VIC Container Deployment Using docker-compose Results in "Connection pool is full"

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
Running docker-compose to deploy containers results in the following output messages.

WARNING: Connection pool is full, discarding connection: <VCH_IP>

Environment

VMware vSphere Integrated Containers 1.x

Cause

Docker Compose connection pool default limit is 64 which becomes full due to the number of parallel operations run that run.

Resolution

Currently there is not a way of increasing the connection pool limit. For current information regarding the connection pool limit and configuration reach out to the community for Docker Compose at https://github.com/docker/compose/

Workaround:
Workaround for steps to limit operations from exceeding the connection pool limit.

The ability to limit the number of parallel operations was added to Docker Compose 1.19.0. Update to Docker Compose 1.19.0 or later and set the following environmental variables.

COMPOSE_PARALLEL_LIMIT=25
DOCKER_HOST=VCH_IP_OR_FQDN:2375

If the VCH is configured to require TLS use the following environmental variables. 

COMPOSE_TLS_VERSION=TLSv1_2
COMPOSE_PARALLEL_LIMIT=25
DOCKER_HOST=VCH_IP_OR_FQDN:2376