Index: ql/src/java/org/apache/hadoop/hive/ql/exec/FunctionRegistry.java =================================================================== --- ql/src/java/org/apache/hadoop/hive/ql/exec/FunctionRegistry.java (revision 1354789) +++ ql/src/java/org/apache/hadoop/hive/ql/exec/FunctionRegistry.java (working copy) @@ -22,6 +22,7 @@ import java.lang.reflect.Method; import java.net.URL; import java.util.ArrayList; +import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedHashMap; @@ -241,7 +242,7 @@ /** * The mapping from expression function names to expression classes. */ - static Map mFunctions = new LinkedHashMap(); + static Map mFunctions = Collections.synchronizedMap(new LinkedHashMap()); static { registerUDF("concat", UDFConcat.class, false); registerUDF("substr", UDFSubstr.class, false);