server-zd reference

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server-zd is a Dex Server whose only runtime dependency is object storage, such as Amazon S3 or an S3-compatible store. It keeps Flow state in a local store and commits every write to object storage before it acknowledges the write. The local disk is only a cache. A node rebuilds it from the latest snapshot and the command log in object storage.

server-zd serves the FlowService, WorkerTaskService, and AdminService API. It supports only pull Workers. Run Dex Web as a separate process; server-zd does not serve it. For local development, run dexcli dev, which starts server-zd and Dex Web. To run one production node on local disk without external object storage, see Single node on local disk. This reference covers server-zd 0.1. See Server for how server-zd fits with the other components.

Pages

• Flow and Step runtime: start options, Flow configuration, waits, Step decisions, Step options, and failure and redelivery.
• Data primitive semantics: detailed rules for Attributes, RPCs, Channels, Streams, and SubFlows, such as indexes, hard-delete Attributes, locks, transactional RPCs, and Stream limits.
• Client requests: how the server handles each Client request, including Attribute reads, waits, and their limits.
• Install and configure: install, minimal production configuration, a single node on local disk, retention, history window, limits, performance tuning, and Streams.
• Kubernetes deployment: the StatefulSet, graceful shutdown, the local store volume, and health checks.
• High availability: the lease, hot standby, and step down.
• Object storage and backup: credentials, IAM policy, encryption, versioning, and restore.
• Authentication: API and admin credentials.
• Workers and task queue: the Worker protocol, routing, capacity, shutdown, dispatch settings, and the Step task queue.
• Search backends: the external search projection and PostgreSQL search.
• Attribute Store sync: behavior, configuration, fencing, retries, and table contracts.
• Metrics and alerts: the Prometheus endpoint and alert rules.
• Upgrades and compatibility: protocol versions, upgrade order, and rollback.

Unsupported features

server-zd rejects these options with INVALID_ARGUMENT:

• A Flow start delay, which is flow_start_delay_seconds greater than zero. Tracked in issue 995.
• A Flow-level retry policy, which is retry_policy in the Flow start options. Tracked in issue 996. Step-level retry is supported.

The only Attribute Store is PostgreSQL. Redis is tracked in issue 616.

Release notes

Each server-zd release lists its breaking changes, features, fixes, and upgrade steps. See the server-zd releases on GitHub.