /c:10 /j:dead /f:Direct=OS:il-mark-w2k3\private$\test
And this does not:
mqsender.exe /c:10 /j:dead /f:Direct=http://il-mark-w2k3/msmq/private$/test
I checked that MSMQ virtual directory exists. How can I trace the MSMQ operation to try and understand what is going on?
Thanks.
EDIT
All the commands work as expected when ran locally on the server.
Navigating to http://il-mark-w2k3/msmq/private$/test in the browser on the agent (and the server) results in 501 - Header values specify a method that is not implemented. The same error is received when navigating to http://il-mark-w2k3/msmq. I suppose that is OK, after all it is not 404 - Not Found, right?
EDIT2
I have succeeded to resolve the issue. IIS lacked Anonymous Authentication, it became obvious from observing its log - 401.2 HTTP error was there. All worked well after it was enabled. The mistery remains why did MSMQ display Class Unknown on the dead messages? On other machine the same setup produces Error : 401, which makes much more sense.
The logging for MSMQ is internal so you won't easily be able to see exactly why the message didn't get delivered without raising a support case with Microsoft.
I have a few blog posts on solving various MSMQ/HTTP issues.
The 17 entitled "MSMQ messages using HTTP just won't get delivered" may help.
Also make sure you check the IIS logs for information.
Cheers
John Breakwell
There is a public queue named queue1 on machine A. I want to send messages to this queue from machine B. In order to achieve this, I wrote that c# code.
if (MessageQueue.Exists("machineA\queue1"))
{
label1.Text = "queue found";
}
else
{
label1.Text = "queue could not be found";
}
But Exists() method return false on machine B. The same code works well on machine C.
I found somethings related with msmq domain mode and workgroup mode. I think that msmq installed in workgoup mode on machine B.
How can I change this configuration from workgroup mode to domain mode?
HKEY_LOCAL_MACHINE\Software\Microsoft\MSMQ\Parameters\
Check the data for the REG_DWORD workgroup. Is it 1 or 0?
1 is workgroup mode.
0 is AD mode
Basically the difference between domain and work group mode is not defined by the value of the registry flag "workgroup" mentioned by #engin. This flag just reflects current operational mode but doesn't set it.
Whether you run in domain or workgroup mode is defined whether you installed MSMQ on domain controller or on a member server. Details about differences between these two modes can be found here: https://support.microsoft.com/en-us/kb/884974/
MSMQ 1.0 used to support domain mode only. Current MSMQ version is 5.0.
Next you may see quite interesting behavior when you installed MSMQ on your DC, your workgroup flag continuously reverts to 1 after each MSMQ service restart. This means that you have to grant Network Service account the Create MSMQ Configuration Objects permission to the computer object in Active Directory Domain Services before installing the Directory Services Integration feature on a computer that is a domain controller.
You may find details on how to do it here:
https://technet.microsoft.com/en-us/library/cc730960.aspx
MSMQ runs under the (less privileged) Network Service account instead of (all powerful) Local System account starting from version 4.0 (Vista/Server 2008)
So to answer #mkus question more directly to "set" domain mode you just install MSMQ on domain controller and make sure that proper permissions in place for Network Service account. Once this is done you well see it operating in domain mode with workgroup flag switched to 0 automatically to reflect this.
Also couple of links to clarify issues around MSMQ objects permissions and when/why you need to set them:
http://blogs.msdn.com/b/johnbreakwell/archive/2009/08/03/default-msmq-queue-permissions-have-changed-in-msmq-4-0.aspx. In short starting from MSMQ 4.0 Everyone and Anonymous Logon were removed from default MSMQ objects ACLs as precaution against DoS attacks (though there are exlusions to this change and Workgroup mode is one of those).
And as you may read in Technet article below you need to go a grant certain rigts to MSMQ objects either to Network Service OR to Computer accounts when installing the Routing Service feature on a Windows Server 2008 R2 (or later) computer that is not a domain controller OR when installing the Directory Service Integration feature of Message Queuing on a Windows Server 2008 R2 (or later) computer that is a domain controller. See details here:
https://technet.microsoft.com/en-us/library/cc749102(v=ws.10).aspx
Run Server Manager on the machine that is hosting the queue. Right-click on Features and click "add features"
Drill down under Message Queuing and under Message Queuing Services. You should see a checkbox for Directory Service Integration.
Check it and click install.
Usually you have to reboot the server for it to show the change.
I ran into some problems, no matter how much I installed or uninstalled MSMQ or restarted, I still wasn't able to use the queue. So I wanted to post some links here
http://support.microsoft.com/kb/935498
When it gets to a part about "To work around this problem, use the Active Directory Users and Computer Microsoft Management Console (MMC)...". Below is how you do that.
How to delete from active directory
http://technet.microsoft.com/en-us/library/cc773660(v=WS.10).aspx
"Delete stale computer objects" is the part you are interested in.
I also found this nice error in the event log "The Message Queuing service will not join the domain. An MSMQ Configuration (msmq) object exists in the new domain with an ID differing from the service ID. Please delete the MSMQ Configuration object in the new domain, restart the Message Queuing service, and log on again."- which helped to point out they way.
I have face this issue for windows server 2016, where even thought I was changing registry value to domain mode "0", it reverts to "1", after server restart.
To solve the issue on OS 2016, we need to uninstall below MSMQ feature as they are deprecated from OS 2016 onward.
Message Queuing Trigger
Multicasting support
Routing Service