Hydro Deploy

Hydro comes equipped with a Rust-native built-in deployment system, Hydro Deploy, which allows you to deploy your Hydro app to a variety of platforms. With Hydro Deploy, you can spin up complex services with just a few lines of Rust!

We have actually already been using Hydro Deploy in all of the examples so far, but without any special configuration:

examples/first_ten.rs

use std::sync::Arc;

use hydro_deploy::Deployment;
use hydro_deploy::gcp::GcpNetwork;
use hydro_lang::location::{Location, NetworkHint};
use tokio::sync::RwLock;
use tokio_util::codec::LinesCodec;

#[tokio::main]
async fn main() {
    let gcp_project = std::env::args()
        .nth(1)
        .expect("Expected GCP project as first argument");

    let mut deployment = Deployment::new();
    let vpc = Arc::new(RwLock::new(GcpNetwork::new(&gcp_project, None)));

    let flow = hydro_lang::compile::builder::FlowBuilder::new();
    let process = flow.process();
    let external = flow.external::<()>();

    let (port, input, output) =
        process.bind_single_client::<_, _, LinesCodec>(&external, NetworkHint::Auto);
    output.complete(hydro_template::echo_capitalize(input));

    let nodes = flow
        .with_process(
            &process,
            deployment
                .GcpComputeEngineHost()
                .project(gcp_project.clone())
                .machine_type("e2-micro")
                .image("debian-cloud/debian-11")
                .region("us-west1-a")
                .network(vpc.clone())
                .add(),
        )
        .with_external(&external, deployment.Localhost())
        .deploy(&mut deployment);

    deployment.deploy().await.unwrap();

    let raw_port = nodes.raw_port(port);
    let server_port = raw_port.server_port().await;

    println!("Please connect a client to port {:?}", server_port);

    deployment.start_ctrl_c().await.unwrap();
}

TODO(mingwei): Explain the details/nuances of the example and simple configurations.

TrybuildHost

TrybuildHost provides additional options for compiling your Hydro app, such as setting rustflags, enabling features, or setting up performance profiling.

hydro_test/examples/perf_compute_pi.rs

.with_process(
    &leader,
    TrybuildHost::new(create_host(&mut deployment))
        .rustflags(rustflags)
        .additional_hydro_features(vec!["runtime_measure".to_string()])
        // ...

TODO(mingwei)

Performance Profiling

Hydro Deploy also supports performance profiling with flamegraphs, which can be used to visualize which parts of your code are taking the most time to execute.

TrybuildHost provides a tracing method that will automatically generate a flamegraph after your app has run:

hydro_test/examples/perf_compute_pi.rs

.tracing(
    TracingOptions::builder()
        .perf_raw_outfile("leader.perf.data")
        .samply_outfile("leader.profile")
        .fold_outfile("leader.data.folded")
        .flamegraph_outfile("leader.svg")
        .frequency(frequency)
        .setup_command(hydro_deploy::rust_crate::tracing_options::DEBIAN_PERF_SETUP_COMMAND)
        .build(),
),

The TracingOptions builder has several options, such as sampling frequency, output file names, tracing options, and optionally a setup command to run before the profiling starts. The setup_command can be used to install the profiling, in this case we use the provided DEBIAN_PERF_SETUP_COMMAND which installs perf and sets some kernel parameters to enable tracing.

You may need to use TrybuildHost to set the following rustflags to enable detailed performance profiling:

hydro_test/examples/perf_compute_pi.rs

rustflags = "-C opt-level=3 -C codegen-units=1 -C strip=none -C debuginfo=2 -C lto=off";

Different platforms require particular configuration to enable CPU profiling. Each platform uses a different tool to collect CPU profiling data, but Hydro Deploy will automatically process the resulting traces and download the resulting flamegraph:

• Linux: perf for CPU profiling
• macOS: samply for CPU profiling
• Windows: samply for CPU profiling

For example, on GCP Linux machines, you may need to include additional rustflags:

hydro_test/examples/perf_compute_pi.rs

rustflags = "-C opt-level=3 -C codegen-units=1 -C strip=none -C debuginfo=2 -C lto=off -C link-args=--no-rosegment";