WRITE_ERR Notification

The potential possibility of a disk write failure may go unreported with the c-tree Server. A particular scenario has been identified where in the event of a data or index file write failure, the c-tree Server continues operations, and assumes the cache has been properly flushed to disk. While the transaction logs maintain data integrity, particular transactions may be marked as not flushed to disk, holding previous transaction logs from being discarded.

To detect this situation may occur, a notification is now logged to CTSTATUS.FCS when and if a WRITE_ERR occurs. The log entry will include the file name, the offset of the write attempt, the system error code, the size of the write request and the number of bytes written. Optionally, the contents of the write request can be output to a file as well.

Note: These entries should be extremely rare!

This behavior is on by default. If this is undesirable, a new server configuration keyword will inhibit these messages:

CTSTATUS MASK_WRITE_ERR

An additional new server configuration keyword will cause the contents of the write request to be appended to the WRITE_ERR.FCS file.

DIAGNOSTICS WRITE_ERR_DUMP

If the write is for more than 32K bytes, then only the first 32K bytes are output to the file.