intra_pod_shmem

Communications over Shared Memory

Problem

You want to make Connext containers communicate over shared memory.

Solution

Containers in a pod share the same IPC namespace, which means they can communicate with each other using standard inter-process communications such as SystemV semaphores or POSIX shared memory. If containers are in the same pod, Connext containers with a version above 6.0 can communicate over shared memory with the default settings. (Please see this if you use an older version.) A Connext container can use both shared memory transport for container-to-container communications (in the same pod) and UDP transport for pod-to-pod communications.

Required Docker Images

• RTI Cloud Discovery Service
• RTI DDS Ping

Steps

Create a ConfigMap for RTI License.

$ kubectl create configmap rti-license --from-file rti_license.dat

This command creates a ConfigMap to store the RTI License, which is necessary for running RTI CDS in the evaluation package.

Create a Deployment and a Service for Cloud Discovery Service.

$ kubectl create -f rticlouddiscoveryservice.yaml

Use this command to create a Deployment and a Service for the RTI CDS.

Create a publisher and subscriber over shared memory transport.

$ kubectl create -f rtiddsping_shmem.yaml

This command deploys the RTI DDS Ping Publisher and Subscriber that communicate over shared memory transport.

Deploy a subscriber over UDP transport.

$ kubectl create -f rtiddsping_sub.yaml This command deploys the RTI DDS Ping Subscriber that communicates using UDP transport.