[ovs-dev] [PATCH RFC] ovsdb-server: Preserve remotes across crash and restart.
Gurucharan Shetty
shettyg at nicira.com
Thu Jun 13 15:50:42 UTC 2013
On Thu, Jun 13, 2013 at 8:29 AM, Gurucharan Shetty <shettyg at nicira.com>wrote:
> On Wed, Jun 12, 2013 at 5:10 PM, Ben Pfaff <blp at nicira.com> wrote:
>
>> ---
>> This is unpolished but it shows the approach I have in mind.
>> Sending out for comments on the approach.
>>
> I am fine with the approach. The two negatives I see with this:
> * If /tmp is cleaned up routinely, we will loose the information. If we
> decide to put this in /etc/openvswitch, it may look a little dirty when
> program is abnormally terminated.
>
This concern is probably invalid. I don't think there is a possibility that
a second file with the same name will be created if the first one is
deleted.
> * If we have multiple run time data, (ex: add/remove databases) we may
> need multiple files.
>
> If you are fine with this, I am fine with it.
>
>
>
>>
>> diff --git a/ovsdb/ovsdb-server.c b/ovsdb/ovsdb-server.c
>> index 20e1964..d87360a 100644
>> --- a/ovsdb/ovsdb-server.c
>> +++ b/ovsdb/ovsdb-server.c
>> @@ -81,8 +81,14 @@ struct add_remote_aux {
>> struct sset *remotes;
>> struct db *dbs;
>> size_t n_dbs;
>> + FILE *config_tmpfile;
>> };
>> static unixctl_cb_func ovsdb_server_add_remote;
>> +
>> +struct remove_remote_aux {
>> + struct sset *remotes;
>> + FILE *config_tmpfile;
>> +};
>> static unixctl_cb_func ovsdb_server_remove_remote;
>> static unixctl_cb_func ovsdb_server_list_remotes;
>>
>> @@ -99,6 +105,9 @@ static void update_remote_status(const struct
>> ovsdb_jsonrpc_server *jsonrpc,
>> const struct sset *remotes,
>> struct db dbs[], size_t n_dbs);
>>
>> +static void save_config(FILE *config_file, const struct sset *);
>> +static void load_config(FILE *config_file, struct sset *);
>> +
>> int
>> main(int argc, char *argv[])
>> {
>> @@ -112,6 +121,8 @@ main(int argc, char *argv[])
>> int retval;
>> long long int status_timer = LLONG_MIN;
>> struct add_remote_aux add_remote_aux;
>> + struct remove_remote_aux remove_remote_aux;
>> + FILE *config_tmpfile;
>>
>> struct db *dbs;
>> int n_dbs;
>> @@ -125,7 +136,14 @@ main(int argc, char *argv[])
>>
>> parse_options(&argc, &argv, &remotes, &unixctl_path, &run_command);
>>
>> + config_tmpfile = tmpfile();
>> + if (!config_tmpfile) {
>> + ovs_fatal(errno, "failed to create temporary file");
>> + }
>> +
>> + save_config(config_tmpfile, &remotes);
>> daemonize_start();
>> + load_config(config_tmpfile, &remotes);
>>
>> n_dbs = MAX(1, argc);
>> dbs = xcalloc(n_dbs + 1, sizeof *dbs);
>> @@ -195,10 +213,13 @@ main(int argc, char *argv[])
>> add_remote_aux.remotes = &remotes;
>> add_remote_aux.dbs = dbs;
>> add_remote_aux.n_dbs = n_dbs;
>> + add_remote_aux.config_tmpfile = config_tmpfile;
>> unixctl_command_register("ovsdb-server/add-remote", "REMOTE", 1, 1,
>> ovsdb_server_add_remote, &add_remote_aux);
>> + remove_remote_aux.remotes = &remotes;
>> + remove_remote_aux.config_tmpfile = config_tmpfile;
>> unixctl_command_register("ovsdb-server/remove-remote", "REMOTE", 1,
>> 1,
>> - ovsdb_server_remove_remote, &remotes);
>> + ovsdb_server_remove_remote,
>> &remove_remote_aux);
>> unixctl_command_register("ovsdb-server/list-remotes", "", 0, 0,
>> ovsdb_server_list_remotes, &remotes);
>>
>> @@ -922,7 +943,9 @@ ovsdb_server_add_remote(struct unixctl_conn *conn,
>> int argc OVS_UNUSED,
>> : parse_db_column(aux->dbs, aux->n_dbs, remote,
>> &db, &table, &column));
>> if (!retval) {
>> - sset_add(aux->remotes, remote);
>> + if (sset_add(aux->remotes, remote)) {
>> + save_config(aux->config_tmpfile, aux->remotes);
>> + }
>> unixctl_command_reply(conn, NULL);
>> } else {
>> unixctl_command_reply_error(conn, retval);
>> @@ -934,14 +957,15 @@ ovsdb_server_add_remote(struct unixctl_conn *conn,
>> int argc OVS_UNUSED,
>> * that ovsdb-server services. */
>> static void
>> ovsdb_server_remove_remote(struct unixctl_conn *conn, int argc
>> OVS_UNUSED,
>> - const char *argv[], void *remotes_)
>> + const char *argv[], void *aux_)
>> {
>> - struct sset *remotes = remotes_;
>> + struct remove_remote_aux *aux = aux_;
>> struct sset_node *node;
>>
>> - node = sset_find(remotes, argv[1]);
>> + node = sset_find(aux->remotes, argv[1]);
>> if (node) {
>> - sset_delete(remotes, node);
>> + sset_delete(aux->remotes, node);
>> + save_config(aux->config_tmpfile, aux->remotes);
>> unixctl_command_reply(conn, NULL);
>> } else {
>> unixctl_command_reply_error(conn, "no such remote");
>> @@ -1092,3 +1116,48 @@ usage(void)
>> leak_checker_usage();
>> exit(EXIT_SUCCESS);
>> }
>> +
>> +static void
>> +save_config(FILE *config_file, const struct sset *remotes)
>> +{
>> + const char *remote;
>> + struct json *json;
>> + char *s;
>> +
>> + if (ftruncate(fileno(config_file), 0) == -1) {
>> + ovs_fatal(errno, "truncate failed");
>> + }
>> +
>> + json = json_array_create_empty();
>> + SSET_FOR_EACH (remote, remotes) {
>> + json_array_add(json, json_string_create(remote));
>> + }
>> + s = json_to_string(json, 0);
>> + json_destroy(json);
>> +
>> + if (fputs(s, config_file) == EOF || fflush(config_file) == EOF) {
>> + ovs_fatal(errno, "write failed");
>> + }
>> + free(s);
>> +}
>> +
>> +static void
>> +load_config(FILE *config_file, struct sset *remotes)
>> +{
>> + struct json *json;
>> + size_t i;
>> +
>> + sset_clear(remotes);
>> +
>> + rewind(config_file);
>> + json = json_from_stream(config_file);
>> + if (json->type == JSON_STRING) {
>> + ovs_fatal(0, "reading json failed (%s)", json_string(json));
>> + }
>> + ovs_assert(json->type == JSON_ARRAY);
>> + for (i = 0; i < json->u.array.n; i++) {
>> + const struct json *remote = json->u.array.elems[i];
>> + sset_add(remotes, json_string(remote));
>> + }
>> + json_destroy(json);
>> +}
>> --
>> 1.7.2.5
>>
>> _______________________________________________
>> dev mailing list
>> dev at openvswitch.org
>> http://openvswitch.org/mailman/listinfo/dev
>>
>
>
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