commit 148c2410af4dd084009a5625d0687987dc85dc42 Author: Mike Perry mikeperry-git@torproject.org Date: Wed Jan 31 16:27:50 2018 +0000

Bug 24769: Reduce and parameterize the cbt learning idle timeout.

This is only half of the changes needed. We should also parameterize the number of concurrent cbt learning circuits in needs_circuits_for_build(). --- changes/bug24769 | 7 +++++++ src/or/circuitlist.c | 18 ++++++++++++++---- 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/changes/bug24769 b/changes/bug24769 new file mode 100644 index 000000000..5aee8daa2 --- /dev/null +++ b/changes/bug24769 @@ -0,0 +1,7 @@ + o Minor bugfixes (performance): + - Reduce the number of circuits that can be opened at once during the + circuit build timeout phase. This is done by increasing the idle timeout + to 3 minutes, and lowering the maximum number of concurrent learning + circuits to 10. Fixes Bug 24769; bugfix on 0.3.1.1-alpha. + + diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c index 8c02cd1c1..06e955a8f 100644 --- a/src/or/circuitlist.c +++ b/src/or/circuitlist.c @@ -897,8 +897,10 @@ init_circuit_base(circuit_t *circ)

/** If we haven't yet decided on a good timeout value for circuit * building, we close idle circuits aggressively so we can get more - * data points. */ -#define IDLE_TIMEOUT_WHILE_LEARNING (1*60) + * data points. These are the default, min, and max consensus values */ +#define DFLT_IDLE_TIMEOUT_WHILE_LEARNING (3*60) +#define MIN_IDLE_TIMEOUT_WHILE_LEARNING (10) +#define MAX_IDLE_TIMEOUT_WHILE_LEARNING (1000*60)

/** Allocate space for a new circuit, initializing with <b>p_circ_id</b> * and <b>p_conn</b>. Add it to the global circuit list. @@ -931,7 +933,11 @@ origin_circuit_new(void) circuit_build_times_needs_circuits(get_circuit_build_times())) { /* Circuits should be shorter lived if we need more of them * for learning a good build timeout */ - circ->circuit_idle_timeout = IDLE_TIMEOUT_WHILE_LEARNING; + circ->circuit_idle_timeout = + networkstatus_get_param(NULL, "cbtlearntimeout", + DFLT_IDLE_TIMEOUT_WHILE_LEARNING, + MIN_IDLE_TIMEOUT_WHILE_LEARNING, + MAX_IDLE_TIMEOUT_WHILE_LEARNING); } else { // This should always be larger than the current port prediction time // remaining, or else we'll end up with the case where a circuit times out @@ -951,7 +957,11 @@ origin_circuit_new(void) "%d seconds of predictive building remaining.", circ->circuit_idle_timeout, prediction_time_remaining); - circ->circuit_idle_timeout = IDLE_TIMEOUT_WHILE_LEARNING; + circ->circuit_idle_timeout = + networkstatus_get_param(NULL, "cbtlearntimeout", + DFLT_IDLE_TIMEOUT_WHILE_LEARNING, + MIN_IDLE_TIMEOUT_WHILE_LEARNING, + MAX_IDLE_TIMEOUT_WHILE_LEARNING); }

log_info(LD_CIRC,