Product Documentation

Database Administrator's Guide

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IDLE_NONTRANFLUSH and IDLE_TRANFLUSH

Note: As of FairCom DB V11, these keywords have been replaced by the following keywords:
TRAN_DATA_FLUSH_SEC
NONTRAN_DATA_FLUSH_SEC
TRAN_INDEX_FLUSH_SEC
NONTRAN_INDEX_FLUSH_SEC


IDLE_TRANFLUSH <idle check interval seconds>

IDLE_NONTRANFLUSH <idle check interval seconds>

FairCom DB flushes data and index caches during idle time, launching two idle thread processes at start-up: One thread flushes transaction-file buffers and the other flushes non-transaction-file buffers. The threads wake-up periodically and check if the FairCom Server is idle to begin flushing. Subsequent activity terminates the flushes. Low priority background threads, such as the delete node thread, do not affect the idle state, however, FairCom DB clients and transaction checkpoints modify the idle status.

Filesystem Flush Performance

Starting with V8 the default behavior of the idle flush threads was changed to skip internal filesystem flush calls for better performance when performing the idle flush operation. Flushing the filesystem buffers guarantees data is secured to disk at a performance cost. To revert this behavior, add the #SAVE option after the checkpoint time which will ensure data safety in nearly all cases. Note that flushing filesystem buffers will cause measurable delays when large caches are in use, and you may notice transaction slowdowns during this period.

IDLE_TRANFLUSH <idle check interval in seconds>#SAVE

IDLE_NONTRANFLUSH <idle check interval in seconds>#SAVE

The default interval is 15 seconds. Setting the interval to zero or a negative value disables the thread.

Default: 15 seconds

See Also

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