Allow retry strategies to be configured

[romac]

Crate

ibc-relayer

Summary

Add configuration options to specify the retry strategies to be used in various places.

Problem Definition

As some chains may be slower or faster than other, the performance and reliability of Hermes could be improved by allowing to configure the retry strategies per-chain.

Proposal

Add a retry_strategies section to ChainConfig which might look like:

[chains]
id = 'ibc-0'
# ...

[chains.retry_strategies]
wait_for_tx_commit = { type = "Fixed", interval = 300, max_total_delay = 12_000 }
worker = { type = "ConstantGrowth", initial_delay = 200, increment = 100, max_delay = 500, max_total_delay = 2000 }
default = { type = "Fibonacci", initial_delay = 1000, max_delay = 60_000, max_total_delay = 600_000 }

pub struct ChainConfig {
  // ...

  #[serde(default)]
  retry_strategies: RetryStrategies
}

#[derive(Serialize, Deserialize)]
pub struct RetryStrategies {
  wait_for_tx_commit: RetryStrategy,
  worker: RetryStrategy,
  default: RetryStrategy,
}

impl Default for RetryStrategies {
  // ...
}

#[derive(Serialize, Deserialize)]
#[serde(tag = "type")]
pub enum RetryStrategy {
  Fixed { interval: u64, max_total_delay: u64 },
  Fibonacci { initial_delay: u64, max_delay: u64, max_total_delay: u64 },
  ConstantGrowth { initial_delay: u64, increment: u64, max_delay: u64, max_total_delay: u64 },
}

Acceptance Criteria

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For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate milestone (priority) applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned