guide-tokio-console.md

Developer guide: tokio-console

This guide details how to run tokio-console with Materialize.

Overview

First, install tokio-console. We require support for Unix domain sockets, which is still pending upstream, so we need to install from a fork for now.

cargo install tokio-console --git https://github.com/MaterializeInc/tokio-console.git

Then run environmentd:

./bin/environmentd --tokio-console

(Note that this may slow down environmentd a lot, as it increases the amount of tracing by a lot, and may inadvertently turn on debug logging for rdkafka.)

In the output of the above command, take note of the tokio-console listen addresses for the different processes, e.g.:

environmentd: [...]  INFO mz_ore::tracing: starting tokio console on http://127.0.0.1:6669
compute-cluster-u1-replica-1: [...]  INFO mz_ore::tracing: starting tokio console on /var/folders/30/[...]3ee9
compute-cluster-s1-replica-2: [...]  INFO mz_ore::tracing: starting tokio console on /var/folders/30/[...]f5b6
compute-cluster-s2-replica-3: [...]  INFO mz_ore::tracing: starting tokio console on /var/folders/30/[...]7af2

Then, in a different tmux pane/terminal, run the tokio-console command with the listen address of your process of interest:

tokio-console <listen-address>

This README has some docs on how to navigate the ui.

Notes on compilation times:

RUSTFLAGS="--cfg tokio_unstable" forces a recompilation of our entire dependency tree. Note that this also clashes with the compilation cache that rust-analyzer uses, and may cause regular recompilations. To avoid this, you can add:

[build]
rustflags = ["--cfg", "tokio_unstable"]

to our cargo config temporarily, or your cargo config in $HOME, which can make RA and cargo use the same flags. Please be careful to not add it under the x86_64-unknown-linux-gnu target section if you aren't running on that target (i.e. you are using a macbook).