[jboss-jira] [JBoss JIRA] (JGRP-1947) JGRP000006 errors triggered by nmap TCP Connect scanning JGroups ports

[Justin Cranford (JIRA)]

Justin Cranford created JGRP-1947:
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             Summary: JGRP000006 errors triggered by nmap TCP Connect scanning JGroups ports
                 Key: JGRP-1947
                 URL: https://issues.jboss.org/browse/JGRP-1947
             Project: JGroups
          Issue Type: Bug
    Affects Versions: 3.4.6
         Environment: Java 7u80 x32
Tomcat 7.0.62
HA-JDBC 3.0.4-SNAPSHOT + JGroups 3.4.6
nmap 5.5.1
            Reporter: Justin Cranford
            Assignee: Bela Ban


I am running a two node Tomcat cluster. Both JGroups and Hazelcast are used for different parts of application clustering - JGroups for HA-JDBC, and Hazelcast for application locks outside of HA-JDBC.

Hazelcast is not relevant to JGroups, except I included the Hazelcast errors because they happen at the same time as the JGroups JGRP000006 errors. This gave me a hint of why I see JGRP000006, because the Hazelcast error is more specific about root cause.

Basically if I run a nmap TCP Connect scan on my servers like so, this opens/closes empty TCP connections. JGroups reports these events as JGRP000006, whereas Hazelcast reports them as "java.io.IOException[Connection reset by peer]".

I am wondering if JGroups can handle these nmap TCP Connect scans more gracefully, or even log a more descriptive error with the JGRP000006 error code.

My Tomcat errors for both JGroups and Hazelcast

Jul 31, 2015 12:27:52 AM com.hazelcast.nio.SocketAcceptor
INFO: [10.0.0.85]:5900 [ClusterManager] [3.2.4] Accepting socket connection from /10.0.0.86:40527
Jul 31, 2015 12:27:52 AM com.hazelcast.nio.TcpIpConnectionManager
INFO: [10.0.0.85]:5900 [ClusterManager] [3.2.4] 5900 accepted socket connection from /10.0.0.86:40527
Jul 31, 2015 12:27:52 AM org.jgroups.logging.JDKLogImpl warn
WARNING: JGRP000006: failed accepting connection from peer
java.net.SocketException: Connection reset
        at java.net.SocketInputStream.read(Unknown Source)
        at java.net.SocketInputStream.read(Unknown Source)
        at java.io.BufferedInputStream.fill(Unknown Source)
        at java.io.BufferedInputStream.read1(Unknown Source)
        at java.io.BufferedInputStream.read(Unknown Source)
        at java.io.DataInputStream.readFully(Unknown Source)
        at org.jgroups.blocks.TCPConnectionMap$TCPConnection.readPeerAddress(TCPConnectionMap.java:494)
        at org.jgroups.blocks.TCPConnectionMap$TCPConnection.<init>(TCPConnectionMap.java:376)
        at org.jgroups.blocks.TCPConnectionMap$Acceptor.handleAccept(TCPConnectionMap.java:298)
        at org.jgroups.blocks.TCPConnectionMap$Acceptor.run(TCPConnectionMap.java:282)
        at java.lang.Thread.run(Unknown Source)

Jul 31, 2015 12:27:52 AM com.hazelcast.nio.TcpIpConnection
INFO: [10.0.0.85]:5900 [ClusterManager] [3.2.4] Connection [/10.0.0.86:40527] lost. Reason: java.io.IOException[Connection reset by peer]

My nmap scan which triggers the JGRP000006 errors:

root at myserver:~$ nmap -n -T4 -sT -PN --max-scan-delay 0ms --min-rate 1000000 --max-retries 0 -p 443,3306,5900,7900,7901 10.0.0.85

Starting Nmap 5.51 ( http://nmap.org ) at 2015-07-31 01:33 UTC
Cannot find nmap-payloads. UDP payloads are disabled.
Nmap scan report for 10.0.0.85
Host is up (0.00035s latency).
PORT     STATE SERVICE
443/tcp  open  https
3306/tcp open  mysql
5900/tcp open  vnc
7900/tcp open  mevent
7901/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 0.04 seconds



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