We Keep Coding

ADO.NET FirebirdSql.Data.FirebirdClient.FbException: "Unable to complete network request to host "

I have a pretty strange problem when trying to connect my C# program to an existing Firebird server.
First of all, this is reproducable with the default connection example from the Firebird documentation at https://github.com/FirebirdSQL/NETProvider/blob/master/Provider/docs/ado-net.md
using (var connection = new FBConnection("database=192.168.0.150:c:\\Data\\demo.fdb;user=sysdba;password=m#sterkey"))
{
connection.Open();
using (var transaction = connection.BeginTransaction())
{
using (var command = new FbCommand("select * from demo", connection, transaction))
{
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
var values = new object[reader.FieldCount];
reader.GetValues(values);
Console.WriteLine(string.Join("|", values));
}
}
}
}
}
It all works fine when I am on my machine, I also can connect to a Firebird server on my coworkers PC.
But I cannot connect to the Firebird server on my other development server. I found an answer in another question and want to tell you that the server does not have internet access.
https://stackoverflow.com/a/57569057/2785084
This is the exception I get:
FirebirdSql.Data.FirebirdClient.FbException: "Unable to complete
network request to host " No message for error code 335544721 found."
IscException: Unable to complete network request to host " No message
for error code 335544721 found. IOException: Unable to read data from
the transport connection: An existing connection was forcibly closed
by the remote host
I already updated to the latest stable Version of Firebird. I can guarantee that the server is running and no firewall is blocking my connection, because when I try to connect with our old Delphi program, everything works. I also can connect using the lightweight Firebird management tool Flamerobin from Flamerobin.org, which is written in C++, I think.
When I try to connect with DBeaver I get the following message:
[SQLState:28000, ISC error code:335544472] Your user name and
password are not defined. Ask your database administrator to set up a
Firebird login.
I'm pretty sure that the user and password are correct. I do not use the default password, but a password with an # sign in it, maybe it has something to do with that.
I now have 2 programs that can Connect (Delphi and C++), and two that cannot connect (C# and Java). Does anyone have any clue or tweak how to change the connection that I can connect to the server?

Thanks to Mark Rotteveel for the comment which got me to the solution.
I can connect with the default password "masterkey", so it is obvious that the srp user was created with the default credentials and therefore a connection with the other credentials is not possible.
I have to correct the users in my old server.
Thanks for the hint that ADO.NET only supports srp.

Unable to send a message with AMQP.Lite and IBMMQ 8.0

I'm developing a new service based on our infrastructure that uses IBMMQ 8.0 (I've to admit that I'm not a guru of IBMMQ and I've used it as a simple integration without diving in it's implementation).
I'm trying right now to use It with amqpnetlite (in order to use it with .NET Core).
Till now here's my snippet
Address address = new Address("amqp://10.112.62.102:1414");
Connection connection = new Connection(address);
Session session = new Session(connection);
Message message = new Message("Hello AMQP!");
var sender = new SenderLink(session, "AONMQCOL1", "MQ_TEST");
sender.Send(message);
Console.WriteLine("Sent Hello AMQP!");
I got an exception AmqpException: The transport 'TcpTransport' is closed. when performing the Send. On the connection object I've got IsClosed = false so I think the connection is open.
Just as confirmation, what should I put as "address" and "name" on the SenderLink's constructor?
Thanks

What is the exact version of MQ Server you are running? i.e. issue the dspmqver command.
You need to be at Command Level 801 which was added in Fixack 2 of IBM MQ v8. i.e. IBM MQ v8.0.0.2. See here for more details.
Did you start the AMQP service and then start the channel?
i.e. runmqsc commands:
START SERVICE(SYSTEM.AMQP.SERVICE)
START CHANNEL(SYSTEM.DEF.AMQP)
Finally, are you connecting to the correct port #? The default port # is 5672.

Reading from stream failed - mysql_native_password error

I have been facing the following error intermittently.
Authentication to host '127.0.0.1' for user 'root' using method 'mysql_native_password' failed with message: Reading from the stream has failed.
It shots up any time and I am at my wits end. I also posted a bug on MySQL bugs and solutions are not proving to be effective in any way.I hope you guys can help me out.
Here is the link to MySQL Bug for details: Never seems to go away!
Some more detail: I have a client-server system but this bug occurs on the server system(where MySQL database is installed) when a local running app on the server system tries to run a query.
I had already opened a question here but since has been dead. Just a caveat I thought that skip-name-resolve solved the issue but it seems to just have lowered the frequency. Hope someone would help me out this time around.
EDIT: The MySQL guys say that in a client server setup server may close a connection if it is unused for a long time. However, this is not what I am facing as I create a new connection everytime I want to execute a query. I made this point clear in the last comment on the MySQL Bugs.

Guys I tried this: "SslMode=None" in the connection string, but if you need SSL then read this:
http://www.voidcn.com/article/p-phfoefri-bpr.html
here is a sample connection string that works:
connectionString="Server=192.168.10.5;Database=mydata;Uid=root;Pwd=****;SslMode=None"
Hope this helps

I've been getting this error, quite frequently with Amazon's MySQL RDS instances. And most multi-AZ instances.
It would be interesting to compare notes to see if others mostly get this issue with RDS also?
Amazon is known to rely heavily on "fast" DNS changes to switch over stuff with things like ELBs. I wonder if the same thing is happening with RDS? Or some other internal AWS switching is messing up the idle connections in the pool.
This would explain why the Oracle devs can't reproduce it and don't see it as much of an issue.
Anyway I've had to just deal with it and add retry logic when opening a connection.

This issue is caused by Ssl.
Solution 1: SSL is not required. Since it is caused by SSL, we can turn off SSL by appending "SslMode=None" to the connection string.
Solution 2: SSL is required, server identity is important and needs to be verified. The server needs a internet connection to do the cert verification. Please note the crypto API doesn't update CTL for every process. The CTL is maintained at operating system level. Once you connect the server to connect and make an SSL database connection to the server, the CTL will be updated automatically. Then you may disconnect the internet connection. Note again the CTL has its expiration date and after that the Windows needs to update it again. This will occur probably after several months.
Solution 3: SSL is required but the server identity is not important. Typically SSL is only used to encrypt the network transport in this case. We can turn off CTL update:
Press Win+R to open the "Run" dialog
Type "gpedit.msc" (without quotes) and press Enter
In the "Local Group Policy Editor", expand "Computer Configuration", expand "Administrative Templates", expand "System", expand "Internet Communication Management", and then click "Internet Communication settings".
In the details panel, double-click "Turn off Automatic Root Certificates Update", clickEnabled, then click OK. This change will be effective immediatelly without restart.
http://www.voidcn.com/article/p-phfoefri-bpr.html

unfortunately, this error occurs if the application and mysql are on the same computer, if you move it to a different computer it is fine.
I tried many ways but for now there is no other solution. bug has been reported many times by others https://bugs.mysql.com/bug.php?id=76597

I had the exact same problem performing the upgrade on a windows form application. The solution I found was to change the server, because that one was in trouble. On the server that was presenting the similar situation you described had installed WordPress with MYSQL 5.6.34, on the other I did a clean install with MYSQL version 5.6.26.
I don't know if it has to do with the environment variables used. I believe it has nothing to do with Connection Timeout, if it is a property that is used only with the open connection. This error occurred in a shared environment as well as in a local installation with Maria DB. Another problem I found was that one of the selection commands that retrieved the data was having a problem in its formation not respecting the blanks:
SELECT COLUNA1, COLUNA2 FROM TABLE;
I made the change to SELECT COLUMN1, COLUMN2 FROM TABLE;
I am still testing on this solution I presented, and as of the time of posting there were no more errors.

I was getting the error
Authentication to host 'localhost' for user 'root' using method 'mysql_native_password' failed with message: Reading from the stream
I solved it when I put SslMode=None in my connection string.
However, I checked that the message is different from you
Check my connection
connection.ConnectionString = "server=myadressserver;userid=myuser;password=mypassword;database=test;SslMode=None";

c# programmatically reading emails from the Exchange server

When you search on web you will find very easy answers for "How to read emails programmatically"... Al the websites are explaining most of the same like this page.
http://omegacoder.com/?p=454
// depends from Exchange server version
service.Credentials = new NetworkCredential("MDR", "password", "zzz");
service.AutodiscoverUrl("mdr#zzz.be");
object o = service.FindItems(WellKnownFolderName.Inbox, new ItemView(10));
FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, new ItemView(10));
foreach (Item item in findResults.Items)
{
Console.WriteLine(item.Subject);
}
it fails when it executes the autodiscoverURL line. The error says "The Autodiscover service couldn't be located."
So I googled further and found this site from Microsoft https://www.testexchangeconnectivity.com/#&&/wEXAQUBcwUBME93h2+JjI0+MV2gTqcRL0g43z9m Here you can test your mail server....
When I pass the parameters I get the error below....
But I still don't understand what the problem is? Do I need to add a record to DNS ? Can someone help?
Attempting to test potential Autodiscover URL https://autodiscover.zzz.be/AutoDiscover/AutoDiscover.xml
Testing of this potential Autodiscover URL failed.
Test Steps
Attempting to resolve the host name autodiscover.ncb.be in DNS.
The host name resolved successfully.
Additional Details
IP addresses returned: 213.246.192.205
Testing TCP port 443 on host autodiscover.ncb.be to ensure it's listening and open.
The specified port is either blocked, not listening, or not producing the expected response.
Tell me more about this issue and how to resolve it
Additional Details
A network error occurred while communicating with the remote host.
Exception details:
Message: No connection could be made because the target machine actively refused it 213.246.192.205:443
Type: System.Net.Sockets.SocketException
Stack trace:
at System.Net.Sockets.TcpClient.Connect(String hostname, Int32 port)
at Microsoft.Exchange.Tools.ExRca.Tests.TcpPortTest.PerformTestReally()
Attempting to contact the Autodiscover service using the HTTP redirect method.
The attempt to contact Autodiscover using the HTTP Redirect method failed.
Test Steps
Attempting to resolve the host name autodiscover.zzz.be in DNS.
The host name resolved successfully.
Additional Details
IP addresses returned: 213.246.192.205
Testing TCP port 80 on host autodiscover.zzz.be to ensure it's listening and open.
The port was opened successfully.
ExRCA is checking the host autodiscover.zzz.be for an HTTP redirect to the Autodiscover service.
ExRCA failed to get an HTTP redirect response for Autodiscover.
Additional Details
A Web exception occurred because an HTTP 404 - NotFound response was received from IIS7.
Attempting to contact the Autodiscover service using the DNS SRV redirect method.
ExRCA failed to contact the Autodiscover service using the DNS SRV redirect method.
Test Steps
Attempting to locate SRV record _autodiscover._tcp.ncb.be in DNS.
The Autodiscover SRV record wasn't found in DNS.
Tell me more about this issue and how to resolve it

You don't necessarily need to use the autodiscovery if you already know the address of your exchange server. Try the following instead (for more info, look here:
service.Url = new Uri("https://hostname/EWS/Exchange.asmx");
Replace "hostname" with the hostname for your exchange server.

I hope you should have the solution by this time now. This is just to help anyone bumped on this post.
I found the solution on one of the technet article, I twick to suite me, and is working fine for me.
Just replace the line in your code with following:
service.AutodiscoverUrl("user#yourdomain.com",
delegate
{
return true;
});
I had some other issues but not related to this bit though.
Happy Coding,
Sanjay.

I had the same issue with AutoDiscover. It's not necessary, you can specify your URL like
Uri myUri = new Uri("https://Hostname/ews/exchange.asmx");
userData.AutodiscoverUrl = myUri;
service.Url = myUri;
As the hostname you can put the Server IP address like 192.168.100.10
Alternatively, to find what your Exchange server hostname is (in in fact the whole url to use) if you are using Outlook, go to your computer start bar, where the Date and time is showing, you will find the Outlook icon, hold Ctrl + right click on the outlook icon and click “Test Email Auto Configuration”
Check the "Use AutoDiscover" checkbox. Enter an email address hosted on that Exchange Server along with its password and you will recieve a bunch of url's. Use the 1 that says "Availability Service URL"

Consider that the credentials being passed need to have permission to the given exchange mailbox / server. In my case using a different set of credentials that are properly permissioned works but not for a service account which I'm trying to get to work.
Once I discover what exactly the account needs to be permissioned for I will update it here.
Update: My issue was the service account was from a domain different than the domain on which the exchange 2007 instance is running, even though there is a trust relationship between the two. I found this is a documented known issue in Exchange 2007 in how it looks up accounts in its forest. In the end had to create an identical service account (name/pass) on the domain on which the exchange server is sitting and specify username as {exchange_domain}{service_account_name}. The windows service that calls EWS runs as {original_domain}{service_account_name}.
For reference, the exception was:
Microsoft.Exchange.WebServices.Data.ServiceResponseException:
Failed to get valid Active Directory information for the calling account. Confirm that it is a valid Active Directory account.

What should the client do while the TIBCO EMS server attempts failover?

The TIBCO EMS user's guide (pg 292) says:
The backup server will work indefinitely to either A) become the
primary server or B) reconnect to the primary server. It also says
clients may receive fail-over notification when the switch is successful (see also TIBCO EMS .NET reference pg 220).
I have some questions spinning off of these facts...
What kind of errors occur on the client side while the servers are attempting fail-over/reconnect?
What is the appropriate response from the client?
Get new Connection objects from the ConnectionFactory until one works?
Wait for fail-over notification? (are current Connection instances fixed at this time? or do I need to get a new instance?)
I hope the scenario is clear, any related information or advice would be appreciated too.

I can at least answer #1 above.
If you have enabled Tibems.SetExceptionOnFTSwitch(true); and have set up an exception handler to capture the messages the server sends to the client, you will see the following:
For single-server, non-fault tolerant connection failures:
"Connection has been terminated".
For fault-tolerant connection failures:
"Connection has performed fault-tolerant switch to "
If you attempt to publish while the connection is down, a TIBCO.EMS.IllegalStateException is thrown with the "Producer is closed" message.
for #2 above, I think the answer is to allow the EMS library to handle as much as possible. Once we got the EMS reconnect functionality to work, it gracefully tried to reconnect until the server became available again and once it reconnected, it was like there was never a problem. The only gotcha is probably if you try to publish a message before the ems connection is back. This is where the exception handler comes in, Once notified that you are in failover mode, you can adjust exception handling on the publisher side to suppress the error until the connection is back. The thing I don't know is how do you tell when you've exhausted all reconnect attempts.
Anyway, Seems like our two worlds are closely related when it comes to EMS - hope our findings (based on your comments on my questions) help you.

We use TEMS (Tibco EMS - a Tibco Product for WCF) So it becomes a custom binding. We tried to break it by doing things like bounce the server to force switch overs and it works really well. make sure you are using version 1.2 not 1.1 because you cannot do anything other then client acknowledgement.