tools/scyllatop: some sensible default metrics

Previosly if the user did not specify any metrics, scyllatop use
whatever it could find. Now we have some preset defaults which are
probably more interesting.

Signed-off-by: Yoav Kleinberger <yoav@scylladb.com>
Message-Id: <1458658804-377-1-git-send-email-yoav@scylladb.com>

tools/scyllatop/defaults.py

@@ -0,0 +1,14 @@
+DEFAULT_METRIC_PATTERNS = [
+        '*cache*',
+        '*disk*',
+        '*transport*',
+        '*netlink*',
+        '*network*',
+        '*storage_proxy*',
+        '*la*',
+        '*reactor*',
+        '*idle*',
+        '*interface*',
+        '*memory*',
+        '*cpu*',
+]

tools/scyllatop/livedata.py

@@ -2,6 +2,7 @@ import logging
 import fnmatch
 import time
 import metric
+import defaults
 
 
 class LiveData(object):
@@ -25,9 +26,8 @@ class LiveData(object):
     def _initializeMetrics(self, metricPatterns):
         if len(metricPatterns) > 0:
             self._setupUserSpecifiedMetrics(metricPatterns)
-            return
-
-        self._measurements = metric.Metric.discover(self._collectd)
+        else:
+            self._setupUserSpecifiedMetrics(defaults.DEFAULT_METRIC_PATTERNS)
 
     def _setupUserSpecifiedMetrics(self, metricPatterns):
         availableSymbols = [m.symbol for m in metric.Metric.discover(self._collectd)]