def test_plugin_run_with_None(self):
"""
The plugin's run() method fills in the _cpu_usage_points with
accumulated samples after each C{monitor.step_size} period.
Holes in the data (in case of error the method returns None) are
handled gracefully, and are filled with averaged data.
"""
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
def fake_get_cpu_usage(self):
return 1.0
def fake_get_cpu_usage_none(self):
return None
plugin._get_cpu_usage = fake_get_cpu_usage
self.reactor.advance(self.monitor.step_size)
plugin._get_cpu_usage = fake_get_cpu_usage_none
self.reactor.advance(self.monitor.step_size)
self.assertNotEqual([], plugin._cpu_usage_points)
self.assertEqual([(300, 1.0)], plugin._cpu_usage_points)
# If we record values once again the "blank" period will be smoothed
# over with the new points.
plugin._get_cpu_usage = fake_get_cpu_usage
self.reactor.advance(self.monitor.step_size)
self.assertEqual([(300, 1.0), (600, 1.0), (900, 1.0)],
plugin._cpu_usage_points)
def test_get_cpu_usage_file_unreadable(self):
"""
When the file is unreadable or somehow creates an IOError (like when
it doesn't exist), the method returns None.
"""
self.log_helper.ignore_errors("Could not open.*")
thefile = "/tmp/whatever/I/do/not/exist"
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
result = plugin._get_cpu_usage(stat_file=thefile)
self.assertIs(None, result)
def test_plugin_run(self):
"""
The plugin's run() method fills in the _cpu_usage_points with
accumulated samples after each C{monitor.step_size} period.
"""
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
def fake_get_cpu_usage(self):
return 1.0
plugin._get_cpu_usage = fake_get_cpu_usage
self.reactor.advance(self.monitor.step_size * 2)
self.assertNotEqual([], plugin._cpu_usage_points)
self.assertEqual([(300, 1.0), (600, 1.0)], plugin._cpu_usage_points)
def test_get_cpu_usage_multiline_files(self):
"""
The C{_get_cpu_usage} method parses multiline stat files correctly.
"""
contents1 = "cpu 100 100 100 100 100 100 100 0 0 0\nsome garbage"
thefile = self._write_stat_file(contents1)
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
result = plugin._get_cpu_usage(stat_file=thefile)
# The first run will return None since we don't have a previous measure
# yet.
self.assertIs(None, result)
result = plugin._get_cpu_usage(stat_file=thefile)
self.assertIs(None, result)
def test_get_cpu_usage_file_not_changed(self):
"""
When the stat file did not change between calls, the
C{_get_cpu_usage} method returns None.
"""
contents1 = "cpu 100 100 100 100 100 100 100 0 0 0"
thefile = self._write_stat_file(contents1)
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
result = plugin._get_cpu_usage(stat_file=thefile)
# The first run will return None since we don't have a previous measure
# yet.
self.assertIs(None, result)
result = plugin._get_cpu_usage(stat_file=thefile)
self.assertIs(None, result)
def test_exchange_messages(self):
"""
The CPU usage plugin queues message when manager.exchange()
is called.
"""
self.mstore.set_accepted_types(["cpu-usage"])
plugin = CPUUsage(create_time=self.reactor.time)
plugin._cpu_usage_points = [(60, 1.0)]
self.monitor.add(plugin)
self.monitor.exchange()
self.assertMessages(self.mstore.get_pending_messages(),
[{
"type": "cpu-usage",
"cpu-usages": [(60, 1.0)]
}])
def test_get_cpu_usage_0_percent_usage(self):
"""
When two consecutive calls to C{_get_cpu_usage} show a CPU usage of
0% (all the changes are in the idle column) the method returns 0.
"""
contents1 = "cpu 100 100 100 100 100 100 100 0 0 0"
contents2 = "cpu 100 100 100 200 100 100 100 0 0 0"
thefile = self._write_stat_file(contents1)
thefile2 = self._write_stat_file(contents2)
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
result = plugin._get_cpu_usage(stat_file=thefile)
# The first run will return None since we don't have a previous measure
# yet.
self.assertIs(None, result)
result = plugin._get_cpu_usage(stat_file=thefile2)
self.assertEqual(result, 0)
def test_get_cpu_usage_after_reboot(self):
"""
When the computer just rebooted, we might have a case where the
previous values are larger that the current values (since the kernel
counts quantums allocated since boot). In this case, the method should
return None.
"""
contents1 = "cpu 100 100 100 100 100 100 100 0 0 0"
measure1 = (700, 100)
measure2 = (900, 10)
thefile = self._write_stat_file(contents1)
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
plugin._persist.set(LAST_MESURE_KEY, measure2)
result = plugin._get_cpu_usage(stat_file=thefile)
self.assertIs(None, result)
self.assertEqual(measure1, plugin._persist.get(LAST_MESURE_KEY))
def test_never_exchange_empty_messages(self):
"""
The plugin will create a message with an empty
C{cpu-usages} list when no previous data is available. If an empty
message is created during exchange, it should not be queued.
"""
self.mstore.set_accepted_types(["cpu-usage"])
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
self.monitor.exchange()
self.assertEqual(len(self.mstore.get_pending_messages()), 0)
def test_no_message_if_not_accepted(self):
"""
Don't add any messages at all if the broker isn't currently
accepting their type.
"""
interval = 30
plugin = CPUUsage(create_time=self.reactor.time, interval=interval)
self.monitor.add(plugin)
self.reactor.advance(self.monitor.step_size * 2)
self.monitor.exchange()
self.mstore.set_accepted_types(["cpu-usage"])
self.assertMessages(list(self.mstore.get_pending_messages()), [])
def test_create_message(self):
"""
Calling create_message returns an expected message.
"""
plugin = CPUUsage(create_time=self.reactor.time)
self.monitor.add(plugin)
plugin._cpu_usage_points = []
message = plugin.create_message()
self.assertIn("type", message)
self.assertEqual(message["type"], "cpu-usage")
self.assertIn("cpu-usages", message)
cpu_usages = message["cpu-usages"]
self.assertEqual(len(cpu_usages), 0)
point = (60, 1.0)
plugin._cpu_usage_points = [point]
message = plugin.create_message()
self.assertIn("type", message)
self.assertEqual(message["type"], "cpu-usage")
self.assertIn("cpu-usages", message)
cpu_usages = message["cpu-usages"]
self.assertEqual(len(cpu_usages), 1)
self.assertEqual(point, cpu_usages[0])