Database Administrator's Guide

Communications Errors (127/128)

When a communication error such as VDP_ERROR (127 or 128) occurs, the FairCom Server logs an entry in the Server Status Log CTSTATUS.FCS. This is not a serious situation unless the client application is also getting errors such as 127, 128, or similar errors.

The context of the communications error is that a server thread gets a notification that a message is available, but when the server performs a read, nothing is returned.

This can be caused by:

Physical network problems
An overworked network transport layer that is timing out and doing retries
Clients exit without calling CloseISAM() or StopUser(), or end users that turn their machines off without properly logging out of the application. This category includes client application crashes.

To ensure the errors are not serious, try to reconcile the communications errors in the log with the client events that triggered them. Since these errors do not usually happen frequently and user names are provided, it should be easy to determine which event caused this situation.

To avoid these errors, ensure the FairCom Server’s host machine is not burdened beyond its capacity. Using a more powerful machine or limiting the number and types of applications on a machine can improve performance and limit errors at the communication level. Also, ensure no specific application is over-using resources on the host machine. If appropriate in the server's operating environment, increasing the priority of the FairCom Server can eliminate or reduce communications errors. This should be done cautiously as it will affect other applications running on the same machine.

The error messages in the Server Status Log can be turned off, but unless they are an inconvenience, this is NOT recommended. The messages serve as a good health check on the state of your network and may be an early warning of more serious network and system problems. To disable the messages, add

CTSTATUS_MASK VDP_ERROR

to the ctsrvr.cfg file and restart the FairCom Server.

DYNAMIC_DUMP_FILES	Suppress the logging of the names of the files backed up by a dynamic dump operation.
MATCH_FILE_ID	Suppresses "Matching file Ids" messages. Such messages can be output several situations: If the files share the same FairCom 12-byte file ID, but are different files in which case an open error should result. If the files are the same file, but have been opened with different names (or paths). When the file ID is reassigned because the ID was changed, for example, the file is a copy of an original file.
PRIME_CACHE_AT_STARTUP	Suppress log messages while cache priming is enabled.
WARNING_AUTO_TRNLOG	Suppresses the logging of the message: "WARNING: could not turn on AUTO_PREIMG/AUTO_TRNLOG for ... (filename)" when the AUTO_PREIMG or AUTO_TRNLOG configuration option matches the name of a c-tree index file that was not created with support for transaction control.
WARNING_FCRP_ERR	Eliminates FCRPT_ERR (14) errors in CTSTATUS.FCS.
WARNING_PAGESIZE	Disables logging PAGE_SIZE warning messages to CTSTATUS.FCS,
WARNING_PAGESIZE_SEEALL	Logs all PAGE_SIZE warnings to CTSTATUS.FCS for debugging.
WRITE_ERR	Suppresses WRITE_ERR messages. See DIAGNOSTICS WRITE_ERR_DUMP DIAGNOSTICS WRITE_ERR_DUMP The potential possibility of a disk write failure may go unreported with the FairCom DB Server. With a data or index file write failure, the FairCom DB Server could possibly continue operations, and assume 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. This server configuration keyword will cause the contents of the write request to be appended to the WRITE_ERR.FCS file. If the write is for more than 32K bytes, then only the first 32K bytes are output to the file. 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
VDP_ERROR	Suppresses logging of communications errors.