Improve timeseries comments and fix Prometheus settings

scripts/lua/admin/prefs.lua

@@ -1394,7 +1394,7 @@ function printStatsTimeseries()
   print('<tr><th colspan=2 class="info">'..i18n('prefs.timeseries_database')..'</th></tr>')
 
   local elementToSwitch = {"ts_post_data_url", "influx_dbname", "influx_retention", "row_toggle_influx_auth", "influx_username", "influx_password", "row_ts_high_resolution"}
-  local showElementArray = {false, true}
+  local showElementArray = {false, true, false}
 
   local javascriptAfterSwitch = "";
   javascriptAfterSwitch = javascriptAfterSwitch.."  if($(\"#id-toggle-timeseries_driver\").val() == \"influxdb\") {\n"
@@ -1406,7 +1406,7 @@ function printStatsTimeseries()
   javascriptAfterSwitch = javascriptAfterSwitch.."      $(\"#influx_password\").css(\"display\",\"none\");\n"
   javascriptAfterSwitch = javascriptAfterSwitch.."    }\n"
   javascriptAfterSwitch = javascriptAfterSwitch.."    $(\"#old_rrd_files_retention\").css(\"display\",\"none\");\n"
-  javascriptAfterSwitch = javascriptAfterSwitch.."  } else {\n"
+  javascriptAfterSwitch = javascriptAfterSwitch.."  } else if($(\"#id-toggle-timeseries_driver\").val() == \"rrd\") {\n"
   javascriptAfterSwitch = javascriptAfterSwitch.."    $(\"#old_rrd_files_retention\").css(\"display\",\"table-row\");\n"
   javascriptAfterSwitch = javascriptAfterSwitch.."  }\n"
 
@@ -1964,6 +1964,24 @@ if tonumber(_POST["ts_high_resolution"]) ~= nil then
     end
   end
 
+  -- When high resolution timeseries are enabled, the ntopng C core creates
+  -- timeseries rings with diffent slots. Each slot holds a snapshot of the
+  -- host/interface timeseries in a given time interval. For example, if 10s
+  -- resolution is choose, each slot holds a snapshot representing an interval
+  -- of 10s. Periodically (in NetworkInterface::periodicStatsUpdate) the slots
+  -- are polulated and then in minute.lua they are read and exported.
+  --
+  -- This Redis preferences tell the C core how to configure the ring:
+  --  - ntopng.prefs.ts_write_slots: the number of slots to allocate in the ring
+  --  - ntopng.prefs.ts_write_steps: how many ticks of NetworkInterface::periodicStatsUpdate
+  --    are necessary to fill a slot.
+  --
+  -- For the example above of 10s resolution:
+  --  - ntopng.prefs.ts_write_slots = 60 / 10 = 6 slots, + 1 extra slot as buffer (see above) = 7
+  --  - ntopng.prefs.ts_write_steps = 60 / 6 slots = 10s / 5 (5s is the periodicStatsUpdate interval) = 2
+  --
+  -- See TimseriesRing.cpp for more details.
+  --
   ntop.setPref("ntopng.prefs.ts_write_slots", tostring(math.ceil(new_slots)))
   ntop.setPref("ntopng.prefs.ts_write_steps", tostring(math.ceil(new_steps)))
 end

scripts/lua/modules/timeseries/drivers/rrd.lua

@@ -62,7 +62,6 @@ end
 
 -- ##############################################
 
--- TODO remove after migrating to the new path format
 -- Maps second tag name to getRRDName
 local HOST_PREFIX_MAP = {
   host = "",
@@ -153,40 +152,6 @@ function driver.schema_get_full_path(schema, tags)
   return full_path
 end
 
--- TODO remove after migration
-function find_schema(rrdFile, rrdfname, tags, ts_utils)
-  -- try to guess additional tags
-  local v = string.split(rrdfname, "%.rrd")
-  if((v ~= nil) and (#v == 1)) then
-    local app = v[1]
-
-    if interface.getnDPIProtoId(app) ~= -1 then
-      tags.protocol = app
-    elseif interface.getnDPICategoryId(app) ~= -1 then
-      tags.category = app
-    end
-  end
-
-  for schema_name, schema in pairs(ts_utils.getLoadedSchemas()) do
-    -- verify tags compatibility
-    for tag in pairs(schema.tags) do
-      if tags[tag] == nil then
-        goto next_schema
-      end
-    end
-
-    local full_path = driver.schema_get_full_path(schema, tags)
-
-    if full_path == rrdFile then
-      return schema_name
-    end
-
-    ::next_schema::
-  end
-
-  return nil
-end
-
 -- ##############################################
 
 local function getRRAParameters(step, resolution, retention_time)

scripts/lua/modules/timeseries/ts_utils_core.lua

@@ -175,7 +175,7 @@ end
 function ts_utils.getQueryDriver()
   local drivers = ts_utils.listActiveDrivers()
 
-  -- TODO: for now prefer the influx driver if present
+  -- NOTE: prefer the InfluxDB driver if available, RRD as fallback
   local driver = drivers[2] or drivers[1]
 
   return driver
@@ -288,12 +288,6 @@ function ts_utils.query(schema_name, tags, tstart, tend, options)
     return nil
   end
 
-  -- TODO: temporary fix for "process:memory"
-  if schema_name == "process:memory" then
-    tags = table.clone(tags)
-    tags.ifid = nil
-  end
-
   if not schema:verifyTags(tags) then
     return nil
   end
@@ -740,7 +734,6 @@ end
 
 -- ##############################################
 
--- TODO make standard and document
 function ts_utils.queryMean(schema_name, tstart, tend, tags, options)
   if not isUserAccessAllowed(tags) then
     return nil