I am making rest call to IBM Cloud BPM. Some times calls are working fine.But sometimes it is giving following error.
java.io.IOException: An existing connection was forcibly closed by the remote host.
java.io.IOException: An existing connection was forcibly closed by the remote host
at sun.nio.ch.SocketDispatcher.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
Can any one help me on how to solve this issue.
Any help is greatly appreciated.
Such behavior could be explained if the HTTP Client you use opens persistent connections to the server, and the server occasionally terminates them.
Normally, the connection to an HTTP server is closed after each response. With HTTP "keep-alive" you keep the underlying TCP connection open until certain criteria are met. What those conditions are depends on the server, which is free to close the connection after an arbitrary timeout or number of requests (just as long as it returns the response to the current request).
When the server closes such a connection the client usually reopens it again, and depending on implementation, may throw an exception or print a warning.
For example, Vert.x HttpClient (which opens persistent connections by default) also throws...
java.io.IOException: An existing connection was forcibly closed by the remote host
...when the server terminates them.
I had this error when consuming my API from an outside PC, but when calling from the same PC it worked fine.
To fix to, I went to Control Panel
Right click in Java icon
Go to Advanced Tab
Then check Enable Operating System's restricted environment
Apply and Save
This fixed my problem.
I have faced same issue on windows server.
Then I checked memory utilization of server and it taking more memory so my application is not running.
I have singoff some user profile from
Task Manager-->Users Tab--> Right click and Sign Off
This solution worked for me.
I am using Linux Mint 14 KDE. I've successfully created Java tcp server and client, server IP:port is 10.10.1.10:9900 and my client IP:port 10.10.1.10:9901. When i connect my client for the first time everything is OK. The client connects and sends some data and disconnects. When i try connecting the client with the server right after disconnecting i get the next Exception.
java.net.BindException: Address already in use
If i wait more than 1 minute everything is OK. On other forums i read that after closing the socket there is a tcp time_wait that is 60 seconds (1 minute). After changing it to 0 everything worked (If someone want to change it just add this line net.ipv4.tcp_fin_timeout=0 in /etc/sysctl.conf and execute this line in your terminal as root service networking restart). The next day i tried to do one more test and i got the same exception. I checked if the time is still 0 (U can check it with writing this in command line cat /proc/sys/net/ipv4/tcp_fin_timeout as root) and it was 0. I still had to wait 1 minute before reconnecting the client.
Can someone help me how to configure that way so i don't get this exception. Waiting 1 minute is too much for real-time application. I know i can do this with letting the OS dynamically assign port number that is free, but that is not what my application needs are.
After creating your client socket, but before binding it or connecting to the remote server, you should call Socket.setReuseAddress(true) to enable reusing the client port.
Don't specify a fixed client port, use zero. That way you will get a fresh one every time, or until you run out, which means you should be doing connection pooling at the client.
I have an apache proxy between browser and my custom web server. So after starting the webserver, I can access my web application for like 4-5 hours. After that I get this error
Proxy Error The proxy server received an invalid response from an
upstream server. The proxy server could not handle the request GET /.
Reason: Error reading from remote server
To access the web application again, I have to restart the web server. I tried to check the log I got from my web server and only error in that log , I am finding is this
com.mysql.jdbc.CommunicationsException: Communications link failure
due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.SocketException MESSAGE: Connection timed out
STACKTRACE:
java.net.SocketException: Connection timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:146)
at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1910)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2304)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2803)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1573)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3170)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3099)
at com.mysql.jdbc.Statement.execute(Statement.java:695)
at hra.database.Pool.getConnection(Pool.java:62)
** END NESTED EXCEPTION **
Last packet sent to the server was 925624 ms ago.
And I tried to fix this database error, but I still get the above mentioned proxy error, so definitely the log information is not useful.
This is what I am getting from Apache Proxy log
(70007)The timeout specified has expired: proxy: error reading status
line from remote server
Does anyone know what can be the issue or any helpful pointers to fix this issue?
apache proxy fails because customwebserver does not answer. your
customwebserver logs a crash waiting for mysql to answer. rebooting
customwebserver fixes it, so mysql is not the problem. it looks like the problem the way your customwebserver handles its connections to mysql.
can we see your jdbc config? do you have autoReconnect=true ?
What is likely happening is that your up-stream server is shutting itself down because of inactivity. Find the setting on the server that controls that and turn it up.
I can see that you see two connection timeout errors
Apache Proxy Web server timing out while connecting to custom web server
Custom web server timing out while connecting to database
If the timeout set on proxy server is less than timeout set for database connection, before the database connection times out, proxy server would time out as well.
As a first thing resolve all DB connectivity issues and test your application by directly connecting to custom web server (not via proxy).
Observe and identify normal response time and max response time.
Set proxy time out ProxyTimeout to be a value that is more than (max response time) + (network delay)
If possible you may share proxy server configurations to help you further.
I think like stated by the previous answer that you encounter a timeout raised by one of the members of your infrastructure:
server
network device (routers are clever beasts but firewalls can be clever too)
Did you setup a real connection pool ? Using heart beat mechanism to keep alive connections ?
This induces some network traffic but avoids such problems ?
Try to use a network capture tool to have many logs to analyze
HTH
jerome
This question already has answers here:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
(51 answers)
Closed 6 years ago.
My program that connects to a MySQL database was working fine. Then, without changing any code used to set up the connection, I get this exception:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
What happened?
The code used to get the connection:
private static Connection getDBConnection() throws SQLException, InstantiationException, IllegalAccessException, ClassNotFoundException {
String username = "user";
String password = "pass";
String url = "jdbc:mysql://www.domain.com:3306/dbName?connectTimeout=3000";
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
This is a wrapped exception and not really interesting. It is the root cause of the exception which actually tells us something about the root cause. Please look a bit further in the stacktrace. The chance is big that you'll then face a SQLException: Connection refused or SQLException: Connection timed out.
If this is true in your case as well, then all the possible causes are:
IP address or hostname in JDBC URL is wrong.
Hostname in JDBC URL is not recognized by local DNS server.
Port number is missing or wrong in JDBC URL.
DB server is down.
DB server doesn't accept TCP/IP connections.
Something in between Java and DB is blocking connections, e.g. a firewall or proxy.
To solve the one or the either, follow the following advices:
Verify and test them with ping.
Refresh DNS or use IP address in JDBC URL instead.
Verify it based on my.cnf of MySQL DB.
Start it.
Verify if mysqld is started without the --skip-networking option.
Disable firewall and/or configure firewall/proxy to allow/forward the port.
By the way (and unrelated to the actual problem), you don't necessarily need to load the JDBC driver on every getConnection() call. Just only once during startup is enough.
check your wait timeout set on the DB server.
Some times it defaults to 10 seconds. This looses the connection in 10 seconds.
mysql> show global variables like '%time%' ;
update it make it something like 28800
mysql> SET GLOBAL wait_timeout = 28800;
I've been having this issue also for about 8-9 days.
Here's some background: I'm developing a simple Java application that runs in bash.
Details:
Spring 2.5.6
Hibernate3.2.3.ga
With maven.
(The base of the project is from mkyong.com , the spring tutorial without anotations )
MySQL version:
[jvazquez#archbox ~]$ mysql --version
mysql Ver 14.14 Distrib 5.5.9, for Linux (i686) using readline 5.1
Linux archbox 2.6.37-ARCH #1 SMP PREEMPT Fri Feb 18 16:58:42 UTC 2011 i686 Intel(R) Core(TM)2 Quad CPU Q8200 # 2.33GHz GenuineIntel GNU/Linux
The application works fine in Arch Linux, Mac OS X 10.6, and FreeBSD 7.2.
When I moved the jar file to another arch linux in a different host, using the same mysql, a similar my.cnf, and the similar kernel version, the connection died and obtained the same error as the original poster:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:
Communications link failure
I tried every possible combination for this that I found on so and the forums (http://forums.mysql.com/read.php?39,180347,180347#msg-180347 for example, which is closed now and I can't post .. ), specifically:
Triple check that I wasn't using skip
networking. (verified with ps aux
and the my.cnf)
Tried enable log_warnings=1 in the my.cnf but obviously, I wasn't hitting the
server so I didn't saw anything while using the app
SHOW ENGINE innodb STATUS didn't show anything at all; during the tests I could connect via shell, and php also connected to the mysql server
/etc/hosts has localhost 127.0.0.1
Tried the jdbc properties using localhost and 127.0.0.1 with no results
Tried adding c3p0 and changed the max_wait
Max connections in the my.cnf was changed to 900 , 2000 and still nothing my.cnf
Added wait_timeout = 60 my.cnf
Added net_wait_timeout = 360 my.cnf
Added the destroy-method="close" spring.xml
As it was pointed out (if you look up for the same exception , you will find several so threads about the issue Reproduce com.mysql.jdbc.exceptions.jdbc4.CommunicationsException with a setup of Spring, hibernate and C3P0
for example ).
If you are using tomcat, please check the security exception (again, it is on SO, you will find it )
Check that you can resolve that url that you are using
Try adding c3p0.
Verify that there isn't a firewall rejecting your connections
Finally , if you are using GNU/Linux ( ARch linux for example and you indeed obtain this exception )
Try
MySQL Forums :: JDBC and Java :: EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost
If the link get's removed, just add mysqld:ALL to /etc/hosts.allow
I know that is a bit extense, but it may help anybody using GNU/Linux and having this exception and this thread seemed the best place to post my research.
Hope it helps
I got the same error
but then I figured it out its because the Mysql server is not running at that time.
So to change the status of the server
Go to Task Manager
Go to Services
then search for your Mysql server(eg:for my case its MYSQL56)
then you will see under the status column it says its not running
by right clicking and select start
Hope this will help.
We have a piece of software (webapp with Tomcat) using Apache commons connection pooling, and worked great for years. In the last month I had to update the libraries due to an old bug we were encountering. The bug had been fixed in a recent version.
Shortly after deploying this, we started getting exactly these messages. Out of the thousands of connections we'd get a day, a handful (under 10, usually) would get this error message. There was no real pattern, except they would sometimes cluster in little groups of 2 to 5.
I changed the options to on the pool to validate the connection every time one is taken from or put back in the pool (if one is found bad, a new one is generated instead) and the problem went away.
Have you updated your MySQL jar lately? It seems like there may be a new setting that didn't used to be there in our (admittedly very old) jar.
I agree with BalusC to try some other options on your config, such as those you're passing to MySQL (in addition to the connection timeout).
If this failure is transient like mine was, instead of permanent, then you could use a simple try/catch and a loop to keep trying until things succeed or use a connection pool to handle that detail for you.
Other random idea: I don't know what happens why you try to use a closed connection (which exception you get). Could you be accidentally closing the connection somewhere?
Ensure skip-networking is commented out in my.cnf/my.ini
As BalusC mentioned, it would be very useful to post the full stacktrace (always post a full stacktrace, it is useless and frustrating to have only the first lines of a stacktrace).
Anyway, you mentioned that your code was working fine and that this problem started suddenly to occur without any code change so I'm wondering if this could be related to you other question Problem with not closing db connection while debugging? Actually, if this problem started while debugging, then I think it is (you ran out of connections). In that case, restart you database server (and follow the suggestions of the other question to avoid this situation).
I encountered same problem. I am using spring & dbcp & mysql 5.5But If I change localhost to 192.168.1.110 then everything works. What make things more weird is mysql -h localhost just works fine.
update: Finally found a solution. Changing bindaddress to localhost or 127.0.0.1 in my.conf will fix the problem.
In my case, the local loopback interface wasn't started, so "localhost" couldn't be resolved.
You can check this by running "ifconfig" and you should see an interface called "lo". If it is not up, you can activate it by running "ifup lo" or "ifconfig lo up".
In my case, the mysql.com downloaded Connector/J 5.1.29 .jar had this error whereas the 5.1.29 .jar downloaded from the MvnRepository did not.
This happened when building a Google appengine application in Android Studio (gradle, Windows x64), communicating to a Linux MySQL server on the local network/local VM.
I see you are connecting to a remote host. Now the question is what type of a network are you using to connect to the internet?
WINDOWS
If it's a mobile broadband device then get your machines IP address and add it to your hosting server so that your host server can allow connections coming from your machine.[your host might have turned this off due to security reasons].
Note that every time you use a different network device your IP changes.
If you are using a LAN then set a static IP address on your machine then add it to your host.
I hope this helps!! :)
I got the communications failure error when using a java.sql.PreparedStatement with a specific statement.
This was running against MySQL 5.6, Tomcat 7.0.29 and JDK 1.7.0_67 on a Windows 7 x64 machine.
The cause turned out to be setting an integer to a string parameter and a string to an integer parameter then trying to perform executeQuery on the prepared statement. After I corrected the order of parameter setting the statement performed correctly.
This had nothing to do with network issues as the wording of the error message suggested.
The escential problem is that Mysql JDBC pool connections is not used, then the Timeout from Mysql, close the Connections. You need change the pool Parameters to get restart connection when the connection has failures, on this way:
Connection Validation: Required (Check)
Validation Method: autocommit
You can change the Validation Method if you cannot get it works!
If you use WAMP, make sure it is online. What I did was, first turned my firewall off, then it worked, so after that I allowed connection for all local ports, specially port 80. Than I got rid of this problem. For me it was the Firewall who was blocking the connection.
I had the same problem and I used most of the params (autoreconnect etc..), but didn't try the (test_on_idle, or test_on_connect) , I am going to do them next.
However, I had this hack that got me through this:
I have a cron job called Healthcheck, It wakes up every 10 mins and makes a REST API call to the server. The web / app server picks this up, connects to the db, makes a small change and comes back with a 'yes all quiet on western front' or 'shitshappening'. When the latter, it sends a pager / email to the right people.
It has the side effect of always keeping the db connection pool fresh. So long as this cron is running, I don't have the db connection timeout issues. otherwise, they crop up.
I'll like to combine both my initial problem which leads me to this one and this one.
my first problem was to be able to connect jaspersoft ireport 3.7.0 to MSSQL2005.I downloaded the jar from microsoft downloads and added the `jdbc4.jar` from the `irepot>tool>classpath>add jar`.
It went fine but i needed the port number other than 1433 since i'm using a named instance.so my first question is on which port to connect to a MSSQL2005 named instance?
During my search on google i found lot's of article like [this one][1] and [link text][2].i first did: `start>Microsoft SQL Server 2005>configuration tools>Sql Server Surface Area Configuration>Surface Area Configuration for service and connections` and allow remote connection.
I located listenALL at `Microsoft SQL Server 2005>configuration tools>Sql Server Surface Area Configuration>Sql Server configuration manager>protocol for instancename>TCPIP>protocol` which was yes
I Located IPALL at `Microsoft SQL Server 2005>configuration tools>Sql Server Surface Area Configuration>Sql Server configuration manager>protocol for instancename>TCPIP>IP addresses` and as in the second link i posted ,i removed `0` from TCP Dynamic Ports and assigne `90000` to TCP Port
I try to restart the database engine it keeps on saying: `the request failed or the service did not respond in a timely fashion. even though i undo every thing but still.Doesn't start from service manager.And it affected the SQLEXPress that got installed after i installed Visual Studio
i uninstalled the named instance but the SQLExpress is having the same behavior
Anyone to help me?this is critical thanks for reading this
Try to find free port with help of TCPview and then assign your DB Server to it.