python: Monitor Database table to manage lifecycle of IDL client.

The Python IDL implementation supports ovsdb cluster connections.
This patch is a follow up to commit 31e434fc98, it adds the option of
connecting to the leader (the default) in the Raft-based cluster. It mimics
the exisiting C IDL support for clusters introduced in commit 1b1d2e6daa.

The _Server database schema is first requested, then a monitor of the
Database table in the _Server Database. Method __check_server_db verifies
the eligibility of the server. If the attempt to obtain a monitor of the
_Server database fails and a cluster id was not provided this implementation
proceeds to request the data monitor. If a cluster id was provided via the
set_cluster_id method then the connection is aborted and a connection to a
different node is instead attempted, until a valid cluster node is found.
Thus, when supplied, cluster id is interpreted as the intention to only
allow connections to a clustered database. If not supplied, connections to
standalone nodes, or nodes that do not have the _Server database are
allowed. change_seqno is not incremented in the case of Database table
updates.

Acked-by: Numan Siddique <nusiddiq@redhat.com>
Signed-off-by: Ted Elhourani <ted.elhourani@nutanix.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

python/ovs/db/idl.py

@@ -38,6 +38,8 @@ ROW_DELETE = "delete"
 OVSDB_UPDATE = 0
 OVSDB_UPDATE2 = 1
 
+CLUSTERED = "clustered"
+
 
 class Idl(object):
     """Open vSwitch Database Interface Definition Language (OVSDB IDL).
@@ -92,10 +94,13 @@ class Idl(object):
 """
 
     IDL_S_INITIAL = 0
-    IDL_S_MONITOR_REQUESTED = 1
+    IDL_S_SERVER_SCHEMA_REQUESTED = 1
-    IDL_S_MONITOR_COND_REQUESTED = 2
+    IDL_S_SERVER_MONITOR_REQUESTED = 2
+    IDL_S_DATA_MONITOR_REQUESTED = 3
+    IDL_S_DATA_MONITOR_COND_REQUESTED = 4
 
-    def __init__(self, remote, schema_helper, probe_interval=None):
+    def __init__(self, remote, schema_helper, probe_interval=None,
+                 leader_only=True):
         """Creates and returns a connection to the database named 'db_name' on
         'remote', which should be in a form acceptable to
         ovs.jsonrpc.session.open().  The connection will maintain an in-memory
@@ -119,6 +124,9 @@ class Idl(object):
 
         The IDL uses and modifies 'schema' directly.
 
+        If 'leader_only' is set to True (default value) the IDL will only
+        monitor and transact with the leader of the cluster.
+
         If "probe_interval" is zero it disables the connection keepalive
         feature. If non-zero the value will be forced to at least 1000
         milliseconds. If None it will just use the default value in OVS.
@@ -137,6 +145,20 @@ class Idl(object):
         self._last_seqno = None
         self.change_seqno = 0
         self.uuid = uuid.uuid1()
+
+        # Server monitor.
+        self._server_schema_request_id = None
+        self._server_monitor_request_id = None
+        self._db_change_aware_request_id = None
+        self._server_db_name = '_Server'
+        self._server_db_table = 'Database'
+        self.server_tables = None
+        self._server_db = None
+        self.server_monitor_uuid = uuid.uuid1()
+        self.leader_only = leader_only
+        self.cluster_id = None
+        self._min_index = 0
+
         self.state = self.IDL_S_INITIAL
 
         # Database locking.
@@ -172,6 +194,12 @@ class Idl(object):
                 remotes.append(r)
         return remotes
 
+    def set_cluster_id(self, cluster_id):
+        """Set the id of the cluster that this idl must connect to."""
+        self.cluster_id = cluster_id
+        if self.state != self.IDL_S_INITIAL:
+            self.force_reconnect()
+
     def index_create(self, table, name):
         """Create a named multi-column index on a table"""
         return self.tables[table].rows.index_create(name)
@@ -222,7 +250,7 @@ class Idl(object):
             if seqno != self._last_seqno:
                 self._last_seqno = seqno
                 self.__txn_abort_all()
-                self.__send_monitor_request()
+                self.__send_server_schema_request()
                 if self.lock_name:
                     self.__send_lock_request()
                 break
@@ -230,6 +258,7 @@ class Idl(object):
             msg = self._session.recv()
             if msg is None:
                 break
+
             if (msg.type == ovs.jsonrpc.Message.T_NOTIFY
                     and msg.method == "update2"
                     and len(msg.params) == 2):
@@ -239,7 +268,15 @@ class Idl(object):
                     and msg.method == "update"
                     and len(msg.params) == 2):
                 # Database contents changed.
-                self.__parse_update(msg.params[1], OVSDB_UPDATE)
+                if msg.params[0] == str(self.server_monitor_uuid):
+                    self.__parse_update(msg.params[1], OVSDB_UPDATE,
+                                        tables=self.server_tables)
+                    self.change_seqno = initial_change_seqno
+                    if not self.__check_server_db():
+                        self.force_reconnect()
+                        break
+                else:
+                    self.__parse_update(msg.params[1], OVSDB_UPDATE)
             elif (msg.type == ovs.jsonrpc.Message.T_REPLY
                   and self._monitor_request_id is not None
                   and self._monitor_request_id == msg.id):
@@ -248,16 +285,66 @@ class Idl(object):
                     self.change_seqno += 1
                     self._monitor_request_id = None
                     self.__clear()
-                    if self.state == self.IDL_S_MONITOR_COND_REQUESTED:
+                    if self.state == self.IDL_S_DATA_MONITOR_COND_REQUESTED:
                         self.__parse_update(msg.result, OVSDB_UPDATE2)
                     else:
-                        assert self.state == self.IDL_S_MONITOR_REQUESTED
+                        assert self.state == self.IDL_S_DATA_MONITOR_REQUESTED
                         self.__parse_update(msg.result, OVSDB_UPDATE)
 
                 except error.Error as e:
                     vlog.err("%s: parse error in received schema: %s"
                              % (self._session.get_name(), e))
                     self.__error()
+            elif (msg.type == ovs.jsonrpc.Message.T_REPLY
+                  and self._server_schema_request_id is not None
+                  and self._server_schema_request_id == msg.id):
+                # Reply to our "get_schema" of _Server request.
+                try:
+                    self._server_schema_request_id = None
+                    sh = SchemaHelper(None, msg.result)
+                    sh.register_table(self._server_db_table)
+                    schema = sh.get_idl_schema()
+                    self._server_db = schema
+                    self.server_tables = schema.tables
+                    self.__send_server_monitor_request()
+                except error.Error as e:
+                    vlog.err("%s: error receiving server schema: %s"
+                             % (self._session.get_name(), e))
+                    if self.cluster_id:
+                        self.__error()
+                        break
+                    else:
+                        self.change_seqno = initial_change_seqno
+                        self.__send_monitor_request()
+            elif (msg.type == ovs.jsonrpc.Message.T_REPLY
+                  and self._server_monitor_request_id is not None
+                  and self._server_monitor_request_id == msg.id):
+                # Reply to our "monitor" of _Server request.
+                try:
+                    self._server_monitor_request_id = None
+                    self.__parse_update(msg.result, OVSDB_UPDATE,
+                                        tables=self.server_tables)
+                    self.change_seqno = initial_change_seqno
+                    if self.__check_server_db():
+                        self.__send_monitor_request()
+                        self.__send_db_change_aware()
+                    else:
+                        self.force_reconnect()
+                        break
+                except error.Error as e:
+                    vlog.err("%s: parse error in received schema: %s"
+                             % (self._session.get_name(), e))
+                    if self.cluster_id:
+                        self.__error()
+                        break
+                    else:
+                        self.change_seqno = initial_change_seqno
+                        self.__send_monitor_request()
+            elif (msg.type == ovs.jsonrpc.Message.T_REPLY
+                  and self._db_change_aware_request_id is not None
+                  and self._db_change_aware_request_id == msg.id):
+                # Reply to us notifying the server of our change awarness.
+                self._db_change_aware_request_id = None
             elif (msg.type == ovs.jsonrpc.Message.T_REPLY
                   and self._lock_request_id is not None
                   and self._lock_request_id == msg.id):
@@ -275,10 +362,20 @@ class Idl(object):
                 # Reply to our echo request.  Ignore it.
                 pass
             elif (msg.type == ovs.jsonrpc.Message.T_ERROR and
-                  self.state == self.IDL_S_MONITOR_COND_REQUESTED and
+                  self.state == self.IDL_S_DATA_MONITOR_COND_REQUESTED and
                   self._monitor_request_id == msg.id):
                 if msg.error == "unknown method":
                     self.__send_monitor_request()
+            elif (msg.type == ovs.jsonrpc.Message.T_ERROR and
+                  self._server_schema_request_id is not None and
+                  self._server_schema_request_id == msg.id):
+                self._server_schema_request_id = None
+                if self.cluster_id:
+                    self.force_reconnect()
+                    break
+                else:
+                    self.change_seqno = initial_change_seqno
+                    self.__send_monitor_request()
             elif (msg.type in (ovs.jsonrpc.Message.T_ERROR,
                                ovs.jsonrpc.Message.T_REPLY)
                   and self.__txn_process_reply(msg)):
@@ -342,6 +439,9 @@ class Idl(object):
         In the meantime, the contents of the IDL will not change."""
         self._session.force_reconnect()
 
+    def session_name(self):
+        return self._session.get_name()
+
     def set_lock(self, lock_name):
         """If 'lock_name' is not None, configures the IDL to obtain the named
         lock from the database server and to avoid modifying the database when
@@ -440,12 +540,19 @@ class Idl(object):
             if not new_has_lock:
                 self.is_lock_contended = True
 
+    def __send_db_change_aware(self):
+        msg = ovs.jsonrpc.Message.create_request("set_db_change_aware",
+                                                 [True])
+        self._db_change_aware_request_id = msg.id
+        self._session.send(msg)
+
     def __send_monitor_request(self):
-        if self.state == self.IDL_S_INITIAL:
+        if (self.state in [self.IDL_S_SERVER_MONITOR_REQUESTED,
-            self.state = self.IDL_S_MONITOR_COND_REQUESTED
+                           self.IDL_S_INITIAL]):
+            self.state = self.IDL_S_DATA_MONITOR_COND_REQUESTED
             method = "monitor_cond"
         else:
-            self.state = self.IDL_S_MONITOR_REQUESTED
+            self.state = self.IDL_S_DATA_MONITOR_REQUESTED
             method = "monitor"
 
         monitor_requests = {}
@@ -467,20 +574,50 @@ class Idl(object):
         self._monitor_request_id = msg.id
         self._session.send(msg)
 
-    def __parse_update(self, update, version):
+    def __send_server_schema_request(self):
+        self.state = self.IDL_S_SERVER_SCHEMA_REQUESTED
+        msg = ovs.jsonrpc.Message.create_request(
+            "get_schema", [self._server_db_name, str(self.uuid)])
+        self._server_schema_request_id = msg.id
+        self._session.send(msg)
+
+    def __send_server_monitor_request(self):
+        self.state = self.IDL_S_SERVER_MONITOR_REQUESTED
+        monitor_requests = {}
+        table = self.server_tables[self._server_db_table]
+        columns = [column for column in six.iterkeys(table.columns)]
+        for column in six.itervalues(table.columns):
+            if not hasattr(column, 'alert'):
+                column.alert = True
+        table.rows = custom_index.IndexedRows(table)
+        table.need_table = False
+        table.idl = self
+        monitor_request = {"columns": columns}
+        monitor_requests[table.name] = [monitor_request]
+        msg = ovs.jsonrpc.Message.create_request(
+            'monitor', [self._server_db.name,
+                             str(self.server_monitor_uuid),
+                             monitor_requests])
+        self._server_monitor_request_id = msg.id
+        self._session.send(msg)
+
+    def __parse_update(self, update, version, tables=None):
         try:
-            self.__do_parse_update(update, version)
+            if not tables:
+                self.__do_parse_update(update, version, self.tables)
+            else:
+                self.__do_parse_update(update, version, tables)
         except error.Error as e:
             vlog.err("%s: error parsing update: %s"
                      % (self._session.get_name(), e))
 
-    def __do_parse_update(self, table_updates, version):
+    def __do_parse_update(self, table_updates, version, tables):
         if not isinstance(table_updates, dict):
             raise error.Error("<table-updates> is not an object",
                               table_updates)
 
         for table_name, table_update in six.iteritems(table_updates):
-            table = self.tables.get(table_name)
+            table = tables.get(table_name)
             if not table:
                 raise error.Error('<table-updates> includes unknown '
                                   'table "%s"' % table_name)
@@ -605,6 +742,58 @@ class Idl(object):
                 self.notify(op, row, Row.from_json(self, table, uuid, old))
         return changed
 
+    def __check_server_db(self):
+        """Returns True if this is a valid server database, False otherwise."""
+        session_name = self.session_name()
+
+        if self._server_db_table not in self.server_tables:
+            vlog.info("%s: server does not have %s table in its %s database"
+                      % (session_name, self._server_db_table,
+                         self._server_db_name))
+            return False
+
+        rows = self.server_tables[self._server_db_table].rows
+
+        database = None
+        for row in six.itervalues(rows):
+            if self.cluster_id:
+                if self.cluster_id in \
+                   map(lambda x: str(x)[:4], row.cid):
+                    database = row
+                    break
+            elif row.name == self._db.name:
+                database = row
+                break
+
+        if not database:
+            vlog.info("%s: server does not have %s database"
+                      % (session_name, self._db.name))
+            return False
+
+        if (database.model == CLUSTERED and
+            self._session.get_num_of_remotes() > 1):
+            if not database.schema:
+                vlog.info('%s: clustered database server has not yet joined '
+                          'cluster; trying another server' % session_name)
+                return False
+            if not database.connected:
+                vlog.info('%s: clustered database server is disconnected '
+                          'from cluster; trying another server' % session_name)
+                return False
+            if (self.leader_only and
+                not database.leader):
+                vlog.info('%s: clustered database server is not cluster '
+                          'leader; trying another server' % session_name)
+                return False
+            if database.index:
+                if database.index[0] < self._min_index:
+                    vlog.warn('%s: clustered database server has stale data; '
+                              'trying another server' % session_name)
+                    return False
+                self._min_index = database.index[0]
+
+        return True
+
     def __column_name(self, column):
         if column.type.key.type == ovs.db.types.UuidType:
             return ovs.ovsuuid.to_json(column.type.key.type.default)

python/ovs/reconnect.py

@@ -344,6 +344,9 @@ class Reconnect(object):
                 else:
                     self.info_level("%s: error listening for connections"
                                     % self.name)
+            elif self.state == Reconnect.Reconnect:
+                self.info_level("%s: connection closed by client"
+                                % self.name)
             elif self.backoff < self.max_backoff:
                 if self.passive:
                     type_ = "listen"

tests/ovsdb-idl.at

@@ -11,7 +11,42 @@ ovsdb_start_idltest () {
     ovsdb-server -vconsole:warn --log-file --detach --no-chdir --pidfile --remote=punix:socket ${1:+--remote=$1} db || return $?
     on_exit 'kill `cat ovsdb-server.pid`'
 }
-])
+
+# ovsdb_cluster_start_idltest [REMOTE] [SCHEMA]
+#
+# Creates a database using SCHEMA (default: idltest.ovsschema) and
+# starts a database cluster listening on punix:socket and REMOTE (if
+# specified).
+ovsdb_cluster_start_idltest () {
+   local n=$1
+   ovsdb-tool create-cluster s1.db $abs_srcdir/idltest.ovsschema unix:s1.raft || return $?
+   cid=`ovsdb-tool db-cid s1.db`
+   schema_name=`ovsdb-tool schema-name $abs_srcdir/idltest.ovsschema`
+   for i in `seq 2 $n`; do
+     ovsdb-tool join-cluster s$i.db $schema_name unix:s$i.raft unix:s1.raft || return $?
+   done
+   for i in `seq $n`; do
+     ovsdb-server -vraft -vconsole:warn --detach --no-chdir --log-file=s$i.log --pidfile=s$i.pid --unixctl=s$i --remote=punix:s$i.ovsdb ${2:+--remote=$2} s$i.db || return $?
+   done
+   on_exit 'kill `cat s*.pid`'
+}
+
+# ovsdb_cluster_leader [REMOTES] [DATABASE]
+#
+# Returns the leader of the DATABASE cluster.
+ovsdb_cluster_leader () {
+   remotes=$(echo $1 | tr "," "\n")
+   for remote in $remotes; do
+      ovsdb-client dump $remote _Server Database name leader | grep $2 | grep -q true
+      if [[ $? == 0 ]]; then
+        port=$(echo $remote | cut -d':' -f 3)
+        log=$(grep --include=s\*.log -rlnw -e "listening on port $port" ./)
+        pid=$(echo $log | sed 's/\(.*\.\)log/\1pid/' )
+        echo "${remote}|${pid}"
+        return
+      fi
+   done
+}])
 
 # OVSDB_CHECK_IDL_C(TITLE, [PRE-IDL-TXN], TRANSACTIONS, OUTPUT, [KEYWORDS],
 #                   [FILTER])
@@ -1466,40 +1501,44 @@ OVSDB_CHECK_IDL_NOTIFY([simple idl verify notify],
        "where": [["i", "==", 0]]}]' \
     'reconnect']],
   [[000: empty
-001: {"error":null,"result":[{"uuid":["uuid","<0>"]},{"uuid":["uuid","<1>"]}]}
+000: event:create, row={uuid=<0>}, updates=None
-002: event:create, row={i=0 r=0 b=false s= u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>}, updates=None
+000: event:create, row={uuid=<1>}, updates=None
-002: event:create, row={i=1 r=2 b=true s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>}, updates=None
+001: {"error":null,"result":[{"uuid":["uuid","<2>"]},{"uuid":["uuid","<3>"]}]}
-002: i=0 r=0 b=false s= u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
+002: event:create, row={i=0 r=0 b=false s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>}, updates=None
-002: i=1 r=2 b=true s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+002: event:create, row={i=1 r=2 b=true s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>}, updates=None
+002: i=0 r=0 b=false s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>
+002: i=1 r=2 b=true s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
 003: {"error":null,"result":[{"count":2}]}
-004: event:update, row={i=1 r=2 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>}, updates={b=true uuid=<0>}
+004: event:update, row={i=1 r=2 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>}, updates={b=true uuid=<2>}
-004: i=0 r=0 b=false s= u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
+004: i=0 r=0 b=false s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>
-004: i=1 r=2 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+004: i=1 r=2 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
 005: {"error":null,"result":[{"count":2}]}
-006: event:update, row={i=0 r=123.5 b=false s= u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>}, updates={r=0 uuid=<1>}
+006: event:update, row={i=0 r=123.5 b=false s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>}, updates={r=0 uuid=<3>}
-006: event:update, row={i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>}, updates={r=2 uuid=<0>}
+006: event:update, row={i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>}, updates={r=2 uuid=<2>}
-006: i=0 r=123.5 b=false s= u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
+006: i=0 r=123.5 b=false s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>
-006: i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+006: i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
-007: {"error":null,"result":[{"uuid":["uuid","<6>"]}]}
+007: {"error":null,"result":[{"uuid":["uuid","<8>"]}]}
-008: event:create, row={i=-1 r=125 b=false s= u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>}, updates=None
+008: event:create, row={i=-1 r=125 b=false s= u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>}, updates=None
-008: i=-1 r=125 b=false s= u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
+008: i=-1 r=125 b=false s= u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>
-008: i=0 r=123.5 b=false s= u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
+008: i=0 r=123.5 b=false s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>
-008: i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+008: i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
 009: {"error":null,"result":[{"count":2}]}
-010: event:update, row={i=-1 r=125 b=false s=newstring u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>}, updates={s= uuid=<6>}
+010: event:update, row={i=-1 r=125 b=false s=newstring u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>}, updates={s= uuid=<8>}
-010: event:update, row={i=0 r=123.5 b=false s=newstring u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>}, updates={s= uuid=<1>}
+010: event:update, row={i=0 r=123.5 b=false s=newstring u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>}, updates={s= uuid=<3>}
-010: i=-1 r=125 b=false s=newstring u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
+010: i=-1 r=125 b=false s=newstring u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>
-010: i=0 r=123.5 b=false s=newstring u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
+010: i=0 r=123.5 b=false s=newstring u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>
-010: i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+010: i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
 011: {"error":null,"result":[{"count":1}]}
-012: event:delete, row={i=0 r=123.5 b=false s=newstring u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>}, updates=None
+012: event:delete, row={i=0 r=123.5 b=false s=newstring u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>}, updates=None
-012: i=-1 r=125 b=false s=newstring u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
+012: i=-1 r=125 b=false s=newstring u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>
-012: i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+012: i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
 013: reconnect
-014: event:create, row={i=-1 r=125 b=false s=newstring u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>}, updates=None
+014: event:create, row={i=-1 r=125 b=false s=newstring u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>}, updates=None
-014: event:create, row={i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>}, updates=None
+014: event:create, row={i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>}, updates=None
-014: i=-1 r=125 b=false s=newstring u=<2> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
+014: event:create, row={uuid=<0>}, updates=None
-014: i=1 r=123.5 b=false s=mystring u=<3> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<4> <5>] uuid=<0>
+014: event:create, row={uuid=<1>}, updates=None
+014: i=-1 r=125 b=false s=newstring u=<4> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<8>
+014: i=1 r=123.5 b=false s=mystring u=<5> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<6> <7>] uuid=<2>
 015: done
 ]])
 
@@ -1853,3 +1892,33 @@ m4_define([CHECK_STREAM_OPEN_BLOCK_PY],
 
 CHECK_STREAM_OPEN_BLOCK_PY([Check PY2 Stream open block], [$HAVE_PYTHON2], [$PYTHON2])
 CHECK_STREAM_OPEN_BLOCK_PY([Check PY3 Stream open block], [$HAVE_PYTHON3], [$PYTHON3])
+
+# same as OVSDB_CHECK_IDL but uses Python IDL implementation with tcp
+# with multiple remotes to assert the idl connects to the leader of the Raft cluster
+m4_define([OVSDB_CHECK_IDL_LEADER_ONLY_PYN],
+  [AT_SETUP([$1])
+   AT_SKIP_IF([test $7 = no])
+   AT_KEYWORDS([ovsdb server idl Python leader_only with tcp socket])
+   m4_define([LPBK],[127.0.0.1])
+   AT_CHECK([ovsdb_cluster_start_idltest $2 "ptcp:0:"LPBK])
+   PARSE_LISTENING_PORT([s2.log], [TCP_PORT_1])
+   PARSE_LISTENING_PORT([s3.log], [TCP_PORT_2])
+   PARSE_LISTENING_PORT([s1.log], [TCP_PORT_3])
+   remotes=tcp:LPBK:$TCP_PORT_1,tcp:LPBK:$TCP_PORT_2,tcp:LPBK:$TCP_PORT_3
+   pids=$(cat s2.pid s3.pid s1.pid | tr '\n' ',')
+   echo $pids
+   AT_CHECK([$8 $srcdir/test-ovsdb.py  -t30 idl-cluster $srcdir/idltest.ovsschema $remotes $pids $3],
+        [0], [stdout], [ignore])
+   remote=$(ovsdb_cluster_leader $remotes "idltest")
+   leader=$(echo $remote | cut -d'|' -f 1)
+   AT_CHECK([grep -F -- "${leader}" stdout], [0], [ignore])
+   AT_CLEANUP])
+
+m4_define([OVSDB_CHECK_IDL_LEADER_ONLY_PY],
+   [OVSDB_CHECK_IDL_LEADER_ONLY_PYN([$1 - Python2 (leader only)], [$2], [$3], [$4], [$5], [$6],
+                 [$HAVE_PYTHON], [$PYTHON])
+    OVSDB_CHECK_IDL_LEADER_ONLY_PYN([$1 - Python3 (leader only)], [$2], [$3], [$4], [$5], [$6],
+                 [$HAVE_PYTHON3], [$PYTHON3])])
+
+OVSDB_CHECK_IDL_LEADER_ONLY_PY([Check Python IDL connects to leader], 3, ['remote'])
+OVSDB_CHECK_IDL_LEADER_ONLY_PY([Check Python IDL reconnects to leader], 3, ['remote' '+remotestop' 'remote'])

tests/test-ovsdb.py

@@ -758,6 +758,70 @@ def do_idl_passive(schema_file, remote, *commands):
     print("%03d: done" % step)
 
 
+def do_idl_cluster(schema_file, remote, pid, *commands):
+    schema_helper = ovs.db.idl.SchemaHelper(schema_file)
+
+    if remote.startswith("ssl:"):
+        if len(commands) < 3:
+            sys.stderr.write("SSL connection requires private key, "
+                             "certificate for private key, and peer CA "
+                             "certificate as arguments\n")
+            sys.exit(1)
+        ovs.stream.Stream.ssl_set_private_key_file(commands[0])
+        ovs.stream.Stream.ssl_set_certificate_file(commands[1])
+        ovs.stream.Stream.ssl_set_ca_cert_file(commands[2])
+        commands = commands[3:]
+
+    schema_helper.register_all()
+    idl = ovs.db.idl.Idl(remote, schema_helper)
+
+    step = 0
+    seqno = 0
+    commands = list(commands)
+    for command in commands:
+        if command.startswith("+"):
+            # The previous transaction didn't change anything.
+            command = command[1:]
+        else:
+            # Wait for update.
+            while idl.change_seqno == seqno and not idl.run():
+                poller = ovs.poller.Poller()
+                idl.wait(poller)
+                poller.block()
+            step += 1
+
+        seqno = idl.change_seqno
+
+        if command == "reconnect":
+            print("%03d: reconnect" % step)
+            sys.stdout.flush()
+            step += 1
+            idl.force_reconnect()
+        elif command == "remote":
+            print("%03d: %s" % (step, idl.session_name()))
+            sys.stdout.flush()
+            step += 1
+        elif command == "remotestop":
+            r = idl.session_name()
+            remotes = remote.split(',')
+            i = remotes.index(r)
+            pids = pid.split(',')
+            command = None
+            try:
+                command = "kill %s" % pids[i]
+            except ValueError as error:
+                sys.stderr.write("Cannot find pid of remote: %s\n"
+                                 % os.strerror(error))
+                sys.exit(1)
+            os.popen(command)
+            print("%03d: stop %s" % (step, pids[i]))
+            sys.stdout.flush()
+            step += 1
+
+    idl.close()
+    print("%03d: done" % step)
+
+
 def usage():
     print("""\
 %(program_name)s: test utility for Open vSwitch database Python bindings
@@ -861,7 +925,8 @@ def main(argv):
                 "parse-table": (do_parse_table, (2, 3)),
                 "parse-schema": (do_parse_schema, 1),
                 "idl": (do_idl, (2,)),
-                "idl_passive": (do_idl_passive, (2,))}
+                "idl_passive": (do_idl_passive, (2,)),
+                "idl-cluster": (do_idl_cluster, (3,))}
 
     command_name = args[0]
     args = args[1:]