Hi, While running Adam Genomics [https://github.com/bigdatagenomics/adam], which uses Avro, on Apache Spark we discovered that threads (tasks in Spark context) block inside Avro while executing the getDefaultValue(Field field) method inside GenericData.java [https://github.com/apache/avro/blob/trunk/lang/java/avro/src/main/java/org/apache/avro/generic/GenericData.java]
Cause: use of SynchronizedMap Resolution: use ConcurrentHashMap instead Affected versions: 1.7.4 and above Issue and associated patch are already logged in jira (https://issues.apache.org/jira/browse/AVRO-1760). After applying the patch, we are able to gain a 3.4x performance improvement. For details, see attached. Thank you, Mulugeta
