Andreas Neumann created TEPHRA-256:
--------------------------------------
Summary: Transaction Log Synchronization is overly complex and too
restrictive
Key: TEPHRA-256
URL: https://issues.apache.org/jira/browse/TEPHRA-256
Project: Tephra
Issue Type: Bug
Reporter: Andreas Neumann
Assignee: Poorna Chandra
It is had to understand what is going on in this code. There is a lot of
synchronization, which essentially makes the log writing a bottleneck under
high load (and we have seen that in some deployments).
Also, some threads my return from the sync() before all the edits have been
synced. This is because there is no synchronization around the sync() on the
file system, and multiple threads my call it at the same time.
SequenceFileWriter does not appear to be thread-safe, so some calls may return
before the sync is actually done. However, it is hard to argue because because
sync() is not documented well, and it is also deprecated and replaced with
hflush() and hsync(), which have clearer semantics.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
