Handle ICA timeouts

[uditvira]

https://docs.neutron.org/tutorials/cosmwasm_ica/#timeout

[uditvira]

Main points

• We should set large packet timeouts
• If timeout occurs, it should be assumed that channel is closed
• We can recover the account and reopen the channel by reregistering the ICA with the same port ID
• We should run our own relayers while the covenant is being operated

[uditvira]

Documenting further for clarity.

There are two distinct settings where timeouts are required.

1. Timeouts for Neutron Submit TX's, where a message is sent by controller to host chain over an ICA.

We will call these ICA timeouts

Example:

let stride_submit_msg = NeutronMsg::submit_tx(
    controller_conn_id,
    INTERCHAIN_ACCOUNT_ID.to_string(),
    vec![protobuf.clone()],
    "".to_string(),
    timeout,
    fee,
    );

ICA timeout strategy

• These timeouts are in seconds
• They should be configurable
• On timeout, we have to reregister the ICA to reopen the channel
• Timeouts are expected if relayers have problems
• We will typically set the timeout to 4-6 hours to give us enough time to fiddle with relayers if we need to.

2. Timeouts for an IBC transfer message where the source chain is a host chain.

We will call these IBC transfer timeouts

Example:

  let stride_msg = MsgTransfer {
      source_port: "transfer".to_string(),
      source_channel: gaia_stride_channel,
      token: Some(coin), 
      sender: address,
      receiver: autopilot_receiver,
      timeout_height: Some(Height {
          revision_number: 3,
          revision_height: 1000,
      }),
      timeout_timestamp: 0,
  };

IBC transfer timeout strategy

• These timeouts can be specified with a height or with a timestamp. The height is for the destination chain receiving the IBC message. So, for example, if we are sending ATOM from the Hub to Stride, the timeout height pertains to Stride.
• Since we are avoiding ICQ, we will not know heights of various destination chains. Instead, we should set a timestamp based timeout.
• We should set "timeoutHeight": { "revisionNumber": "0", "revisionHeight": "0"},
• Timestamp is unix format in nanonseconds (e.g., 1689816468825353728 is Thu Jul 20 2023 01:27:48 GMT+0000). We can use current block timestamp + some timeout interval.
• The timeout intervals should be configurable
• Our neutron contracts will be unaware of potential IBC timeouts on host chains
• We should set these timeouts to a few minutes to an hour.