Re: Archive Command Configuration

Steve Crawford wrote:
>> ...I have a
>> cron job from the production database that runs every 5-10min to
>> check if there are any new archive logs and copy new archive logs to
>> the remote stand by failover machine.
>>
>> The problem with this scenario is that there might be a possibility
>> that I might scp a partially filled archive log over to the remote
>> machine on a heavily updated databases with batch jobs runnings most
>> of the time  like ours.
>>
>>   So, inorder to over come this we want to change the archive_command to
>>
>> archive_command = 'cp %p /archives-temp/%f && mv /archives-temp/%f
>> /archives/%f'
>> ( I could do remote copy also with the command but I dont want to go
>> that route because of network problems. )
>>
>> ....
>>
>>  My question is there any problem in using this approach ? will I run
>> into problems in the future ? are there any other better ways of
>> solving this problem ?
>
> Looks like it should work but have you considered using rsync instead?
> If the file grows from one pass to the next, rsync will send the
> differences.
>
> Given the small number of files (at least far fewer thatn the
> half-million file trees my rsyncs process every 10 minutes) in the
> archive directory, rsync will probably only take a fraction of a
> second to determine whether or not any transfers are needed. I'll bet
> that you could run rsync every 15 seconds with virtually no increase
> in system load other than whatever is required to transfer the data
> and you have that load already.
>
> Rsync can also handle deleting files from the receiving end if you wish.
>
> I am starting to work on a wal-shipping backup and I plan to try rsync
> first.
>
> Some advice. I make extensive use of rsync. The core skeleton of my
> scripts goes something like this:
>
> cd /the/appropriate/place
> if [ -f rsync.lockfile ]
>   # Exit - new pass started before previously
>   # started rsync completed
>   exit
> fi
> date > rsync.lockfile
> rsync <your parameters as appropriate>
> rm rsync.lockfile
>
> I run another script on the target machine that periodically checks
> the age of rsync.lockfile and sends alerts if it is excessively old
> (where excessive will be determined by the specifics of your setup - I
> use one hour).
>
> Cheers,
> Steve
>
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Hi Steve,

   Thanks! for the quick reply,  I thought about rsync too, but wasnt
sure about completely how it handles partial files. I use rsync for all
the backups, it works fine for all the application except for our mail
application it copies the files but at the end of the job it gives me
message like

------------------------------------------------------------------------------------
send_files failed to open //this/file/ : No such file or directory

rsync error: some files could not be transferred (code 23) at main.c(1158)
------------------------------------------------------------------------------------

  Considering it is copying all our mail messages and it takes a lot of
time to rsync the whole thing, there might be changes to the file or
file gets deleted completely from time it gets the files to rsync and do
the actual rsync.

 Pallav.