TrxRegionEndpoint coprocessor performScan error
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Trafodion |
Fix Committed
|
High
|
Selvaganesan Govindarajan |
Bug Description
During the execution of the SQL regression test, catman1/TEST137, an occasional HBase error is returned.
55> Unexpected EXCEPTION : *** ERROR[8448] Unable to access Hbase interface. Call to ExpHbaseInterfa
java.util.
java.util.
java.util.
org.trafodion.
. [2015-01-29 06:07:47]
Analysis has shown that a TrxRegionEndpoint coprocessor "openScanner" API call error can be reported as a TrxRegionEndpoint coprocessor "performScan" error.
The TrxRegionEndpoint coprocessor "performScan" API call error can also be returned when SQL performs a multi-threaded prefetch operation.
The TrxRegionEndpoint coprocessor "performScan" API calls can be executed out of sequence causing scanner sequence numbers to
not match. The coprocessor returns the error, as the client/server scanner sequence numbers must match.
Per Selva --
If a scanner is closed before the next call completes, it results in OutOfOrderScann erNextException . Trafodion engine can close the scanner when the next is active in a different thread with pre-fetch concept. The fix is to cancel the pending next before the scanner is closed.
Thanks to Oliver and Joanie for tracking this down. Ran catman1/TEST137 many times successfully