When a client asks for an old-style directory and our write bucket

is empty, don't give it to him. This way small servers can continue
to serve the directory *sometimes*, without getting overloaded.


svn:r5968
This commit is contained in:
Roger Dingledine 2006-02-11 23:15:40 +00:00
parent 484a3f3d77
commit e847085c04
3 changed files with 20 additions and 4 deletions

View File

@ -1036,6 +1036,13 @@ connection_bucket_write_limit(connection_t *conn)
return at_most;
}
/** Return 1 if the global write bucket has no bytes in it,
* or return 0 if it does. */
int global_write_bucket_empty(void)
{
return global_write_bucket <= 0;
}
/** We just read num_read onto conn. Decrement buckets appropriately. */
static void
connection_read_bucket_decrement(connection_t *conn, int num_read)

View File

@ -1387,10 +1387,6 @@ directory_handle_command_get(connection_t *conn, char *headers,
int deflated = !strcmp(url,"/tor/dir.z");
dlen = dirserv_get_directory(&cp, deflated);
note_request(url, dlen);
tor_free(url);
if (dlen == 0) {
notice(LD_DIRSERV,"Client asked for the mirrored directory, but we "
"don't have a good one yet. Sending 503 Dir not available.");
@ -1398,9 +1394,21 @@ directory_handle_command_get(connection_t *conn, char *headers,
/* try to get a new one now */
if (!already_fetching_directory(DIR_PURPOSE_FETCH_DIR))
directory_get_from_dirserver(DIR_PURPOSE_FETCH_DIR, NULL, 1);
tor_free(url);
return 0;
}
if (global_write_bucket_empty()) {
info(LD_DIRSERV,
"Client asked for the mirrored directory, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_http_status_line(conn, 503, "Directory busy, try again later");
tor_free(url);
return 0;
}
note_request(url, dlen);
debug(LD_DIRSERV,"Dumping %sdirectory to client.",
deflated?"deflated ":"");
format_rfc1123_time(date, time(NULL));

View File

@ -1635,6 +1635,7 @@ int retry_all_listeners(int force, smartlist_t *replaced_conns,
smartlist_t *new_conns);
int connection_bucket_write_limit(connection_t *conn);
int global_write_bucket_empty(void);
void connection_bucket_init(void);
void connection_bucket_refill(struct timeval *now);