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  1. Core Server
  2. SERVER-18763

Use get_mempolicy() or /proc/zoneinfo instead of /sys/devices/system/node/node1 to determine if NUMA is present

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      Description

      When the NUMA startup warning tries to determine if the host has more than 1 NUMA node, it looks for the existence of /sys/devices/system/node/node1. However, this is needlessly fragile because /sys might

      1. not be mounted,
      2. be mounted elsewhere,
      3. be missing certain hardware info (eg. NUMA nodes), or
      4. have restricted ownership or permissions (or be subject to other MAC restrictions like SELinux or AppArmor).

      Better approaches to determine the number of NUMA nodes are to either use the get_mempolicy() Linux syscall, or as a fallback, look for a line starting with "Node 1" in /proc/zoneinfo.

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          is related to

          New Feature - A new feature of the product, which has yet to be developed. SERVER-24133 Memory policy update from the mongod process

          • Minor - P4 - Minor loss of function, or other problem where easy workaround is present.
          • Open
          related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-10623 Mongod fails to start as unprivileged user when {{/sys/devices/system/node}} is not readable and executable.

          • Major - P3 - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. SERVER-12464 Mongod fails to start as unprivileged user when {{/sys/devices/system/node}} is not readable and executable.

          • Major - P3 - Major loss of function.
          • Closed

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              Assignee:
              backlog-server-platform DO NOT USE - Backlog - Platform Team
              Reporter:
              kevin.pulo Kevin Pulo
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                Created:
                Updated: