Arpit Agarwal created HDFS-8163:
-----------------------------------
Summary: Using monotonicNow for block report scheduling causes
test failures on recently restarted systems
Key: HDFS-8163
URL: https://issues.apache.org/jira/browse/HDFS-8163
Project: Hadoop HDFS
Issue Type: Bug
Components: datanode
Affects Versions: 2.6.1
Reporter: Arpit Agarwal
Priority: Blocker
{{BPServiceActor#blockReport}} has the following check:
{code}
List<DatanodeCommand> blockReport() throws IOException {
// send block report if timer has expired.
final long startTime = monotonicNow();
if (startTime - lastBlockReport <= dnConf.blockReportInterval) {
return null;
}
{code}
Many tests set lastBlockReport to zero to trigger an immediate block report via
{{BPServiceActor#triggerBlockReportForTests}}. However if the machine was
restarted recently then this startTime could be less than
{{dnConf.blockReportInterval}} and the block report is not sent.
{{Time#monotonicNow}} uses {{System#nanoTime}} which represents time elapsed
since an arbitrary origin. The time should be used only for comparison with
values returned by {{System#nanoTime}}.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
