[KUDU-3273] NPE in AsyncKuduClient.discoverTablets() instead of NonCoveredRangeException

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.10.0, 1.10.1, 1.11.0, 1.12.0, 1.11.1, 1.13.0, 1.14.0
• Fix Version/s: 1.15.0
• Component/s: client, java
• Labels: Java client
• Assignee: Unassigned
• Reporter: Alexey Serbin
• Created: 07/Apr/21 22:53
• Updated: 07/May/21 07:06
• Resolved: 07/May/21 07:06

Description

It's reported that in some scenarios AsyncKuduClient.discoverTablets() throws NullPointerException instead of NonCoveredRangeException. As the source code suggests, that might happen when TableLocationsCache.get() returns null: https://github.com/apache/kudu/blob/0e1a1545b827d9a3d5d50fd3d54f60bdea83f40c/java/kudu-client/src/main/java/org/apache/kudu/client/TableLocationsCache.java#L84

The exact sequence of actions to reproduce the issue wasn't provided, but the following trace was reported with kudu-client of 1.10.0 version, but I guess the issue is present even in Kudu 1.14.0 (see https://github.com/apache/kudu/blob/f396e485089f43c925ccbd41efe951b2ad5187b9/java/kudu-client/src/main/java/org/apache/kudu/client/AsyncKuduClient.java#L2428)

java.lang.NullPointerException
 	at org.apache.kudu.client.AsyncKuduClient.discoverTablets(AsyncKuduClient.java:2335)
 	at org.apache.kudu.client.AsyncKuduClient$MasterLookupCB.call(AsyncKuduClient.java:2192)
 	at org.apache.kudu.client.AsyncKuduClient$MasterLookupCB.call(AsyncKuduClient.java:2173)
 	at com.stumbleupon.async.Deferred.doCall(Deferred.java:1280)
 	at com.stumbleupon.async.Deferred.addCallbacks(Deferred.java:685)
 	at com.stumbleupon.async.Deferred.addCallback(Deferred.java:721)
 	at org.apache.kudu.client.AsyncKuduClient.locateTablet(AsyncKuduClient.java:1726)
 	at org.apache.kudu.client.AsyncKuduClient.loopLocateTable(AsyncKuduClient.java:1851)
 	at org.apache.kudu.client.AsyncKuduClient.locateTable(AsyncKuduClient.java:1894)
 	at org.apache.kudu.client.AsyncKuduClient.syncLocateTable(AsyncKuduClient.java:1798)
 	at org.apache.kudu.client.KuduTable.getTabletsLocations(KuduTable.java:233)
 	at org.apache.kudu.client.KuduTable.getTabletsLocations(KuduTable.java:213)