| --- |
| license: | |
| 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 |
| |
| https://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. |
| --- |
| |
| # Worker |
| The main functions of Celeborn `Worker` are: |
| |
| - Store, serve, and manage `PartitionLocation` data. See [Storage](../../developers/storage) |
| - Traffic control through `Back Pressure` and `Congestion Control`. See |
| [Traffic Control](../../developers/trafficcontrol) |
| - Support rolling upgrade through `Graceful Shutdown` |
| - Support elasticity through `Decommission Shutdown` |
| - Self health check |
| |
| Celeborn `Worker` has four dedicated servers: |
| |
| - `Controller` handles control messages, i.e. `ReserveSlots`, `CommitFiles`, and `DestroyWorkerSlots` |
| - `Push Server` handles primary input data, i.e. `PushData` and `PushMergedData`, and push related control messages |
| - `Replicate Server` handles replica input data, it has the same logic with `Push Server` |
| - `Fetch Server` handles fetch requests, i.e. `ChunkFetchRequest`, and fetch related control messages |
