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Home > Archive > SQL Anywhere database replication > March 2006 > SysRemoteUser Log_Sent column
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SysRemoteUser Log_Sent column
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| Jim Diaz 2006-03-30, 8:24 pm |
| I'm reviewing the output of the SysRemoteUser table of a database with 20 or
so remote users, and find that the log_sent column value is different for
most of them. I'm used to seeing this value the same for all remote users.
I don't have alot of information on this database, my question is under what
conditions would this happen?
Thanks
Jim Diaz
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| Nick Elson 2006-03-31, 1:24 pm |
| It has always been possible for each user to be logged with
a different value for this column.
I have seen it a number of times when the consolidated
dbremote is being ran under low memory conditions.
Some possible factors that can contribute to this include
- increased number of remotes
- replication of larger transactions
[LOBs might also play a role here]
- changes to the publication or subscription design
- replication of more complex transactions that
cause message fan-outs to have highly unique
message streams to individual remotes
- removing or reducing the -m switch setting when
dbremote
- increasing the -l value without also increasing the -m
switch to cover the extra memory requirements of
generating large messages
What I have seen happen, is dbremote's send phase becomes
so memory constrained it stops generating messages to all
remotes simultaneously and will start generating messages
to one remote at a time. In that event the transaction log
section is rescanned as many times as it takes and the
ending offsets will be different is there is any concurrent
commit activity on the consolidated database [possibly
due to just dbremote updates to sys.sysremoteuser to
log the sending times and offsets.]
Only under simltaneous send conditions will the ending
offsets match up.
When they do not match up, it is likely dbremote is taking
a lot more time to do the same job as before.
So try bumping up the -m setting.
"Jim Diaz" < jimdiazatemprisecorp
orationdotcom> wrote in message
news:442c75c1$1@foru
ms-1-dub...
> I'm reviewing the output of the SysRemoteUser table of a database with 20
> or so remote users, and find that the log_sent column value is different
> for most of them. I'm used to seeing this value the same for all remote
> users. I don't have alot of information on this database, my question is
> under what conditions would this happen?
>
> Thanks
>
> Jim Diaz
>
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