diff --git a/docker/asyncloop.nim b/docker/asyncloop.nim
index 957a266c..71171a03 100644
--- a/docker/asyncloop.nim
+++ b/docker/asyncloop.nim
@@ -23,6 +23,8 @@ when defined(chronosDurationThreshold):
   import pkg/metrics
 
   declareGauge(chronosCallbackDuration, "chronos callback duration")
+  declareGauge(chronosConstant, "chronos constant")
+  declareCounter(chronosCallbackCounter, "chronos callback counter")
 
 export Port, SocketFlag
 export timer
@@ -226,9 +228,6 @@ type
 const chronosDurationThreshold {.intdefine.} = 0
 
 template newAsyncCallback*(cbFunc: CallbackFunc, udataPtr: pointer = nil): AsyncCallback =
-  # when defined(chronosDurationThreshold):
-  #   AsyncCallback(function: cbFunc, udata: udataPtr, location: getStackTrace())
-  # else:
   AsyncCallback(function: cbFunc, udata: udataPtr)
 
 when defined(chronosDurationThreshold):
@@ -337,7 +336,10 @@ template processCallbacks(loop: untyped) =
           durationNs = getMonoTime().ticks - startTime
           durationUs = durationNs div 1000
 
-        chronosCallbackDuration.set(durationUs.int64)
+        chronosCallbackDuration.set(durationNs)
+        chronosConstant.set(123)
+        chronosCallbackCounter.inc()
+
         if durationUs > chronosDurationThreshold:
 
           # callable.location*: array[2, ptr SrcLoc]
diff --git a/docker/srcloc.nim b/docker/srcloc.nim
index 321c9e7f..6edaefb5 100644
--- a/docker/srcloc.nim
+++ b/docker/srcloc.nim
@@ -17,7 +17,6 @@ type
     procedure*: cstring
     file*: cstring
     line*: int
-    trace*: cstring
 
 proc `$`*(loc: ptr SrcLoc): string =
   var res = $loc.file
@@ -29,15 +28,12 @@ proc `$`*(loc: ptr SrcLoc): string =
     res.add("[unspecified]")
   else:
     res.add($loc.procedure)
-  res.add("[")
-  res.add($loc.trace)
-  res.add("]")
   res
 
 proc srcLocImpl(procedure: static string,
                 file: static string, line: static int): ptr SrcLoc =
   var loc {.global.} = SrcLoc(
-    file: cstring(file), line: line, procedure: procedure, trace: "a"
+    file: cstring(file), line: line, procedure: procedure
   )
   return addr(loc)