Full ERROR Message Example

ERROR [MemtableFlushWriter:14] 2020-08-08 20:41:06,813 LogTransaction.java:223 - Unable to delete /path/to/data_file_directories/system/size_estimates-<cfid>/ac_txn_flush_<uuid>.log as it does not exist, see debug log file for stack trace

What does this ERROR message mean?

This message means a transaction log, used to track the state of sstable files involved in a compaction, could not be deleted because it could not be found in the filesystem.

Why does this ERROR occur?

When the change to using file-based compaction tracking instead of the compactions_in_progress table was made, a cleanup task for the transaction files was also introduced. When a node starts, or, at the end of a compaction, an obsolete transaction file will be deleted. This error is thrown by the cleanup task when it tries to delete the file, if the file is not found at the expected location. This can occur due to corruption in the underlying filesystem or because the indicated file was deleted by something outside the database node.

How do you fix this ERROR?

To resolve this, it would be best to check the debug.log on the node, for more information about the underlying filesystem error. If there's no issue with the filesystem, ensure there are no programs that may be removing files from the DSE node's directory paths. The file may be manually removed, and the node restarted. It is important to repair the node if this occurs.

See CASSANDRA-7066 for more details.