Deploy Configuration Changes to a DataStax Enterprise Cluster
DataStax Mission Control is currently in Public Preview. DataStax Mission Control is not intended for production use, has not been certified for production workloads, and might contain bugs and other functional issues. There is no guarantee that DataStax Mission Control will ever become generally available. DataStax Mission Control is provided on an “AS IS” basis, without warranty or indemnity of any kind. If you are interested in trying out DataStax Mission Control please join the Public Preview. |
To make a configuration change, modify and submit the MissionControlCluster
manifest (object).
This section partially covers configuration options and their values. An example workflow and specific guidance for key configuration topics are provided. |
K8ssandra enables authentication and authorization by default.
It uses the Cassandra default PasswordAuthenticator
and CassandraAuthorizer
functionality.
Explore topic-specific configuration:
Performance impact
Increasing the heap
size parameter that is used by all objects in the cluster may increase the time it takes to find, process, and collect objects included in the heap
.
Timeout settings are adjusted to increase throughput and maintain near ideal requests per second, yielding better performance.
Prerequisites
-
The
kubectl
CLI tool. -
Kubeconfig file
orcontext
pointing to aControl Plane
Kubernetes cluster.
Example of a configuration change
This example uses resource_name.kind.yaml
as the filename of the MissionControlCluster
Custom Resource.
In this file, increase the heap
size and adjust both the write_request_timeout_in_ms
and read_request_timeout_in_ms
settings. Then deploy these configuration changes to an Control Plane
Kubernetes cluster.
In this example a Kubernetes cluster exists with a certain number of nodes. The amount of memory allocated to the Java Virtual Machine (JVM) needs to increase. This memory is shared by instances of all the objects created during the runtime of an application.
The |
Workflow of user and operators
-
User submits a modified
MissionControlCluster
to theControl Plane
cluster. -
Cluster-level operator detects change, modifies datacenter-level resource (
CassandraDatacenter
). -
Datacenter-level operator detects change, modifies rack-level resource.
-
Datacenter-level operator repeats steps 3-5 for all racks in the datacenter.
-
Cluster-level operator repeats steps 2-6 for all datacenters in the cluster.
Procedure
Two Kubernetes clusters exist for this example, a |
-
Modify the
resource_name.kind.yaml
file to define theMissionControlCluster config
specification. Set updatedheap
parameters for thejvmOptions
key. Increase both the initial and the maximum heap sizes from1Gi
to2Gi
. Further modify thewrite_request_timeout_in_ms
andread_request_timeout_in_ms
properties for thecassandraYaml
key as follows:... config: cassandraYaml: write_request_timeout_in_ms: 5000 read_request_timeout_in_ms: 10000 jvmOptions: heap_initial_size: 2Gi heap_max_size: 2Gi
The
MissionControlCluster config:
specification supports 3 keys:-
cassandraYaml
-
dseYaml
-
jvmOptions
-
-
Submit the modified
MissionControlCluster
manifest,resource_name.kind.yaml
, to theControl Plane
Kubernetes cluster from a terminal window.kubectl apply -f resource_name.cassandratask.yaml
-
Monitor the progress of the task from the
Data Plane
cluster by submitting the following command:-
kubectl
command -
Sample result
kubectl get cassandradatacenter dc1 -o yaml
status: cassandraOperatorProgress: Updating conditions: - lastTransitionTime: "2022-10-19T19:08:09Z" message: "" reason: "" status: "True" type: Healthy - lastTransitionTime: "2022-10-19T19:08:10Z" message: "" reason: "" status: "False" type: Stopped ... - lastTransitionTime: "2022-10-19T19:10:43Z" message: "" reason: "" status: "True" type: Updating ...
The
status
field is set to "False" when theUpdating
operation completes.Changes are applied in the same order in which the racks are declared in the
MissionControlCluster
manifest.The configuration changes are applied in a rolling fashion one rack at a time and one DSE node at a time within each rack. The changes also trigger a rolling restart as part of the update. The configuration updates take effect as soon as the update is finished.
-
-
Submit the following command to check the
cassandra.yaml
file and verify that the update is complete:-
kubectl
command -
Sample result
kubectl exec -it demo-dc1-rack1-sts-0 -c cassandra -- cat resources/cassandra/conf/cassandra.yaml | grep ^'write\|read'_request_timeout_in_ms
write_request_timeout_in_ms: 5000 read_request_timeout_in_ms: 10000
-
-
Submit the following command to check the
jvm-server.options
file and verify that it, too, reflects the update:-
kubectl
command -
Sample result
kubectl exec -it demo-dc1-rack1-sts-0 -c cassandra -- cat resources/cassandra/conf/jvm-server.options | grep ^'-Xmx\|-Xms'
-Xms2147483648 -Xmx2147483648
The values are shown in bytes.
DataStax Mission Control operators perform the conversion from 2Gi to the appropriate number of bytes.
-
What’s next
-
Explore configuration examples and keys for common DataStax Enterprise configuration files:
-
DSE namespace contains classes for accessing and managing data from DSE clusters.
-