Merge "Add hardware memory buffer and cache metrics"

specs/liberty/memory-buffer-and-cache-metrics.rst

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+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+=============================================================
+Add hardware.memory.buffer and hardware.memory.cached metrics
+=============================================================
+
+https://blueprints.launchpad.net/ceilometer/+spec/hardware-memory-buffer-and-cache-metrics
+
+Add hardware.memory.buffer and hardware.memory.cached metrics to monitor
+the memory buffer size and memory cache size of a physical machine through
+SNMP.
+
+
+Problem description
+===================
+
+Currently Ceilometer only support 4 memory oid of SNMP:
+    _memory_total_oid = "1.3.6.1.4.1.2021.4.5.0"
+    _memory_avail_real_oid = "1.3.6.1.4.1.2021.4.6.0"
+    _memory_total_swap_oid = "1.3.6.1.4.1.2021.4.3.0"
+    _memory_avail_swap_oid = "1.3.6.1.4.1.2021.4.4.0"
+
+But in practice, memory cache and buffer size are also very useful information
+to determine the status of a physical machine.
+
+
+Proposed change
+===============
+
+Add two metrics, hardware.memory.buffer and hardware.memory.cached, to
+monitor the memory buffer size and memory cache size of a physical machine.
+
+To achieve this, we need add two SNMP oid and two hardware pollsters.
+
+Firstly, add two oid in SNMP inspector:
+
+    _memory_buffer_oid = "1.3.6.1.4.1.2021.4.14.0"
+    _memory_cached_oid = "1.3.6.1.4.1.2021.4.15.0"
+
+Secondly, add two Hardware Pollsters in hardware.pollsters.memory:
+
+    * MemoryBufferPollster
+    * MemoryCachedPollster
+
+
+Alternatives
+------------
+
+None
+
+Data model impact
+-----------------
+
+None
+
+REST API impact
+---------------
+
+None
+
+Security impact
+---------------
+
+None
+
+Pipeline impact
+---------------
+
+None
+
+Other end user impact
+---------------------
+
+None
+
+Performance/Scalability Impacts
+-------------------------------
+
+None
+
+Other deployer impact
+---------------------
+
+None
+
+Developer impact
+----------------
+
+None
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Primary assignee:
+    luogangyi
+
+Work Items
+----------
+
+* Add two oid in SNMP inspector:
+
+    _memory_buffer_oid = "1.3.6.1.4.1.2021.4.14.0"
+    _memory_cached_oid = "1.3.6.1.4.1.2021.4.15.0"
+
+* Add two Hardware Pollsters in hardware.pollsters.memory:
+
+    * MemoryBufferPollster
+    * MemoryCachedPollster
+
+Future lifecycle
+================
+
+None
+
+Dependencies
+============
+
+None
+
+
+Testing
+=======
+
+Need unit test
+
+Documentation Impact
+====================
+
+None
+
+
+References
+==========
+
+[1] oid references http://www.net-snmp.org/docs/mibs/ucdavis.html
+