Apache Ignite optimized for GKE

Out take on running Apache Ignite in GKE properly.

The main differences to the official guide:

• Switch to SSD PD since Apache Ignite quickly becomes IO bound
• WAL is kept on the same disk as the main data - provisioning dedicated disk for WAL is a waste since IO performance on GCE depends on a volume size and we do want WAL to reside on high-performance media
• GKE cluster is launched over two availability zones
• Stateful set is run as one pod per node, on a dedicated node-pool:
  • Ensures performance uniformity
  • Java is not necessary good at detecting container limits, hence running Java workloads as 1 container per host is still a very reasonable consideration, particularly for database workloads
• Stateful set launches pods in parallel to speed up the startup
• Localized config file through k8s configmap instead of pulling it from 3rd party GitHub repo
• Changed ignite k8s service to create internal L4 TCP Load Balancer instead of public L3 load balancer as it is in the community guide (which opens you freshly created cluster to the world)
• Propagating k8s node's availability zone name into Ignite pod and providing a proper cache template in the node config.
• Switched Load Balancer session affinity to Round Robbin to ensure even client load distribution

How to launch the setup

To create a new GKE cluster and launch Apache Ignite into it, use the following commands:

make PROJECT=<your project name> gke-create
make ignite-launch

Wait till pods are up (run kubectl get pods and confirm the status of each pod is "Running").

Then run make ignite-activate - only required for the first time after cluster creation.

If you change ignite-config.xml you can apply new config and restart the cluster (the data is preserved) by running make ignite rerun.

REST API quick access

• To activate REST API port forwarding on localhost:8080 run make por-forward
• Then you can register on console.gridgain.com for free, download their agent and to run it locally to have a UI view on your cluster
• Also you can access your cluster's REST API on localhost:8080

Zone-Awareness

Cluster K8s setup has zone-awareness pre-configured, including a proper cache-templated called zone-awareness-cache. To test zone awareness allocation you can:

• Create a test cache from template by running make create-cache CACHE=<your cache name
• Check that partitions are properly distributed between zones (i.e. that there are no both primary and backup partition in the same node): ./check.py <your cache name> (the tool requires Python 3.6+ available. No extra libraries are needed)

Test Client

To build the test client:

• Clone this git repo
• Navigate to the IgniteClient directory
• Build the local Dockerfile and give it an appropriate tag. E.g. docker build -t ignite_test .

On build success, to run the test client:

• To view all command line options, run without arguments: docker run ignite_test:

Options category 'misc':
  --[no]get (a boolean; default: "false")
    Perform GET requests. true/false
  --[no]help [-h] (a boolean; default: "false")
    Prints usage info.
  --[no]put (a boolean; default: "false")
    Perform PUT requests. true/false
Options category 'server settings':
  --host [-o] (a string; default: "")
    The Ignite server host.
  --name [-n] (a string; default: "test-cache")
    The name of the cache.
  --port [-p] (an integer; default: "10800")
    The server port.
Options category 'test setup':
  --count [-c] (an integer; default: "100")
    The count of objects to be processed.
  --lowerbound [-l] (an integer; default: "1")
    The lower bound of the integer key range.
  --sockets [-s] (an integer; default: "3")
    Parallel socket count.
  --upperbound [-u] (an integer; default: "-1")
    The upper bound of the integer key range. Must be set for random key 
    selection. If less than lower bound or left blank, upper bound will be 
    lower bound+count-1 and each key will be selected in that range will be 
    selected exactly once.

• The only required argument is the --host option. E.g. if the load balancer listens on IP 10.128.0.21 then the command docker run ignite_test --host 10.128.0.21 can be used to establish connectivity (3 connections by default, this can be adjusted using the --sockets option). This will not try to insert or retrieve any data from the cluster. To put or get items the --put and/or --get options need to be specified.
• This command inserts, then tries to retrieve 100,000 objects with random keys between 1 and 100,000,000: docker run ignite_test --get --put --host 10.128.0.21 --count 100000 --upperbound 100000000