WL#2943: SHOW CLUSTERLOG THRESHOLD LEVELS: Implement statement

Affects: Server-7.1   —   Status: Un-Assigned   —   Priority: Medium

There currently doesn't seem to be anyway of showing the active 
threshold levels for each category. If this is so, then a command for 
this should be added

Something like:

ndb_mgm>SHOW CLUSTERLOG LEVELS


And this would list the threshould for each category