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stone commented on CASSANDRA-11569: ----------------------------------- use ipfw tool to set datacenter latency. I also use trace to confirm the latency is valuable. QueryTrace queryTrace = executionInfo.getQueryTrace(); when there is 10ms latency,no problem.and when there is 100ms latency,I will got an error as the crosslatency is too large. so I doubt the value of CrossNodeLatency > Track message latency across DCs > -------------------------------- > > Key: CASSANDRA-11569 > URL: https://issues.apache.org/jira/browse/CASSANDRA-11569 > Project: Cassandra > Issue Type: Improvement > Components: Observability > Reporter: Chris Lohfink > Assignee: Chris Lohfink > Priority: Minor > Attachments: CASSANDRA-11569.patch > > > Since we have the timestamp a message is created and when arrives, we can get > an approximate time it took relatively easy and would remove necessity for > more complex hacks to determine latency between DCs. > Although is not going to be very meaningful when ntp is not setup, it is > pretty common to have NTP setup and even with clock drift nothing is really > hurt except the metric becoming whacky. -- This message was sent by Atlassian JIRA (v6.3.4#6332)