The javadoc for SimpleDateFormat will confirm: this class isn’t thread safe. Internally, it mutates several mutable fields in the process of parsing and formatting. Accessing instances of SimpleDateFormat from multiple threads concurrently (to perform either operation) can lead to either unexpected “impossible“ exceptions or silently corrupt results.

To fix this issue, the following usages (at least, I only looked through 1.3.8 not master to find these) need to be modified to either put the SimpleDateFormat inside of a ThreadLocal, create each SimpleDateFormat instance per usage, or use JDK 8’s DateTimeFormatter which is immutable and thread safe:

• Hive-JSON-Serde/json-serde-cdh5-shim/src/main/java/org/openx/data/jsonserde/objectinspector/primitive/JavaStringDateObjectInspector.java

  Line 16 in 8d5c1bf

  private static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

• Hive-JSON-Serde/json-serde/src/main/java/org/openx/data/jsonserde/objectinspector/primitive/ParsePrimitiveUtils.java

  Line 28 in 8d5c1bf

  public final static DateFormat UTC_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");

• Hive-JSON-Serde/json-serde/src/main/java/org/openx/data/jsonserde/objectinspector/primitive/ParsePrimitiveUtils.java

  Line 29 in 8d5c1bf

  public final static DateFormat OFFSET_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");

• Hive-JSON-Serde/json-serde/src/main/java/org/openx/data/jsonserde/objectinspector/primitive/ParsePrimitiveUtils.java

  Line 30 in 8d5c1bf

  public final static DateFormat NON_UTC_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

• Hive-JSON-Serde/json-serde/src/main/java/org/openx/data/jsonserde/objectinspector/primitive/ParsePrimitiveUtils.java

  Line 31 in 8d5c1bf

  static DateFormat[] dateFormats = { UTC_FORMAT, OFFSET_FORMAT,NON_UTC_FORMAT};