kubernetes/manifests-raw/dgraph/dgraph-ha.yaml
# This highly available config creates 3 Dgraph Zeros and 3 Dgraph Alphas with 3
# replicas. The Dgraph cluster will still be available to service requests even
# when one Zero and/or one Alpha are down.
#
# There are 3 services can can be used to expose outside the cluster as needed:
# dgraph-zero-public - To load data using Live & Bulk Loaders
# dgraph-alpha-public - To connect clients and for HTTP APIs
apiVersion: v1
kind: Service
metadata:
name: dgraph-zero-public
labels:
app: dgraph-zero
monitor: zero-dgraph-io
spec:
type: ClusterIP
ports:
- port: 5080
targetPort: 5080
name: grpc-zero
- port: 6080
targetPort: 6080
name: http-zero
selector:
app: dgraph-zero
---
apiVersion: v1
kind: Service
metadata:
name: dgraph-alpha-public
labels:
app: dgraph-alpha
monitor: alpha-dgraph-io
spec:
type: ClusterIP
ports:
- port: 8080
targetPort: 8080
name: http-alpha
- port: 9080
targetPort: 9080
name: grpc-alpha
selector:
app: dgraph-alpha
---
# This is a headless service which is necessary for discovery for a dgraph-zero StatefulSet.
# https://kubernetes.io/docs/tutorials/stateful-application/basic-stateful-set/#creating-a-statefulset
apiVersion: v1
kind: Service
metadata:
name: dgraph-zero
labels:
app: dgraph-zero
spec:
ports:
- port: 5080
targetPort: 5080
name: grpc-zero
clusterIP: None
# We want all pods in the StatefulSet to have their addresses published for
# the sake of the other Dgraph Zero pods even before they're ready, since they
# have to be able to talk to each other in order to become ready.
publishNotReadyAddresses: true
selector:
app: dgraph-zero
---
# This is a headless service which is necessary for discovery for a dgraph-alpha StatefulSet.
# https://kubernetes.io/docs/tutorials/stateful-application/basic-stateful-set/#creating-a-statefulset
apiVersion: v1
kind: Service
metadata:
name: dgraph-alpha
labels:
app: dgraph-alpha
spec:
ports:
- port: 7080
targetPort: 7080
name: grpc-alpha-int
clusterIP: None
# We want all pods in the StatefulSet to have their addresses published for
# the sake of the other Dgraph alpha pods even before they're ready, since they
# have to be able to talk to each other in order to become ready.
publishNotReadyAddresses: true
selector:
app: dgraph-alpha
---
# This StatefulSet runs 3 Dgraph Zero.
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: dgraph-zero
spec:
serviceName: "dgraph-zero"
replicas: 3
selector:
matchLabels:
app: dgraph-zero
template:
metadata:
labels:
app: dgraph-zero
spec:
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: app
operator: In
values:
- dgraph-zero
topologyKey: kubernetes.io/hostname
containers:
- name: zero
image: dgraph/dgraph:latest
imagePullPolicy: IfNotPresent
ports:
- containerPort: 5080
name: grpc-zero
- containerPort: 6080
name: http-zero
volumeMounts:
- name: datadir
mountPath: /dgraph
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
command:
- bash
- "-c"
- |
set -ex
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
idx=$(($ordinal + 1))
if [[ $ordinal -eq 0 ]]; then
exec dgraph zero --my=$(hostname -f):5080 --raft="idx=$idx" --replicas 3
else
exec dgraph zero --my=$(hostname -f):5080 --peer dgraph-zero-0.dgraph-zero.${POD_NAMESPACE}:5080 --raft="idx=$idx" --replicas 3
fi
livenessProbe:
httpGet:
path: /health
port: 6080
initialDelaySeconds: 15
periodSeconds: 10
timeoutSeconds: 5
failureThreshold: 6
successThreshold: 1
readinessProbe:
httpGet:
path: /health
port: 6080
initialDelaySeconds: 15
periodSeconds: 10
timeoutSeconds: 5
failureThreshold: 6
successThreshold: 1
terminationGracePeriodSeconds: 60
volumes:
- name: datadir
persistentVolumeClaim:
claimName: datadir
updateStrategy:
type: RollingUpdate
volumeClaimTemplates:
- metadata:
name: datadir
annotations:
volume.alpha.kubernetes.io/storage-class: anything
spec:
accessModes:
- "ReadWriteOnce"
resources:
requests:
storage: 5Gi
---
# This StatefulSet runs 3 replicas of Dgraph Alpha.
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: dgraph-alpha
spec:
serviceName: "dgraph-alpha"
replicas: 3
selector:
matchLabels:
app: dgraph-alpha
template:
metadata:
labels:
app: dgraph-alpha
spec:
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: app
operator: In
values:
- dgraph-alpha
topologyKey: kubernetes.io/hostname
# Initializing the Alphas:
#
# You may want to initialize the Alphas with data before starting, e.g.
# with data from the Dgraph Bulk Loader: https://dgraph.io/docs/deploy/#bulk-loader.
# You can accomplish by uncommenting this initContainers config. This
# starts a container with the same /dgraph volume used by Alpha and runs
# before Alpha starts.
#
# You can copy your local p directory to the pod's /dgraph/p directory
# with this command:
#
# kubectl cp path/to/p dgraph-alpha-0:/dgraph/ -c init-alpha
# (repeat for each alpha pod)
#
# When you're finished initializing each Alpha data directory, you can signal
# it to terminate successfully by creating a /dgraph/doneinit file:
#
# kubectl exec dgraph-alpha-0 -c init-alpha touch /dgraph/doneinit
#
# Note that pod restarts cause re-execution of Init Containers. Since
# /dgraph is persisted across pod restarts, the Init Container will exit
# automatically when /dgraph/doneinit is present and proceed with starting
# the Alpha process.
#
# Tip: StatefulSet pods can start in parallel by configuring
# .spec.podManagementPolicy to Parallel:
#
# https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#deployment-and-scaling-guarantees
#
# initContainers:
# - name: init-alpha
# image: dgraph/dgraph:latest
# command:
# - bash
# - "-c"
# - |
# trap "exit" SIGINT SIGTERM
# echo "Write to /dgraph/doneinit when ready."
# until [ -f /dgraph/doneinit ]; do sleep 2; done
# volumeMounts:
# - name: datadir
# mountPath: /dgraph
containers:
- name: alpha
image: dgraph/dgraph:latest
imagePullPolicy: IfNotPresent
ports:
- containerPort: 7080
name: grpc-alpha-int
- containerPort: 8080
name: http-alpha
- containerPort: 9080
name: grpc-alpha
volumeMounts:
- name: datadir
mountPath: /dgraph
env:
# This should be the same namespace as the dgraph-zero
# StatefulSet to resolve a Dgraph Zero's DNS name for
# Alpha's --zero flag.
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
# dgraph versions earlier than v1.2.3 and v20.03.0 can only support one zero:
# `dgraph alpha --zero dgraph-zero-0.dgraph-zero.${POD_NAMESPACE}:5080`
# dgraph-alpha versions greater than or equal to v1.2.3 or v20.03.1 can support
# a comma-separated list of zeros. The value below supports 3 zeros
# (set according to number of replicas)
command:
- bash
- "-c"
- |
set -ex
dgraph alpha --my=$(hostname -f):7080 --zero dgraph-zero-0.dgraph-zero.${POD_NAMESPACE}:5080,dgraph-zero-1.dgraph-zero.${POD_NAMESPACE}:5080,dgraph-zero-2.dgraph-zero.${POD_NAMESPACE}:5080
livenessProbe:
httpGet:
path: /health?live=1
port: 8080
initialDelaySeconds: 15
periodSeconds: 10
timeoutSeconds: 5
failureThreshold: 6
successThreshold: 1
readinessProbe:
httpGet:
path: /health
port: 8080
initialDelaySeconds: 15
periodSeconds: 10
timeoutSeconds: 5
failureThreshold: 6
successThreshold: 1
terminationGracePeriodSeconds: 600
volumes:
- name: datadir
persistentVolumeClaim:
claimName: datadir
updateStrategy:
type: RollingUpdate
volumeClaimTemplates:
- metadata:
name: datadir
annotations:
volume.alpha.kubernetes.io/storage-class: anything
spec:
accessModes:
- "ReadWriteOnce"
resources:
requests:
storage: 5Gi