--- a/patchablegraph.py	Wed Nov 24 10:21:06 2021 -0800
+++ b/patchablegraph.py	Wed Nov 24 19:47:06 2021 -0800
@@ -22,7 +22,7 @@
 """
 import json, logging, itertools, html
 
-from greplin import scales
+from prometheus_client import Counter, Gauge, Summary
 from rdfdb.grapheditapi import GraphEditApi
 from rdflib import ConjunctiveGraph
 from rdflib.namespace import NamespaceManager
@@ -35,6 +35,13 @@
 
 log = logging.getLogger('patchablegraph')
 
+SERIALIZE_CALLS = Summary('serialize_calls', 'PatchableGraph.serialize calls')
+PATCH_CALLS = Summary('patch_calls', 'PatchableGraph.patch calls')
+STATEMENT_COUNT = Gauge('statement_count', 'current PatchableGraph graph size')
+OBSERVERS_CURRENT = Gauge('observers_current', 'current observer count')
+OBSERVERS_ADDED = Counter('observers_added', 'observers added')
+
+
 # forked from /my/proj/light9/light9/rdfdb/rdflibpatch.py
 def _graphFromQuads2(q):
     g = ConjunctiveGraph()
@@ -81,10 +88,8 @@
         with self._serialize.time():
             return self._graph.serialize(*arg, **kw)
 
-    _patch = scales.PmfStat('patch')
-    _len = scales.IntStat('statementCount')
     def patch(self, p):
-        with self._patch.time():
+        with PATCH_CALLS.labels(graph=self.label).time():
             # assuming no stmt is both in p.addQuads and p.delQuads.
             dels = set([q for q in p.delQuads if inGraph(q, self._graph)])
             adds = set([q for q in p.addQuads if not inGraph(q, self._graph)])
@@ -97,17 +102,15 @@
                        perfect=False) # true?
             for ob in self._observers:
                 ob(patchAsJson(p))
-            self._len = len(self._graph)
+            STATEMENT_COUNT.labels(graph=self.label).set(len(self._graph))
 
     def asJsonLd(self):
         return graphAsJson(self._graph)
 
-    _currentObservers = scales.IntStat('observers/current')
-    _observersAdded = scales.IntStat('observers/added')
     def addObserver(self, onPatch):
         self._observers.append(onPatch)
-        self._currentObservers = len(self._observers)
-        self._observersAdded += 1
+        OBSERVERS_CURRENT.labels(graph=self.label).set(len(self._observers))
+        OBSERVERS_ADDED.labels(graph=self.label).inc()
 
     def removeObserver(self, onPatch):
         try:
@@ -119,9 +122,8 @@
     def setToGraph(self, newGraph):
         self.patch(Patch.fromDiff(self._graph, newGraph))
 
-    _sendSimpleGraph = scales.PmfStat('serve/simpleGraph')
-    _sendFullGraph = scales.PmfStat('serve/events/sendFull')
-    _sendPatch = scales.PmfStat('serve/events/sendPatch')
+
+SEND_SIMPLE_GRAPH = Summary('send_simple_graph', 'calls to _writeGraphResponse')
 
 
 class CycloneGraphHandler(PrettyErrorHandler, cyclone.web.RequestHandler):
@@ -129,7 +131,7 @@
         self.masterGraph = masterGraph
 
     def get(self):
-        with self.masterGraph._sendSimpleGraph.time():
+        with SEND_SIMPLE_GRAPH.time():
             self._writeGraphResponse()
 
     def _writeGraphResponse(self):
@@ -210,6 +212,10 @@
         ''')
 
 
+SEND_FULL_GRAPH = Summary('send_full_graph', 'fullGraph SSE events')
+SEND_PATCH = Summary('send_patch', 'patch SSE events')
+
+
 class CycloneGraphEventsHandler(cyclone.sse.SSEHandler):
     """
     One session with one client.
@@ -226,14 +232,14 @@
         self.masterGraph = masterGraph
 
     def bind(self):
-        with self.masterGraph._sendFullGraph.time():
+        with SEND_FULL_GRAPH.time():
             graphJson = self.masterGraph.asJsonLd()
             log.debug("send fullGraph event: %s", graphJson)
             self.sendEvent(message=graphJson, event=b'fullGraph')
             self.masterGraph.addObserver(self.onPatch)
 
     def onPatch(self, patchJson):
-        with self.masterGraph._sendPatch.time():
+        with SEND_PATCH.time():
             # throttle and combine patches here- ideally we could see how
             # long the latency to the client is to make a better rate choice
             self.sendEvent(message=patchJson, event=b'patch')

--- a/setup.py	Wed Nov 24 10:21:06 2021 -0800
+++ b/setup.py	Wed Nov 24 19:47:06 2021 -0800
@@ -10,7 +10,7 @@
         'twisted',
         'rdflib >= 6.0.1',
         'rdfdb >= 0.8.0',
-        'scales @ git+http://github.com/drewp/scales.git@448d59fb491b7631877528e7695a93553bfaaa93',
+        'prometheus_client',
         'cycloneerr',
         'twisted_sse >= 0.3.0',
     ],