nifi-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mark Payne <>
Subject Re: Opening socket connection to server localhost/ Will not attempt to authenticate using SASL (unknown error)
Date Fri, 15 Apr 2016 18:31:21 GMT

The INFO level message here is ZooKeeper's way of indicating that you are not configured
to use Kerberized connections when communicating with the ZooKeeper Server. If you are
aware of that, then it is no issue. While it indicates that it is an unknown error, it is
not something
that should be concerning.

The fact that you are seeing Connection refused likely indicates that either (a) your conf/state-mangement.xml
is not configured properly to talk to a ZooKeeper cluster, or (b) that ZooKeeper cluster is
down, or
(c) you are talking to an embedded ZooKeeper cluster and the other nodes in the ZooKeeper
ensemble just
have not yet come up. If this is the case, you should see this only on startup, and it should
then go away after
the other nodes have joined the cluster.

These warning messages are a bit concerning when you first see them, though. I have created
a ticket [1]
to look at how we can tone down the ZooKeeper logging to avoid these 'false alarm' log messages.


[1] <>

> On Apr 14, 2016, at 3:48 PM, McDermott, Chris Kevin (MSDU - STaTS/StorefrontRemote) <>
> I’m seeing this a lot in my logs.  Does anyone have any idea what it is about?
> The cluster view in the UI shows all nodes connected.
> 2016-04-14 19:45:29,310 INFO [Framework Task Thread Thread-2-SendThread(localhost:2181)]
org.apache.zookeeper.ClientCnxn Opening socket connection to server localhost/
Will not attempt to authenticate using SASL (unknown error)
> 2016-04-14 19:45:29,313 WARN [Framework Task Thread Thread-2-SendThread(localhost:2181)]
org.apache.zookeeper.ClientCnxn Session 0x0 for server null, unexpected error, closing socket
connection and attempting reconnect
> Connection refused
> at Method) ~[na:1.8.0_45]
> at ~[na:1.8.0_45]
> at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(
> at org.apache.zookeeper.ClientCnxn$ ~[na:na]

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message