My questions are simple: 
what causes crashes?
what is health?
how do we stop health from degrading?

Following is the status of my db-
msearch_stats_db:
  database name: msearch_stats_db
  state: running
  locked: no
  scenarios: mal sql msql
  start count: 140
  stop count: 1
  crash count: 138
  current uptime: 1m 49s
  average uptime: 15m 33s
  maximum uptime: 15m 33s
  minimum uptime: 15m 33s
  last start with crash: 2013-02-10 17:32:36
  last start: 2013-02-10 17:32:47
  last stop: 2013-02-06 11:27:15
  average of crashes in the last start attempt: 0
  average of crashes in the last 10 start attempts: 0.90
  average of crashes in the last 30 start attempts: 0.97

Regards,
Tapomay.