| // Copyright 2019 The LUCI Authors. |
| // |
| // Licensed 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. |
| |
| // Package dispatcher implements a super-charged version of a buffered channel |
| // connected to a (potentially) parallelized work dispatcher. |
| // |
| // This can be used when you have a mismatch between the rate of production of |
| // items and the rate of consumption of those items. For example: |
| // |
| // - if you have a producer which constantly produces new world states, |
| // and you want to sink the latest one into a slow external RPC (but still |
| // do retries if no new state appears). |
| // - if you have bursty user data which you'd like to batch according to some |
| // maximum batch size, but you don't want the data to get too stale in case |
| // you don't hit that batch limit. |
| // - your external RPC can absorb almost infinite data, and the order of |
| // delivery doesn't matter, but you don't want to block the data producer. |
| // - etc. |
| // |
| // The dispatcher can be configured to: |
| // - Buffer a certain amount of work (with possible backpressure to the |
| // producer). |
| // - Batch pending work into chunks for the send function. |
| // - Drop stale work which is no longer important to send. |
| // - Enforce a maximum QPS on the send function (even with parallel senders). |
| // - Retry batches independently with configurable per-batch retry policy. |
| package dispatcher |
