yinzhijian opened a new issue #8550: URL: https://github.com/apache/incubator-doris/issues/8550
### Search before asking - [X] I had searched in the [issues](https://github.com/apache/incubator-doris/issues?q=is%3Aissue) and found no similar issues. ### Description ### background Current situation of doris is that the cluster is balanced, but the disks of a backend may be unbalanced. for example, backend A have two disks: disk1 and disk2, disk1's usage is 98%, but disk2's usage is only 40%. disk1 is unable to take more data, therefore only one disk of backend A can take new data, the avaiable write throughput of backend A is only half of its ability, and we can not resolve this through load or partition rebalace now. so we introduce disk rebalancer, disk rebalancer is different from other rebalancer(load or partition) which take care of cluster-wide data balancing. it takes care about backend-wide data balancing. ### schedule strategies: 1. normally, disk rebalance task will be scheduled when cluster is balanced . 2. if user has set some backends that have high priority of disk rebalance, then disk rebalance task of the prior backends will be scheduled, no matter if cluster is balanced. ### pick disk strategies: #### defintion: 1. high load disk/path: 10% greater than avg disk usage 2. mid load disk/path: -10% < avg disk usage <+10% 3. low load disk/path: 10% less than avg disk usage #### strategies: 1. if we have **high** load disks: source : we only pick a tablet from **high** load disks dest disk: if we have **low** load disks, we only pick a disk from **low** load disks else we will pick a disk from **mid** load disks 2. if we only have **mid** and **low** load disks: source : we only pick a tablet from **mid** load disks dest disk: we only pick disk from **low** load disks 3. if we only have **mid** load disks: it means backend is balanced, we have nothing to do. ### Admin SQL Support #### 1. set some backends have high priority of disk rebalance ADMIN REBALANCE DISK [ON ("BackendHost1:BackendHeartBeatPort1", "BackendHost2:BackendHeartBeatPort2", ...)]; #### 2. cancel high priority of disk rebalance of backends ADMIN CANCEL REBALANCE DISK [ON ("BackendHost1:BackendHeartBeatPort1", "BackendHost2:BackendHeartBeatPort2", ...)]; ### Use case _No response_ ### Related issues _No response_ ### Are you willing to submit PR? - [X] Yes I am willing to submit a PR! ### Code of Conduct - [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct) -- 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]
