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Posted to user@cassandra.apache.org by "techpyaasa ." <te...@gmail.com> on 2017/09/08 18:27:22 UTC

Limit on number of connections to Cassandra

Hi

Is there any limit on number of client connections to Cassandra just like
MySQL etc., ?

If YES, what is that & how can we set that?

If NO , how will get to know that node has reached it's capacity serving
client requests/over loaded?

Using C*-2.1.17 , datastax java driver


Thanks
Techpyaasa

Re: Limit on number of connections to Cassandra

Posted by Andy Tolbert <an...@datastax.com>.
Hello,

If I'm understanding the question correctly, as of C* 2.0.15 / 2.1.5 via
CASSANDRA-8086 <https://issues.apache.org/jira/browse/CASSANDRA-8086> you
can limit the maximum number of connections allowed to a C* node via
native_transport_max_concurrent_connections
<http://cassandra.apache.org/doc/latest/configuration/cassandra_config_file.html?highlight=native_transport_max_concurrent_connections#native-transport-max-concurrent-connections>
in
cassandra.yaml.

As far as the java driver goes, newer versions (i.e. 2.1.10+, 3.0.1+)
behave in such a way that as long as the driver can maintain at least one
connection to a node it considers it up.  If it can no longer maintain
connection it will not send requests to it and will try reconnecting per
the configured retry policy.  By default with C* 2.1+ (protocol version
V3+), the driver will only maintain one connection per host in local data
center, although you can tweak this using PoolingOptions
<http://docs.datastax.com/en/developer/java-driver/3.3/manual/pooling/#configuring-the-connection-pool>
.

Thanks,
Andy


On Fri, Sep 8, 2017 at 1:27 PM techpyaasa . <te...@gmail.com> wrote:

> Hi
>
> Is there any limit on number of client connections to Cassandra just like
> MySQL etc., ?
>
> If YES, what is that & how can we set that?
>
> If NO , how will get to know that node has reached it's capacity serving
> client requests/over loaded?
>
> Using C*-2.1.17 , datastax java driver
>
>
> Thanks
> Techpyaasa
>