Deploy a Sharded Cluster
Note
At any place on this page that says Ops Manager, you can substitute Cloud Manager.
Important
You can use the Kubernetes Operator to deploy MongoDB resources with Cloud Manager and with Ops Manager version 6.0.x or later.
You can use the Atlas Operator to deploy MongoDB resources to Atlas.
Warning
Kubernetes Operator doesn't support arbiter nodes.
Sharded clusters provide horizontal scaling for large data sets and enable high throughput operations by distributing the data set across a group of servers.
To learn more about sharding, see Sharding Introduction in the MongoDB manual.
Use this procedure to deploy a new sharded cluster that Ops Manager manages. Later, you can use Ops Manager to add shards and perform other maintenance operations on the cluster.
Considerations
Do Not Deploy Monitoring Agents Inside and Outside Kubernetes
Due to Kubernetes network translation, a Monitoring Agent outside Kubernetes cannot monitor MongoDB instances inside Kubernetes. For this reason, k8s and non-k8s deployments in the same project are not supported. Use separate projects.
Choose Whether to Encrypt Connections
When you deploy your sharded cluster via the Kubernetes Operator, you must choose whether to encrypt connections using TLS certificates.
The following procedure for TLS-Encrypted connections:
Establishes TLS-encrypted connections between cluster shards.
Establishes TLS-encrypted connections between client applications and MongoDB deployments.
Requires valid certificates for TLS encryption.
The following procedure for Non-Encrypted Connections:
Doesn't encrypt connections between cluster shards.
Doesn't encrypt connections between client applications and MongoDB deployments.
Has fewer setup requirements than a deployment with TLS-encrypted connections.
Note
You can't secure a Standalone Instance of MongoDB in a Kubernetes cluster.
To set up TLS encryption for a replica set, see Deploy a Replica Set.
Select the appropriate tab based on whether you want to encrypt your replica set connections with TLS.
Prerequisites
To deploy a sharded cluster using an object, you must:
Have or create an Ops Manager instance or a Cloud Manager organization.
Have or install the MongoDB Enterprise Kubernetes Operator.
Create or generate a Kubernetes Operator ConfigMap.
Create credentials for the Kubernetes Operator or configure a different secret storage tool.
Note
To avoid storing secrets in single-cluster Kubernetes deployments, you can migrate all secrets to a secret storage tool. Deployments on multiple Kubernetes clusters don't support storing secrets in secret storage tools, such as HashiCorp Vault.
Generate one TLS certificate for each of the following components:
Each shard in your sharded cluster. Ensure that you add SANs for each Kubernetes pod that hosts a shard member to the certificate.
In your TLS certificates, the SAN for each shard pod must use the following format:
<pod-name>.<metadata.name>-sh.<namespace>.svc.cluster.local Your config servers. Ensure that you add SANs for each Kubernetes pod that hosts your config servers to the certificate.
In your TLS certificates, the SAN for each config server pod must use the following format:
<pod-name>.<metadata.name>-cs.<namespace>.svc.cluster.local Your
mongos
instances. Ensure that you add SANs for each Kubernetes pod that hosts amongos
to the certificate.In your TLS certificates, the SAN for each
mongos
pod must use this format:<pod-name>.<metadata.name>-svc.<namespace>.svc.cluster.local
Your project's MongoDB Agent. For the MongoDB Agent certificate, ensure that you meet the following requirements:
The Common Name in the TLS certificate is not empty.
The combined Organization and Organizational Unit in each TLS certificate differs from the Organization and Organizational Unit in the TLS certificate for your replica set members.
You must possess the CA certificate and the key that you used to sign your TLS certificates.
Important
The Kubernetes Operator uses kubernetes.io/tls secrets to store TLS certificates and private keys for Ops Manager and MongoDB resources. Starting in Kubernetes Operator version 1.17.0, the Kubernetes Operator doesn't support concatenated PEM files stored as Opaque secrets.
To deploy a sharded cluster using an object, you must:
Have or create an Ops Manager instance or a Cloud Manager organization.
Have or install the MongoDB Enterprise Kubernetes Operator.
Create or generate a Kubernetes Operator ConfigMap.
Create credentials for the Kubernetes Operator or configure a different secret storage tool.
Note
To avoid storing secrets in single-cluster Kubernetes deployments, you can migrate all secrets to a secret storage tool. Deployments on multiple Kubernetes clusters don't support storing secrets in secret storage tools, such as HashiCorp Vault.
Deploy a Sharded Cluster
Configure kubectl
to default to your namespace.
If you have not already, run the following command to execute all
kubectl
commands in the namespace you created.
Note
If you are deploying an Ops Manager resource in a multi-Kubernetes cluster MongoDB deployment:
Set the
context
to the name of the central cluster, such as:kubectl config set context "$MDB_CENTRAL_CLUSTER_FULL_NAME"
.Set the
--namespace
to the same scope that you used for your multi-Kubernetes cluster MongoDB deployment, such as:kubectl config --namespace "mongodb"
.
kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>
Create the secret for your Shards' TLS certificates.
Run this kubectl
command to create a new secret that stores
the sharded cluster shards' certificates:
kubectl -n mongodb create secret tls <prefix>-<metadata.name>-0-cert \ --cert=<shard-0-tls-cert> \ --key=<shard-0-tls-key> kubectl -n mongodb create secret tls <prefix>-<metadata.name>-1-cert \ --cert=<shard-1-tls-cert> \ --key=<shard-1-tls-key>
If you're using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.
Create the secret for your config servers' TLS certificate.
Run this kubectl
command to create a new secret that stores
the sharded cluster config servers' certificate:
kubectl -n mongodb create secret tls <prefix>-<metadata.name>-config-cert \ --cert=<config-tls-cert> \ --key=<config-tls-key>
If you're using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.
Create the secret for your mongos servers' TLS certificate.
Run this kubectl
command to create a new secret that stores
the sharded cluster mongos
certificate:
kubectl -n mongodb create secret tls <prefix>-<metadata.name>-mongos-cert \ --cert=<mongos-tls-cert> \ --key=<mongos-tls-key>
If you're using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.
Create the secret for your agent's TLS certificate.
Run this kubectl
command to create a new secret that stores
the agent's TLS certificate:
kubectl create secret tls <prefix>-<metadata.name>-agent-certs \ --cert=<agent-tls-cert> \ --key=<agent-tls-key>
If you're using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.
Create the ConfigMap to link your CA with your deployment.
Run this kubectl
command to link your CA to your sharded
cluster and specify the CA certificate file that you must always
name ca-pem
for the MongoDB
resource:
kubectl create configmap custom-ca --from-file=ca-pem=<your-custom-ca-file>
Copy the sample sharded cluster resource.
Change the settings of this YAML file to match your desired sharded cluster configuration.
Change the settings to match your desired sharded cluster configuration.
1 2 apiVersion: mongodb.com/v1 3 kind: MongoDB 4 metadata: 5 name: <my-sharded-cluster> 6 spec: 7 shardCount: 2 8 mongodsPerShardCount: 3 9 mongosCount: 2 10 configServerCount: 3 11 version: "4.2.2-ent" 12 opsManager: 13 configMapRef: 14 name: <configMap.metadata.name> 15 # Must match metadata.name in ConfigMap file 16 credentials: <mycredentials> 17 type: ShardedCluster 18 persistent: true 19 ...
19 security: 20 tls: 21 ca: <custom-ca> 22 certsSecretPrefix: <prefix> 23 ...
Paste the copied example to create a new sharded cluster resource.
Open your preferred text editor and paste the object specification into a new text file.
Configure the settings highlighted in the preceding step as follows.
Key | Type | Description | Example |
---|---|---|---|
string | Label for this Kubernetes sharded cluster object. Resource names must be 44 characters or less. To learn more, see | myproject | |
integer | Number of shards to deploy. | 2 | |
integer | Number of shard members per shard. | 3 | |
integer | Number of shard routers to deploy. | 2 | |
integer | Number of members of the config server replica set. | 3 | |
string | Version of MongoDB that this sharded cluster should run. The format should be IMPORTANT: Ensure that you choose a compatible MongoDB Server version. Compatible versions differ depending on the base image that the MongoDB database resource uses. To learn more about MongoDB versioning, see MongoDB Versioning in the MongoDB Manual. | For best results, use the latest available enterprise MongoDB version that is compatible with your Ops Manager version. | |
string | Name of the ConfigMap with the Ops Manager connection
configuration. The
This value must exist on the same namespace as the resource you want to create. IMPORTANT: The Kubernetes Operator tracks any changes to the
ConfigMap and reconciles the state of the | <myproject> | |
string | Name of the secret you created as Ops Manager API authentication credentials for the Kubernetes Operator to communicate with Ops Manager. The Ops Manager Kubernetes Secret object holding the Credentials must exist on the same Namespace as the resource you want to create. IMPORTANT: The Kubernetes Operator tracks any changes to the Secret
and reconciles the state of the | <mycredentials> | |
string | Type of MongoDB resource to create. | ShardedCluster | |
string | Optional. Flag indicating if this If this value is To change your Persistent Volume Claims configuration, configure the following collections to meet your deployment requirements:
WARNING: Grant your containers permission to write to your Persistent Volume.
The Kubernetes Operator sets If you do not use Persistent Volumes, the Disk Usage and Disk IOPS charts cannot be displayed in either the Processes tab on the Deployment page or in the Metrics page when reviewing the data for this deployment. | true |
Configure the TLS settings for your sharded cluster resource using a custom certificate authority (CA).
To enable TLS in your deployment, configure the following settings in your Kubernetes object:
Key | Type | Necessity | Description | Example |
---|---|---|---|---|
spec.security | string | Required | Add the ConfigMap's name that stores the custom CA
that you used to sign your deployment's TLS certificates. | <custom-ca> |
spec.security | string | Required | Add the For example, if you call your deployment | devDb |
Add any additional accepted settings for a sharded cluster deployment.
You can also add any of the following optional settings to the object specification file for a sharded cluster deployment:
Warning
You must set spec.clusterDomain
if your Kubernetes cluster has
a default domain
other than the default cluster.local
. If you neither use the
default nor set the spec.clusterDomain
option, the
Kubernetes Operator might not function as expected.
For config server
For shard routers
For shard members
Start your sharded cluster deployment.
Invoke the following Kubernetes command to create your sharded cluster:
kubectl apply -f <sharded-cluster-conf>.yaml
Check the log after running this command. If the creation was successful, you should see a message similar to the following:
2018-06-26T10:30:30.346Z INFO operator/shardedclusterkube.go:52 Created! {"sharded cluster": "my-sharded-cluster"}
Track the status of your sharded cluster deployment.
To check the status of your MongoDB
resource, use the following
command:
kubectl get mdb <resource-name> -o yaml -w
With the -w
(watch) flag set, when the configuration changes, the output
refreshes immediately until the status phase achieves the Running
state.
To learn more about resource deployment statuses, see Troubleshoot the Kubernetes Operator.
After you encrypt your database resource with TLS, you can secure the following:
Renew TLS Certificates for a Sharded Cluster
Renew your TLS certificates periodically using the following procedure:
Configure kubectl
to default to your namespace.
If you have not already, run the following command to execute all
kubectl
commands in the namespace you created.
Note
If you are deploying an Ops Manager resource in a multi-Kubernetes cluster MongoDB deployment:
Set the
context
to the name of the central cluster, such as:kubectl config set context "$MDB_CENTRAL_CLUSTER_FULL_NAME"
.Set the
--namespace
to the same scope that you used for your multi-Kubernetes cluster MongoDB deployment, such as:kubectl config --namespace "mongodb"
.
kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>
Renew the secret for your Shards' TLS certificates.
Run this kubectl
command to renew an existing secret that
stores the sharded cluster shards' certificates:
kubectl -n mongodb create secret tls <prefix>-<metadata.name>-0-cert \ --cert=<shard-0-tls-cert> \ --key=<shard-0-tls-key> \ --dry-run=client \ -o yaml | kubectl apply -f - kubectl -n mongodb create secret tls <prefix>-<metadata.name>-1-cert \ --cert=<shard-1-tls-cert> \ --key=<shard-1-tls-key> \ --dry-run=client \ -o yaml | kubectl apply -f -
Renew the secret for your config server's TLS certificates.
Run this kubectl
command to renew an existing secret that
stores the sharded cluster config server's certificates:
kubectl -n mongodb create secret tls <prefix>-<metadata.name>-config-cert \ --cert=<config-tls-cert> \ --key=<config-tls-key> \ --dry-run=client \ -o yaml | kubectl apply -f -
Renew the secret for your mongos server's TLS certificates.
Run this kubectl
command to renew an existing secret that
stores the sharded cluster mongos
certificates:
kubectl -n mongodb create secret tls <prefix>-<metadata.name>-mongos-cert \ --cert=<mongos-tls-cert> \ --key=<mongos-tls-key> \ --dry-run=client \ -o yaml | kubectl apply -f -
Configure kubectl
to default to your namespace.
If you have not already, run the following command to execute all
kubectl
commands in the namespace you created.
Note
If you are deploying an Ops Manager resource in a multi-Kubernetes cluster MongoDB deployment:
Set the
context
to the name of the central cluster, such as:kubectl config set context "$MDB_CENTRAL_CLUSTER_FULL_NAME"
.Set the
--namespace
to the same scope that you used for your multi-Kubernetes cluster MongoDB deployment, such as:kubectl config --namespace "mongodb"
.
kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>
Copy the sample sharded cluster resource.
Change the settings of this YAML file to match your desired sharded cluster configuration.
This is a YAML file that you can modify to meet your desired configuration. Change the settings to match your desired sharded cluster configuration.
1 2 apiVersion: mongodb.com/v1 3 kind: MongoDB 4 metadata: 5 name: <my-sharded-cluster> 6 spec: 7 shardCount: 2 8 mongodsPerShardCount: 3 9 mongosCount: 2 10 configServerCount: 3 11 version: "4.2.2-ent" 12 opsManager: 13 configMapRef: 14 name: <configMap.metadata.name> 15 # Must match metadata.name in ConfigMap file 16 credentials: <mycredentials> 17 type: ShardedCluster 18 persistent: true 19 ...
Paste the copied example to create a new sharded cluster resource.
Open your preferred text editor and paste the object specification into a new text file.
Configure the settings highlighted in the preceding step as follows.
Key | Type | Description | Example |
---|---|---|---|
string | Label for this Kubernetes sharded cluster object. Resource names must be 44 characters or less. To learn more, see | myproject | |
integer | Number of shards to deploy. | 2 | |
integer | Number of shard members per shard. | 3 | |
integer | Number of shard routers to deploy. | 2 | |
integer | Number of members of the config server replica set. | 3 | |
string | Version of MongoDB that this sharded cluster should run. The format should be IMPORTANT: Ensure that you choose a compatible MongoDB Server version. Compatible versions differ depending on the base image that the MongoDB database resource uses. To learn more about MongoDB versioning, see MongoDB Versioning in the MongoDB Manual. | For best results, use the latest available enterprise MongoDB version that is compatible with your Ops Manager version. | |
string | Name of the ConfigMap with the Ops Manager connection
configuration. The
This value must exist on the same namespace as the resource you want to create. IMPORTANT: The Kubernetes Operator tracks any changes to the
ConfigMap and reconciles the state of the | <myproject> | |
string | Name of the secret you created as Ops Manager API authentication credentials for the Kubernetes Operator to communicate with Ops Manager. The Ops Manager Kubernetes Secret object holding the Credentials must exist on the same Namespace as the resource you want to create. IMPORTANT: The Kubernetes Operator tracks any changes to the Secret
and reconciles the state of the | <mycredentials> | |
string | Type of MongoDB resource to create. | ShardedCluster | |
string | Optional. Flag indicating if this If this value is To change your Persistent Volume Claims configuration, configure the following collections to meet your deployment requirements:
WARNING: Grant your containers permission to write to your Persistent Volume.
The Kubernetes Operator sets If you do not use Persistent Volumes, the Disk Usage and Disk IOPS charts cannot be displayed in either the Processes tab on the Deployment page or in the Metrics page when reviewing the data for this deployment. | true |
Add any additional accepted settings for a sharded cluster deployment.
You can also add any of the following optional settings to the object specification file for a sharded cluster deployment:
Warning
You must set spec.clusterDomain
if your Kubernetes cluster has
a default domain
other than the default cluster.local
. If you neither use the
default nor set the spec.clusterDomain
option, the
Kubernetes Operator might not function as expected.
For config server
For shard routers
For shard members
Start your sharded cluster deployment.
Invoke the following Kubernetes command to create your sharded cluster:
kubectl apply -f <sharded-cluster-conf>.yaml
Check the log after running this command. If the creation was successful, you should see a message similar to the following:
2018-06-26T10:30:30.346Z INFO operator/shardedclusterkube.go:52 Created! {"sharded cluster": "my-sharded-cluster"}
Track the status of your sharded cluster deployment.
To check the status of your MongoDB
resource, use the following
command:
kubectl get mdb <resource-name> -o yaml -w
With the -w
(watch) flag set, when the configuration changes, the output
refreshes immediately until the status phase achieves the Running
state.
To learn more about resource deployment statuses, see Troubleshoot the Kubernetes Operator.