Internode Transport Metrics and Baseline

Status: current OSS behavior. This document describes the metrics and baseline runner used to observe the existing tcp-http internode transport adapter. It does not add a backend, change runtime behavior, or make performance claims.

Scope

The current OSS adapter scope is:

tcp-http is the default and only supported internode data transport backend;
tcp is a legacy alias for tcp-http;
unsupported backend values fail closed during transport construction;
metrics and baseline artifacts are used to understand the current data-plane behavior.

Operation Metrics

Operation-level internode metrics are defined in crates/io-metrics/src/internode_metrics.rs.

Metric	Labels	Meaning
`rustfs_system_network_internode_operation_sent_bytes_total`	`operation`, `backend`	Bytes sent for a known internode operation.
`rustfs_system_network_internode_operation_recv_bytes_total`	`operation`, `backend`	Bytes received for a known internode operation.
`rustfs_system_network_internode_operation_requests_outgoing_total`	`operation`, `backend`	Outgoing requests opened for a known internode operation.
`rustfs_system_network_internode_operation_requests_incoming_total`	`operation`, `backend`	Incoming requests handled for a known internode operation.
`rustfs_system_network_internode_operation_errors_total`	`operation`, `backend`	Errors observed for a known internode operation.

Current operation label values are:

Operation	Transport path	Notes
`read_file_stream`	HTTP `/rustfs/rpc/read_file_stream`	Remote disk read stream opened by `InternodeDataTransport::open_read`.
`put_file_stream`	HTTP `/rustfs/rpc/put_file_stream`	Remote disk write stream opened by `InternodeDataTransport::open_write`.
`walk_dir`	HTTP `/rustfs/rpc/walk_dir`	Remote walk-dir stream opened by `InternodeDataTransport::open_walk_dir`.
`grpc_read_all`	gRPC `ReadAll`	Unary bytes response outside the adapter.
`grpc_write_all`	gRPC `WriteAll`	Unary bytes request outside the adapter.

Current backend label values are:

Backend	Meaning
`tcp-http`	Current HTTP stream backend for adapter-routed operations.
`grpc`	Current gRPC path for `ReadAll` and `WriteAll`.
`unknown`	Aggregate internode metric path when an operation-specific backend is not available.

The backend label reflects the current instrumentation source, for example the tcp-http stream path, gRPC path, or aggregate unknown path. It does not imply additional supported transport backends.

Metric labels must stay low cardinality. Do not add object names, full paths, full URLs, peer-specific dynamic strings, request IDs, or other per-request values as labels.

Current Instrumentation Points

Area	File	Current signal
Outgoing HTTP stream requests	`crates/rio/src/http_reader.rs`	Outgoing request count, sent bytes for writer bodies, received bytes for reader bodies, and errors for known `/rustfs/rpc/` operations.
Incoming HTTP stream requests	`rustfs/src/storage/rpc/http_service.rs`	Incoming request count, sent bytes for read and walk streams, received bytes for put streams, and route errors.
gRPC `ReadAll` / `WriteAll`	`rustfs/src/storage/rpc/disk.rs`	Incoming request count, sent/received bytes, and errors with the `grpc` backend label.

Known gaps:

Operation-level metrics do not currently expose latency histograms.
The baseline runner reads Prometheus text output only when --metrics-url is provided.
Metrics are useful for attribution, but they do not replace end-to-end correctness tests or object benchmark output.

Baseline Runner

Use scripts/run_internode_transport_baseline.sh to run the current S3 PUT/GET matrix against one or more configured endpoints.

Required inputs:

--access-key
--secret-key

Common optional inputs:

--tool warp|s3bench
--scenarios name=url,...
--sizes 4KiB,1MiB,...
--concurrencies 1,16,...
--duration 90s
--metrics-url http://host:port/metrics
--out-dir target/bench/internode-transport/manual-run
--dry-run

Dry-run example:

bash

scripts/run_internode_transport_baseline.sh \
  --access-key minioadmin \
  --secret-key minioadmin \
  --scenarios local=http://127.0.0.1:9000,distributed=http://127.0.0.1:9001 \
  --sizes 4KiB,1MiB \
  --concurrencies 1 \
  --duration 10s \
  --dry-run

Real baseline example with metrics:

bash

RUSTFS_INTERNODE_DATA_TRANSPORT=tcp-http \
scripts/run_internode_transport_baseline.sh \
  --access-key "$RUSTFS_ACCESS_KEY" \
  --secret-key "$RUSTFS_SECRET_KEY" \
  --scenarios local=http://127.0.0.1:9000,distributed=http://127.0.0.1:9001 \
  --metrics-url http://127.0.0.1:9000/metrics \
  --out-dir target/bench/internode-transport/manual-run

The real baseline requires a running RustFS deployment and working benchmark tool. Do not invent or copy synthetic benchmark numbers into PR descriptions.

Output Artifacts

The baseline runner writes:

File	Created when	Contents
`run_manifest.txt`	Always	Timestamp, git commit, dirty flag, Rust compiler version, kernel string, scenario matrix, tool, workload settings, metrics URL, and redacted credentials.
`summary.csv`	Always	`scenario`, `endpoint`, `workload`, `concurrency`, `size`, `status`, `throughput`, `requests_per_sec`, `avg_latency`, `error_count`, `log_file`, and `run_dir`.
`internode_metric_deltas.csv`	When `--metrics-url` is set	`scenario`, `workload`, `concurrency`, `size`, metric name, operation, backend, before value, after value, and delta.

In dry-run mode, the runner still creates the manifest and CSV headers, and the underlying object benchmark command is printed with credentials redacted.

Interpretation

Use baseline artifacts to record and inspect the current tcp-http adapter behavior across commits, environments, and scenario matrices. A baseline run is valid only for the exact environment and command recorded in run_manifest.txt.

Baseline artifacts should state whether metrics were collected. When internode_metric_deltas.csv is absent, benchmark output cannot attribute internode operation deltas from Prometheus metrics.