tm-load-test

tm-load-test is a distributed load testing tool (and framework) for load testing Tendermint networks and aims to effectively be the successor to tm-bench.

Naturally, any transactions sent to a Tendermint network are specific to the ABCI application running on that network. As such, the tm-load-test tool comes with built-in support for the kvstore ABCI application, but you can build your own clients for your own apps.

Requirements

tm-load-test is currently tested using Go v1.20.

Building

To build the tm-load-test binary in the build directory:

make

Usage

tm-load-test can be executed in one of two modes: standalone, or coordinator/worker.

Standalone Mode

In standalone mode, tm-load-test operates in a similar way to tm-bench:

tm-load-test -c 1 -T 10 -r 1000 -s 250 \
    --broadcast-tx-method async \
    --endpoints ws://tm-endpoint1.somewhere.com:26657/websocket,ws://tm-endpoint2.somewhere.com:26657/websocket

To see a description of what all of the parameters mean, simply run:

tm-load-test --help

Coordinator/Worker Mode

In coordinator/worker mode, which is best used for large-scale, distributed load testing, tm-load-test allows you to have multiple worker machines connect to a single coordinator to obtain their configuration and coordinate their operation.

The coordinator acts as a simple WebSockets host, and the workers are WebSockets clients.

On the coordinator machine:

# Run tm-load-test with similar parameters to the standalone mode, but now
# specifying the number of workers to expect (--expect-workers) and the host:port
# to which to bind (--bind) and listen for incoming worker requests.
tm-load-test \
    coordinator \
    --expect-workers 2 \
    --bind localhost:26670 \
    -c 1 -T 10 -r 1000 -s 250 \
    --broadcast-tx-method async \
    --endpoints ws://tm-endpoint1.somewhere.com:26657/websocket,ws://tm-endpoint2.somewhere.com:26657/websocket

On each worker machine:

# Just tell the worker where to find the coordinator - it will figure out the rest.
tm-load-test worker --coordinator localhost:26680

For more help, see the command line parameters' descriptions:

tm-load-test coordinator --help
tm-load-test worker --help

Endpoint Selection Strategies

As of v0.5.1, an endpoint selection strategy can now be given to tm-load-test as a parameter (--endpoint-select-method) to control the way in which endpoints are selected for load testing. There are several options:

1. supplied (the default) - only use the supplied endpoints (via the --endpoints parameter) to submit transactions.
2. discovered - only use endpoints discovered through the supplied endpoints (by way of crawling the Tendermint peers' network info), but do not use any of the supplied endpoints.
3. any - use both the supplied and discovered endpoints to perform load testing.

NOTE: These selection strategies only apply if, and only if, the --expect-peers parameter is supplied and is non-zero. The default behaviour if --expect-peers is not supplied is effectively the supplied endpoint selection strategy.

Minimum Peer Connectivity

As of v0.6.0, tm-load-test can now wait for a minimum level of P2P connectivity before starting the load testing. By using the --min-peer-connectivity command line switch, along with --expect-peers, one can restrict this.

What this does under the hood is that it checks how many peers are in each queried peer's address book, and for all reachable peers it checks what the minimum address book size is. Once the minimum address book size reaches the configured value, the load testing can begin.

Customizing

To implement your own client type to load test your own Tendermint ABCI application, see the loadtest package docs here.

Monitoring

As of v0.4.1, tm-load-test exposes a number of metrics when in coordinator/worker mode, but only from the coordinator's web server at the /metrics endpoint. So if you bind your coordinator node to localhost:26670, you should be able to get these metrics from:

curl http://localhost:26670/metrics

The following kinds of metrics are made available here:

• Total number of transactions recorded from the coordinator's perspective (across all workers)
• Total number of transactions sent by each worker
• The status of the coordinator node, which is a gauge that indicates one of the following codes:
  • 0 = Coordinator starting
  • 1 = Coordinator waiting for all peers to connect
  • 2 = Coordinator waiting for all workers to connect
  • 3 = Load test underway
  • 4 = Coordinator and/or one or more worker(s) failed
  • 5 = All workers completed load testing successfully
• The status of each worker node, which is also a gauge that indicates one of the following codes:
  • 0 = Worker connected
  • 1 = Worker accepted
  • 2 = Worker rejected
  • 3 = Load testing underway
  • 4 = Worker failed
  • 5 = Worker completed load testing successfully
• Standard Prometheus-provided metrics about the garbage collector in tm-load-test
• The ID of the load test currently underway (defaults to 0), set by way of the --load-test-id flag on the coordinator

Aggregate Statistics

As of tm-load-test v0.7.0, one can now write simple aggregate statistics to a CSV file once testing completes by specifying the --stats-output flag:

# In standalone mode
tm-load-test -c 1 -T 10 -r 1000 -s 250 \
    --broadcast-tx-method async \
    --endpoints ws://tm-endpoint1.somewhere.com:26657/websocket,ws://tm-endpoint2.somewhere.com:26657/websocket \
    --stats-output /path/to/save/stats.csv

# From the coordinator in coordinator/worker mode
tm-load-test \
    coordinator \
    --expect-workers 2 \
    --bind localhost:26670 \
    -c 1 -T 10 -r 1000 -s 250 \
    --broadcast-tx-method async \
    --endpoints ws://tm-endpoint1.somewhere.com:26657/websocket,ws://tm-endpoint2.somewhere.com:26657/websocket \
    --stats-output /path/to/save/stats.csv

The output CSV file has the following format at present:

Parameter,Value,Units
total_time,10.002,seconds
total_txs,9000,count
avg_tx_rate,899.818398,transactions per second

Development

To run the linter and the tests:

make lint
make test

Integration Testing

Integration testing requires Docker to be installed locally.

make integration-test

This integration test:

1. Sets up a 4-validator, fully connected Tendermint Core-based network on a 192.168.0.0/16 subnet (the same kind of testnet as the Tendermint Core localnet).
2. Executes integration tests against the network in series (it's important that integration tests be executed in series so as to not overlap with one another).
3. Tears down the 4-validator network, reporting code coverage.