On Fri, Sep 23, 2022 at 8:39 PM Bowen Song via user < user@cassandra.apache.org> wrote:
> What's your definition of "sync"? Streaming all the existing data to the > new DC? or the time lag between a write request is completed in one DC and > the other DC? > > The former can be estimated based on a few facts about your setup (number > of nodes, data size, etc.) and some measured data (streaming speed). > > The latter is usually just slightly above the network latency, but can > spike up if and when the network between DCs suffer from temporary > connectivity issues. > Hi Bowen, Thanks for the quick response. I was referring to streaming all the existing data to the new DC(DC2). We have > On 23/09/2022 15:58, Kaushal Shriyan wrote: > > Hi, > > Is there a way to measure cassandra nodes data sync time between DC1 and > DC2? Currently DC1 is the prod datacenter. I am adding DC2 to the new data > center by referring to > https://docs.apigee.com/private-cloud/v4.51.00/adding-data-center?hl=en. > > https://docs.apigee.com/release/supported-software > Cassandra version :- 2.1.22 > > Is there a way to measure the time taken to sync the data in current prod > DC1 (Cassandra Node 1, 2 ,3) and the new DC2 (Cassandra Node 4, 5 ,6)? > > Thanks in advance. > > Best Regards, > > Kaushal > > Hi Bowen, Thanks for the quick response. Streaming all the existing data from the current prod DC1 (Cassandra Node 1, 2 ,3) to the new DC2 (Cassandra Node 4, 5 ,6). Data bandwidth between DC1 and DC2 is around 50 Mbps. Please let me know if you need any additional details. Thanks in advance. /opt/apigee/apigee-cassandra/bin/nodetool status Datacenter: dc-1 ================ Status=Up/Down |/ State=Normal/Leaving/Joining/Moving -- Address Load Tokens Owns (effective) Host ID Rack UN 192.198.11.4 1.43 GB 1 100.0% dbfbd44f-kec5-4f91-bc7d-c31582aec35a ra-1 UN 192.198.11.128 1.43 GB 1 100.0% bc55019c-8ccb-4403-9dc4-481b90a262f6 ra-1 UN 192.198.11.3 1.43 GB 1 100.0% 4402901c-4562-4f0f-b14a-4eed40a9836c ra-1 *On Node1* du -ch /opt/apigee/data/apigee-cassandra/data 1.7G total *On Node2* du -ch /opt/apigee/data/apigee-cassandra/data *On Node3* du -ch /opt/apigee/data/apigee-cassandra/data Best Regards, Kaushal
