feat: add updated span events + trace more methods (#1259)

* observability: add updated span events + traace more methods

This change carves out parts of PR #1241 in smaller pieces to
ease with smaller reviews.
This change adds more span events, updates important spans
to make them more distinct like changing:

"CloudSpanner.ReadWriteTransaction" to more direct and more
pointed spans like:
* CloudSpanner.Transaction.execute_streaming_sql

Also added important spans:
* CloudSpanner.Database.run_in_transaction
* CloudSpanner.Session.run_in_transaction

* all: update review comments + show type for BeginTransaction + remove prints

* Remove requested span event "Using Transaction"

* Move attempts into try block

* Transform Session.run_in_transaction retry exceptions into events

* More comprehensive test for events and attributes for pool.get

* Add test guards against Python3.7 for which OpenTelemetry is unavailable + address test feedback

* Remove span event per mutation in favour of future TODO

Referencing issue #1269, this update removes adding
a span event per mutation, in favour of a future TODO.

* Sort system-test.test_transaction_abort_then_retry_spans spans by create time

* Delint tests

google/cloud/spanner_v1/_opentelemetry_tracing.py

@@ -56,11 +56,11 @@ def get_tracer(tracer_provider=None):
 
 
 @contextmanager
-def trace_call(name, session, extra_attributes=None, observability_options=None):
+def trace_call(name, session=None, extra_attributes=None, observability_options=None):
     if session:
         session._last_use_time = datetime.now()
 
-    if not HAS_OPENTELEMETRY_INSTALLED or not session:
+    if not (HAS_OPENTELEMETRY_INSTALLED and name):
         # Empty context manager. Users will have to check if the generated value is None or a span
         yield None
         return
@@ -72,20 +72,24 @@ def trace_call(name, session, extra_attributes=None, observability_options=None)
     # on by default.
     enable_extended_tracing = True
 
+    db_name = ""
+    if session and getattr(session, "_database", None):
+        db_name = session._database.name
+
     if isinstance(observability_options, dict):  # Avoid false positives with mock.Mock
         tracer_provider = observability_options.get("tracer_provider", None)
         enable_extended_tracing = observability_options.get(
             "enable_extended_tracing", enable_extended_tracing
         )
+        db_name = observability_options.get("db_name", db_name)
 
     tracer = get_tracer(tracer_provider)
 
     # Set base attributes that we know for every trace created
-    db = session._database
     attributes = {
         "db.type": "spanner",
         "db.url": SpannerClient.DEFAULT_ENDPOINT,
-        "db.instance": "" if not db else db.name,
+        "db.instance": db_name,
         "net.host.name": SpannerClient.DEFAULT_ENDPOINT,
         OTEL_SCOPE_NAME: TRACER_NAME,
         OTEL_SCOPE_VERSION: TRACER_VERSION,

google/cloud/spanner_v1/batch.py

@@ -70,6 +70,8 @@ def insert(self, table, columns, values):
         :param values: Values to be modified.
         """
         self._mutations.append(Mutation(insert=_make_write_pb(table, columns, values)))
+        # TODO: Decide if we should add a span event per mutation:
+        # https://github.com/googleapis/python-spanner/issues/1269
 
     def update(self, table, columns, values):
         """Update one or more existing table rows.
@@ -84,6 +86,8 @@ def update(self, table, columns, values):
         :param values: Values to be modified.
         """
         self._mutations.append(Mutation(update=_make_write_pb(table, columns, values)))
+        # TODO: Decide if we should add a span event per mutation:
+        # https://github.com/googleapis/python-spanner/issues/1269
 
     def insert_or_update(self, table, columns, values):
         """Insert/update one or more table rows.
@@ -100,6 +104,8 @@ def insert_or_update(self, table, columns, values):
         self._mutations.append(
             Mutation(insert_or_update=_make_write_pb(table, columns, values))
         )
+        # TODO: Decide if we should add a span event per mutation:
+        # https://github.com/googleapis/python-spanner/issues/1269
 
     def replace(self, table, columns, values):
         """Replace one or more table rows.
@@ -114,6 +120,8 @@ def replace(self, table, columns, values):
         :param values: Values to be modified.
         """
         self._mutations.append(Mutation(replace=_make_write_pb(table, columns, values)))
+        # TODO: Decide if we should add a span event per mutation:
+        # https://github.com/googleapis/python-spanner/issues/1269
 
     def delete(self, table, keyset):
         """Delete one or more table rows.
@@ -126,6 +134,8 @@ def delete(self, table, keyset):
         """
         delete = Mutation.Delete(table=table, key_set=keyset._to_pb())
         self._mutations.append(Mutation(delete=delete))
+        # TODO: Decide if we should add a span event per mutation:
+        # https://github.com/googleapis/python-spanner/issues/1269
 
 
 class Batch(_BatchBase):
@@ -207,7 +217,7 @@ def commit(
         )
         observability_options = getattr(database, "observability_options", None)
         with trace_call(
-            "CloudSpanner.Commit",
+            f"CloudSpanner.{type(self).__name__}.commit",
             self._session,
             trace_attributes,
             observability_options=observability_options,

google/cloud/spanner_v1/database.py

@@ -70,6 +70,7 @@
 from google.cloud.spanner_v1._opentelemetry_tracing import (
     add_span_event,
     get_current_span,
+    trace_call,
 )
 
 
@@ -720,6 +721,7 @@ def execute_pdml():
 
                 iterator = _restart_on_unavailable(
                     method=method,
+                    trace_name="CloudSpanner.ExecuteStreamingSql",
                     request=request,
                     transaction_selector=txn_selector,
                     observability_options=self.observability_options,
@@ -881,20 +883,25 @@ def run_in_transaction(self, func, *args, **kw):
         :raises Exception:
             reraises any non-ABORT exceptions raised by ``func``.
         """
-        # Sanity check: Is there a transaction already running?
-        # If there is, then raise a red flag. Otherwise, mark that this one
-        # is running.
-        if getattr(self._local, "transaction_running", False):
-            raise RuntimeError("Spanner does not support nested transactions.")
-        self._local.transaction_running = True
-
-        # Check out a session and run the function in a transaction; once
-        # done, flip the sanity check bit back.
-        try:
-            with SessionCheckout(self._pool) as session:
-                return session.run_in_transaction(func, *args, **kw)
-        finally:
-            self._local.transaction_running = False
+        observability_options = getattr(self, "observability_options", None)
+        with trace_call(
+            "CloudSpanner.Database.run_in_transaction",
+            observability_options=observability_options,
+        ):
+            # Sanity check: Is there a transaction already running?
+            # If there is, then raise a red flag. Otherwise, mark that this one
+            # is running.
+            if getattr(self._local, "transaction_running", False):
+                raise RuntimeError("Spanner does not support nested transactions.")
+            self._local.transaction_running = True
+
+            # Check out a session and run the function in a transaction; once
+            # done, flip the sanity check bit back.
+            try:
+                with SessionCheckout(self._pool) as session:
+                    return session.run_in_transaction(func, *args, **kw)
+            finally:
+                self._local.transaction_running = False
 
     def restore(self, source):
         """Restore from a backup to this database.
@@ -1120,7 +1127,12 @@ def observability_options(self):
         if not (self._instance and self._instance._client):
             return None
 
-        return getattr(self._instance._client, "observability_options", None)
+        opts = getattr(self._instance._client, "observability_options", None)
+        if not opts:
+            opts = dict()
+
+        opts["db_name"] = self.name
+        return opts
 
 
 class BatchCheckout(object):

google/cloud/spanner_v1/pool.py

@@ -28,6 +28,7 @@
 from google.cloud.spanner_v1._opentelemetry_tracing import (
     add_span_event,
     get_current_span,
+    trace_call,
 )
 from warnings import warn
 
@@ -237,29 +238,41 @@ def bind(self, database):
             session_template=Session(creator_role=self.database_role),
         )
 
-        returned_session_count = 0
-        while not self._sessions.full():
-            request.session_count = requested_session_count - self._sessions.qsize()
+        observability_options = getattr(self._database, "observability_options", None)
+        with trace_call(
+            "CloudSpanner.FixedPool.BatchCreateSessions",
+            observability_options=observability_options,
+        ) as span:
+            returned_session_count = 0
+            while not self._sessions.full():
+                request.session_count = requested_session_count - self._sessions.qsize()
+                add_span_event(
+                    span,
+                    f"Creating {request.session_count} sessions",
+                    span_event_attributes,
+                )
+                resp = api.batch_create_sessions(
+                    request=request,
+                    metadata=metadata,
+                )
+
+                add_span_event(
+                    span,
+                    "Created sessions",
+                    dict(count=len(resp.session)),
+                )
+
+                for session_pb in resp.session:
+                    session = self._new_session()
+                    session._session_id = session_pb.name.split("/")[-1]
+                    self._sessions.put(session)
+                    returned_session_count += 1
+
             add_span_event(
                 span,
-                f"Creating {request.session_count} sessions",
+                f"Requested for {requested_session_count} sessions, returned {returned_session_count}",
                 span_event_attributes,
             )
-            resp = api.batch_create_sessions(
-                request=request,
-                metadata=metadata,
-            )
-            for session_pb in resp.session:
-                session = self._new_session()
-                session._session_id = session_pb.name.split("/")[-1]
-                self._sessions.put(session)
-                returned_session_count += 1
-
-        add_span_event(
-            span,
-            f"Requested for {requested_session_count} sessions, returned {returned_session_count}",
-            span_event_attributes,
-        )
 
     def get(self, timeout=None):
         """Check a session out from the pool.
@@ -550,25 +563,30 @@ def bind(self, database):
             span_event_attributes,
         )
 
-        returned_session_count = 0
-        while created_session_count < self.size:
-            resp = api.batch_create_sessions(
-                request=request,
-                metadata=metadata,
-            )
-            for session_pb in resp.session:
-                session = self._new_session()
-                session._session_id = session_pb.name.split("/")[-1]
-                self.put(session)
-                returned_session_count += 1
+        observability_options = getattr(self._database, "observability_options", None)
+        with trace_call(
+            "CloudSpanner.PingingPool.BatchCreateSessions",
+            observability_options=observability_options,
+        ) as span:
+            returned_session_count = 0
+            while created_session_count < self.size:
+                resp = api.batch_create_sessions(
+                    request=request,
+                    metadata=metadata,
+                )
+                for session_pb in resp.session:
+                    session = self._new_session()
+                    session._session_id = session_pb.name.split("/")[-1]
+                    self.put(session)
+                    returned_session_count += 1
 
-            created_session_count += len(resp.session)
+                created_session_count += len(resp.session)
 
-        add_span_event(
-            current_span,
-            f"Requested for {requested_session_count} sessions, return {returned_session_count}",
-            span_event_attributes,
-        )
+            add_span_event(
+                span,
+                f"Requested for {requested_session_count} sessions, returned {returned_session_count}",
+                span_event_attributes,
+            )
 
     def get(self, timeout=None):
         """Check a session out from the pool.