| Use Case | Description |
|----------|-------------|
| Telemetry ingestion | Text files from remote sensors (e.g., temperature, vibration) are linked via a monitored folder and stored in Cassandra for long-term analytics. |
| Traffic management | .txt logs from loop detectors or cameras are processed via a symlink and loaded into Cassandra for low-latency querying. |
| Backup/archival | Folder links point to network storage; Cassandra stores metadata pointers to original .txt files. |
Issue: You placed a .txt configuration file inside a symlinked directory, but Cassandra throws FileNotFoundException.
Cause: The symlink points to a location not readable by the cassandra user.
Fix: Adjust permissions on the target: chown -R cassandra:cassandra /real/path Filedot Folder Link Cassandra -TMC- txt
Cassandra expects exclusive access to its data directories. Using folder links (symlinks/junctions) introduces risks: | Use Case | Description | |----------|-------------| |
| Risk | Consequence | |------|-------------| | Loops | Recursive directory traversal crashes the node. | | Broken links | Cassandra fails to write SSTables, leading to write timeouts. | | Cross-device links | Performance penalties and backup inconsistencies. | | Permission mismatches | Java (Cassandra) fails to follow link due to permission differences. | | Issue: You placed a
Best practice: Avoid symlinks under data/, commitlog/, or saved_caches/. If necessary, use mount binds (mount --bind) instead, which are invisible to Cassandra as links.