alto-chain

A minimal (and wicked fast) blockchain built with the Commonware Library.

Status

alto-chain is ALPHA software and is not yet recommended for production use. Developers should expect breaking changes and occasional instability.

Setup

Local

To run this example, you must first install Rust.

Create Artifacts

To configure indexer upload, add --indexer-port <port> to the generate local command. The first validator is configured to push data to it.

cargo run --bin setup -- generate --peers 5 --bootstrappers 1 --worker-threads 3 --log-level info --message-backlog 16384 --mailbox-size 16384 --deque-size 10 --signature-threads 2 --output test local --start-port 3000 --indexer-port 8080

If setup succeeds, you should see the following output:

2025-12-23T13:41:54.034863Z  INFO setup: generated network key identity=8b2c34e0356beb83874317f8f04fb211e4d3ed34640631a36ff191cb3fcd9768403b8749824b41ff770a92e40885174b15516db966816870ba9619a64b4d5b79ea7b4a73240710169ecc44da0951cdd60e2db65544cba5647f81ab19ca50cf4e
2025-12-23T13:41:54.037106Z  INFO setup: wrote peer configuration file path="04dc128c6fc22cb93a9eb785c48d4251346eb7b387cd2a66599cc59a3ce47a37.yaml"
2025-12-23T13:41:54.037417Z  INFO setup: wrote peer configuration file path="0b2412d7eb2238b319920504f19b28447c7dbb3c58059c97d22cc0d27ea31e81.yaml"
2025-12-23T13:41:54.037690Z  INFO setup: wrote peer configuration file path="71943989f39d485eb8a1f7c8f9909673caaa658d12a586c93f37575dae44438f.yaml"
2025-12-23T13:41:54.037966Z  INFO setup: wrote peer configuration file path="c58244243f263ebc975640d5bb4e43e8e78e4b41361e4e7984cd8b027480558a.yaml"
2025-12-23T13:41:54.038228Z  INFO setup: wrote peer configuration file path="f26a6d4f52c4d595b6cb659b643968b0e1fc9931b460c6407be10cebe4eeff2d.yaml"
2025-12-23T13:41:54.038232Z  INFO setup: setup complete bootstrappers=["71943989f39d485eb8a1f7c8f9909673caaa658d12a586c93f37575dae44438f"]
To start local indexer, run:
cargo run --bin indexer -- --port 8080 --identity 8b2c34e0356beb83874317f8f04fb211e4d3ed34640631a36ff191cb3fcd9768403b8749824b41ff770a92e40885174b15516db966816870ba9619a64b4d5b79ea7b4a73240710169ecc44da0951cdd60e2db65544cba5647f81ab19ca50cf4e
To start validators, run:
04dc128c6fc22cb93a9eb785c48d4251346eb7b387cd2a66599cc59a3ce47a37: cargo run --bin validator -- --peers=<your-path>/test/peers.yaml --config=<your-path>/test/04dc128c6fc22cb93a9eb785c48d4251346eb7b387cd2a66599cc59a3ce47a37.yaml
0b2412d7eb2238b319920504f19b28447c7dbb3c58059c97d22cc0d27ea31e81: cargo run --bin validator -- --peers=<your-path>/test/peers.yaml --config=<your-path>/test/0b2412d7eb2238b319920504f19b28447c7dbb3c58059c97d22cc0d27ea31e81.yaml
71943989f39d485eb8a1f7c8f9909673caaa658d12a586c93f37575dae44438f: cargo run --bin validator -- --peers=<your-path>/test/peers.yaml --config=<your-path>/test/71943989f39d485eb8a1f7c8f9909673caaa658d12a586c93f37575dae44438f.yaml
c58244243f263ebc975640d5bb4e43e8e78e4b41361e4e7984cd8b027480558a: cargo run --bin validator -- --peers=<your-path>/test/peers.yaml --config=<your-path>/test/c58244243f263ebc975640d5bb4e43e8e78e4b41361e4e7984cd8b027480558a.yaml
f26a6d4f52c4d595b6cb659b643968b0e1fc9931b460c6407be10cebe4eeff2d: cargo run --bin validator -- --peers=<your-path>/test/peers.yaml --config=<your-path>/test/f26a6d4f52c4d595b6cb659b643968b0e1fc9931b460c6407be10cebe4eeff2d.yaml
Indexer URL: http://localhost:8080 (pushed by 04dc128c6fc22cb93a9eb785c48d4251346eb7b387cd2a66599cc59a3ce47a37)
To view metrics, run:
04dc128c6fc22cb93a9eb785c48d4251346eb7b387cd2a66599cc59a3ce47a37: curl http://localhost:3001/metrics
0b2412d7eb2238b319920504f19b28447c7dbb3c58059c97d22cc0d27ea31e81: curl http://localhost:3003/metrics
71943989f39d485eb8a1f7c8f9909673caaa658d12a586c93f37575dae44438f: curl http://localhost:3005/metrics
c58244243f263ebc975640d5bb4e43e8e78e4b41361e4e7984cd8b027480558a: curl http://localhost:3007/metrics
f26a6d4f52c4d595b6cb659b643968b0e1fc9931b460c6407be10cebe4eeff2d: curl http://localhost:3009/metrics

Start Validators

Run the emitted start commands in separate terminals:

cargo run --bin validator -- --peers=<your-path>/test/peers.yaml --config=<your-path>/test/10cf8d03daca2332213981adee2a4bfffe4a1782bb5cce036c1d5689c6090997.yaml

It is necessary to start at least one bootstrapper for any other peers to connect (used to exchange IPs to dial, not as a relay).

[Optional] Configure Explorer

cargo run --bin setup -- explorer --dir test --backend-url <backend URL> local

Debugging

Too Many Open Files

If you see an error like unable to append to journal: Runtime(BlobOpenFailed("engine-consensus", "00000000000000ee", Os { code: 24, kind: Uncategorized, message: "Too many open files" })), you may need to increase the maximum number of open files. You can do this by running:

ulimit -n 65536

MacOS defaults to 256 open files, which is too low for the default settings (where 1 journal file is maintained per recent view).

Remote

To run this example, you must first install Rust and Docker.

Install commonware-deployer

cargo install commonware-deployer

Create Artifacts

To configure indexer upload, add --indexer-url <URL> --indexer-count <count> to the generate remote command. Indexers are selected in round-robin fashion across regions.

Global

cargo run --bin setup -- generate --peers 50 --bootstrappers 5 --worker-threads 2 --log-level info --message-backlog 16384 --mailbox-size 16384 --deque-size 10 --signature-threads 2 --output assets remote --regions us-west-1,us-east-1,eu-west-1,ap-northeast-1,eu-north-1,ap-south-1,sa-east-1,eu-central-1,ap-northeast-2,ap-southeast-2 --monitoring-instance-type c8g.4xlarge --monitoring-storage-size 100 --instance-type c8g.large --storage-size 25 --dashboard dashboard.json

This configuration consumes ~10MB of disk space per hour per validator (~5 views per second). With 25GB of storage allocated, validators will exhaust available storage in ~3 months.

USA

cargo run --bin setup -- generate --peers 50 --bootstrappers 5 --worker-threads 2 --log-level info --message-backlog 16384 --mailbox-size 16384 --deque-size 10 --signature-threads 2 --output assets remote --regions us-east-1,us-east-2,us-west-1,us-west-2 --monitoring-instance-type c8g.4xlarge --monitoring-storage-size 100 --instance-type c8g.large --storage-size 75 --dashboard dashboard.json

This configuration consumes ~30MB of disk space per hour per validator (~13 views per second). With 75GB of storage allocated, validators will exhaust available storage in ~3 months.

[Optional] Configure Explorer

cargo run --bin setup -- explorer --dir assets --backend-url <backend URL> remote

Build Validator Binary

Build Cross-Platform Compiler

docker build -t validator-builder .

Compile Binary for ARM64

docker run -it -v ${PWD}/..:/alto validator-builder

Local Compilation

Before running this command, ensure you change any version dependencies you'd like to compile locally to path dependencies in Cargo.toml.

docker run -it -v ${PWD}/..:/alto -v ${PWD}/../../monorepo:/monorepo validator-builder

Emitted binary validator is placed in assets.

Deploy Validator Binary

cd assets
deployer ec2 create --config config.yaml

Monitor Performance on Grafana

Visit http://<monitoring-ip>:3000/d/chain

This dashboard is only accessible from the IP used to deploy the infrastructure.

[Optional] Update Validator Binary

Re-Compile Binary for ARM64

docker run -it -v ${PWD}/..:/alto validator-builder

Restart Validator Binary on EC2 Instances

deployer ec2 update --config config.yaml

[Optional] Profile Validator

Collect a CPU profile from a running validator using samply:

deployer ec2 profile --config config.yaml --instance <instance-name> --binary validator-debug

The validator-debug binary contains debug symbols for symbolication. The profile will be saved locally and can be viewed in the Firefox Profiler.

Destroy Infrastructure

deployer ec2 destroy --config config.yaml

Debugging

Missing AWS Credentials

If commonware-deployer can't detect your AWS credentials, you'll see a "Request has expired." error:

2025-03-05T01:36:47.550105Z  INFO deployer::ec2::create: created EC2 client region="eu-west-1"
2025-03-05T01:36:48.268330Z ERROR deployer: failed to create EC2 deployment error=AwsEc2(Unhandled(Unhandled { source: ErrorMetadata { code: Some("RequestExpired"), message: Some("Request has expired."), extras: Some({"aws_request_id": "006f6b92-4965-470d-8eac-7c9644744bdf"}) }, meta: ErrorMetadata { code: Some("RequestExpired"), message: Some("Request has expired."), extras: Some({"aws_request_id": "006f6b92-4965-470d-8eac-7c9644744bdf"}) } }))

EC2 Throttling

EC2 instances may throttle network traffic if a workload exceeds the allocation for a particular instance type. To check if an instance is throttled, SSH into the instance and run:

ethtool -S ens5 | grep "allowance"

If throttled, you'll see a non-zero value for some "allowance" item:

bw_in_allowance_exceeded: 0
bw_out_allowance_exceeded: 14368
pps_allowance_exceeded: 0
conntrack_allowance_exceeded: 0
linklocal_allowance_exceeded: 0