Apache Iggy Streaming Expert

Scope

Iggy deployment, stream and topic design, producer and consumer patterns, Docker Compose, SDK usage, and MCP-oriented AI workflows.

For general Compose file structure use the docker-compose skill; this skill covers the Iggy-specific settings inside it.

Current Facts

Release guidance checked on 2026-11-03. Recheck the linked sources before selecting versions for a new deployment; preserve existing project pins.

• Current server release: 0.9.0, released September 18, 2026, following graduation from the Incubator. Older 0.8.0 and 0.7.0 artifacts retain -incubating.
• Server image: apache/iggy:0.9.0. Web UI, MCP, and Connect have separate image/version streams; verify their tags independently. edge builds are development snapshots.
• SDK compatibility for server 0.9: Rust iggy 0.11.0, CLI 0.14.0, Python apache-iggy 0.9.0 (Python 3.10+), Java 0.9.0, Node 0.10.0, Go/C# 0.9.0. Match the compatibility matrix, not just version-number equality.
• Ports: HTTP 3000, QUIC UDP 8080, TCP 8090, WebSocket 8092.
• 0.9 upgrade boundary: on-disk data, wire protocol, and configuration changed. A 0.9 server cannot read a 0.8 data directory, and there is no in-place migration. Clients and server must cut over together.

Inspect First

Establish before recommending or changing anything:

1. Server and data-directory versions. Determine whether this is a fresh 0.9 deployment or a migration with data that must be exported and replayed.
2. Deployment target: local binary, Docker, Compose, Kubernetes/Helm, or SDK-only client work.
3. The installed SDK package version, separately from the server version. For Python, check the installed apache-iggy methods and server compatibility before writing detailed code.
4. For connection failures, which transport and port are in use, and whether the server is bound to 0.0.0.0 rather than loopback inside the container.

Decision Rules

• Choose transport by requirement: TCP for throughput, QUIC for latency, HTTP for REST and admin, WebSocket for browser-compatible clients.
• Set wildcard listeners for transports exposed from a container, together with IGGY_NODE_ADVERTISED_ADDRESS reachable by the clients. In 0.9 a wildcard bind without an advertised address prevents startup.
• Persist /app/local_data for the published 0.9 image, or explicitly set IGGY_PATH and mount that path. The repository-built image uses /local_data; do not assume those image layouts are interchangeable.
• Account for io_uring and thread-affinity requirements. Compose examples often need SYS_NICE, seccomp:unconfined, and memlock ulimits.
• Pin exact version tags in production rather than latest, and pin server and SDK versions independently.
• For 0.8 to 0.9, replace moved configuration keys, including IGGY_SYSTEM_PATH with IGGY_PATH. Review per-topic durability settings; the old enforce_fsync switches no longer apply.

Safety

• Supply IGGY_ROOT_USERNAME and IGGY_ROOT_PASSWORD through environment or secret files, never hardcoded in a committed Compose file, and change the defaults before exposing any port beyond localhost.
• Before a 0.8 to 0.9 cutover, preserve the old volume and a compatible server for rollback, export required data, and validate replay into a separate empty directory. A backup of 0.8 files is not directly readable by 0.9.
• Never use --fresh as a repair step on valuable data: it wipes the local replica directory. Bootstrap credentials do not replace recovered credentials.
• Do not publish QUIC, TCP, or HTTP ports on a public interface without authentication configured.
• Deleting a stream or topic removes its persisted segments. Confirm the exact target name before running any delete.

Verify

• Confirm the server answers on the intended transport, not merely that the container is running: an HTTP request to the server or a CLI ping.
• List streams and topics back after creating them.
• Send and consume one test message end to end before calling a pipeline working.
• After an upgrade, confirm the client SDK version actually negotiates with the server version.
• For container deployments, verify the mounted path matches IGGY_PATH and that clients can reach the advertised address returned by the server.
• Report server version, SDK version, transport, and exactly what you exercised.

Update Checklist

• Recheck Iggy downloads and the version-specific migration guide.
• Recheck SDK package versions separately; server, Rust, Python, Java, Go, C#, and Web UI versions may differ.

Sources

• Iggy releases
• 0.8 to 0.9 upgrade requirements
• SDK compatibility matrix
• Published image paths and networking
• Python package