The IB Gateway JVM uses non-blocking I/O on port 4002, which causes
EAGAIN errors with ibapi's blocking Client::connect(). The gnzsnz
image provides socat on port 4004 as a stable proxy that bridges
blocking clients to the non-blocking gateway socket.
Port 4004 is the correct client-facing port for paper mode (4003 for
live). The K8s readiness probe stays on 4002 since TCP probes work
fine with non-blocking sockets.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
47cea06e86