close idle dir-fetch circs early

This commit is contained in:
Roger Dingledine 2010-04-23 18:35:11 -04:00
parent 6ad09cc6af
commit cb31978adb
4 changed files with 63 additions and 3 deletions

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@ -0,0 +1,7 @@
o Major bugfixes:
- Relays now close idle circuits early if it looks like they were
intended for directory fetches. Such circuits are unlikely to
be re-used, and tens of thousands of them were piling up at the
fast relays, causing the relays to run out of sockets and memory.
Bugfix on 0.2.0.22-rc (where clients started tunneling their
directory fetches over TLS).

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@ -17,7 +17,7 @@ extern circuit_t *global_circuitlist; /* from circuitlist.c */
/********* END VARIABLES ************/
static void circuit_expire_old_circuits(time_t now);
static void circuit_expire_old_circuits_clientside(time_t now);
static void circuit_increment_failure_count(void);
/** Return 1 if <b>circ</b> could be returned by circuit_get_best().
@ -544,7 +544,7 @@ circuit_build_needed_circs(time_t now)
time_to_new_circuit = now + options->NewCircuitPeriod;
if (proxy_mode(get_options()))
addressmap_clean(now);
circuit_expire_old_circuits(now);
circuit_expire_old_circuits_clientside(now);
#if 0 /* disable for now, until predict-and-launch-new can cull leftovers */
circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL);
@ -628,7 +628,7 @@ circuit_detach_stream(circuit_t *circ, edge_connection_t *conn)
* for too long and has no streams on it: mark it for close.
*/
static void
circuit_expire_old_circuits(time_t now)
circuit_expire_old_circuits_clientside(time_t now)
{
circuit_t *circ;
time_t cutoff = now - get_options()->CircuitIdleTimeout;
@ -660,6 +660,53 @@ circuit_expire_old_circuits(time_t now)
}
}
/** How long do we wait before killing circuits with the properties
* described below?
*
* Probably we could choose a number here as low as 5 to 10 seconds,
* since these circs are used for begindir, and a) generally you either
* ask another begindir question right after or you don't for a long time,
* b) clients at least through 0.2.1.x choose from the whole set of
* directory mirrors at each choice, and c) re-establishing a one-hop
* circuit via create-fast is a light operation assuming the TLS conn is
* still there.
*
* I expect "b" to go away one day when we move to using directory
* guards, but I think "a" and "c" are good enough reasons that a low
* number is safe even then.
*/
#define IDLE_ONE_HOP_CIRC_TIMEOUT 60
/** Find each non-origin circuit that has been unused for too long,
* has no streams on it, used a create_fast, and ends here: mark it
* for close.
*/
void
circuit_expire_old_circuits_serverside(time_t now)
{
circuit_t *circ;
or_circuit_t *or_circ;
time_t cutoff = now - IDLE_ONE_HOP_CIRC_TIMEOUT;
for (circ = global_circuitlist; circ; circ = circ->next) {
if (circ->marked_for_close || CIRCUIT_IS_ORIGIN(circ))
continue;
or_circ = TO_OR_CIRCUIT(circ);
/* If the circuit has been idle for too long, and there are no streams
* on it, and it ends here, and it used a create_fast, mark it for close.
*/
if (or_circ->is_first_hop && !circ->n_conn &&
!or_circ->n_streams && !or_circ->resolving_streams &&
or_circ->p_conn &&
or_circ->p_conn->timestamp_last_added_nonpadding <= cutoff) {
log_info(LD_CIRC, "Closing circ_id %d (empty %d secs ago)",
or_circ->p_circ_id,
(int)(now - or_circ->p_conn->timestamp_last_added_nonpadding));
circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
}
}
}
/** Number of testing circuits we want open before testing our bandwidth. */
#define NUM_PARALLEL_TESTING_CIRCS 4

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@ -1058,6 +1058,10 @@ run_scheduled_events(time_t now)
if (have_dir_info && !we_are_hibernating())
circuit_build_needed_circs(now);
/* every 10 seconds, but not at the same second as other such events */
if (now % 10 == 5)
circuit_expire_old_circuits_serverside(now);
/** 5. We do housekeeping for each connection... */
connection_or_set_bad_connections();
for (i=0;i<smartlist_len(connection_array);i++) {

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@ -2834,6 +2834,8 @@ int circuit_conforms_to_options(const origin_circuit_t *circ,
void circuit_build_needed_circs(time_t now);
void circuit_detach_stream(circuit_t *circ, edge_connection_t *conn);
void circuit_expire_old_circuits_serverside(time_t now);
void reset_bandwidth_test(void);
int circuit_enough_testing_circs(void);