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  1. Lustre
  2. LU-2934

Add LNet Router Priority Parameter

Details

    • New Feature
    • Resolution: Fixed
    • Minor
    • Lustre 2.5.0
    • Lustre 2.5.0
    • None
    • 7051

    Description

      This is the ticket to implement http://jira.whamcloud.com/browse/FUJ-2.

      A new parameter is added to the definition of a route: priority. This can take on a value of 0 or 1. 0 means the route has a normal priority, 1 means it is a high priority route and will be used before a normal priority route.

      Attachments

        Issue Links

          is related to

          Bug - A problem which impairs or prevents the functions of the product. LU-3836 There is no error message when setting priority > 1 for lnet routes

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Task - A task that needs to be done. LUDOC-157 LNet Router Priority Parameter doc changes

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

          Activity

            [LU-2934] Add LNet Router Priority Parameter
            jlevi Jodi Levi (Inactive) added a comment -

            Patches landed to Master in 2.5.0.

            jlevi Jodi Levi (Inactive) added a comment - Patches landed to Master in 2.5.0.
            doug Doug Oucharek (Inactive) added a comment -

            Test plan has been updated to match design changes.

            Isaac and I have discussed his concerns via email.

            doug Doug Oucharek (Inactive) added a comment - Test plan has been updated to match design changes. Isaac and I have discussed his concerns via email.
            adilger Andreas Dilger added a comment -

            Doug, could you please answer Isaac's previous question:

            Sorry Doug, it's still not clear to me why this patch is needed. Can you please give me an example where the precedence can't be expressed by the current 'hops' and a new 'priority' must be added to support it? There has to be a use case where the 'hops' doesn't work to justify a new precedence mechanism.

            adilger Andreas Dilger added a comment - Doug, could you please answer Isaac's previous question: Sorry Doug, it's still not clear to me why this patch is needed. Can you please give me an example where the precedence can't be expressed by the current 'hops' and a new 'priority' must be added to support it? There has to be a use case where the 'hops' doesn't work to justify a new precedence mechanism.
            isaac Isaac Huang (Inactive) added a comment -

            Sorry Doug, it's still not clear to me why this patch is needed. Can you please give me an example where the precedence can't be expressed by the current 'hops' and a new 'priority' must be added to support it? There has to be a use case where the 'hops' doesn't work to justify a new precedence mechanism.

            isaac Isaac Huang (Inactive) added a comment - Sorry Doug, it's still not clear to me why this patch is needed. Can you please give me an example where the precedence can't be expressed by the current 'hops' and a new 'priority' must be added to support it? There has to be a use case where the 'hops' doesn't work to justify a new precedence mechanism.
            doug Doug Oucharek (Inactive) added a comment -

            Test Plan for Route Priority project

            doug Doug Oucharek (Inactive) added a comment - Test Plan for Route Priority project
            doug Doug Oucharek (Inactive) added a comment -

            The implementation is the same as for hops, except that priority has a value of 0 or 1 (normal priority and high priority). It is then just a priority "flag". In the algorithm for selecting a route, high priority takes precedence over hops.

            So, a high priority route will always be used over a route which has a normal priority and a lower hop count.

            Technically, the current hop count can be used for priority (lower hop count is higher priority), but in cases where the customer wants to use hop count for hops and have a way to flag routes which must always be used first, the addition of a priority flag is needed.

            doug Doug Oucharek (Inactive) added a comment - The implementation is the same as for hops, except that priority has a value of 0 or 1 (normal priority and high priority). It is then just a priority "flag". In the algorithm for selecting a route, high priority takes precedence over hops. So, a high priority route will always be used over a route which has a normal priority and a lower hop count. Technically, the current hop count can be used for priority (lower hop count is higher priority), but in cases where the customer wants to use hop count for hops and have a way to flag routes which must always be used first, the addition of a priority flag is needed.
            isaac Isaac Huang (Inactive) added a comment -

            Hi Doug, can you please explain how this is different from the hops of a route and how is it going to work together with hops? Thanks!

            isaac Isaac Huang (Inactive) added a comment - Hi Doug, can you please explain how this is different from the hops of a route and how is it going to work together with hops? Thanks!
            doug Doug Oucharek (Inactive) added a comment -

            The patch for this change is: http://review.whamcloud.com/#change,5663

            doug Doug Oucharek (Inactive) added a comment - The patch for this change is: http://review.whamcloud.com/#change,5663

            People

              doug Doug Oucharek (Inactive)
              doug Doug Oucharek (Inactive)
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              Dates

                Created:
                Updated:
                Resolved: