atris commented on a change in pull request #96: URL: https://github.com/apache/solr/pull/96#discussion_r643429971
########## File path: solr/solr-ref-guide/src/circuit-breakers.adoc ########## @@ -94,16 +114,45 @@ Configuration for CPU utilization based circuit breaker: Note that this configuration will be overridden by the global circuit breaker flag -- if circuit breakers are disabled, this flag will not help you. -The triggering threshold is defined in units of CPU utilization. The configuration to control this is as below: +The triggering threshold is defined in percent CPU usage. A value of "0" maps to 0% usage +and a value of "100" maps to 100% usage. This circuit breaker will trip when the CPU usage is +equal to or greater than 75%: [source,xml] ---- <str name="cpuThreshold">75</str> ---- +=== System Load Average Circuit Breaker +This circuit breaker tracks system load average and triggers if the recent load average exceeds a configurable threshold. + +This is tracked with the JMX metric `OperatingSystemMXBean.getSystemLoadAverage()`. That measures the +recent load average for the whole system. A "load average" is the number of processes using or waiting for a CPU, +usually averaged over one minute. Some systems include processes waiting on IO in the load average. Check the +documentation for your system and JVM to understand this metric. For more information, see the +https://en.wikipedia.org/wiki/Load_(computing)[Wikipedia page for Load], + +Configuration for load average circuit breaker: + +[source,xml] +---- +<str name="loadAverageEnabled">true</str> +---- + +Note that this configuration will be overridden by the global circuit breaker flag -- if circuit breakers are disabled, this flag +will not help you. + +The triggering threshold is a floating point number matching load average. This circuit breaker will trip when the Review comment: Cool, then this stands resolved -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
