Open Stack

Hi, I'd like you to take a look at this patch for potential
DocImpact.
https://review.openstack.org/29737

Log:
commit 5e780094dfe6c752511d4d3eaa3c41b0a0e73ec2
Author: Zhiteng Huang <zhiteng.huang at intel.com>
Date:   Sat May 18 22:21:28 2013 +0800

    Implement QoS support for volumes
    
    This patch is to implement generic Quality-of-Service(QoS) support for volumes.
    While QoS can mean a lot things, here in this implementation it mainly refers
    to throttling/rate-limiting and performance assurance. The goal is 1) to add an
    interface so that cloud/Cinder admins can use to express QoS requirements for
    volumes; 2) to define common performance characteristics for volume; 3) to
    change scheduler so that it can filter out unqualified back-ends.
    
    Note that while it's possible for Cinder to set the granularity of QoS control
    to every single volume, this patch puts the control granularity to the level
    of volumes of the same type to minimize the impact of other Cinder parts.
    In other words, the design is to bond QoS with volume types. So Cinder admin
    can create various volume types with different QoS requirements, and volumes
    of same volume type share the same QoS specifications.
    
    Changes:
      - Add a quality_of_services table to accommadate QoS requirements for volume
      types. Follow eight fields are used to describe performance characteristics:
        * total_bytes_sec: total throughput limit in bytes per second. This cannot
          appear with read_bytes_sec or write_bytes_sec.
        * read_bytes_sec: read throughput limit in bytes per second.
        * write_bytes_sec: write throughput limit in bytes per second.
    
        * total_iops_sec: total I/O operations per second. This cannot appear with
          read_iops_sec or write_iops_sec.
        * read_iops_sec: read I/O operations per second.
        * write_iops_sec: write I/O operations per second.
    
        Two additional keys:
        * 'qos_type' key is to describe the levels of QoS: rate-limit, best effort
          perf assurance and perf guarantee.
        * 'control_location' is to store the value where admin would like the QoS
          policy to be enforced.
      - Add 'volume_type_qos' API extension to allow mofication of type QoS.
      - Add 'supported_QoS_types' to host capabilities, lvm/solidfire driver
      changes are made as an example.
      - Add 'qos_specs' to filter properties for a volume create request.
      - Add QoSFilter for filter scheduler.
    
    TODO:
      Add unittests.
    
    DocImpact
    
    implement blueprint: pass-ratelimit-info-to-nova
    
    Change-Id: Iabc61b941aaff10395b30e2045e3421369a317e2