[IMPALA-5823] SET_DENY_RESERVATION_PROBABILITY debug action is not always effective

• Type: Sub-task
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: Impala 2.10.0
• Fix Version/s: Impala 2.10.0
• Component/s: Backend
• Target Version: Impala 2.10.0
• Epic Color: ghx-label-9
• Assignee: Tim Armstrong
• Reporter: Tim Armstrong
• Created: 21/Aug/17 21:21
• Updated: 23/Aug/17 15:01
• Resolved: 23/Aug/17 15:01

Description

The debug action is only effective if the client is already registered. In many cases this is not true because buffer pool client registration was deferred until later in Open() as part of the IMPALA-4862 changes.

    if (buffer_pool_client_.is_registered()) {
      // Parse [0.0, 1.0] probability.
      StringParser::ParseResult parse_result;
      double probability = StringParser::StringToFloat<double>(
          debug_action_param_.c_str(), debug_action_param_.size(), &parse_result);
      if (parse_result != StringParser::PARSE_SUCCESS || probability < 0.0
          || probability > 1.0) {
        return Status(Substitute(
            "Invalid SET_DENY_RESERVATION_PROBABILITY param: '$0'", debug_action_param_));
      }
      buffer_pool_client_.SetDebugDenyIncreaseReservation(probability);
    }

This means that we didn't have quite as much test coverage as we thought we had.