revise readme

README.md

@@ -2,4 +2,21 @@
 
 Using Influx, Telegraf, etc.
 
-![Monitoring](https://raw.githubusercontent.com/hannesm/monitoring-experiments/master/one.png)
+![Monitoring](https://raw.githubusercontent.com/roburio/monitoring-experiments/master/one.png)
+
+# Dynamic adjustments of Log level and Metrics reporting
+
+The create function has a *listener_port* argument. If this is provided, then
+on the given port TCP connections to the unikernel are possible. Each connection
+can transmit a command (as text) to adjust log level and enable or disable
+metrics sources:
+
+The log level (prefix `L`) is specified, the same as the command-line argument `-l`:
+- `L*:debug` all log sources are enabled on the *debug* level
+- `Lmonitoring-experiments:error` the log source monitoring-experiments is set to the *error* level
+- `L*:info,monitoring-experiments:debug` all log sources are enabled on the *info* level, and the log source monitoring-experiments is set to the *debug* level
+
+The metrics (prefix `M`) sources can be enabled and disabled based on source name.
+First, if present, the all command is executed, then specific sources:
+- `M*:disable,memory:enable,net-solo5:enable` disables all metrics sources, and then enables *memory* and *net-solo5*
+- `Mnet-solo5:disable` disables the *net-solo5* metrics source.

src/monitoring_experiments.ml

@@ -81,34 +81,22 @@ let adjust_metrics s =
         | [ src ; en ] ->
           let* en_or_d = enable_of_str en in
           Ok (`Src src, en_or_d)
-        | [ "src" ; src ; en ] ->
-          let* en_or_d = enable_of_str en in
-          Ok (`Src src, en_or_d)
-        | [ "tag" ; src ; en ] ->
-          let* en_or_d = enable_of_str en in
-          Ok (`Tag src, en_or_d)
         | _ -> Error ("couldn't decode metrics " ^ s))
       (String.split_on_char ',' s)
   in
-  let* (all, tags, srcs) =
+  let* (all, srcs) =
     List.fold_left (fun acc t ->
-        let* (all, tags, srcs) = acc in
+        let* (all, srcs) = acc in
         let* t = t in
         match t with
-        | `All, en_or_d -> Ok (Some en_or_d, tags, srcs)
-        | `Src s, en_or_d -> Ok (all, tags, (s, en_or_d) :: srcs)
-        | `Tag t, en_or_d -> Ok (all, (t, en_or_d) :: tags, srcs))
-      (Ok (None, [], [])) ts
+        | `All, en_or_d -> Ok (Some en_or_d, srcs)
+        | `Src s, en_or_d -> Ok (all, (s, en_or_d) :: srcs))
+      (Ok (None, [])) ts
   in
   (match all with
    | Some `Enable -> Metrics.enable_all ()
    | Some `Disable -> Metrics.disable_all ()
    | None -> ());
-  List.iter
-    (function
-      | t, `Enable -> Metrics.enable_tag t
-      | t, `Disable -> Metrics.disable_tag t)
-    tags ;
   List.iter (fun (src, e_or_d) ->
       match List.find_opt (fun s -> Metrics.Src.name s = src) (Metrics.Src.list ()), e_or_d with
       | Some src, `Enable -> Metrics.Src.enable src