Hi Julian, I don't believe changing the journal sizes would have an impact in this case because the message indicates the slowness is most likely related to applying the data to the mirror databases, not transferring it from the primary.  The reason I say this is because there are two separate System Monitor alerts you could have:

  MirrorJournalLatencyTime:  time between when the last journal file was received from the primary and when it was written to the journal disk.

  MirrorDatabaseLatencyTime:  time between when the last journal file was received from the primary and when it was applied to the mirror database(s).

So in your case the backup's mirror mechanism that reads the copied journal data and then applies it to the mirror databases does not seem to be able to keep up with the rate of updates from the primary.  If it were due to slowness copying journals, you should be seeing the MirrorJournalLatencyTime alert instead.  You can read these definitions in the System Monitor documentation:


If this continues to be an issue I recommend contacting Support (617-621-0700 or Support@InterSystems.com) and we can help to investigate this behavior.

Great article Murray, thank you for the examples!

I work with pButtons data on a daily basis and am always looking for ways to quickly parse specific data out of the html files.  There are several html tags I utilize for extracting specific sections of the files:

  • All section names are contained within <div> tags of the format:  <div id=mgstat>
  • All data for a section is encompassed within <pre></pre> tags.

Several personal pButtons parsing utilities use the <div> tags to determine the section name, then use the <pre></pre> tags to parse out the data for each section.  The section names can be used to create a distinct filename for each section, where I can then write out the data from the section for viewing/charting.  Sometimes the html text and first lines of the data can end up on the same line in the file, so to parse all data may require some creativity.