Exa-to-Exa Import failure on single-node clusters when importing data from multi-node clusters while connected to nodes other than Node 0

Details

Detail name Value
Changelog Number 24917
Type Bug
Status Resolved
Affected Versions Exasol 8.32.0
Fix Versions Exasol 2025.1.0
Resolution Date 2025-07-08

Description

Exa-to-Exa import operation fails when a single-node Exasol database cluster attempts to import data from a multi-node Exasol database cluster under certain conditions. Specifically, the issue arises when the single-node cluster connects to a node other than Node 0 on the multi-node cluster.

Environment

  • Source DB: Single-node Exasol cluster ≥ 8.32.0
  • Destination DB: Multi-node Exasol cluster ≥ 8.32.0

Error Message

ETL-4218: Reading data failed from external EXASolution. If using user defined statement, please check it. In the case the following error message doesn't help you, please contact support. [Socket error. Connection interrupted. sslreadtimeout: SSL sslreadtimeout: connection closed by remote host (Session: *************) Error receiving message from Exasol. Socket failure. (Session: *************) Error code was 0 Server communication error. Error getting more lines: execute statement. sslreadtimeout: SSL sslreadtimeout: connection closed by remote host (Session: *************) Error receiving message from Exasol. Socket failure. (Session: *************) Error code was 0 Server communication error.] (Session: *************)

Impacted System

  1. The import operation either fails with the above error message OR hangs indefinitely.
  2. The issue occurs in the following scenario:
  • Source DB: Single-node Exasol cluster.
  • Destination DB: Multi-node Exasol cluster.
  • Cluster connection: Established to a node other than Node 0 of the Destination DB

Workarounds

Until a permanent fix is applied, users can employ the following workarounds:

  1. Add nodes to the Source DB cluster: Convert the Source DB into at least a 2-node setup to avoid encountering the issue.
  2. Connect to Node 0: Avoid connecting to any node other than Node 0 of the Destination DB. Please contact Exasol Support to help you identify which node has logical number 0.
  3. Use JDBC for import: Use JDBC-based data import instead of the IMPORT FROM EXA statement.
  4. Reverse the import logic: Execute an EXPORT FROM EXA statement from the Destination DB, reversing the direction of data transfer.

Fix

The underlying issue has been identified and resolved in newer releases.