I am getting the following error trying to read from a socket. I'm doing a readInt() on that InputStream, and I am getting this error. Perusing the documentation this suggests that the client part of the connection closed the connection. In this scenario, I am the server.
I have access to the client log files and it is not closing the connection, and in fact its log files suggest I am closing the connection. So does anybody have an idea why this is happening? What else to check for? Does this arise when there are local resources that are perhaps reaching thresholds?
I do note that I have the following line:
socket.setSoTimeout(10000);
just prior to the readInt(). There is a reason for this (long story), but just curious, are there circumstances under which this might lead to the indicated error? I have the server running in my IDE, and I happened to leave my IDE stuck on a breakpoint, and I then noticed the exact same errors begin appearing in my own logs in my IDE.
Anyway, just mentioning it, hopefully not a red herring. :-(
There are several possible causes.
The other end has deliberately reset the connection, in a way which I will not document here. It is rare, and generally incorrect, for application software to do this, but it is not unknown for commercial software.
More commonly, it is caused by writing to a connection that the other end has already closed normally. In other words an application protocol error.
It can also be caused by closing a socket when there is unread data in the socket receive buffer.
In Windows, 'software caused connection abort', which is not the same as 'connection reset', is caused by network problems sending from your end. There's a Microsoft knowledge base article about this.
Connection reset simply means that a TCP RST was received. This happens when your peer receives data that it can't process, and there can be various reasons for that.
The simplest is when you close the socket, and then write more data on the output stream. By closing the socket, you told your peer that you are done talking, and it can forget about your connection. When you send more data on that stream anyway, the peer rejects it with an RST to let you know it isn't listening.
In other cases, an intervening firewall or even the remote host itself might "forget" about your TCP connection. This could happen if you don't send any data for a long time (2 hours is a common time-out), or because the peer was rebooted and lost its information about active connections. Sending data on one of these defunct connections will cause a RST too.
Update in response to additional information:
Take a close look at your handling of the SocketTimeoutException. This exception is raised if the configured timeout is exceeded while blocked on a socket operation. The state of the socket itself is not changed when this exception is thrown, but if your exception handler closes the socket, and then tries to write to it, you'll be in a connection reset condition. setSoTimeout() is meant to give you a clean way to break out of a read() operation that might otherwise block forever, without doing dirty things like closing the socket from another thread.
Whenever I have had odd issues like this, I usually sit down with a tool like WireShark and look at the raw data being passed back and forth. You might be surprised where things are being disconnected, and you are only being notified when you try and read.
You should inspect full trace very carefully,
I've a server socket application and fixed a java.net.SocketException: Connection reset case.
In my case it happens while reading from a clientSocket Socket object which is closed its connection because of some reason. (Network lost,firewall or application crash or intended close)
Actually I was re-establishing connection when I got an error while reading from this Socket object.
Socket clientSocket = ServerSocket.accept();
is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
int readed = is.read(); // WHERE ERROR STARTS !!!
The interesting thing is for my JAVA Socket if a client connects to my ServerSocket and close its connection without sending anything is.read() is being called repeatedly.It seems because of being in an infinite while loop for reading from this socket you try to read from a closed connection.
If you use something like below for read operation;
while(true)
{
Receive();
}
Then you get a stackTrace something like below on and on
java.net.SocketException: Socket is closed
at java.net.ServerSocket.accept(ServerSocket.java:494)
What I did is just closing ServerSocket and renewing my connection and waiting for further incoming client connections
String Receive() throws Exception
{
try {
int readed = is.read();
....
}catch(Exception e)
{
tryReConnect();
logit(); //etc
}
//...
}
This reestablises my connection for unknown client socket losts
private void tryReConnect()
{
try
{
ServerSocket.close();
//empty my old lost connection and let it get by garbage col. immediately
clientSocket=null;
System.gc();
//Wait a new client Socket connection and address this to my local variable
clientSocket= ServerSocket.accept(); // Waiting for another Connection
System.out.println("Connection established...");
}catch (Exception e) {
String message="ReConnect not successful "+e.getMessage();
logit();//etc...
}
}
I couldn't find another way because as you see from below image you can't understand whether connection is lost or not without a try and catch ,because everything seems right . I got this snapshot while I was getting Connection reset continuously.
Embarrassing to say it, but when I had this problem, it was simply a mistake that I was closing the connection before I read all the data. In cases with small strings being returned, it worked, but that was probably due to the whole response was buffered, before I closed it.
In cases of longer amounts of text being returned, the exception was thrown, since more then a buffer was coming back.
You might check for this oversight. Remember opening a URL is like a file, be sure to close it (release the connection) once it has been fully read.
I had the same error. I found the solution for problem now. The problem was client program was finishing before server read the streams.
I had this problem with a SOA system written in Java. I was running both the client and the server on different physical machines and they worked fine for a long time, then those nasty connection resets appeared in the client log and there wasn't anything strange in the server log. Restarting both client and server didn't solve the problem. Finally we discovered that the heap on the server side was rather full so we increased the memory available to the JVM: problem solved! Note that there was no OutOfMemoryError in the log: memory was just scarce, not exhausted.
Check your server's Java version. Happened to me because my Weblogic 10.3.6 was on JDK 1.7.0_75 which was on TLSv1. The rest endpoint I was trying to consume was shutting down anything below TLSv1.2.
By default Weblogic was trying to negotiate the strongest shared protocol. See details here: Issues with setting https.protocols System Property for HTTPS connections.
I added verbose SSL logging to identify the supported TLS. This indicated TLSv1 was being used for the handshake.
-Djavax.net.debug=ssl:handshake:verbose:keymanager:trustmanager -Djava.security.debug=access:stack
I resolved this by pushing the feature out to our JDK8-compatible product, JDK8 defaults to TLSv1.2. For those restricted to JDK7, I also successfully tested a workaround for Java 7 by upgrading to TLSv1.2. I used this answer: How to enable TLS 1.2 in Java 7
I also had this problem with a Java program trying to send a command on a server via SSH. The problem was with the machine executing the Java code. It didn't have the permission to connect to the remote server. The write() method was doing alright, but the read() method was throwing a java.net.SocketException: Connection reset. I fixed this problem with adding the client SSH key to the remote server known keys.
In my case was DNS problem .
I put in host file the resolved IP and everything works fine.
Of course it is not a permanent solution put this give me time to fix the DNS problem.
In my experience, I often encounter the following situations;
If you work in a corporate company, contact the network and security team. Because in requests made to external services, it may be necessary to give permission for the relevant endpoint.
Another issue is that the SSL certificate may have expired on the server where your application is running.
I've seen this problem. In my case, there was an error caused by reusing the same ClientRequest object in an specific Java class. That project was using Jboss Resteasy.
Initially only one method was using/invoking the object ClientRequest (placed as global variable in the class) to do a request in an specific URL.
After that, another method was created to get data with another URL, reusing the same ClientRequest object, though.
The solution: in the same class was created another ClientRequest object and exclusively to not be reused.
In my case it was problem with TSL version. I was using Retrofit with OkHttp client and after update ALB on server side I should have to delete my config with connectionSpecs:
OkHttpClient.Builder clientBuilder = new OkHttpClient.Builder();
List<ConnectionSpec> connectionSpecs = new ArrayList<>();
connectionSpecs.add(ConnectionSpec.COMPATIBLE_TLS);
// clientBuilder.connectionSpecs(connectionSpecs);
So try to remove or add this config to use different TSL configurations.
I used to get the 'NotifyUtil::java.net.SocketException: Connection reset at java.net.SocketInputStream.read(SocketInputStream.java:...' message in the Apache Console of my Netbeans7.4 setup.
I tried many solutions to get away from it, what worked for me is enabling the TLS on Tomcat.
Here is how to:
Create a keystore file to store the server's private key and
self-signed certificate by executing the following command:
Windows:
"%JAVA_HOME%\bin\keytool" -genkey -alias tomcat -keyalg RSA
Unix:
$JAVA_HOME/bin/keytool -genkey -alias tomcat -keyalg RSA
and specify a password value of "changeit".
As per https://tomcat.apache.org/tomcat-7.0-doc/ssl-howto.html
(This will create a .keystore file in your localuser dir)
Then edit server.xml (uncomment and edit relevant lines) file (%CATALINA_HOME%apache-tomcat-7.0.41.0_base\conf\server.xml) to enable SSL and TLS protocol:
<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
maxThreads="150" scheme="https" secure="true"
clientAuth="false" sslProtocol="TLS" keystorePass="changeit" />
I hope this helps
I have a Windows application (APP) and Audio Processing Object (APO) loaded by AudioDG.exe that communicate via gRPC:
APP part that is written in C# creates server via Grpc.Core.
APO part creates client via grpc++.
Server is on 127.0.0.1:20000 (I can see it's up and listening with netstat -ano).
I can confirm that APO is loaded into audio device graph by inspecting it with process explorer.
Everything worked like a charm on Windows 8 and 10, but on 11 it cannot communicate at all - I get either Error Code 14, Unavailable, failed to connect to all addresses or 4, Deadline Exceeded.
After enabling debug traces, I now see "socket is null" description for "connect failed" error:
I0207 16:20:59.916447 0 ..\..\..\src\core\ext\filters\client_channel\subchannel.cc:950: subchannel 000001D8B9B01E20 {address=ipv4:127.0.0.1:10000, args=grpc.client_channel_factory=0x1d8bb660460, grpc.default_authority=127.0.0.1:10000, grpc.internal.subchannel_pool=0x1d8b8c291b0, grpc.primary_user_agent=grpc-csharp/2.43.0 (.NET Framework 4.8.4470.0; CLR 4.0.30319.42000; net45; x64), grpc.resource_quota=0x1d8b8c28d90, grpc.server_uri=dns:///127.0.0.1:10000}: connect failed: {"created":"#1644240059.916000000","description":"socket is null","file":"..\..\..\src\core\lib\iomgr\tcp_client_windows.cc","file_line":112}
What I've tried so far:
Updating both parts to the latest grpc versions.
Using "no proxy", "Http2UnencryptedSupport" and other env variables.
Using "localhost" or "0.0.0.0" instead of "127.0.0.1".
Updating connection to use self signed SSL certificates (root CA, server cert + key, client cert + key).
Adding inbound / outbound rules for my port, and then disabling firewall completely.
Creating server on APO side and trying to connect with the client in APP.
Everything works (both insecure and SSL creds) if I create both client and server in C# part, but as soon as it's APP-APO communication it feels blocked or sandboxed.
What has been changed in Windows 11 that can "block" gRPC?
Thanks in advance!
In your input you write:
Server is at 127.0.0.1:20000
Further looking at the logs, you can see that:
The server is located at
grpc.server_uri=dns:///127.0.0.1:10000
Based on the question posed and the amount of data provided, I would check which port the server is really using and which port the client is looking for a connection on.
The easiest way to do this is to use the built-in Resource Monitor application. On the Network tab, in the TCP Connections list, you can find the application and the port it uses.
You can also use the PowerShell command
Test-NetConnection -Port 10000 -InformationLevel "Detailed"
Test-NetConnection -Port 20000 -InformationLevel "Detailed"
At least this is the first thing I would check based on what you described.
Regarding your question about the changes in Windows 11, I do not think that this is something that's causing problems for you. However, Windows 11 has additional security features compared to Windows 10, try disabling the security features completely as a test. Perhaps this will help solve the problem.
As for ASP.NET Core 6.0 itself (if I understood the version correctly), then there is a possibility that the server part, working not in the sandbox of the programming environment, still does not accept the client certificate. At the program level, you can try to fix this by adding the following exception to the code:
// This switch must be set before creating the GrpcChannel/HttpClient.
AppContext.SetSwitch(
"System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);
// The port number(5000) must match the port of the gRPC server.
var channel = GrpcChannel.ForAddress("http://localhost:5000");
var client = new Greet.GreeterClient(channel);
More troubleshooting issues with ASP.NET Core 6.0 Microsoft described in detail here.
https://learn.microsoft.com/en-us/aspnet/core/grpc/troubleshoot?view=aspnetcore-6.0
I hope it was useful and at least one of the solutions I suggested will help solve your problem. In any case, if I had more information, I think I could help you more accurately.
I want to write a CLLE Program to transfer Files from the IFS to a Webserver.
The Webserver is registered in the Hosttable from the Iseries.
(commandline: CFGTCP -> Option 10 -> Scroll to the Webserver IP)
Current CLLE Program: (only the ftp-access)
PGM
OVRDBF FILE(INPUT) TOFILE(CMDDTAR7_2/US9FIP) OVRSCOPE(*JOB)
OVRDBF FILE(OUTPUT) TOFILE(CMDDTAR7_2/US9FOP) +
OVRSCOPE(*JOB)
FTP RMTSYS('10.1.2.99')
ENDPGM
After i call my Program i get some results in a PF-File.
The Results are in German but i translated shortly for you.
The Connection is unavalable to 10.1.2.99 on Port 21. Try it again later.
[...]
My Question at the end.
Do you have some solutions for me to transfer xml files to my Webserver from the iseries?
You're writing about a web server and you want to transfer files by ftp. Perhaps you're mixing up protocols here. I'll concentrate to resolve your apparent ftp connection problem.
Seems that the destination host 10.1.2.99 doesn't accept connections on Port 21.
Please make sure, there's no firewall or other stuff blocking your request to the destination host. Moreover, on the host 10.1.2.99 try telnet 10.1.2.99 ftp or ftp 10.1.2.99 in a command window, depending on OS and installed components.
Before automating, just test manually if you can successfully connect and log in via standard command line: ftp 10.1.2.99.
Transferring data by FTP is just fine in a local LAN. Beware that any data including username and password will be transferred in clear text and thus can be possibly read by others as the intended hosts.
Following up to your comment: Actually there are many possibilities to copy files. If you're running a recent version of IBM i, I'd opt for using scp. It's encrypted and thus safe for running outside of local LANs. Great to automate by utilizing Key-Authentication instead of passwords. And many web hosting companies offer scp/sftp access.
I am trying to run ftp client and server.
The connection successful only if both server and client windows firewall is turned off.
I tried to turn the firewall on and allow roll for:
1. (inbound and outbound) tcp port 20-21 allow
2. allow end point communication for server-client
However, my problem still not solved.
Anyone has any other ideas?
Thanks ahead
Fixed it. The server throw an exception. I found it when i created log file on both server and client side
When trying to receive a (large, approx. 100MB) file using an FTP adapter in BizTalk 2006, we run into the following problem, which causes the file to be processed over and over again.
Retrieving the file succeeds; it is placed into the MessageBox and processed properly
When the FTP adapter issues the DELE statement, it never reaches the FTP server the file is on (we have verified this by taking a look at the FTP server's logs)
there are no signs of timeouts on the FTP server; the FTP server log does not mention a timeout occurring
After the interval time set on the adapter expires, the FTP server will still find the large file that we have already processed in the previous run, because the DELE statement failed
The event log in BizTalk states that ‘The connection to the FTP server was broken prematurely’. That is why we think there is a timeout issue.
We have seen that retrieval of the file takes around 35 minutes. The FTP server timeout is set to 1 hour. no problems there I guess.
Then we found the following article: http://www.ncftp.com/ncftpd/doc/misc/ftp_and_firewalls.html#FirewallTimeouts. It states that a firewall / routing device might be responsible for the timeouts. The team managing our firewalls and routers told us that there were no timeouts set here.
Which leaves us in the dark on the cause of our problem. Does anyone of you have any suggestions? Or even better, the solution!!
Have you tried the solutions in this article?
I avoid using the FTP adapter. Instead I use a third party utility to retrieve files and move the transferred file to a file adapter receive location. Third party utilities allow you to configure rules, recovery actions etc, freeing BizTalk from having to manage the transfer.