Hello Experts,
I have two clusters of three nodes each that I need to keep in sync using vbr replicate.
I did the following:
- On the master cluster : Added two nodes + Rebalance
- On the replication cluster : Added two nodes
Then I run vbr replicate from the master cluster to the 2nd one and re-run the replication multiple times (without adding data):
Replication 1 Approximate bytes to copy: 8710674037 of 11005070916 total.
Replication 2 Approximate bytes to copy: 131287023 of 11003237414 total.
Replication 3 Approximate bytes to copy: 0 of 11003237414 total.
My question : Why the replication 2 had still data to replicate while no new data was added in mean time?
I've run multiple tests and found the same behaviour, second replication move data even if no data was added to the any cluster, only the third one have nothing to do.
I also did the same by adding only one node then rebalance and got the below.
Replication 1 Approximate bytes to copy: 9116700248 of 10398237944 total. ==> OK
Replication 2 Approximate bytes to copy: 81689996 of 10396713131 total. ==> Not sure I understand! I expected to see 0 bytes to copy.
Replication 3 Approximate bytes to copy: 0 of 10396713131 total.
Curious to know what the 2nd replicate is doing.
Note: I made sure that rebalance is complete before running the vbr replicate tool. there was also no running operation in TUPLE_MOVER_OPERATIONS table.
FYI: I m running these tests on my small environment to better schedule and plan a rebalance operation followed by a replication on a 50Tb cluster.
Many thanks for your help.
Mkheir
