Parallelize and timeout ssdp queries

Badly behaving 'desc.tmpl' servers exist in the world,
do not get tripped up or slowed down too much by
having aggressive timeout and making it parallel.

confluent_server/confluent/discovery/protocols/ssdp.py

@@ -35,6 +35,7 @@ import confluent.log as log
 import confluent.netutil as netutil
 import eventlet.green.select as select
 import eventlet.green.socket as socket
+import eventlet.greenpool as gp
 import time
 try:
     from eventlet.green.urllib.request import urlopen
@@ -275,13 +276,26 @@ def _find_service(service, target):
         if timeout < 0:
             timeout = 0
         r, _, _ = select.select((net4, net6), (), (), timeout)
+    querypool = gp.GreenPool()
+    pooltargs = []
     for nid in peerdata:
         for url in peerdata[nid].get('urls', ()):
             if url.endswith('/desc.tmpl'):
-                info = urlopen(url).read()
-                if b'<friendlyName>Athena</friendlyName>' in info:
-                    peerdata[nid]['services'] = ['service:thinkagile-storage']
-                    yield peerdata[nid]
+                pooltargs.append((url, peerdata[nid]))
+    for pi in querypool.imap(check_cpstorage, pooltargs):
+        if pi is not None:
+            yield pi
+
+def check_cpstorage(urldata):
+    url, data = urldata
+    try:
+        info = urlopen(url, timeout=1).read()
+        if b'<friendlyName>Athena</friendlyName>' in info:
+            data['services'] = ['service:thinkagile-storage']
+            return data
+    except Exception:
+        pass
+    return None
 
 
 def _parse_ssdp(peer, rsp, peerdata):