Jilles van Gurp created ZOOKEEPER-1476:
------------------------------------------
Summary: ipv6 reverse dns related timeouts on OSX connecting to
localhost
Key: ZOOKEEPER-1476
URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1476
Project: ZooKeeper
Issue Type: Bug
Reporter: Jilles van Gurp
Priority: Minor
We observed a weird, random issue trying to create zookeeper client connections
on osx. Sometimes it would work and sometimes it would fail. Also it is
randomly very slow. It turns out both issues have the same cause.
My hosts file on osx (which is an unmodified default one), lists three entries
for localhost:
127.0.0.1 localhost
::1 localhost
fe80::1%lo0 localhost
We saw zookeeper trying to connect to fe80:0:0:0:0:0:0:1%1 sometimes, which is
not listed (actually one in four times, it seems to round robin over the
addresses).
Whenever that happens, it sometimes works and sometimes fails. In both cases
it's very slow. Reason: the reverse lookup for fe80:0:0:0:0:0:0:1%1 can't be
resolved using the hosts file and it falls back to actually using the dns.
Sometimes it actually works but other times it fails/times out after about 5
seconds. Probably a platform specific settings with dns setup hide this problem
on linux.
As a workaround, we preresolve localhost now:
Inet4Address.getByName("localhost"). This always resolves to 127.0.0.1 on my
machine and works fast.
This fixes the issue for us. We're not sure where the fe80:0:0:0:0:0:0:1%1
address comes from though. I don't recall having this issue with other server
side software so this might be a mix of platform setup, osx specific defaults,
and zookeeper behavior.
I've seen one ticket that relates to ipv6 in zookeeper that might be related:
ZOOKEEPER-667. Perhaps the workaround for that ticket introduced this problem?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
