Nikita Vetoshkin created ZOOKEEPER-1595:
-------------------------------------------
Summary: Socket's should be read until exhausted
Key: ZOOKEEPER-1595
URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1595
Project: ZooKeeper
Issue Type: Improvement
Components: server
Environment: Tested on Linux x64 with Oracle JDK6
Reporter: Nikita Vetoshkin
Priority: Minor
{{doIO}} method in {{NIOServerCnxn}} should read (and write too) until
{{read}}/{{write}} returns 0.
It's a common practice when working with non-blocking sockets. When an
underlying system call (multiplexer) signals, that socket is readable, one
should {{recv(2)}} all data from kernel buffer until {{recv}} fails with
{{EAGAIN}} or {{EWOULDBLOCK}}.
Patch does two things (I know it's not a good idea to mix several changes, but
I could stand it):
* splits {{doIO}} into {{doRead}} and {{doWrite}}
* wraps reading with {{while (true)}}
It's pretty easy to instrument code with a counter and print how many loops we
performed until the socket was not readable again.
I wrote a simple python script (http://pastebin.com/N5ifM330) which creates
6000 nodes with 5k data each, having 20 concurrent create requests in progress
through one connnection.
With this script and strace attached to JVM I counted epoll_wait syscalls
during the test and I got ~9500 before vs ~8000 after.
Run time measurement is very rough, but it's around ~19 secs. before vs 17.5
after.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
