Bug 2911 - répondre au questionnaire ur1 sur les besoins en informatique

- added a graph that show the age pyramid of the machines

cluster_stats.py

@@ -235,6 +235,40 @@ def draw_dp_gflops_price_over_time_over_time_graph(inventory, from_date, to_date
     ax.grid(True)
     return fig
 
+def draw_age_pyramid_graph(inventory):
+    """
+    :param Inventory inventory: the inventory database
+    """
+
+    oldest_age = 20
+    age_histogram = np.zeros(shape=(oldest_age))
+
+    rows = inventory.query("SELECT * FROM machines")
+
+    for row in rows:
+        (name, serial_number, affectation, machine_spec_id, command_id, price_ex_vat, pos_x, pos_y, pos_z, inv_number)=row
+        is_cluster_node = is_cluster_node_name(name)
+        if is_cluster_node:
+            purchase_date = inventory.get_machine_purchase_date(name)
+            if purchase_date is not None:
+                purchase_time = matplotlib.dates.date2num(purchase_date.date())
+                age = datetime.datetime.now() - purchase_date
+                age_histogram[age.days / 365] += 1
+                # print(name, age)
+
+    fig, ax = plt.subplots()
+    ax.bar(range(oldest_age), age_histogram)
+    ax.set_xlabel('age (in years)')
+    ax.set_xticks(range(oldest_age))
+    
+    ax.set_ylabel(u'number of compute nodes')
+    ax.set_title('compute_nodes_age_pyramid')
+    
+    # format the ticks
+    ax.grid(True)
+    return fig
+
+
 class IFigureHandler(object):
     """
     specifies what to do with generated figures
@@ -305,4 +339,7 @@ def draw_graphs(inventory, from_time, to_time, figure_handler):
     fig = draw_dp_gflops_price_over_time_over_time_graph(inventory, from_time.date(), to_time.date())
     figure_handler.on_figure_ended(fig)
 
+    fig = draw_age_pyramid_graph(inventory)
+    figure_handler.on_figure_ended(fig)
+
     figure_handler.on_finalize()