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YufeiLiu commented on FLINK-15959: ---------------------------------- I've made some modification of description according to the comments, please tell me if I've missed anything. [~sewen] Can I take this task if the improvement is necessary. > Add min/max number of slots configuration to limit total number of slots > ------------------------------------------------------------------------ > > Key: FLINK-15959 > URL: https://issues.apache.org/jira/browse/FLINK-15959 > Project: Flink > Issue Type: Improvement > Components: Runtime / Coordination > Affects Versions: 1.11.0 > Reporter: YufeiLiu > Priority: Major > > Flink removed `-n` option after FLIP-6, change to ResourceManager start a new > worker when required. But I think maintain a certain amount of slots is > necessary. These workers will start immediately when ResourceManager starts > and would not release even if all slots are free. > Here are some resons: > # Users actually know how many resources are needed when run a single job, > initialize all workers when cluster starts can speed up startup process. > # Job schedule in topology order, next operator won't schedule until prior > execution slot allocated. The TaskExecutors will start in several batchs in > some cases, it might slow down the startup speed. > # Flink support > [FLINK-12122|https://issues.apache.org/jira/browse/FLINK-12122] [Spread out > tasks evenly across all available registered TaskManagers], but it will only > effect if all TMs are registered. Start all TMs at begining can slove this > problem. > *suggestion:* > * Add config "taskmanager.minimum.numberOfTotalSlots" and > "taskmanager.maximum.numberOfTotalSlots", default behavior is still like > before. > * Start plenty number of workers to satisfy minimum slots when > ResourceManager accept leadership(subtract recovered workers). > * Don't comlete slot request until minimum number of slots are registered, > and throw exeception when exceed maximum. -- This message was sent by Atlassian Jira (v8.3.4#803005)