Merge pull request #6 from signalfx/mv_metric_namepart_to_dim

Refactor cpucore and blkio metrics to define core and block devices as dimensions

CHANGELOG.md

@@ -0,0 +1,55 @@
+### CHANGELOG
+
+This file documents important changes to the Docker plugin for collectd. 
+
+- [2016-08-03: Dimensionalize block I/O and CPU per-core metrics](#2016-08-03-dimensionalize-block-i-o-and-cpu-per-core-metrics)
+
+#### 2016-08-03: Dimensionalize block I/O and CPU per-core metrics
+
+Prior to this update, the plugin transmitted block I/O and CPU per-core metrics
+with the names of the block device and CPU core respectively included as part of
+the metric name. In this update, this information has been removed from metric
+names to dimensions.
+
+SignalFx's built-in dashboards have been updated to accommodate metrics from
+both before and after this change. 
+
+When you upgrade to this version, any custom SignalFx charts and detectors that
+you have built that include block I/O or per-core CPU metrics may need to be
+modified to include the new metric names. Modify charts as follows: 
+
+1. Whenever a chart uses an affected metric (see below), add a new plot to the
+chart that uses the new metric name instead. 
+1. On the new plot, apply a filter by the new dimensions, with a value that 
+matches the contents of the previous metric name.
+1. If your chart uses a timeseries expression that refers to the previous metric,
+clone the expression, then modify any letter references in the clone to refer to
+the new plot instead of the old one. 
+
+For detectors, follow the procedure above, then select the new plot or new
+timeseries expression as the signal. 
+
+##### Block I/0: blkio.io_service_bytes_recursive.*
+
+In this update, the block device identifier has been moved from metric names
+to the dimensions called "device_major" and "device_minor". 
+
+For example: 
+
+|        | Metric name | device_major | device_minor |
+|--------|-------------|--------------|--------------|
+| Before | `blkio.io_service_bytes_recursive-252-0.read` | _n/a_ | _n/a_ |
+| After  | `blkio.io_service_bytes_recursive.read` | `252` | `0` |
+
+
+##### CPU statistics per core: cpu.percpu.usage
+
+In this update, the CPU core identifier has been moved from metric names to
+the dimension called "core". 
+
+For example: 
+
+|        | Metric name | core |
+|--------|-------------|--------------|
+| Before | `cpu.percpu.usage.cpu0` | _n/a_ |
+| After  | `cpu.percpu.usage` | `cpu0` |

README.md

@@ -179,8 +179,7 @@ everything else from the plugin:
 </Chain>
 ```
 
-For convenience, you'll find those configuration blocks in the provided
-sample configuration file [`dockerplugin.conf`](dockerplugin.conf).
+For convenience, you'll find those configuration blocks in the example configuration file [`10-docker.conf`](https://github.com/signalfx/integrations/blob/master/collectd-docker/10-docker.conf).
 
 ## Requirements
 

dockerplugin.py

@@ -121,22 +121,34 @@ def read_blkio_stats(container, dimensions, stats, t):
         # numbers). We need to group and report the stats of each block
         # device independently.
         blkio_stats = {}
+        blkio_major_stats = {}
+        blkio_minor_stats = {}
+
         for value in values:
+
             k = '{key}-{major}-{minor}'.format(key=key,
                                                major=value['major'],
                                                minor=value['minor'])
+
             if k not in blkio_stats:
                 blkio_stats[k] = []
             blkio_stats[k].append(value['value'])
+            blkio_major_stats[k] = value['major']
+            blkio_minor_stats[k] = value['minor']
 
         for type_instance, values in blkio_stats.items():
+            # add block device major and minor as dimensions
+            blkioDims = dimensions.copy()
+            blkioDims['device_major'] = str(blkio_major_stats[type_instance])
+            blkioDims['device_minor'] = str(blkio_minor_stats[type_instance])
+
             if len(values) == 5:
-                emit(container, dimensions, 'blkio', values,
-                     type_instance=type_instance, t=t)
+                emit(container, blkioDims, 'blkio', values,
+                     type_instance=key, t=t)
             elif len(values) == 1:
                 # For some reason, some fields contains only one value and
                 # the 'op' field is empty. Need to investigate this
-                emit(container, dimensions, 'blkio.single', values,
+                emit(container, blkioDims, 'blkio.single', values,
                      type_instance=key, t=t)
             else:
                 log.warning(('Unexpected number of blkio stats for '
@@ -150,8 +162,10 @@ def read_cpu_stats(container, dimensions, stats, t):
     cpu_usage = stats['cpu_usage']
     percpu = cpu_usage['percpu_usage']
     for cpu, value in enumerate(percpu):
-        emit(container, dimensions, 'cpu.percpu.usage', [value],
-             type_instance='cpu%d' % (cpu,), t=t)
+        percpuDims = dimensions.copy()
+        percpuDims['core'] = ('cpu%d' % (cpu))
+        emit(container, percpuDims, 'cpu.percpu.usage', [value],
+             type_instance='', t=t)
 
     items = sorted(stats['throttling_data'].items())
     emit(container, dimensions, 'cpu.throttling_data',