Support of v0.2 protocol

doc/index.rst

@@ -30,6 +30,7 @@ Documentation of  telemetry
 
    user_guide
    client-python
+   protocol
    developer_guide
    api
    faq

doc/protocol.rst

@@ -0,0 +1,53 @@
+Telemetry Protocol Specification
+================================
+
+Exasol telemetry uses simplistic protocol sending events happened in the the software.
+Every event has a timestamp attached to be used for server-side analytics.
+All the data one the server are immediately aggregated and anonymized and no personal information
+is transferred or stored.
+
+The data is transferred in json format and at the moment there are two versions of the protocol.
+
+Version 0.1
+-----------
+.. code:: json
+
+    {
+        "version": "0.1",
+        "timestamp": 1787036195,
+        "features": {
+            "mcp-server.started": [1787036195]
+        }
+    }
+
+Transferred data has the following fields:
+
+-  ``version``: string specifying the protocol version
+-  ``timestamp``: UTC timestamp of the transmission attempt
+-  ``features``: dictionary with pairs ``feature-name`` and vector of timestamps when the event happened.
+
+Recording of both event timestamp and transmission timestamp allows to check the clock discrepancies on the client
+side and filter out outliers.
+
+Version 0.2
+-----------
+
+This is an extension of version 0.1, sample data is below.
+.. code:: json
+
+    {
+        "version": "0.2",
+        "category": "mcp-server",
+        "productVersion": "0.22",
+        "timestamp": 1787036195,
+        "features": {
+            "started": [1787036195]
+        }
+    }
+
+In this version we have two new top-level fields added:
+
+-  ``category``: name of the product
+-  ``productVersion``: version of the product
+
+The name of the product is no longer prepended to the features, which makes the data more compact.