ovs-vsctl: Try connecting only once for active connections by default.
[sliver-openvswitch.git] / ovsdb / jsonrpc-server.c
index 06e3acc..6e0a6f6 100644 (file)
@@ -1,4 +1,4 @@
-/* Copyright (c) 2009, 2010, 2011 Nicira Networks
+/* Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 
 #include "jsonrpc-server.h"
 
-#include <assert.h>
 #include <errno.h>
 
 #include "bitmap.h"
@@ -30,6 +29,8 @@
 #include "ovsdb.h"
 #include "reconnect.h"
 #include "row.h"
+#include "server.h"
+#include "simap.h"
 #include "stream.h"
 #include "table.h"
 #include "timeval.h"
@@ -50,6 +51,8 @@ static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
+static void ovsdb_jsonrpc_session_get_memory_usage_all(
+    const struct ovsdb_jsonrpc_remote *, struct simap *usage);
 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
 static void ovsdb_jsonrpc_session_set_all_options(
@@ -57,9 +60,12 @@ static void ovsdb_jsonrpc_session_set_all_options(
 static bool ovsdb_jsonrpc_session_get_status(
     const struct ovsdb_jsonrpc_remote *,
     struct ovsdb_jsonrpc_remote_status *);
+static void ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *);
+static void ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *);
 
 /* Triggers. */
 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
+                                         struct ovsdb *,
                                          struct json *id, struct json *params);
 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
@@ -70,7 +76,7 @@ static void ovsdb_jsonrpc_trigger_complete_done(
 
 /* Monitors. */
 static struct json *ovsdb_jsonrpc_monitor_create(
-    struct ovsdb_jsonrpc_session *, struct json *params);
+    struct ovsdb_jsonrpc_session *, struct ovsdb *, struct json *params);
 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
     struct ovsdb_jsonrpc_session *,
     struct json_array *params,
@@ -80,7 +86,7 @@ static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
 /* JSON-RPC database server. */
 
 struct ovsdb_jsonrpc_server {
-    struct ovsdb *db;
+    struct ovsdb_server up;
     unsigned int n_sessions, max_sessions;
     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
 };
@@ -92,22 +98,38 @@ struct ovsdb_jsonrpc_remote {
     struct ovsdb_jsonrpc_server *server;
     struct pstream *listener;   /* Listener, if passive. */
     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
+    uint8_t dscp;
 };
 
 static struct ovsdb_jsonrpc_remote *ovsdb_jsonrpc_server_add_remote(
-    struct ovsdb_jsonrpc_server *, const char *name);
+    struct ovsdb_jsonrpc_server *, const char *name,
+    const struct ovsdb_jsonrpc_options *options
+);
 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
 
+/* Creates and returns a new server to provide JSON-RPC access to an OVSDB.
+ *
+ * The caller must call ovsdb_jsonrpc_server_add_db() for each database to
+ * which 'server' should provide access. */
 struct ovsdb_jsonrpc_server *
-ovsdb_jsonrpc_server_create(struct ovsdb *db)
+ovsdb_jsonrpc_server_create(void)
 {
     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
-    server->db = db;
+    ovsdb_server_init(&server->up);
     server->max_sessions = 64;
     shash_init(&server->remotes);
     return server;
 }
 
+/* Adds 'db' to the set of databases served out by 'svr'.  Returns true if
+ * successful, false if 'db''s name is the same as some database already in
+ * 'server'. */
+bool
+ovsdb_jsonrpc_server_add_db(struct ovsdb_jsonrpc_server *svr, struct ovsdb *db)
+{
+    return ovsdb_server_add_db(&svr->up, db);
+}
+
 void
 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 {
@@ -117,15 +139,18 @@ ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
         ovsdb_jsonrpc_server_del_remote(node);
     }
     shash_destroy(&svr->remotes);
+    ovsdb_server_destroy(&svr->up);
     free(svr);
 }
 
 struct ovsdb_jsonrpc_options *
-ovsdb_jsonrpc_default_options(void)
+ovsdb_jsonrpc_default_options(const char *target)
 {
     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
-    options->probe_interval = RECONNECT_DEFAULT_PROBE_INTERVAL;
     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
+    options->probe_interval = (stream_or_pstream_needs_probes(target)
+                               ? RECONNECT_DEFAULT_PROBE_INTERVAL
+                               : 0);
     return options;
 }
 
@@ -152,7 +177,7 @@ ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 
         remote = shash_find_data(&svr->remotes, node->name);
         if (!remote) {
-            remote = ovsdb_jsonrpc_server_add_remote(svr, node->name);
+            remote = ovsdb_jsonrpc_server_add_remote(svr, node->name, options);
             if (!remote) {
                 continue;
             }
@@ -164,13 +189,14 @@ ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 
 static struct ovsdb_jsonrpc_remote *
 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
-                                const char *name)
+                                const char *name,
+                                const struct ovsdb_jsonrpc_options *options)
 {
     struct ovsdb_jsonrpc_remote *remote;
     struct pstream *listener;
     int error;
 
-    error = jsonrpc_pstream_open(name, &listener);
+    error = jsonrpc_pstream_open(name, &listener, options->dscp);
     if (error && error != EAFNOSUPPORT) {
         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
         return NULL;
@@ -180,10 +206,11 @@ ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
     remote->server = svr;
     remote->listener = listener;
     list_init(&remote->sessions);
+    remote->dscp = options->dscp;
     shash_add(&svr->remotes, name, remote);
 
     if (!listener) {
-        ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
+        ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name, true));
     }
     return remote;
 }
@@ -218,6 +245,15 @@ ovsdb_jsonrpc_server_get_remote_status(
     return remote && ovsdb_jsonrpc_session_get_status(remote, status);
 }
 
+void
+ovsdb_jsonrpc_server_free_remote_status(
+    struct ovsdb_jsonrpc_remote_status *status)
+{
+    free(status->locks_held);
+    free(status->locks_waiting);
+    free(status->locks_lost);
+}
+
 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
  * reconnect. */
 void
@@ -247,7 +283,8 @@ ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
             error = pstream_accept(remote->listener, &stream);
             if (!error) {
                 struct jsonrpc_session *js;
-                js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
+                js = jsonrpc_session_open_unreliably(jsonrpc_open(stream),
+                                                     remote->dscp);
                 ovsdb_jsonrpc_session_create(remote, js);
             } else if (error != EAGAIN) {
                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
@@ -275,16 +312,32 @@ ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
         ovsdb_jsonrpc_session_wait_all(remote);
     }
 }
+
+/* Adds some memory usage statistics for 'svr' into 'usage', for use with
+ * memory_report(). */
+void
+ovsdb_jsonrpc_server_get_memory_usage(const struct ovsdb_jsonrpc_server *svr,
+                                      struct simap *usage)
+{
+    struct shash_node *node;
+
+    simap_increase(usage, "sessions", svr->n_sessions);
+    SHASH_FOR_EACH (node, &svr->remotes) {
+        struct ovsdb_jsonrpc_remote *remote = node->data;
+
+        ovsdb_jsonrpc_session_get_memory_usage_all(remote, usage);
+    }
+}
 \f
 /* JSON-RPC database server session. */
 
 struct ovsdb_jsonrpc_session {
-    struct ovsdb_jsonrpc_remote *remote;
     struct list node;           /* Element in remote's sessions list. */
+    struct ovsdb_session up;
+    struct ovsdb_jsonrpc_remote *remote;
 
     /* Triggers. */
     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
-    struct list completions;    /* Completed triggers. */
 
     /* Monitors. */
     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
@@ -297,6 +350,8 @@ struct ovsdb_jsonrpc_session {
 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
+static void ovsdb_jsonrpc_session_get_memory_usage(
+    const struct ovsdb_jsonrpc_session *, struct simap *usage);
 static void ovsdb_jsonrpc_session_set_options(
     struct ovsdb_jsonrpc_session *, const struct ovsdb_jsonrpc_options *);
 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
@@ -311,11 +366,11 @@ ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
     struct ovsdb_jsonrpc_session *s;
 
     s = xzalloc(sizeof *s);
+    ovsdb_session_init(&s->up, &remote->server->up);
     s->remote = remote;
     list_push_back(&remote->sessions, &s->node);
     hmap_init(&s->triggers);
     hmap_init(&s->monitors);
-    list_init(&s->completions);
     s->js = js;
     s->js_seqno = jsonrpc_session_get_seqno(js);
 
@@ -328,9 +383,16 @@ static void
 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 {
     ovsdb_jsonrpc_monitor_remove_all(s);
+    ovsdb_jsonrpc_session_unlock_all(s);
+    ovsdb_jsonrpc_trigger_complete_all(s);
+
+    hmap_destroy(&s->monitors);
+    hmap_destroy(&s->triggers);
+
     jsonrpc_session_close(s->js);
     list_remove(&s->node);
     s->remote->server->n_sessions--;
+    ovsdb_session_destroy(&s->up);
     free(s);
 }
 
@@ -342,6 +404,7 @@ ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
         s->js_seqno = jsonrpc_session_get_seqno(s->js);
         ovsdb_jsonrpc_trigger_complete_all(s);
         ovsdb_jsonrpc_monitor_remove_all(s);
+        ovsdb_jsonrpc_session_unlock_all(s);
     }
 
     ovsdb_jsonrpc_trigger_complete_done(s);
@@ -371,6 +434,7 @@ ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
 {
     jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
+    jsonrpc_session_set_dscp(session->js, options->dscp);
 }
 
 static void
@@ -405,6 +469,27 @@ ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
     }
 }
 
+static void
+ovsdb_jsonrpc_session_get_memory_usage(const struct ovsdb_jsonrpc_session *s,
+                                       struct simap *usage)
+{
+    simap_increase(usage, "triggers", hmap_count(&s->triggers));
+    simap_increase(usage, "monitors", hmap_count(&s->monitors));
+    simap_increase(usage, "backlog", jsonrpc_session_get_backlog(s->js));
+}
+
+static void
+ovsdb_jsonrpc_session_get_memory_usage_all(
+    const struct ovsdb_jsonrpc_remote *remote,
+    struct simap *usage)
+{
+    struct ovsdb_jsonrpc_session *s;
+
+    LIST_FOR_EACH (s, node, &remote->sessions) {
+        ovsdb_jsonrpc_session_get_memory_usage(s, usage);
+    }
+}
+
 static void
 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 {
@@ -439,6 +524,22 @@ ovsdb_jsonrpc_session_set_all_options(
 {
     struct ovsdb_jsonrpc_session *s;
 
+    if (remote->listener) {
+        int error;
+
+        error = pstream_set_dscp(remote->listener, options->dscp);
+        if (error) {
+            VLOG_ERR("%s: set_dscp failed %s",
+                     pstream_get_name(remote->listener), strerror(error));
+        } else {
+            remote->dscp = options->dscp;
+        }
+        /*
+         * XXX race window between setting dscp to listening socket
+         * and accepting socket. Accepted socket may have old dscp value.
+         * Ignore this race window for now.
+         */
+    }
     LIST_FOR_EACH (s, node, &remote->sessions) {
         ovsdb_jsonrpc_session_set_options(s, options);
     }
@@ -450,7 +551,9 @@ ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
 {
     const struct ovsdb_jsonrpc_session *s;
     const struct jsonrpc_session *js;
+    struct ovsdb_lock_waiter *waiter;
     struct reconnect_stats rstats;
+    struct ds locks_held, locks_waiting, locks_lost;
 
     if (list_is_empty(&remote->sessions)) {
         return false;
@@ -468,24 +571,45 @@ ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
     status->sec_since_disconnect = rstats.msec_since_disconnect == UINT_MAX
         ? UINT_MAX : rstats.msec_since_disconnect / 1000;
 
-    return true;
-}
+    ds_init(&locks_held);
+    ds_init(&locks_waiting);
+    ds_init(&locks_lost);
+    HMAP_FOR_EACH (waiter, session_node, &s->up.waiters) {
+        struct ds *string;
+
+        string = (ovsdb_lock_waiter_is_owner(waiter) ? &locks_held
+                  : waiter->mode == OVSDB_LOCK_WAIT ? &locks_waiting
+                  : &locks_lost);
+        if (string->length) {
+            ds_put_char(string, ' ');
+        }
+        ds_put_cstr(string, waiter->lock_name);
+    }
+    status->locks_held = ds_steal_cstr(&locks_held);
+    status->locks_waiting = ds_steal_cstr(&locks_waiting);
+    status->locks_lost = ds_steal_cstr(&locks_lost);
 
-static const char *
-get_db_name(const struct ovsdb_jsonrpc_session *s)
-{
-    return s->remote->server->db->schema->name;
+    status->n_connections = list_size(&remote->sessions);
+
+    return true;
 }
 
-static struct jsonrpc_msg *
-ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
-                            const struct jsonrpc_msg *request)
+/* Examines 'request' to determine the database to which it relates, and then
+ * searches 's' to find that database:
+ *
+ *    - If successful, returns the database and sets '*replyp' to NULL.
+ *
+ *    - If no such database exists, returns NULL and sets '*replyp' to an
+ *      appropriate JSON-RPC error reply, owned by the caller. */
+static struct ovsdb *
+ovsdb_jsonrpc_lookup_db(const struct ovsdb_jsonrpc_session *s,
+                        const struct jsonrpc_msg *request,
+                        struct jsonrpc_msg **replyp)
 {
     struct json_array *params;
-    const char *want_db_name;
-    const char *have_db_name;
     struct ovsdb_error *error;
-    struct jsonrpc_msg *reply;
+    const char *db_name;
+    struct ovsdb *db;
 
     params = json_array(request->params);
     if (!params->n || params->elems[0]->type != JSON_STRING) {
@@ -495,17 +619,156 @@ ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
         goto error;
     }
 
-    want_db_name = params->elems[0]->u.string;
-    have_db_name = get_db_name(s);
-    if (strcmp(want_db_name, have_db_name)) {
+    db_name = params->elems[0]->u.string;
+    db = shash_find_data(&s->up.server->dbs, db_name);
+    if (!db) {
         error = ovsdb_syntax_error(
             request->params, "unknown database",
             "%s request specifies unknown database %s",
-            request->method, want_db_name);
+            request->method, db_name);
         goto error;
     }
 
+    *replyp = NULL;
+    return db;
+
+error:
+    *replyp = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
+    ovsdb_error_destroy(error);
     return NULL;
+}
+
+static struct ovsdb_error *
+ovsdb_jsonrpc_session_parse_lock_name(const struct jsonrpc_msg *request,
+                                      const char **lock_namep)
+{
+    const struct json_array *params;
+
+    params = json_array(request->params);
+    if (params->n != 1 || params->elems[0]->type != JSON_STRING ||
+        !ovsdb_parser_is_id(json_string(params->elems[0]))) {
+        *lock_namep = NULL;
+        return ovsdb_syntax_error(request->params, NULL,
+                                  "%s request params must be <id>",
+                                  request->method);
+    }
+
+    *lock_namep = json_string(params->elems[0]);
+    return NULL;
+}
+
+static void
+ovsdb_jsonrpc_session_notify(struct ovsdb_session *session,
+                             const char *lock_name,
+                             const char *method)
+{
+    struct ovsdb_jsonrpc_session *s;
+    struct json *params;
+
+    s = CONTAINER_OF(session, struct ovsdb_jsonrpc_session, up);
+    params = json_array_create_1(json_string_create(lock_name));
+    jsonrpc_session_send(s->js, jsonrpc_create_notify(method, params));
+}
+
+static struct jsonrpc_msg *
+ovsdb_jsonrpc_session_lock(struct ovsdb_jsonrpc_session *s,
+                           struct jsonrpc_msg *request,
+                           enum ovsdb_lock_mode mode)
+{
+    struct ovsdb_lock_waiter *waiter;
+    struct jsonrpc_msg *reply;
+    struct ovsdb_error *error;
+    struct ovsdb_session *victim;
+    const char *lock_name;
+    struct json *result;
+
+    error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
+    if (error) {
+        goto error;
+    }
+
+    /* Report error if this session has issued a "lock" or "steal" without a
+     * matching "unlock" for this lock. */
+    waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
+    if (waiter) {
+        error = ovsdb_syntax_error(
+            request->params, NULL,
+            "must issue \"unlock\" before new \"%s\"", request->method);
+        goto error;
+    }
+
+    /* Get the lock, add us as a waiter. */
+    waiter = ovsdb_server_lock(&s->remote->server->up, &s->up, lock_name, mode,
+                               &victim);
+    if (victim) {
+        ovsdb_jsonrpc_session_notify(victim, lock_name, "stolen");
+    }
+
+    result = json_object_create();
+    json_object_put(result, "locked",
+                    json_boolean_create(ovsdb_lock_waiter_is_owner(waiter)));
+
+    return jsonrpc_create_reply(result, request->id);
+
+error:
+    reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
+    ovsdb_error_destroy(error);
+    return reply;
+}
+
+static void
+ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *s)
+{
+    struct ovsdb_lock_waiter *waiter, *next;
+
+    HMAP_FOR_EACH_SAFE (waiter, next, session_node, &s->up.waiters) {
+        ovsdb_jsonrpc_session_unlock__(waiter);
+    }
+}
+
+static void
+ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *waiter)
+{
+    struct ovsdb_lock *lock = waiter->lock;
+
+    if (lock) {
+        struct ovsdb_session *new_owner = ovsdb_lock_waiter_remove(waiter);
+        if (new_owner) {
+            ovsdb_jsonrpc_session_notify(new_owner, lock->name, "locked");
+        } else {
+            /* ovsdb_server_lock() might have freed 'lock'. */
+        }
+    }
+
+    ovsdb_lock_waiter_destroy(waiter);
+}
+
+static struct jsonrpc_msg *
+ovsdb_jsonrpc_session_unlock(struct ovsdb_jsonrpc_session *s,
+                             struct jsonrpc_msg *request)
+{
+    struct ovsdb_lock_waiter *waiter;
+    struct jsonrpc_msg *reply;
+    struct ovsdb_error *error;
+    const char *lock_name;
+
+    error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
+    if (error) {
+        goto error;
+    }
+
+    /* Report error if this session has not issued a "lock" or "steal" for this
+     * lock. */
+    waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
+    if (!waiter) {
+        error = ovsdb_syntax_error(
+            request->params, NULL, "\"unlock\" without \"lock\" or \"steal\"");
+        goto error;
+    }
+
+    ovsdb_jsonrpc_session_unlock__(waiter);
+
+    return jsonrpc_create_reply(json_object_create(), request->id);
 
 error:
     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
@@ -514,10 +777,10 @@ error:
 }
 
 static struct jsonrpc_msg *
-execute_transaction(struct ovsdb_jsonrpc_session *s,
+execute_transaction(struct ovsdb_jsonrpc_session *s, struct ovsdb *db,
                     struct jsonrpc_msg *request)
 {
-    ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
+    ovsdb_jsonrpc_trigger_create(s, db, request->id, request->params);
     request->id = NULL;
     request->params = NULL;
     jsonrpc_msg_destroy(request);
@@ -531,30 +794,45 @@ ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
     struct jsonrpc_msg *reply;
 
     if (!strcmp(request->method, "transact")) {
-        reply = ovsdb_jsonrpc_check_db_name(s, request);
+        struct ovsdb *db = ovsdb_jsonrpc_lookup_db(s, request, &reply);
         if (!reply) {
-            reply = execute_transaction(s, request);
+            reply = execute_transaction(s, db, request);
         }
     } else if (!strcmp(request->method, "monitor")) {
-        reply = ovsdb_jsonrpc_check_db_name(s, request);
+        struct ovsdb *db = ovsdb_jsonrpc_lookup_db(s, request, &reply);
         if (!reply) {
             reply = jsonrpc_create_reply(
-                ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
+                ovsdb_jsonrpc_monitor_create(s, db, request->params),
+                request->id);
         }
     } else if (!strcmp(request->method, "monitor_cancel")) {
         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
                                              request->id);
     } else if (!strcmp(request->method, "get_schema")) {
-        reply = ovsdb_jsonrpc_check_db_name(s, request);
+        struct ovsdb *db = ovsdb_jsonrpc_lookup_db(s, request, &reply);
         if (!reply) {
-            reply = jsonrpc_create_reply(
-                ovsdb_schema_to_json(s->remote->server->db->schema),
-                request->id);
+            reply = jsonrpc_create_reply(ovsdb_schema_to_json(db->schema),
+                                         request->id);
         }
     } else if (!strcmp(request->method, "list_dbs")) {
-        reply = jsonrpc_create_reply(
-            json_array_create_1(json_string_create(get_db_name(s))),
-            request->id);
+        size_t n_dbs = shash_count(&s->up.server->dbs);
+        struct shash_node *node;
+        struct json **dbs;
+        size_t i;
+
+        dbs = xmalloc(n_dbs * sizeof *dbs);
+        i = 0;
+        SHASH_FOR_EACH (node, &s->up.server->dbs) {
+            dbs[i++] = json_string_create(node->name);
+        }
+        reply = jsonrpc_create_reply(json_array_create(dbs, n_dbs),
+                                     request->id);
+    } else if (!strcmp(request->method, "lock")) {
+        reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_WAIT);
+    } else if (!strcmp(request->method, "steal")) {
+        reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_STEAL);
+    } else if (!strcmp(request->method, "unlock")) {
+        reply = ovsdb_jsonrpc_session_unlock(s, request);
     } else if (!strcmp(request->method, "echo")) {
         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
     } else {
@@ -600,13 +878,12 @@ ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 
 struct ovsdb_jsonrpc_trigger {
     struct ovsdb_trigger trigger;
-    struct ovsdb_jsonrpc_session *session;
     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
     struct json *id;
 };
 
 static void
-ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
+ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s, struct ovsdb *db,
                              struct json *id, struct json *params)
 {
     struct ovsdb_jsonrpc_trigger *t;
@@ -628,10 +905,7 @@ ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 
     /* Insert into trigger table. */
     t = xmalloc(sizeof *t);
-    ovsdb_trigger_init(s->remote->server->db,
-                       &t->trigger, params, &s->completions,
-                       time_msec());
-    t->session = s;
+    ovsdb_trigger_init(&s->up, db, &t->trigger, params, time_msec());
     t->id = id;
     hmap_insert(&s->triggers, &t->hmap_node, hash);
 
@@ -659,7 +933,9 @@ ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 static void
 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 {
-    struct ovsdb_jsonrpc_session *s = t->session;
+    struct ovsdb_jsonrpc_session *s;
+
+    s = CONTAINER_OF(t->trigger.session, struct ovsdb_jsonrpc_session, up);
 
     if (jsonrpc_session_is_connected(s->js)) {
         struct jsonrpc_msg *reply;
@@ -693,9 +969,9 @@ ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 static void
 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 {
-    while (!list_is_empty(&s->completions)) {
+    while (!list_is_empty(&s->up.completions)) {
         struct ovsdb_jsonrpc_trigger *t
-            = CONTAINER_OF(s->completions.next,
+            = CONTAINER_OF(s->up.completions.next,
                            struct ovsdb_jsonrpc_trigger, trigger.node);
         ovsdb_jsonrpc_trigger_complete(t);
     }
@@ -733,6 +1009,7 @@ struct ovsdb_jsonrpc_monitor_table {
 struct ovsdb_jsonrpc_monitor {
     struct ovsdb_replica replica;
     struct ovsdb_jsonrpc_session *session;
+    struct ovsdb *db;
     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 
     struct json *monitor_id;
@@ -884,7 +1161,7 @@ ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
 }
 
 static struct json *
-ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
+ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s, struct ovsdb *db,
                              struct json *params)
 {
     struct ovsdb_jsonrpc_monitor *m = NULL;
@@ -912,8 +1189,9 @@ ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 
     m = xzalloc(sizeof *m);
     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
-    ovsdb_add_replica(s->remote->server->db, &m->replica);
+    ovsdb_add_replica(db, &m->replica);
     m->session = s;
+    m->db = db;
     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
     m->monitor_id = json_clone(monitor_id);
     shash_init(&m->tables);
@@ -925,7 +1203,7 @@ ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
         const struct json *mr_value;
         size_t i;
 
-        table = ovsdb_get_table(s->remote->server->db, node->name);
+        table = ovsdb_get_table(m->db, node->name);
         if (!table) {
             error = ovsdb_syntax_error(NULL, NULL,
                                        "no table named %s", node->name);
@@ -974,7 +1252,7 @@ ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 
 error:
     if (m) {
-        ovsdb_remove_replica(s->remote->server->db, &m->replica);
+        ovsdb_remove_replica(m->db, &m->replica);
     }
 
     json = ovsdb_error_to_json(error);
@@ -998,7 +1276,7 @@ ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
             return jsonrpc_create_error(json_string_create("unknown monitor"),
                                         request_id);
         } else {
-            ovsdb_remove_replica(s->remote->server->db, &m->replica);
+            ovsdb_remove_replica(m->db, &m->replica);
             return jsonrpc_create_reply(json_object_create(), request_id);
         }
     }
@@ -1010,14 +1288,14 @@ ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
     struct ovsdb_jsonrpc_monitor *m, *next;
 
     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
-        ovsdb_remove_replica(s->remote->server->db, &m->replica);
+        ovsdb_remove_replica(m->db, &m->replica);
     }
 }
 
 static struct ovsdb_jsonrpc_monitor *
 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
 {
-    assert(replica->class == &ovsdb_jsonrpc_replica_class);
+    ovs_assert(replica->class == &ovsdb_jsonrpc_replica_class);
     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
 }