A clustered configuration of two AS 7 instances has an issue with the connection to port 9999 timing out when starting up. The instances are configured as per https://docs.jboss.org/author/display/AS71/AS7+Cluster+Howto. On startup, we get the following error randomly for one or more of the server instances:

[Server:server-two] 16:36:03,492 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-2) MSC00001: Failed to start service jboss.host.controller.client: org.jboss.msc.service.StartException in service jboss.host.controller.client: java.net.ConnectException: JBAS012144: Could not connect to remote://10.108.25.156:9999. The connection timed out
[Server:server-two] at org.jboss.as.server.mgmt.domain.HostControllerServerClient.start(HostControllerServerClient.java:161) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
[Server:server-two] at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
[Server:server-two] at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
[Server:server-two] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) [rt.jar:1.7.0_05]
[Server:server-two] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) [rt.jar:1.7.0_05]
[Server:server-two] at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_05]
[Server:server-two] Caused by: java.net.ConnectException: JBAS012144: Could not connect to remote://nephele-beta-jboss1:9999. The connection timed out
[Server:server-two] at org.jboss.as.protocol.ProtocolChannelClient.connectSync(ProtocolChannelClient.java:155) [jboss-as-protocol-7.1.1.Final.jar:7.1.1.Final]
[Server:server-two] at org.jboss.as.server.mgmt.domain.HostControllerServerConnection.openChannel(HostControllerServerConnection.java:158) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
[Server:server-two] at org.jboss.as.server.mgmt.domain.HostControllerServerConnection.connect(HostControllerServerConnection.java:86) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
[Server:server-two] at org.jboss.as.server.mgmt.domain.HostControllerServerClient.start(HostControllerServerClient.java:135) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
[Server:server-two] ... 5 more

We usually have to restart the master server instance 10-15 times before all server instances start up without this error, which suggests a race condition between the listening and connecting sockets. Note that this is running on the equivalent of a single-core, fairly slow machine currently, which may be exacerbating the effects.