abhishekrb19 opened a new pull request, #16609: URL: https://github.com/apache/druid/pull/16609
Wanted to get CI running. This patch is not in a fully reviewable state yet. ### Problem Currently, broadcast segments are assigned to data servers by the coordinator. This usual route alone can cause data correctness issues because if a process (either a task or server) is using broadcast segments for ingestion or to server queries, the ingestion or query results can be invalid due to the asynchronous nature of segment assignment and loading. Therefore, it's important that a process blocks until the broadcast (bootstrap) segments are loaded first before it can proceed. ### Description This PR adds a new API `/v1/metadata/bootstrapSegments` in the coordinator that returns bootstrap segments. Currently, the set of bootstrap segments only contains broadcast segments. In the future, we can expand on this mechanism to speed up historical upgrades as well. When a process starts up, it'll reach out to the coordinator if it can find one to fetch the bootstrap segments. The bootstrap segments along with any previously cached segments are then loaded on to its storage location by the `SegmentLoadDropHandler`. <!-- Thanks for trying to help us make Apache Druid be the best it can be! Please fill out as much of the following information as is possible (where relevant, and remove it when irrelevant) to help make the intention and scope of this PR clear in order to ease review. --> <!-- Please read the doc for contribution (https://github.com/apache/druid/blob/master/CONTRIBUTING.md) before making this PR. Also, once you open a PR, please _avoid using force pushes and rebasing_ since these make it difficult for reviewers to see what you've changed in response to their reviews. See [the 'If your pull request shows conflicts with master' section](https://github.com/apache/druid/blob/master/CONTRIBUTING.md#if-your-pull-request-shows-conflicts-with-master) for more details. --> <!-- Replace XXXX with the id of the issue fixed in this PR. 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