diff --git a/changes/bug24769 b/changes/bug24769
new file mode 100644
index 0000000000..5aee8daa21
--- /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 8c02cd1c19..06e955a8fd 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 p_circ_id
* and p_conn. 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,