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Can we clarify - Replication rate becomes extremely slow if you start a virtual export job while replication job is running

So, the release notes for 6.1 states that replication can become very slow if an export is happening at the same time as an export and the fix is to schedule these at different times.

  • Is this only when the replication and exports are for the same machine, or any export / replication

Scheduling is actually quite difficult, and perhaps some improvement should be included in the logic for RR, such as

  • If the current replication job includes multiple RPs, don't start an export until the replication job has been completed, at present it starts the export as soon as a new RP has been replicated and then this slows the remainder of the replication and everything else has to sit in a queue
  • If we suspend exports during the replication then the export doesn't join the queue
    • Could potentially watch for event log entries such that when replication is finished then force an export.  However forced exports always join the top of the queue and as such some systems may take forever to export
    • We have systems so they only export once / day (well used to) and the fix for this would complicate matters.

 

Guess we need

  • when an export starts, suspend replication for that machine,
    • if currently replicating it will cancel that job at where it had got to
  • when it finishes exporting suspend exports and re-enable replication
  • when a replication job has completed, re-enable exports for that machine and force an export (though i guess for me I could just exclude that option)

 

When exports get re-enabled daily across the board,

  • check if a replication job is running for that machine, if it is then re-suspend exports

 

am i mistaken in this?  I can't see a realistic way whereby I can schedule replications to happen at a different time to exports since how are you supposed to know when one has happened?

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  • i have a support case open, in fact i have several. i can't believe that an export should drop to KB/s when i have an inbound replication of 1MB/s. in fact that usually drops to KB/s when there is an export running. the new 6.1.2 repository structure appears to be very inefficient.

    disk latencies are still low. hopefully dev get back sooner rather than later.
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  • i have a support case open, in fact i have several. i can't believe that an export should drop to KB/s when i have an inbound replication of 1MB/s. in fact that usually drops to KB/s when there is an export running. the new 6.1.2 repository structure appears to be very inefficient.

    disk latencies are still low. hopefully dev get back sooner rather than later.
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