stone created CASSANDRA-12257:
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Summary: data consistency of multi datacenter
Key: CASSANDRA-12257
URL: https://issues.apache.org/jira/browse/CASSANDRA-12257
Project: Cassandra
Issue Type: Improvement
Components: Coordination
Reporter: stone
Environment:
serveral active-active cassandra datacenter.
set write consistency level=local_quorum to get a high resquest response.
Concern:
we dont know the time of the data arrive other datacenter.
we dont know the size of data that need to be transferred to other datacenter.
Thought:
1.we can get the latency with ping or other monitor tool,but it can not
represent the latency of cassandra data to be transferred from one dc to
another dc.
2.we can measure the latency between dc.but there is a accumulated value from
node started,it cannot represent the latency now.
https://issues.apache.org/jira/browse/CASSANDRA-11569
Scenanio:
one project need to collect information from sensors,which in different
region.2 datacenter,DC1,DC2.sensor1,sensor2 in DC1 region.sensor3,sensor4 in
DC2.
one client in DC1,pull data every 10 minutes.
1.sensor3 in DC2 write a record to DC2 at 8:59:55 ,and arrived DC1 at 9:00:05
2.client in DC1 pull data at 9:00,it should get the record,but it cannot as the
record have not arrive DC1.
3.then client in DC1 will pull data at 9:10.it also can not get the record as
it will pull data from 9:00---9:10,but the record created on 8:59:55
so we will miss the record.
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