From f191be822b265b50339e17b2d95125f43dc700b3 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Wed, 27 Feb 2019 10:21:49 +0000
Subject: [PATCH] Add database version to phonehome stats. (#4753)

---
 changelog.d/4753.misc               |  1 +
 synapse/app/homeserver.py           |  3 +++
 synapse/storage/_base.py            |  8 ++++++++
 synapse/storage/engines/postgres.py | 25 +++++++++++++++++++++++++
 synapse/storage/engines/sqlite.py   |  9 +++++++++
 5 files changed, 46 insertions(+)
 create mode 100644 changelog.d/4753.misc

diff --git a/changelog.d/4753.misc b/changelog.d/4753.misc
new file mode 100644
index 000000000..98532cc97
--- /dev/null
+++ b/changelog.d/4753.misc
@@ -0,0 +1 @@
+Add database version to phonehome stats.
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 05a97979e..e8b6cc311 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -555,6 +555,9 @@ def run(hs):
                 stats["memory_rss"] += process.memory_info().rss
                 stats["cpu_average"] += int(process.cpu_percent(interval=None))
 
+        stats["database_engine"] = hs.get_datastore().database_engine_name
+        stats["database_server_version"] = hs.get_datastore().get_server_version()
+
         logger.info("Reporting stats to matrix.org: %s" % (stats,))
         try:
             yield hs.get_simple_http_client().put_json(
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 5a80eef21..190be34fb 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -1596,6 +1596,14 @@ class SQLBaseStore(object):
 
         return cls.cursor_to_dict(txn)
 
+    @property
+    def database_engine_name(self):
+        return self.database_engine.module.__name__
+
+    def get_server_version(self):
+        """Returns a string describing the server version number"""
+        return self.database_engine.server_version
+
 
 class _RollbackButIsFineException(Exception):
     """ This exception is used to rollback a transaction without implying
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 4004427c7..dc3238501 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -23,6 +23,7 @@ class PostgresEngine(object):
         self.module = database_module
         self.module.extensions.register_type(self.module.extensions.UNICODE)
         self.synchronous_commit = database_config.get("synchronous_commit", True)
+        self._version = None   # unknown as yet
 
     def check_database(self, txn):
         txn.execute("SHOW SERVER_ENCODING")
@@ -87,3 +88,27 @@ class PostgresEngine(object):
         """
         txn.execute("SELECT nextval('state_group_id_seq')")
         return txn.fetchone()[0]
+
+    @property
+    def server_version(self):
+        """Returns a string giving the server version. For example: '8.1.5'
+
+        Returns:
+            string
+        """
+        # note that this is a bit of a hack because it relies on on_new_connection
+        # having been called at least once. Still, that should be a safe bet here.
+        numver = self._version
+        assert numver is not None
+
+        # https://www.postgresql.org/docs/current/libpq-status.html#LIBPQ-PQSERVERVERSION
+        if numver >= 100000:
+            return "%i.%i" % (
+                numver / 10000, numver % 10000,
+            )
+        else:
+            return "%i.%i.%i" % (
+                numver / 10000,
+                (numver % 10000) / 100,
+                numver % 100,
+            )
diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py
index 059ab8105..1bcd5b99a 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -70,6 +70,15 @@ class Sqlite3Engine(object):
             self._current_state_group_id += 1
             return self._current_state_group_id
 
+    @property
+    def server_version(self):
+        """Gets a string giving the server version. For example: '3.22.0'
+
+        Returns:
+            string
+        """
+        return "%i.%i.%i" % self.module.sqlite_version_info
+
 
 # Following functions taken from: https://github.com/coleifer/peewee