What is Health?
Health is a single number representing the performance of a service or JVM. Health is expressed in percentage, ranging from 0 to 100%. 100% healthy service or JVM indicates a situation where all transactions in this JVM/service are completing successfully and completing fast. 0% on the other hand would indicate a JVM where none of the transactions in this JVM/service managed to complete successfully. In addition to communicating the way the JVM/service is performing, health is also used to power the alert system in Plumbr.
Health is being calculated according to the ratio of slow and failed transactions using the following formula:
Health = (# of Successful Transactions + # of Slow Transactions / 2) / # of Total Transactions
For example: if Plumbr has
- monitored 10,000 transactions in a JVM during the selected time period
- detected that 500 of those transactions have been slow
- detected that 500 of those transactions have failed
then the health of this JVM is 92.5%, calculated using the formula above as:
92,5% = (9,000 + 500 / 2) / 10,000
The health for services/JVMs is always calculated for a specific time window (12th – 14th July 2016, last 2 hours, etc), so it is a measure changing over time.