Automatic volume move is on by default with a 600 second delay.
Details
| Detail name | Value |
|---|---|
| Changelog Number | 21459 |
| Type | Improvement |
| Status | Resolved |
| Fix Versions | Exasol 8.31.0, Exasol 8.29.2 |
| Resolution Date | 2024-08-29 |
Background
As described in Fail Safety (On-Prem), when a node becomes unavailable, the data segments it contains may be moved to one of the reserve nodes. This ensures that redundancy is kept. This process can be manually triggered by an administrator.
This process can also be automatically triggered by the Exasol health service. Contrary to what was written in the documentation, this behavior was turned off by default because it’s considered an expensive operation.
Improvement
Updated versions of the software will have this behavior on by default with a 10 minute delay (matching the documentation). This means that if a node is offline for 10 minutes, any data segments it contained will be duplicated to whatever reserve node replaced it. If the node were to come back online in less than 10 minutes the operation is not executed.
Changed behavior
Fail safety mechanisms will copy data segments that resided on an offline node to a reserve node after 10 minutes of it becoming offline.
