Thanks for that, that helps a lot. The next thing to check might be
whether or not your application actually has access to the other nodes.
With that topology, and assuming all the nodes you included in your
original graph are in the 'WDC' data center, I'd be inclined to look for a
network issue of some kind.
Also, it probably doesn't matter, but what OS / Distribution are you
running the servers and clients on?
Check with netcat or something that you can reach all the configured ports
from your application server, but also the driver itself offers some
introspection into its view of individual connection health. This is a
little bit ugly, but this is how we include information about connection
status in an API for health monitoring from a Scala application using the
Java driver; hopefully you can use it to see how to access information
about the driver's view of host health from the application's perspective.
Most importantly I'd suggest looking for host.isUp status and
LoadBalancingPolicy.distance(host) to see that it considers all the hosts
in your target datacenter to be LOCAL.
"hosts" -> {
val hosts: Map[String, Map[String, mutable.Set[Host]]] =
connection.getMetadata
.getAllHosts.asScala
.groupBy(_.getDatacenter)
.mapValues(_.groupBy(_.getRack))
val lbp: LoadBalancingPolicy =
connection.getConfiguration.getPolicies.getLoadBalancingPolicy
JsObject(hosts.map { case (dc: String, rackAndHosts) =>
dc -> JsObject(rackAndHosts.map { case (rack: String, hosts:
mutable.Set[Host]) =>
rack -> JsArray(hosts.map { host =>
Json.obj(
"address" -> host.getAddress.toString,
"socketAddress" -> host.getSocketAddress.toString,
"cassandraVersion" -> host.getCassandraVersion.toString,
"isUp" -> host.isUp,
"hostDistance" -> lbp.distance(host).toString
)
}.toSeq)
}.toSeq)
}.toSeq)
},
On Wed, Apr 13, 2016 at 10:50 PM Anishek Agarwal <anis...@gmail.com> wrote:
> here is the output: every node in a single DC is in the same rack.
>
> Datacenter: WDC5
>
> ================
>
> Status=Up/Down
>
> |/ State=Normal/Leaving/Joining/Moving
>
> -- Address Load Tokens Owns (effective) Host ID
> Rack
>
> UN 10.125.138.33 299.22 GB 256 64.2%
> 8aaa6015-d444-4551-a3c5-3257536df476 RAC1
>
> UN 10.125.138.125 329.38 GB 256 70.3%
> 70be44a2-de17-41f1-9d3a-6a0be600eedf RAC1
>
> UN 10.125.138.129 305.11 GB 256 65.5%
> 0fbc7f44-7062-4996-9eba-2a05ae1a7032 RAC1
>
> Datacenter: WDC
>
> ===============
>
> Status=Up/Down
>
> |/ State=Normal/Leaving/Joining/Moving
>
> -- Address Load Tokens Owns (effective) Host ID
> Rack
>
> UN 10.124.114.105 151.09 GB 256 38.0%
> c432357d-bf81-4eef-98e1-664c178a3c23 RAC1
>
> UN 10.124.114.110 150.15 GB 256 36.9%
> 6f92d32e-1c64-4145-83d7-265c331ea408 RAC1
>
> UN 10.124.114.108 170.1 GB 256 41.3%
> 040ae7e5-3f1e-4874-8738-45edbf576e12 RAC1
>
> UN 10.124.114.98 165.34 GB 256 37.6%
> cdc69c7d-b9d6-4abd-9388-1cdcd35d946c RAC1
>
> UN 10.124.114.113 145.22 GB 256 35.7%
> 1557af04-e658-4751-b984-8e0cdc41376e RAC1
>
> UN 10.125.138.59 162.65 GB 256 38.6%
> 9ba1b7b6-5655-456e-b1a1-6f429750fc96 RAC1
>
> UN 10.124.114.97 164.03 GB 256 36.9%
> c918e497-498e-44c3-ab01-ab5cb4d48b09 RAC1
>
> UN 10.124.114.118 139.62 GB 256 35.1%
> 2bb0c265-a5d4-4cd4-8f50-13b5a9a891c9 RAC1
>
> On Thu, Apr 14, 2016 at 4:48 AM, Eric Stevens <migh...@gmail.com> wrote:
>
>> The output of nodetool status would really help answer some questions. I
>> take it the 8 hosts in your graph are in the same DC. Are the four serving
>> writes in the same logical or physical rack (as Cassandra sees it), while
>> the others are not?
>>
>> On Tue, Apr 12, 2016 at 10:48 PM Anishek Agarwal <anis...@gmail.com>
>> wrote:
>>
>>> We have two DC one with the above 8 nodes and other with 3 nodes.
>>>
>>>
>>>
>>> On Tue, Apr 12, 2016 at 8:06 PM, Eric Stevens <migh...@gmail.com> wrote:
>>>
>>>> Maybe include nodetool status here? Are the four nodes serving reads
>>>> in one DC (local to your driver's config) while the others are in another?
>>>>
>>>> On Tue, Apr 12, 2016, 1:01 AM Anishek Agarwal <anis...@gmail.com>
>>>> wrote:
>>>>
>>>>> hello,
>>>>>
>>>>> we have 8 nodes in one cluster and attached is the traffic patterns
>>>>> across the nodes.
>>>>>
>>>>> its very surprising that only 4 nodes show transmitting (purple)
>>>>> packets.
>>>>>
>>>>> our driver configuration on clients has the following load balancing
>>>>> configuration :
>>>>>
>>>>> new TokenAwarePolicy(
>>>>> new
>>>>> DCAwareRoundRobinPolicy(configuration.get(Constants.LOCAL_DATA_CENTRE_NAME,
>>>>> "WDC")),
>>>>> true)
>>>>>
>>>>>
>>>>> any idea what is that we are missing which is leading to this skewed
>>>>> data read patterns
>>>>>
>>>>> cassandra drivers as below:
>>>>>
>>>>> <dependency>
>>>>> <groupId>com.datastax.cassandra</groupId>
>>>>> <artifactId>cassandra-driver-core</artifactId>
>>>>> <version>2.1.6</version>
>>>>> </dependency>
>>>>> <dependency>
>>>>> <groupId>com.datastax.cassandra</groupId>
>>>>> <artifactId>cassandra-driver-mapping</artifactId>
>>>>> <version>2.1.6</version>
>>>>> </dependency>
>>>>>
>>>>> cassandra version is 2.0.17
>>>>>
>>>>> Thanks in advance for the help.
>>>>>
>>>>> Anishek
>>>>>
>>>>>
>>>
>
