The LAZY_PERSIST Memory Storage Policy
You can store data on configured DataNode memory using the LAZY_PERSIST storage policy.
For LAZY_PERSIST, the first replica is stored on RAM_DISK (DataNode memory), and the remaining replicas are stored on DISK. The fallback storage for both creation and replication is DISK.
The following table summarizes these replication policies:
Policy ID |
Policy Name |
Block Placement (for n replicas) |
Fallback storage for creation |
Fallback storage for replication |
---|---|---|---|---|
15 |
LAZY_PERSIST |
RAM_DISK: 1, DISK:n-1 |
DISK |
DISK |
Note | |
---|---|
Currently, storage policies cannot be edited. |