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Zookeeper, mail # dev - reverse name lookup?


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Re: reverse name lookup?
Marshall McMullen 2012-05-23, 15:09
OK, I think I may have found the culprit.

There are lots of places where we call InetSocketAddress.getHostName(). The
documentation on this is worthless, but looking at the openjdk source
code, getHostName
absolutely triggers a reverse DNS lookup.

I'm going to try modifying these to just use the toString function (which
doesn't do the lookup) and see if I get past this problem.

I'll update with progress.

On Wed, May 23, 2012 at 9:02 AM, Marshall McMullen <
[EMAIL PROTECTED]> wrote:

> Sorry, had jury duty yesterday so wasn't able to respond until now....
>
> No, leader election fails as well. What's interesting is it looks like the
> bind of the leader socket/port itself is never completing. I enable
> tracing, and without a valid DNS server running, all zookeeper servers just
> hang at startup. In the trace file, the last thing printed in every log
> file before the hang is:
>
> 2012-05-23 08:49:29,882 [myid:1] - INFO  [main:QuorumPeerMain@131][] -
> Starting quorum peer
> 2012-05-23 08:49:29,893 [myid:1] - INFO  [main:NIOServerCnxnFactory@108][]
> - binding to port /127.0.0.2:2181
> 2012-05-23 08:49:29,899 [myid:1] - INFO  [main:QuorumPeer@1107][] -
> tickTime set to 2000
> 2012-05-23 08:49:29,899 [myid:1] - INFO  [main:QuorumPeer@1127][] -
> minSessionTimeout set to -1
> 2012-05-23 08:49:29,899 [myid:1] - INFO  [main:QuorumPeer@1138][] -
> maxSessionTimeout set to -1
> 2012-05-23 08:49:29,899 [myid:1] - INFO  [main:QuorumPeer@1153][] -
> initLimit set to 10
>
>
> Now, if I repeat the test with a functioning DNS server running, it churns
> along as expected:
>
> 2012-05-23 08:58:03,468 [myid:1] - INFO  [main:QuorumPeerMain@131][] -
> Starting quorum peer
> 2012-05-23 08:58:03,479 [myid:1] - INFO  [main:NIOServerCnxnFactory@108][]
> - binding to port /127.0.0.2:2181
> 2012-05-23 08:58:03,485 [myid:1] - INFO  [main:QuorumPeer@1107][] -
> tickTime set to 2000
> 2012-05-23 08:58:03,485 [myid:1] - INFO  [main:QuorumPeer@1127][] -
> minSessionTimeout set to -1
> 2012-05-23 08:58:03,485 [myid:1] - INFO  [main:QuorumPeer@1138][] -
> maxSessionTimeout set to -1
> 2012-05-23 08:58:03,485 [myid:1] - INFO  [main:QuorumPeer@1153][] -
> initLimit set to 10
> 2012-05-23 08:58:03,665 [myid:1] - INFO  [main:QuorumPeer@620][] -
> currentEpoch not found! Creating with a reasonable default of 0. This
> should only happen when you are upgrading your installation
> 2012-05-23 08:58:03,666 [myid:1] - INFO  [main:QuorumPeer@635][] -
> acceptedEpoch not found! Creating with a reasonable default of 0. This
> should only happen when you are upgrading your installation
> 2012-05-23 08:58:03,670 [myid:1] - INFO
>  [NIOServerCxn.Factory:/127.0.0.2:2181:NIOServerCnxnFactory@227][] -
> Accepted socket connection from /127.0.0.1:54763
> 2012-05-23 08:58:03,672 [myid:1] - INFO
>  [QuorumPeerListener:QuorumCnxManager$Listener@530][] - My election bind
> port: /127.0.0.2:2183
> 2012-05-23 08:58:03,675 [myid:1] - WARN
>  [NIOServerCxn.Factory:/127.0.0.2:2181:NIOServerCnxn@354][] - Exception
> causing close of session 0x0 due to java.io.IOException: ZooKeeperServer
> not running
> 2012-05-23 08:58:03,675 [myid:1] - DEBUG [QuorumPeer[myid=1]/127.0.0.2:2181
> :QuorumPeer@825][] - Starting quorum peer
> 2012-05-23 08:58:03,675 [myid:1] - DEBUG
> [NIOServerCxn.Factory:/127.0.0.2:2181:NIOServerCnxn@358][] - IOException
> stack trace
>
> So the leader socket/port bind appears to hang indefinitely without DNS.
> As I mentioned before, we are using IP addresses only and in our customer
> environment we will not always have DNS so we'd really like to remove this
> requirement...Anyone have ideas where I can start looking to figure this
> out?
>
>
> On Tue, May 22, 2012 at 1:19 AM, Flavio Junqueira <[EMAIL PROTECTED]>wrote:
>
>> Are they able to elect a leader or not even that?
>>
>> -Flavio
>>
>> On May 22, 2012, at 6:31 AM, Marshall McMullen wrote:
>>
>> > In our Linux environment, we're using IP addresses only for all our
>> > zookeeper servers. We've observed that without a functioning DNS server,