Context:

We have a set of verbose message functions that dump various states of WiredTiger, typically invoked via the 'WT_CONNECTION::debug_info' interface. These functions make use of the 'wt_msg' function. The 'wt_msg' function directly calls the 'WT_EVENT_HANDLER:handle_message' interface function, avoiding any of the styling/formatting enforced by our other internal message interfaces (i.e doesn't call 'eventv'). This is ideal for verbose dump implementations that make use of 'wt_msg'  as they construct custom formatted messages i.e. new line separated, indented sub-messages, across multiple 'wt_msg' calls.

This is however problematic as it doesn't adhere to the new JSON configuration option 'json_output'. That being, non-JSON strings can still possibly be passed via the 'WT_EVENT_HANDLER:handle_message' function when the connection is configured with 'json_output=[message]'.

Definition of Done:

• Investigate and implement a solution to create JSON output in the verbose dump methods, when 'json_output=[message]' is enabled. These include: wt_verbose_dump_cache, wt_verbose_dump_sessions, wt_verbose_dump_handles, wt_verbose_dump_log 
  • This may mean formatting the message into a intermediate buffer.