Improved JDBC/ODBC parallel worker host connections failover
Details
| Detail name | Value |
|---|---|
| Changelog Number | 29957 |
| Type | Bug |
| Status | Resolved |
| Affected Versions | Exasol 8.32.0, JDBC 24.2.0, ODBC 24.2.0 |
| Fix Versions | Exasol 2025.1.14, Exasol 2026.1.2, JDBC 26.2.9, ODBC 26.2.8 |
| Resolution Date | 2026-08-06 |
Description
Parallel worker connections via JDBC/ODBC could fail intermittently when the connection host list contained an invalid or unreachable host. Although workers received valid fallback hosts, the driver randomized the worker host order and could also choose the initial worker host randomly. This meant a worker could try an invalid host first, or use a fallback order that caused avoidable connection failures.
As a result, commands IMPORT/EXPORT FROM/TO EXA might have been sporadically failing if some of hosts in connection string is not connectable.
Workaround
Avoid including invalid or unreachable hosts in the connection string. There is no reliable workaround if the host list can contain such entries.
Fix
JDBC and ODBC parallel worker host handling has been improved to make failover more robust. Worker connections now preserve a clearer primary-and-fallback structure, and fallback handling is randomized per worker instead of reusing the same shared ordering.
Commands IMPORT/EXPORT FROM/TO EXA are now more robust to situations when some of hosts in connection string is not connectable.
