Simulator improvements

[aaronbuchwald]

Why this should be merged

This PR is intended to improve the load simulator. The original code included a lot of unnecessary error handling that complicated the logic. This code should simply:

• fund keys
• generate sequences of transactions
• issue sequence of transactions
• await tx acceptance to mark time to finality from perspective of a client
• confirm all of the transactions

How this works

This PR breaks the load simulator into:

• insecure key management (intended only for testing)
• tx sequence generation
• worker to handle issuance, await acceptance, confirmation via eth_getTransactionByHash

How this was tested

CI and local testing. To verify, create a local network with the avalanche-network-runner and try running the simulator with the following commands to test different scenarios (note: if you run a large amount of volume through the network, then it may increase the base fee, such that previously issued transactions may be underpriced)

How is this documented

This PR updates ./cmd/simulator/README.md with up to date documentation including flag options in the command output.

To see the simulator options run (from the root of the repo):

go run cmd/simulator/main/*.go --help

Output:

# command-line-arguments
ld: warning: could not create compact unwind for _blst_sha256_block_data_order: does not use RBP or RSP based frame
Usage of simulator:
      --config-file string    Specify the config path to use to load a YAML config for the simulator
      --endpoints strings     Specify a comma separated list of RPC Websocket Endpoints (default [ws://127.0.0.1:9650/ext/bc/C/ws])
      --key-dir string        Specify the directory to save private keys in (INSECURE: only use for testing) (default ".simulator/keys")
      --log-level string      Specify the log level to use in the simulator. (default "info")
      --max-fee-cap int       Specify the maximum fee cap to use for transactions denominated in GWei (default 50)
      --max-tip-cap int       Specify the max tip cap for transactions denominated in GWei (default 1)
      --timeout duration      Specify the timeout for the simulator to complete. (default 5m0s)
      --txs-per-worker uint   Specify the number of transactions to create per worker. (default 100)
      --version               Print the version and exit.
      --workers int           Specify the number of workers to create for the simulator. (default 1)

[richardpringle]

My review is a little overly critical; this is how I learn. Feel free to enlighten me on some of my comments, or you can even say, "I agree with your comment, but it's not worth the effort to make the change".

I also may have made comments on files that you moved and didn't change any of the logic... if that's the case, whoops...

[darioush]

LGTM, some nits. Can approve after they are addressed.

[darioush]

nit: should we use workers instead?

[darioush]

could we avoid modifying the config object so it always corresponds to the command line arguments as provided?

[aaronbuchwald]

Updated

[darioush]

lgtm