I'd like to start a Tomcat debug session on my remote host from Eclipse, but it fails with this error:
Failed to connect to remote VM
com.sun.jdi.connect.spi.ClosedConnectionException
My Tomcat is, I think, correctly configured to received debug session on port 8000:
tomcat 18771 1 1 17:18 ? 00:00:16 /usr/lib/jvm/java/bin/java -Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n -Djava.rmi.server.hostname=10.30.0.17 -Dcatalina.ext.dirs=/usr/share/tomcat5/shared/lib:/usr/share/tomcat5/common/lib -Djavax.sql.DataSource.Factory=org.apache.commons.dbcp.BasicDataSourceFactory -Djava.endorsed.dirs=/usr/share/tomcat5/common/endorsed -classpath /usr/lib/jvm/java/lib/tools.jar:/usr/share/tomcat5/bin/bootstrap.jar:/usr/share/tomcat5/bin/commons-logging-api.jar:/usr/share/java/mx4j/mx4j-impl.jar:/usr/share/java/mx4j/mx4j-jmx.jar -Dcatalina.base=/usr/share/tomcat5 -Dcatalina.home=/usr/share/tomcat5 -Djava.io.tmpdir=/usr/share/tomcat5/temp org.apache.catalina.startup.Bootstrap start
There is a firewall between my PC and the remote server, but the port is well opened, as I can see these packets with tcpdump on the server:
17:41:17.110977 IP X.X.X.X.57010 > Y.Y.Y.Y.irdmi: S 868833744:868833744(0) win 8192 <mss 1460,nop,wscale 8,nop,nop,sackOK>
17:41:17.111183 IP Y.Y.Y.Y.irdmi > X.X.X.X.57010: S 3571247457:3571247457(0) ack 868833745 win 5840 <mss 1460,nop,nop,sackOK,nop,wscale 7>
17:41:17.112624 IP X.X.X.X.57010 > Y.Y.Y.Y.irdmi: . ack 1 win 256
17:41:19.113216 IP Y.Y.Y.Y.irdmi > X.X.X.X.57010: F 1:1(0) ack 1 win 46
17:41:19.114246 IP X.X.X.X.57010 > Y.Y.Y.Y.irdmi: P 1:15(14) ack 1 win 256
17:41:19.114279 IP Y.Y.Y.Y.irdmi > X.X.X.X.57010: R 3571247458:3571247458(0) win 0
The only message writtent in Tomcat logs is Debugger failed to attach: timeout during handshake
I can't figure out what's wrong dispite informations I found on the web.
Can anyone can help me?
My server: RHEL 5.9, Tomcat 5.5, java 1.6
Regards, Robert
I solved my issue : there were a packet inspection activated on the firewall between my PC and the server. It lets certain TCP packets trough, so the TCP handshack can occure, but block data TCP packet.
As I understand, first, a TCP connection is made, then an application handshake is done by the java server with TCP data packet. As data packet was filtered by the firewall, the application handshake could not been completed, and the application close the TCP connection by sending a FIN packet.
Regards, Robert