workloads: add apache benchmark

Add a benchmark that load-tests Apache server installed on the target.

wa/workloads/apache.py

@@ -0,0 +1,124 @@
+from __future__ import division
+import os
+import urllib2
+
+from wa import Workload, Parameter, Alias, WorkloadError
+from wa.utils.exec_control import once
+from wa.utils.misc import which, check_output
+
+
+class ApacheBenchmark(Workload):
+
+    name = 'apache'
+    description = '''
+    Load-test an apache installation by issueing parallel requests with ab.
+
+    Run ab, the Apache benchmark on the host, directed at the target as the
+    server.
+
+    .. note:: It is assumed that Apache is already running on target.
+
+    .. note:: Current implmentation only supports a very basic use of the
+              benchmark.
+
+    '''
+
+    parameters = [
+        Parameter('port', kind=int, default=80,
+                  description='''
+                  Port on which Apache is running.
+                  '''),
+        Parameter('path', default='/',
+                  description='''
+                  Path to request.
+                  '''),
+        Parameter('parallel_requests', kind=int, default=350,
+                  description='''
+                  The number of parallel requests at a time.
+                  '''),
+        Parameter('total_requests', kind=int, default=100000,
+                  description='''
+                  The total number of parallel requests.
+                  '''),
+    ]
+
+    aliases = [
+        Alias('ab'),
+    ]
+
+    supported_targets = ['linux']
+
+    @once
+    def initialize(self, context):
+        ab = which('ab')
+        if not ab:
+            msg = 'ab not found on host; make sure apache2-utils (or you distro equivalent) package is installed.'
+            raise WorkloadError(msg)
+
+        response = urllib2.urlopen('http://{}:{}{}'.format(self.target.conn.host, self.port, self.path))
+        code = response.getcode()
+        if code != 200:
+            msg = 'HTTP request failed with status {}; is Apache running on target?'
+            raise WorkloadError(msg.format(code))
+
+    def setup(self, context):
+        template = 'ab -k -c {} -n {} {}:{}{}'
+        self.command = template.format(self.parallel_requests,
+                                       self.total_requests,
+                                       self.target.conn.host,
+                                       self.port,
+                                       self.path)
+        self.output = None
+
+
+    def run(self, context):
+        self.logger.debug(self.command)
+        self.output, _ = check_output(self.command, timeout=300, shell=True)
+
+    def extract_results(self, context):
+        outfile = os.path.join(context.output_directory, 'ab.output')
+        with open(outfile, 'w') as wfh:
+            wfh.write(self.output)
+            context.add_artifact('ab-output', outfile, kind='raw')
+
+    def update_output(self, context):
+        with open(context.get_artifact_path('ab-output')) as fh:
+            server_software = get_line(fh, 'Server Software').split(':')[1].strip()
+            context.add_metadata('server-software', server_software)
+
+            doc_len_str = get_line(fh, 'Document Length').split(':')[1].strip()
+            doc_len = int(doc_len_str.split()[0])
+            context.add_metadata('document-length', doc_len)
+
+            completed = int(get_line(fh, 'Complete requests').split(':')[1].strip())
+            failed = int(get_line(fh, 'Failed requests').split(':')[1].strip())
+            fail_rate =  failed / completed * 100
+            context.add_metric('failed_request', fail_rate, units='percent',
+                               lower_is_better=True)
+
+            rps_str = get_line(fh, 'Requests per second').split(':')[1].strip()
+            rps = float(rps_str.split('[')[0])
+            rps_units = rps_str.split('[')[1].split(']')[0]
+            context.add_metric('requests_per_second', rps, units=rps_units)
+
+            tpr_str = get_line(fh, 'Time per request').split(':')[1].strip()
+            tpr = float(tpr_str.split('[')[0])
+            tpr_units = tpr_str.split('[')[1].split(']')[0]
+            context.add_metric('time_per_request', tpr, units=tpr_units)
+
+            trate_str = get_line(fh, 'Transfer rate').split(':')[1].strip()
+            trate = float(trate_str.split('[')[0])
+            trate_units = trate_str.split('[')[1].split(']')[0]
+            context.add_metric('transfer_rate', trate, units=trate_units)
+
+            pc99 = int(get_line(fh, '99%').split()[1])
+            context.add_metric('request_99percentile', pc99, 'ms')
+
+            pc100 = int(get_line(fh, '100%').split()[1])
+            context.add_metric('longest_request', pc100, 'ms')
+
+
+def get_line(fh, text):
+    for line in fh:
+        if text in line:
+            return line