SQL Anywhere Mobile - MobiLink error

Author

MobiLink error

Doug

2005-06-02, 1:24 pm

We're using MobiLink 7.0.0.313 (*sigh*) and we get the following error in
the remote dbmlsync.exe log file:

I. 06/01 12:22:37. All unpublished rights reserved.

I. 06/01 12:22:37.

I. 06/01 12:22:37. Sybase, Inc. 6475 Christie Avenue, Emeryville, CA 94608,
USA

I. 06/01 12:22:37.

I. 06/01 12:22:37. Connecting to synchronization site database

I. 06/01 12:22:37. Loading synchronization definition

I. 06/01 12:22:37. Begin synchronizing 'mysyncdef' on site '0100043'

I. 06/01 12:22:37. Upload starting at offset 0002919695

E. 06/01 12:22:37. No off-line transaction log file found and on-line
transaction log starts at offset 0002933045.

I. 06/01 12:22:37. We are looking for a transaction log file starting at
offset 0002919695.

I. 06/01 12:22:37. Upload ended at offset 0002919695

Now my question is this: The MobiLink server (dbmlsrv7.exe) log file has no
record of this attempted synchronization! Our verbose startup parameter was
only '-v' and not '-vcnrst'. Is it possible that the sync would fail as it
did above and have no record in the MobiLink server log file?

Breck Carter

2005-06-02, 8:25 pm

A synchronization process is started by the remote client
dbmlsync, and I believe that if it can't get to first base
connecting to the local database or reading the local log
files, it won't bother connecting the MobiLink server.
That's probably what happened here.

BTW, that's a pretty nasty error message, I hope you can
find the missing log file. Either that, or you'll probably
have to stop and restart synchronization altogether to get
it going again, and THAT means any changes made since the
last synch will not be uploaded.

With MobiLink (and SQL Remote) the log file is arguably more
important than the database file. That's what I tell system
administrators, anyway: "If you lose the log file, just run
away!" :)

Breck

> We're using MobiLink 7.0.0.313 (*sigh*) and we get the
> following error in the remote dbmlsync.exe log file:
>
> I. 06/01 12:22:37. All unpublished rights reserved.
>
> I. 06/01 12:22:37.
>
> I. 06/01 12:22:37. Sybase, Inc. 6475 Christie Avenue,
> Emeryville, CA 94608, USA
>
> I. 06/01 12:22:37.
>
> I. 06/01 12:22:37. Connecting to synchronization site
> database
>
> I. 06/01 12:22:37. Loading synchronization definition
>
> I. 06/01 12:22:37. Begin synchronizing 'mysyncdef' on site
> '0100043'
>
> I. 06/01 12:22:37. Upload starting at offset 0002919695
>
> E. 06/01 12:22:37. No off-line transaction log file found
> and on-line transaction log starts at offset 0002933045.
>
> I. 06/01 12:22:37. We are looking for a transaction log
> file starting at offset 0002919695.
>
> I. 06/01 12:22:37. Upload ended at offset 0002919695
>
> Now my question is this: The MobiLink server
> (dbmlsrv7.exe) log file has no record of this attempted
> synchronization! Our verbose startup parameter was only
> '-v' and not '-vcnrst'. Is it possible that the sync would
> fail as it did above and have no record in the MobiLink
> server log file?
>
>
>
>
>

Doug

2005-06-02, 8:25 pm

Thanks Breck. I translated the remote database log file and the first entry
is this:

-CHECKPOINT-0000-00030008762-2005/jun/01 12:28

If you look in my error mesage below, this is six minutes after my sync. The
offset the sunc looked for didn't even
exist in the log file! This remote database has been up since mid-April. I
am surprised to see that the log
starts from a checkpoint only yesterday. Gee, sounds like a new log file was
started, for whatever reason! Sound like that to you too?

<Breck Carter> wrote in message news:429f5670.65a6.1681692777@sybase.com...[color=darkred]
> A synchronization process is started by the remote client
> dbmlsync, and I believe that if it can't get to first base
> connecting to the local database or reading the local log
> files, it won't bother connecting the MobiLink server.
> That's probably what happened here.
>
> BTW, that's a pretty nasty error message, I hope you can
> find the missing log file. Either that, or you'll probably
> have to stop and restart synchronization altogether to get
> it going again, and THAT means any changes made since the
> last synch will not be uploaded.
>
> With MobiLink (and SQL Remote) the log file is arguably more
> important than the database file. That's what I tell system
> administrators, anyway: "If you lose the log file, just run
> away!" :)
>
> Breck
>

Breck Carter

2005-06-02, 8:25 pm

There are several ways a new log file can be started, some
benign and some disastrous to MobiLink synchronization:

- running dbmlsync with the -x option to rename and restart
the log - benign, look for the renamed file as yymmddnn.LOG.

- running dbbackup with -r to rename and restart the log -
also benign, look for the backup or renamed copy

- running dbbackup with -x to backup, delete and restart the
log - also benign, look for the backup copy

- running dbbackup with -xo to delete and restart the log
with no backup - disastrous, the old log data is gone

- BACKUP DATABASE statements that do the same as the
dbbackup scenarios described above.

- running dbeng* with -m to zap the log at every checkpoint
- also disastrous.

IMO only the first choice should be used with MobiLink
remote databases, together with the SET OPTION
DELETE_OLD_LOGS = 'ON'.

If you find one or more files that might be the missing log,
put them all in a folder and specify that folder as the
transaction-logs-directory parameter in the dbmlsync command
line; dbmlsync will search for the stuff it wants, ignore
the rest.

Breck

> Thanks Breck. I translated the remote database log file
> and the first entry is this:
>
> -CHECKPOINT-0000-00030008762-2005/jun/01 12:28
>
> If you look in my error mesage below, this is six minutes
> after my sync. The offset the sunc looked for didn't even
> exist in the log file! This remote database has been up
> since mid-April. I am surprised to see that the log
> starts from a checkpoint only yesterday. Gee, sounds like
> a new log file was started, for whatever reason! Sound
> like that to you too?
>
>
> <Breck Carter> wrote in message
> base connecting to the local database or reading the local
>
>

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