You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@cassandra.apache.org by Anishek Agarwal <an...@gmail.com> on 2015/04/21 13:45:21 UTC
Network transfer to one node twice as others
Hello,
We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
writer test (written in java) that runs 50 threads to populate data to a
single table in a single keyspace.
when i look at the "iftop" I see that the amount of network transfer
happening on two nodes is same but on one of the nodes its almost 2ice as
the other two, Any reason that would be the case ?
Thanks
Anishek
Re: Network transfer to one node twice as others
Posted by Anishek Agarwal <an...@gmail.com>.
Thanks Ryan,
I am using the java driver with token aware policy(dcawarepolicy) we have
all nodes on one DC. model for now is
partition_key, value
I think by hot partition you mean insertions to the same partition key ? we
have RF:3 and CL: 1 (will re run with local quorum as that is what we will
use eventually)
Closing this discussion here, reposting it on javax driver mailing list.
On Wed, Apr 22, 2015 at 7:56 PM, Ryan Svihla <rs...@foundev.pro> wrote:
> Totally depends on the load balancing policy of your driver, your data
> model, consistently level and you’re replication factor. The default token
> aware policy for the DataStax java driver up to 2.1.4 and 2.0.9 would
> largely behave this way if you combined it with a hot partition, and all
> other languages of the DataStax driver to my knowledge behave the same way
> today.
>
> If you’re using the DataStax driver go ahead and change the load balancing
> policy to something like DCAwareRoundRobin only and see if the result is
> different.
>
> Honestly this is probably not a question for the dev mailing list, or even
> the Cassandra user mailing list but likely for whatever driver you’re using.
>
> - Ryan
>
> > On Apr 22, 2015, at 9:16 AM, Anishek Agarwal <an...@gmail.com> wrote:
> >
> > Nope not using thrift
> > On 22-Apr-2015 7:24 pm, "Benedict Elliott Smith" <
> belliottsmith@datastax.com>
> > wrote:
> >
> >> If you're connecting via thrift, all your traffic is most likely being
> >> routed to just one node, which then communicates with the other nodes
> for
> >> you.
> >>
> >> On Wed, Apr 22, 2015 at 6:11 AM, Anishek Agarwal <an...@gmail.com>
> >> wrote:
> >>
> >>> Forwarding it here, someone with Cassandra internals knowledge can help
> >> may
> >>> be....
> >>>
> >>> Additionally, i observe the same behavior for reads too where Network
> >> read
> >>> from one node is twice than other two..
> >>>
> >>>
> >>> ---------- Forwarded message ----------
> >>> From: Anishek Agarwal <an...@gmail.com>
> >>> Date: Tue, Apr 21, 2015 at 5:15 PM
> >>> Subject: Network transfer to one node twice as others
> >>> To: "user@cassandra.apache.org" <us...@cassandra.apache.org>
> >>>
> >>>
> >>> Hello,
> >>>
> >>> We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
> >>> writer test (written in java) that runs 50 threads to populate data to
> a
> >>> single table in a single keyspace.
> >>>
> >>> when i look at the "iftop" I see that the amount of network transfer
> >>> happening on two nodes is same but on one of the nodes its almost 2ice
> as
> >>> the other two, Any reason that would be the case ?
> >>>
> >>> Thanks
> >>> Anishek
> >>>
> >>
>
>
Re: Network transfer to one node twice as others
Posted by Ryan Svihla <rs...@foundev.pro>.
Totally depends on the load balancing policy of your driver, your data model, consistently level and you’re replication factor. The default token aware policy for the DataStax java driver up to 2.1.4 and 2.0.9 would largely behave this way if you combined it with a hot partition, and all other languages of the DataStax driver to my knowledge behave the same way today.
If you’re using the DataStax driver go ahead and change the load balancing policy to something like DCAwareRoundRobin only and see if the result is different.
Honestly this is probably not a question for the dev mailing list, or even the Cassandra user mailing list but likely for whatever driver you’re using.
- Ryan
> On Apr 22, 2015, at 9:16 AM, Anishek Agarwal <an...@gmail.com> wrote:
>
> Nope not using thrift
> On 22-Apr-2015 7:24 pm, "Benedict Elliott Smith" <be...@datastax.com>
> wrote:
>
>> If you're connecting via thrift, all your traffic is most likely being
>> routed to just one node, which then communicates with the other nodes for
>> you.
>>
>> On Wed, Apr 22, 2015 at 6:11 AM, Anishek Agarwal <an...@gmail.com>
>> wrote:
>>
>>> Forwarding it here, someone with Cassandra internals knowledge can help
>> may
>>> be....
>>>
>>> Additionally, i observe the same behavior for reads too where Network
>> read
>>> from one node is twice than other two..
>>>
>>>
>>> ---------- Forwarded message ----------
>>> From: Anishek Agarwal <an...@gmail.com>
>>> Date: Tue, Apr 21, 2015 at 5:15 PM
>>> Subject: Network transfer to one node twice as others
>>> To: "user@cassandra.apache.org" <us...@cassandra.apache.org>
>>>
>>>
>>> Hello,
>>>
>>> We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
>>> writer test (written in java) that runs 50 threads to populate data to a
>>> single table in a single keyspace.
>>>
>>> when i look at the "iftop" I see that the amount of network transfer
>>> happening on two nodes is same but on one of the nodes its almost 2ice as
>>> the other two, Any reason that would be the case ?
>>>
>>> Thanks
>>> Anishek
>>>
>>
Re: Network transfer to one node twice as others
Posted by Anishek Agarwal <an...@gmail.com>.
Nope not using thrift
On 22-Apr-2015 7:24 pm, "Benedict Elliott Smith" <be...@datastax.com>
wrote:
> If you're connecting via thrift, all your traffic is most likely being
> routed to just one node, which then communicates with the other nodes for
> you.
>
> On Wed, Apr 22, 2015 at 6:11 AM, Anishek Agarwal <an...@gmail.com>
> wrote:
>
> > Forwarding it here, someone with Cassandra internals knowledge can help
> may
> > be....
> >
> > Additionally, i observe the same behavior for reads too where Network
> read
> > from one node is twice than other two..
> >
> >
> > ---------- Forwarded message ----------
> > From: Anishek Agarwal <an...@gmail.com>
> > Date: Tue, Apr 21, 2015 at 5:15 PM
> > Subject: Network transfer to one node twice as others
> > To: "user@cassandra.apache.org" <us...@cassandra.apache.org>
> >
> >
> > Hello,
> >
> > We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
> > writer test (written in java) that runs 50 threads to populate data to a
> > single table in a single keyspace.
> >
> > when i look at the "iftop" I see that the amount of network transfer
> > happening on two nodes is same but on one of the nodes its almost 2ice as
> > the other two, Any reason that would be the case ?
> >
> > Thanks
> > Anishek
> >
>
Re: Network transfer to one node twice as others
Posted by Benedict Elliott Smith <be...@datastax.com>.
If you're connecting via thrift, all your traffic is most likely being
routed to just one node, which then communicates with the other nodes for
you.
On Wed, Apr 22, 2015 at 6:11 AM, Anishek Agarwal <an...@gmail.com> wrote:
> Forwarding it here, someone with Cassandra internals knowledge can help may
> be....
>
> Additionally, i observe the same behavior for reads too where Network read
> from one node is twice than other two..
>
>
> ---------- Forwarded message ----------
> From: Anishek Agarwal <an...@gmail.com>
> Date: Tue, Apr 21, 2015 at 5:15 PM
> Subject: Network transfer to one node twice as others
> To: "user@cassandra.apache.org" <us...@cassandra.apache.org>
>
>
> Hello,
>
> We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
> writer test (written in java) that runs 50 threads to populate data to a
> single table in a single keyspace.
>
> when i look at the "iftop" I see that the amount of network transfer
> happening on two nodes is same but on one of the nodes its almost 2ice as
> the other two, Any reason that would be the case ?
>
> Thanks
> Anishek
>
Fwd: Network transfer to one node twice as others
Posted by Anishek Agarwal <an...@gmail.com>.
Forwarding it here, someone with Cassandra internals knowledge can help may
be....
Additionally, i observe the same behavior for reads too where Network read
from one node is twice than other two..
---------- Forwarded message ----------
From: Anishek Agarwal <an...@gmail.com>
Date: Tue, Apr 21, 2015 at 5:15 PM
Subject: Network transfer to one node twice as others
To: "user@cassandra.apache.org" <us...@cassandra.apache.org>
Hello,
We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
writer test (written in java) that runs 50 threads to populate data to a
single table in a single keyspace.
when i look at the "iftop" I see that the amount of network transfer
happening on two nodes is same but on one of the nodes its almost 2ice as
the other two, Any reason that would be the case ?
Thanks
Anishek