GridGain multicast discover does not find cluster nodes - gridgain

Question

I'm trying to setup a gridgain cluster in a cloud environment (opensciencedatacloud.org).
I've verified that UDP multicast is available and port 47400 is open in this environment, but unfortunately GridGain is unable to find the other nodes when they are launched. Do you have clue why it is not working.
Following you can find below the a cluster node log:
INFO o.g.grid.kernal.GridKernal%nextflow - Config URL: n/a
INFO o.g.grid.kernal.GridKernal%nextflow - Daemon mode: off
INFO o.g.grid.kernal.GridKernal%nextflow - OS: Linux 2.6.32-358.2.1.el6.x86_64 amd64
INFO o.g.grid.kernal.GridKernal%nextflow - OS user: root
INFO o.g.grid.kernal.GridKernal%nextflow - Language runtime: Groovy
INFO o.g.grid.kernal.GridKernal%nextflow - VM information: Java(TM) SE Runtime Environment 1.7.0_51-b13 Oracle Corporation Java HotSpot(TM) 64-Bit Server VM 24.51-b03
INFO o.g.grid.kernal.GridKernal%nextflow - VM total memory: 0.83GB
INFO o.g.grid.kernal.GridKernal%nextflow - Remote Management [restart: off, REST: on, JMX (remote: off)]
INFO o.g.grid.kernal.GridKernal%nextflow - GRIDGAIN_HOME=/root
INFO o.g.grid.kernal.GridKernal%nextflow - VM arguments: [-Djava.awt.headless=true]
WARN o.g.grid.kernal.GridKernal%nextflow - SMTP is not configured - email notifications are off.
INFO o.g.grid.kernal.GridKernal%nextflow - Configured caches ['allSessions']
INFO o.g.grid.kernal.GridKernal%nextflow - 3-rd party licenses can be found at: /root/libs/licenses
INFO o.g.grid.kernal.GridKernal%nextflow - Local node user attribute [ROLE=worker]
[gridgain-#5%pub-nextflow%] WARN o.g.grid.kernal.GridDiagnostic - Initial heap size is less than 512MB (59MB). It is highly recommended to allocate at least 512MB of initial heap to run GridGain. Use -Xms512m -Xmx512m to set initial heap size.
INFO o.g.grid.kernal.GridKernal%nextflow - Non-loopback local IPs: 172.16.1.98, fe80:0:0:0:78b5:53ff:fe01:643b%3, fe80:0:0:0:f816:3eff:fe54:f4e8%2, 172.17.42.1
INFO o.g.grid.kernal.GridKernal%nextflow - Enabled local MACs: FA163E54F4E8, 7AB55301643B
INFO o.g.g.s.c.t.GridTcpCommunicationSpi - IPC shared memory server endpoint started [port=48100, tokDir=/root/work/ipc/shmem/cf5dbd14-4bb8-420b-998f-820056aa6d1c-2646]
INFO o.g.g.s.c.t.GridTcpCommunicationSpi - Successfully bound shared memory communication to TCP port [port=48100, locHost=0.0.0.0/0.0.0.0]
INFO o.g.g.s.c.t.GridTcpCommunicationSpi - Successfully bound to TCP port [port=47100, locHost=0.0.0.0/0.0.0.0]
WARN o.g.g.s.c.noop.GridNoopCheckpointSpi - Checkpoints are disabled (to enable configure any GridCheckpointSpi implementation)
INFO o.g.grid.kernal.GridKernal%nextflow - Security status [authentication=off, secure-session=off]
WARN o.g.g.k.p.cache.GridCacheProcessor - Cache write synchronization mode is set to FULL_ASYNC. All single-key 'put' and 'remove' operations will return 'null', all 'putx' and 'removex' operations will return 'true'.
WARN o.g.g.k.p.cache.GridCacheProcessor - Automatically set write order mode to PRIMARY for write synchronization mode [writeSynchronizationMode=FULL_ASYNC, cacheName=allSessions]
WARN o.g.g.k.p.cache.GridCacheProcessor - Query indexing is disabled (queries will not work) for cache: 'allSessions'. To enable change GridCacheConfiguration.isQueryIndexEnabled() property.
INFO o.g.g.k.p.cache.GridCacheDgcManager - <allSessions> DGC trace log disabled.
INFO o.g.g.k.p.cache.GridCacheProcessor - Started cache [name=allSessions, mode=REPLICATED]
INFO org.eclipse.jetty.server.Server - jetty-9.0.5.v20130815
INFO o.e.jetty.server.ServerConnector - Started ServerConnector#7b9617a0{HTTP/1.1}{0.0.0.0:8080}
INFO o.g.g.k.p.r.p.h.j.GridJettyRestProtocol - Command protocol successfully started [name=Jetty REST, host=/0.0.0.0, port=8080]
INFO o.g.g.k.p.r.p.t.GridTcpRestProtocol - Command protocol successfully started [name=TCP binary, host=0.0.0.0/0.0.0.0, port=11211]
INFO o.g.g.s.d.tcp.GridTcpDiscoverySpi - Successfully bound to TCP port [port=47500, localHost=/172.16.1.98]
WARN o.g.g.s.d.t.i.m.GridTcpDiscoveryMulticastIpFinder - GridTcpDiscoveryMulticastIpFinder has no pre-configured addresses (it is recommended in production to specify at least one address in GridTcpDiscoveryMulticastIpFinder.getAddresses() configuration property)
>>> +------------------------------------------------------------------------------------+
>>> GridGain ver. platform-os-6.0.2#20140323-sha1:f9c796a1b29d2d7ce2737e681cbe578b5315d79f
>>> +------------------------------------------------------------------------------------+
>>> OS name: Linux 2.6.32-358.2.1.el6.x86_64 amd64
>>> CPU(s): 2
>>> Heap: 0.83GB
>>> VM name: 2646#node.novalocal
>>> Grid name: nextflow
>>> Local node [ID=CF5DBD14-4BB8-420B-998F-820056AA6D1C, order=1]
>>> Local node addresses: [node.novalocal/172.16.1.98]
>>> Local ports: TCP:8080 TCP:11211 TCP:47100 TCP:47500 TCP:48100
>>> GridGain documentation: http://www.gridgain.com/documentation
INFO o.g.g.k.m.d.GridDiscoveryManager - Topology snapshot [ver=1, nodes=1, CPUs=2, heap=0.83GB]

Answer 1

Usually software firewalls prevent multicast packets. Can you try with firewall disabled on your system?