The brute force way would be: 1) Make client connections to a node in each datacenter from your monitoring tool. 2) Periodically write a row to one datacenter (at whatever consistency level your application typically uses.) 3) Immediately query the other datacenter nodes for the same row key with LOCAL_QUORUM consistency. If not found, execute query again immediately in a loop. 4) Once the row is available, record time since initial write for that datacenter.
DataStax folks: this actually seems like a useful metric for something OpsCenter to track, since it is already doing active statistics collection. On Wed, Jul 30, 2014 at 8:59 AM, Rahul Neelakantan <ra...@rahul.be> wrote: > Rob, > Any ideas you can provide on how to do this will be appreciated, we would > like to build a latency monitoring tool/dashboard that shows how long it > takes for data to get sent across various DCs. > > Rahul Neelakantan > > On Jul 29, 2014, at 8:53 PM, Robert Coli <rc...@eventbrite.com> wrote: > > On Tue, Jul 29, 2014 at 3:15 PM, Rahul Neelakantan <ra...@rahul.be> wrote: > >> Does anyone know of a way to measure/monitor WAN replication latency for >> Cassandra? > > > No. [1] > > =Rob > > [1] There are ways to do something like this task, but you probably don't > actually want to do them. Trying to do them suggests that you are relying > on WAN replication timing for your application, which is something you > almost certainly do not want to do. Why do you believe you have this > requirement? > >
