Logsync and Landshark

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Hi Jaclyn, Hi all,

I'm Gianpiero from Italy. I used the LogSync after reading this interesting post. After i used it, I have two questions I'd like to submit to you and to other mebmers of this community:

For an Oracle dSource, I received an error on the Delphix Engine Demo 4.1.4.0: "Title: Cannot read archived redo logs due to insufficient privileges". Effectively, the DBA had deleted all the contents of the archive directory and so the error is legitimate. But why does Delphix suggest "User Action: .... Alternatively set LogSync to ARCHIVE ONLY mode."? The problem was not of because the online redo logs was missing, but just the archive logs was missing. So I think that if the archive logs are missing I have to switch off the LogSync and it is not enough turn it to ARCHIVE ONLY mode, isn't it?

How much long is the sampling time by which the engine copies the archive log files from the source? Every 5 minutes, every one minute? Because the DBA has scheduled a process that backs up the archive logs on an external storage and then deletes them (for disk space management). Is it sufficient that it deletes all archive log files but the last recent one from the directory of the source oracle database?

Thank you in advance for possible answers.

Gianpiero Piccolo

Note: This conversation was created from a reply on: Tip of the Day: Oracle LogSync Policy Settings.
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Gianpiero Piccolo

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Posted 4 years ago

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Mike Stewart, Employee

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Official Response
Hi Gianpiero,

The error reported should have been "file not found" instead of "insufficient privileges". For the corrrect error you would have gotten a more appropriate user action. The issue has been fixed in later version of Delphix.

It is generally a good idea not to be too agressive when backing up and deleting the archive logs when LogSync is enabled. LogSync monitors the archive logs quite frequently, but for various reasons may fall behind. It is fairly common for LogSync to fall a log or more behind, catch up, then repeat; so a policy of leaving the most recent log will not always work. How long to wait depends on your particular setup and how well LogSync keeps up. I've seen examples where customers wait 12-24 hours before removing the archive logs.

The best way to track LogSync's progress is to look at the "End Stamp" on the last snapshot card for the dSource. The time corresponds to the last redo fetched by LogSync and will advance as LogSync fetches new logs. You can also slide the LogSync control at the top of the snapshot card to see a timeline.

Hope this helps,
MikeĀ