commit 83f29ce70d0846206daa76f7ad8ab2cf3f5efbd6 Author: Mike Perry mikeperry-git@fscked.org Date: Thu Dec 1 20:54:46 2011 -0800

Change how circuit failure is used.

Let's try computing a second error and take their sum. --- NetworkScanners/BwAuthority/README.spec.txt | 16 +++++++--- NetworkScanners/BwAuthority/aggregate.py | 40 +++++++++++++++------------ 2 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/NetworkScanners/BwAuthority/README.spec.txt b/NetworkScanners/BwAuthority/README.spec.txt index acce106..db5c125 100644 --- a/NetworkScanners/BwAuthority/README.spec.txt +++ b/NetworkScanners/BwAuthority/README.spec.txt @@ -369,9 +369,7 @@ 3.1. Modeling Measurement as PID Control

The bandwidth authorities measure F_node: the filtered stream - capacity through a given node (filtering is described in Section 1.6) - times the circuit success rate of circuit EXTENDs to the node - (1.0 - circ_fail_rate). + capacity through a given node (filtering is described in Section 1.6).

In PID control, we add in this extra failure rate as a damper, to prevent the PID control system from driving nodes to CPU overload. Once nodes @@ -509,8 +507,16 @@ retaining PID state.

"bwauthcircs=1" - If present, F_node is multiplied by (1.0 - circ_fail_rate) - as described in Section 3.1. + If present, an additional circ_error value is computed for each + node similar to pid_error of Section 3.1. This value is: + + circ_error = (circ_rate - circ_avg_rate)/circ_avg_rate + + Where circ_rate and circ_avg_rate are the EXTEND success rates + to the node, and the average success rate for the entire node class, + respectively. + + This error value is then added to pid_error.

"bwauthbestratio=0" If absent, the larger of stream bandwidth vs filtered bandwidth diff --git a/NetworkScanners/BwAuthority/aggregate.py b/NetworkScanners/BwAuthority/aggregate.py index 120de07..ccf6436 100755 --- a/NetworkScanners/BwAuthority/aggregate.py +++ b/NetworkScanners/BwAuthority/aggregate.py @@ -449,17 +449,13 @@ def main(argv): plog("NOTICE", "No scan results yet.") sys.exit(1)

- if not cs_junk.use_circ_fails: - plog("INFO", "Ignoring circuit failures") - for n in nodes.itervalues(): - n.circ_fail_rate = 0.0 - for idhex in nodes.iterkeys(): if idhex in prev_consensus: nodes[idhex].flags = prev_consensus[idhex].flags

true_filt_avg = {} true_strm_avg = {} + true_circ_avg = {}

if cs_junk.bwauth_pid_control: # Penalize nodes for circuit failure: it indicates CPU pressure @@ -470,19 +466,21 @@ def main(argv): if cs_junk.group_by_class: for c in ["Guard+Exit", "Guard", "Exit", "Middle"]: c_nodes = filter(lambda n: n.node_class() == c, nodes.itervalues()) - true_filt_avg[c] = sum(map(lambda n: n.filt_bw*(1.0-n.circ_fail_rate), - c_nodes))/float(len(c_nodes)) - true_strm_avg[c] = sum(map(lambda n: n.strm_bw*(1.0-n.circ_fail_rate), - c_nodes))/float(len(c_nodes)) + true_filt_avg[c] = sum(map(lambda n: n.filt_bw, c_nodes))/float(len(c_nodes)) + true_strm_avg[c] = sum(map(lambda n: n.strm_bw, c_nodes))/float(len(c_nodes)) + true_circ_avg[c] = sum(map(lambda n: (1.0-n.circ_fail_rate), + c_nodes))/float(len(c_nodes)) plog("INFO", "Network true_filt_avg["+c+"]: "+str(true_filt_avg[c])) + plog("INFO", "Network true_circ_avg["+c+"]: "+str(true_circ_avg[c])) else: - filt_avg = sum(map(lambda n: n.filt_bw*(1.0-n.circ_fail_rate), - nodes.itervalues()))/float(len(nodes)) - strm_avg = sum(map(lambda n: n.strm_bw*(1.0-n.circ_fail_rate), - nodes.itervalues()))/float(len(nodes)) + filt_avg = sum(map(lambda n: n.filt_bw, nodes.itervalues()))/float(len(nodes)) + strm_avg = sum(map(lambda n: n.strm_bw, nodes.itervalues()))/float(len(nodes)) + circ_avg = sum(map(lambda n: (1.0-n.circ_fail_rate), + nodes.itervalues()))/float(len(nodes)) for c in ["Guard+Exit", "Guard", "Exit", "Middle"]: true_filt_avg[c] = filt_avg true_strm_avg[c] = strm_avg + true_circ_avg[c] = circ_avg else: plog("INFO", "PID control disabled") filt_avg = sum(map(lambda n: n.filt_bw*(1.0-n.circ_fail_rate), @@ -535,16 +533,22 @@ def main(argv): else: n.use_bw = n.ns_bw

- # Penalize nodes for circ failure rate if cs_junk.use_best_ratio and n.sbw_ratio > n.fbw_ratio: - n.pid_error = (n.strm_bw*(1.0-n.circ_fail_rate) - - true_strm_avg[n.node_class()]) \ + n.pid_error = (n.strm_bw - true_strm_avg[n.node_class()]) \ / true_strm_avg[n.node_class()] else: - n.pid_error = (n.filt_bw*(1.0-n.circ_fail_rate) - - true_filt_avg[n.node_class()]) \ + n.pid_error = (n.filt_bw - true_filt_avg[n.node_class()]) \ / true_filt_avg[n.node_class()]

+ # Penalize nodes for circ failure rate + if cs_junk.use_circ_fails: + circ_error = ((1.0-n.circ_fail_rate) - true_circ_avg[n.node_class()]) \ + / true_circ_avg[n.node_class()] + # FIXME: Hrmm, should we only penalize for circ successes, or should + # we reward, too? Let's try both for now. + # if circ_error < 0: + n.pid_error += circ_error + if n.idhex in prev_votes.vote_map: # If there is a new sample, let's use it for all but guards if n.measured_at > prev_votes.vote_map[n.idhex].measured_at: