CEFlushDBVol (CEDB version)

Good day -

We're seeing a very peculiar scenario when using CEFlushDBVol (CEDB
version).

We go through a set of questions which calls CeWriteRecordProps for each
anwser to a group of databases found inside a particular volume. We then
flush the volume, wait 60 seconds and then soft reset the device before
closing the dbs and unmounting the volume.

When we reopen the application and mount the volume, we're not seeing what
we saved and flushed. The results are also inconsistent; that is sometimes
some of the data is there, sometimes not, but never all the data.

Does this mean that, unless you close all your dbs and unmount the volume
before a soft reset, that there is no guarantee that all that we saved and
flushed will be persisted?

The documentation suggests that a flush ensures that any writes to dbs were
written out to permanent storage. Is this not really true then?

That is, is the only way to ensure a complete capture of your data is to
close all the dbs and unmount the volume so that any indexes and internal
data structures get persisted is well?

If so then flushing a volume (at least under CEDB APIs) does not truly flush
everything needed. Obviously a soft-reset is infrequent, but we still need
to sort out how to capture as much of the data in real time as possible.

Unmounting and remounting, especially larger volumes and those located on SD
cards is a time-consuming operation and not something we can do either.

FWIW, we need to use CEDB because our client still uses 2003 devices where
EDB is not supported.

Any help in confirming the actual behaviour of this API would be fantastic.

Thank you for your time,

Tom @ eM LLC

This issue has been resolved. CEFlushDBVol works just fine, we were not
flushing all volumes in play. We've seen reasonable performance too, but I
would suspect that this won't be the same for everyone.

"Empower Mobility LLC" wrote:

> Good day -
>
> We're seeing a very peculiar scenario when using CEFlushDBVol (CEDB
> version).
>
> We go through a set of questions which calls CeWriteRecordProps for each
> anwser to a group of databases found inside a particular volume. We then
> flush the volume, wait 60 seconds and then soft reset the device before
> closing the dbs and unmounting the volume.
>
> When we reopen the application and mount the volume, we're not seeing what
> we saved and flushed. The results are also inconsistent; that is sometimes
> some of the data is there, sometimes not, but never all the data.
>
> Does this mean that, unless you close all your dbs and unmount the volume
> before a soft reset, that there is no guarantee that all that we saved and
> flushed will be persisted?
>
> The documentation suggests that a flush ensures that any writes to dbs were
> written out to permanent storage. Is this not really true then?
>
> That is, is the only way to ensure a complete capture of your data is to
> close all the dbs and unmount the volume so that any indexes and internal
> data structures get persisted is well?
>
> If so then flushing a volume (at least under CEDB APIs) does not truly flush
> everything needed. Obviously a soft-reset is infrequent, but we still need
> to sort out how to capture as much of the data in real time as possible.
>
> Unmounting and remounting, especially larger volumes and those located on SD
> cards is a time-consuming operation and not something we can do either.
>
> FWIW, we need to use CEDB because our client still uses 2003 devices where
> EDB is not supported.
>
> Any help in confirming the actual behaviour of this API would be fantastic.
>
> Thank you for your time,
>
> Tom @ eM LLC