The non local strategy system keyspaces usually contain very litte data.
All the tables within them have to be repaired for all the token ranges,
which could be large in clusters with a large number of nodes. In multiple
DC setup, the repair in RBNO is dominated by the network latency. As a
result, it takes a long time to repair those tables even if they are
almost empty.
To speed up the RBNO bootstrap, especially for starting empty clusters,
this patch enables small table optimization for RBNO for system tables.
We could enable it for small user tables as a follow up.
Tests:
1) A 5ms latency is added to simulate cross dc network delay, 256 tokens
per node, 10 nodes:
- Before
topology_custom dev topology_custom.test_boot_time.1 1287.06s
- After
topology_custom dev topology_custom.test_boot_time.1 12.48s
The test shows 100X boot time improvement
2) A SCT test to bootstrap 3 DCs, 3 nodes in each DC.
- Before
Time to bootstrap = 1h23m
- After
Time to bootstrap = 13m
The test shows 6X bootstrap time improvement
Fixes#19131
9ace191616