talatuyarer commented on code in PR #17940: URL: https://github.com/apache/iceberg/pull/17940#discussion_r3963481852
########## docs/docs/rest-protocol.md: ########## @@ -0,0 +1,180 @@ +--- +title: "REST Catalog Protocol" +--- +<!-- + - Licensed to the Apache Software Foundation (ASF) under one or more + - contributor license agreements. See the NOTICE file distributed with + - this work for additional information regarding copyright ownership. + - The ASF licenses this file to You under the Apache License, Version 2.0 + - (the "License"); you may not use this file except in compliance with + - the License. You may obtain a copy of the License at + - + - http://www.apache.org/licenses/LICENSE-2.0 + - + - Unless required by applicable law or agreed to in writing, software + - distributed under the License is distributed on an "AS IS" BASIS, + - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + - See the License for the specific language governing permissions and + - limitations under the License. + --> + +# REST Catalog Protocol + +## Overview + +As the Iceberg ecosystem grew, every engine and language needed its own client +for every catalog implementation. The REST catalog protocol solves this by +putting the catalog logic behind a common HTTP API, defined by the +[Iceberg REST Catalog API specification](../../rest-catalog-spec.md): a single +client implementation works with any compliant server. Because the server owns +commit logic, the protocol also enables capabilities that client-side catalogs +cannot offer, such as server-side conflict resolution, multi-table commits, +and secure table sharing through credential vending or remote signing. + +This page explains the concepts behind the protocol features and how the Java +client uses them. For configuring a REST catalog connection and the full +client property reference, see the [REST catalog page](rest-catalog.md). + +## Endpoint discovery and server-provided configuration + +On initialization, the client calls the server's configuration route +(`GET /v1/config`, passing the configured `warehouse` as a query parameter if +one is set). The response can adjust the client's configuration in three ways: + +- **`defaults`**: properties the server suggests; the client's own + configuration takes precedence over them. +- **`overrides`**: properties the server requires; they take precedence over + the client's configuration. A common override is `prefix`, which the client + inserts into all subsequent request paths (`/v1/{prefix}/namespaces/...`) + so that one server can host multiple catalogs. +- **`endpoints`**: the list of API endpoints the server supports. The client + only uses features whose endpoints are advertised, so a server that does not + implement, for example, view or scan-planning endpoints simply causes those + features to be unavailable rather than producing failed requests. + +If the server omits the `endpoints` field entirely, the client assumes a +default set of namespace and table endpoints. For older servers that support +views but predate endpoint discovery, set `view-endpoints-supported=true` +(see [REST catalog properties](rest-catalog.md#configuration)). + +## Multi-table transactions Review Comment: @kevinjqliu Fair point — I replaced the section with a 'Commit protocol' section describing the requirements/updates flow, and kept multi-table transactions as a short note there (optional endpoint, Java API only). PTAL -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
