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Posted to user@cassandra.apache.org by Björn Hachmann <bj...@metrigo.de> on 2015/05/05 17:20:22 UTC

Unable to connect via cqlsh or datastax-driver

Hello,

I am unable to connect to the nodes of our second datacenter, not even from
localhost.

The error message I receive is:

Connection error: ('Unable to connect to any servers', {'...':
OperationTimedOut('errors=None, last_host=None',)})


I already checked some things:

   - The node starts to listen for cql clients on the expected port
   (extract from the log):
   Starting listening for CQL clients on .../192.168.1.23:9042
   - The port is open and accepts connections via telnet.
   - nodetool info works and returns:
   Gossip active          : true
   Thrift active          : true
   Native Transport active: true
   - nodetool netstats:
   Mode: NORMAL
   - nodetool statusbinary
   running

Any help would be highly appreciated! Thank you very much.

Kind regards
Björn

Re: Unable to connect via cqlsh or datastax-driver

Posted by Björn Hachmann <bj...@metrigo.de>.
Hi,

as it turned out, the problem was that our secondary DC was indeed
overloaded and therefore dropped read requests which where executed during
connection establishment.

The cause of this overload might be interesting: Actually we ran reversed
values for dclocal_read_repair_chance and read_repair_chance.
dc_local_read_repair_chance had to be 0.1 and read_repair_chance 0.0, but
it was otherwise round. Obviously this was no problem until we setup the
second DC.

Thanks for your time.

Kind regards
Björn Hachmann


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2015-05-06 8:44 GMT+02:00 Anishek Agarwal <an...@gmail.com>:

> did u setup CQLSH_HOST variable to the ip so cqlsh uses that ?
>
> On Tue, May 5, 2015 at 8:50 PM, Björn Hachmann <bjoern.hachmann@metrigo.de
> > wrote:
>
>> Hello,
>>
>> I am unable to connect to the nodes of our second datacenter, not even
>> from localhost.
>>
>> The error message I receive is:
>>
>> Connection error: ('Unable to connect to any servers', {'...':
>> OperationTimedOut('errors=None, last_host=None',)})
>>
>>
>> I already checked some things:
>>
>>    - The node starts to listen for cql clients on the expected port
>>    (extract from the log):
>>    Starting listening for CQL clients on .../192.168.1.23:9042
>>    - The port is open and accepts connections via telnet.
>>    - nodetool info works and returns:
>>    Gossip active          : true
>>    Thrift active          : true
>>    Native Transport active: true
>>    - nodetool netstats:
>>    Mode: NORMAL
>>    - nodetool statusbinary
>>    running
>>
>> Any help would be highly appreciated! Thank you very much.
>>
>> Kind regards
>> Björn
>>
>
>

Re: Unable to connect via cqlsh or datastax-driver

Posted by Anishek Agarwal <an...@gmail.com>.
did u setup CQLSH_HOST variable to the ip so cqlsh uses that ?

On Tue, May 5, 2015 at 8:50 PM, Björn Hachmann <bj...@metrigo.de>
wrote:

> Hello,
>
> I am unable to connect to the nodes of our second datacenter, not even
> from localhost.
>
> The error message I receive is:
>
> Connection error: ('Unable to connect to any servers', {'...':
> OperationTimedOut('errors=None, last_host=None',)})
>
>
> I already checked some things:
>
>    - The node starts to listen for cql clients on the expected port
>    (extract from the log):
>    Starting listening for CQL clients on .../192.168.1.23:9042
>    - The port is open and accepts connections via telnet.
>    - nodetool info works and returns:
>    Gossip active          : true
>    Thrift active          : true
>    Native Transport active: true
>    - nodetool netstats:
>    Mode: NORMAL
>    - nodetool statusbinary
>    running
>
> Any help would be highly appreciated! Thank you very much.
>
> Kind regards
> Björn
>