Variable RPCConfig.retry_delay

Time to wait between two attempts at connecting / reading / writing

struct RPCConfig
{
  // ...
  core.time.Duration retry_delay = Duration(10000000L);
  // ...
}

Whenever an operation is marked as failed, this is the time to wait between each attempt. Note that a smarter client might want to set max_retries to 0, in which case this value has no effect, to implement smarter approaches to retry, e.g. exponential backoff.