# Tenzir Node v4.19.2 ## 馃殌 Features ### Add a throttle operator Aug 5, 2024 路 [@lava](https://github.com/lava) 路 [#4448](https://github.com/tenzir/tenzir/pull/4448) The throttle operator allows for limiting the bandwidth of a pipeline. ## 馃敡 Changes ### Add new expert-only options to control demand Aug 5, 2024 路 [@dominiklohmann](https://github.com/dominiklohmann) 路 [#4447](https://github.com/tenzir/tenzir/pull/4447) We鈥檝e made some changes that optimize Tenzir鈥檚 memory usage. Pipeline operators that emit very small batches of events or bytes at a high frequency now use less memory. The `serve` operator鈥檚 internal buffer is now soft-capped at 1Ki instead of 64Ki events, aligning the buffer size with the default upper limit for the number of events that can be fetched at once from `/serve`. The `export`, `metrics`, and `diagnostics` operators now handle back pressure better and utilize less memory in situations where the node has many small partitions. For expert users, the new `tenzir.demand` configuration section allows for controlling how eagerly operators demand input from their upstream operators. Lowering the demand reduces the peak memory usage of pipelines at some performance cost. ## 馃悶 Bug Fixes ### Emit metrics for events that get emitted as part of push() in the subscribe operator Aug 2, 2024 路 [@Dakostu](https://github.com/Dakostu) 路 [#4439](https://github.com/tenzir/tenzir/pull/4439) The `subscribe` operator now delivers metrics more consistently. [ Download on GitHub ](https://github.com/tenzir/tenzir/releases/tag/v4.19.2) [Get the release artifacts and source code.](https://github.com/tenzir/tenzir/releases/tag/v4.19.2)