bwauth aggregator divides by zero if a node class is missing
The bwauth code expects there to always be a non-zero number of each of "Guard+Exit", "Guard", "Exit", and "Middle" nodes.
In small networks, this isn't always the case:
```
diff --git a/NetworkScanners/BwAuthority/aggregate.py b/NetworkScanners/BwAuthority/aggregate.py
index 01ea8b5..cae436b 100755
--- a/NetworkScanners/BwAuthority/aggregate.py
+++ b/NetworkScanners/BwAuthority/aggregate.py
@@ -489,10 +489,15 @@ def main(argv):
for cl in ["Guard+Exit", "Guard", "Exit", "Middle"]:
c_nodes = filter(lambda n: n.node_class() == cl, nodes.itervalues())
- true_filt_avg[cl] = sum(map(lambda n: n.filt_bw, c_nodes))/float(len(c_nodes))
- true_strm_avg[cl] = sum(map(lambda n: n.strm_bw, c_nodes))/float(len(c_nodes))
- true_circ_avg[cl] = sum(map(lambda n: (1.0-n.circ_fail_rate),
+ if len(c_nodes) > 0:
+ true_filt_avg[cl] = sum(map(lambda n: n.filt_bw, c_nodes))/float(len(c_nodes))
+ true_strm_avg[cl] = sum(map(lambda n: n.strm_bw, c_nodes))/float(len(c_nodes))
+ true_circ_avg[cl] = sum(map(lambda n: (1.0-n.circ_fail_rate),
c_nodes))/float(len(c_nodes))
+ else:
+ true_filt_avg[cl] = 0.0
+ true_strm_avg[cl] = 0.0
+ true_circ_avg[cl] = 0.0
# FIXME: This may be expensive
pid_tgt_avg[cl] = true_filt_avg[cl]
@@ -835,10 +840,13 @@ def main(argv):
c_nodes = filter(lambda n: n.node_class() == cl, nodes.itervalues())
nc_nodes = filter(lambda n: n.pid_error < 0, c_nodes)
pc_nodes = filter(lambda n: n.pid_error > 0, c_nodes)
- plog("INFO", "Avg "+cl+" pid_error="+str(sum(map(lambda n: n.pid_error, c_nodes))/len(c_nodes)))
- plog("INFO", "Avg "+cl+" |pid_error|="+str(sum(map(lambda n: abs(n.pid_error), c_nodes))/len(c_nodes)))
- plog("INFO", "Avg "+cl+" +pid_error=+"+str(sum(map(lambda n: n.pid_error, pc_nodes))/len(pc_nodes)))
- plog("INFO", "Avg "+cl+" -pid_error="+str(sum(map(lambda n: n.pid_error, nc_nodes))/len(nc_nodes)))
+ if len(c_nodes) > 0:
+ plog("INFO", "Avg "+cl+" pid_error="+str(sum(map(lambda n: n.pid_error, c_nodes))/len(c_nodes)))
+ plog("INFO", "Avg "+cl+" |pid_error|="+str(sum(map(lambda n: abs(n.pid_error), c_nodes))/len(c_nodes)))
+ if len(pc_nodes) > 0:
+ plog("INFO", "Avg "+cl+" +pid_error=+"+str(sum(map(lambda n: n.pid_error, pc_nodes))/len(pc_nodes)))
+ if len(nc_nodes) > 0:
+ plog("INFO", "Avg "+cl+" -pid_error="+str(sum(map(lambda n: n.pid_error, nc_nodes))/len(nc_nodes)))
n_nodes = filter(lambda n: n.pid_error < 0, nodes.itervalues())
p_nodes = filter(lambda n: n.pid_error > 0, nodes.itervalues())
```
We could fix this by guarding every division by a length with a check.
Refactoring would make this much easier.
issue