Eric Dong created CASSANDRA-4479: ------------------------------------ Summary: Multiple phi_convict_threshold fields not all settable via JMX Key: CASSANDRA-4479 URL: https://issues.apache.org/jira/browse/CASSANDRA-4479 Project: Cassandra Issue Type: Bug Affects Versions: 1.1.2 Reporter: Eric Dong
If a setting is configurable both via cassandra.yaml and JMX, the two should be consistent, but that is not the case for phi_convict_threshold. I'm trying to set phi_convict_threshold via JMX, which sets FailureDetector.phiConvictThreshold_, but this doesn't update Config.phi_convict_threshold, which gets its value from cassandra.yaml when starting up. Some places, such as FailureDetector.interpret(InetAddress), use FailureDetector.phiConvictThreshold_; others, such as AntiEntropyService.line 813 in cassandra-1.1.2, use Config.phi_convict_threshold: {code} // We want a higher confidence in the failure detection than usual because failing a repair wrongly has a high cost. if (phi < 2 * DatabaseDescriptor.getPhiConvictThreshold()) return; {code} where DatabaseDescriptor.getPhiConvictThreshold() returns Conf.phi_convict_threshold. So, it looks like there are cases where a value is stored in multiple places, and setting the value via JMX doesn't set all of them. I'd say there should only be a single place where a configuration parameter is stored, and that single field: * should read in the value from cassandra.yaml, optionally falling back to a sane default * should be the field that the JMX attribute reads and sets, and * any place that needs the current global setting should get it from that field. However, there could be cases where you read in a global value at the start of a task and keep that value locally until the end of the task. Also, anything settable via JMX should be volatile or set via a synchronized setter, or else according to the Java memory model other threads may be stuck with the old setting. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira