IgniteHeartbeat Thread throws a NullPointerException during start of Ignite service

[michaeldinzinger]

Hi all, thanks for your great work! It appeared to me that the IgniteHeartbeat thread is killed due to a NullPointerException as soon as the IgniteService is started. This happens due to a race condition during the instantiation of the frontier service (class URLFrontierServer line 172). At the end of the instantiation, the IgniteHeartbeat Thread is started (class IgniteService line 392). In case the hostname and the port is not set yet (class URLFrontierServer line 179) when the IgniteHeartbeat Thread is started and calls the sendHeartbeat() method for the first time, the thread throws a NullPointerException.

[16:05:36] Ignite node started OK (id=3d3198aa)
[16:05:36] >>> Ignite cluster is in INACTIVE state (limited functionality available). Use control.(sh|bat) script or IgniteCluster.state(ClusterState.ACTIVE) to change the state.
[16:05:36] Topology snapshot [ver=1, locNode=3d3198aa, servers=1, clients=0, state=INACTIVE, CPUs=12, offheap=6.3GB, heap=2.0GB]
16:05:36.916 [main] INFO  c.u.service.ignite.IgniteService - Ignite loaded in 3371 msec
16:05:36.918 [main] INFO  c.u.service.ignite.IgniteService - Scanning tables to rebuild queues... (can take a long time)
16:05:36.919 [main] INFO  c.u.service.ignite.IgniteService - 0 queues discovered in 3 msec
Exception in thread "IgniteHeartbeat" java.lang.NullPointerException: Ouch! Argument cannot be null: key
    at org.apache.ignite.internal.util.GridArgumentCheck.notNull(GridArgumentCheck.java:49)
    at org.apache.ignite.internal.util.GridArgumentCheck.notNull(GridArgumentCheck.java:61)
    at org.apache.ignite.internal.processors.cache.GridCacheAdapter.put(GridCacheAdapter.java:2485)
    at org.apache.ignite.internal.processors.cache.GridCacheAdapter.put(GridCacheAdapter.java:2466)
    at org.apache.ignite.internal.processors.cache.IgniteCacheProxyImpl.put(IgniteCacheProxyImpl.java:1332)
    at org.apache.ignite.internal.processors.cache.GatewayProtectedCacheProxy.put(GatewayProtectedCacheProxy.java:867)
    at crawlercommons.urlfrontier.service.ignite.IgniteHeartbeat.sendHeartBeat(IgniteHeartbeat.java:40)
    at crawlercommons.urlfrontier.service.cluster.Hearbeat.run(Hearbeat.java:75)
16:05:37.123 [IgniteQueueChecker] INFO  c.u.service.ignite.IgniteService - Found 0 queues, removed 0, total 0 in 8
16:05:37.470 [main] INFO  c.u.service.URLFrontierServer - Started URLFrontierServer [IgniteService] on port 7071 as localhost:7071

[jnioche]

thanks for reporting this @michaeldinzinger any chance you could submit a PR to fix the issue?

[michaeldinzinger]

Yes sure:) I created a pull request #75 which also tackles the issues #73 and #74 (in case they are real issues)

[michaeldinzinger]

I created another one #76 to make it DCO compliant