path: root/0001-multiple-introducer-support.patch

From: Kill Your TV <killyourtv@i2pmail.org>
Date: Wed, 27 Jun 2012 20:59:05 +0000
Subject: multiple introducer support

---
 docs/architecture.rst           |    8 +++--
 docs/configuration.rst          |   12 +++++--
 src/allmydata/client.py         |   70 +++++++++++++++++++++++++++++++++------
 src/allmydata/test/test_web.py  |    6 ++--
 src/allmydata/web/root.py       |   26 +++++++++++----
 src/allmydata/web/welcome.xhtml |   27 +++++++++++----
 6 files changed, 118 insertions(+), 31 deletions(-)

diff --git a/docs/architecture.rst b/docs/architecture.rst
index 9e016e0..d1fba50 100644
--- a/docs/architecture.rst
+++ b/docs/architecture.rst
@@ -78,9 +78,13 @@ private key, which are easy to move to a new host in case the original one
 suffers an unrecoverable hardware problem. Second, even if the private key is
 lost, clients can be reconfigured to use a new introducer.
 
-For future releases, we have plans to decentralize introduction, allowing any
-server to tell a new client about all the others.
+By deploying multiple introducers in a Tahoe-LAFS grid, the above SPoF challenge
+can be overcome. In that case if one introducer fails clients are still be
+able to get announcement about new servers from remaining introducers. This is
+our first step towards implementing a fully distributed introduction.
 
+For future releases, we have plans to enhance our distributed introduction,
+allowing any server to tell a new client about all the others.
 
 File Encoding
 =============
diff --git a/docs/configuration.rst b/docs/configuration.rst
index 31962d4..3f8f5eb 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -33,6 +33,12 @@ create-client``" command will create an initial ``tahoe.cfg`` file for
 you. After creation, the node will never modify the ``tahoe.cfg`` file: all
 persistent state is put in other files.
 
+A second file "BASEDIR/introducers" configures introducers. It is necessary to
+write all FURL entries into this file. Each line in this file contains exactly
+one FURL entry. For backward compatibility reasons, any "introducer.furl"
+entry found in tahoe.cfg file will automatically be copied into this file. Keeping
+any FURL entry in tahoe.cfg file is not recommended for new users.
+
 The item descriptions below use the following types:
 
 ``boolean``
@@ -665,16 +671,16 @@ a legal one.
   timeout.disconnect = 1800
   ssh.port = 8022
   ssh.authorized_keys_file = ~/.ssh/authorized_keys
-  
+
   [client]
   introducer.furl = pb://ok45ssoklj4y7eok5c3xkmj@tahoe.example:44801/ii3uumo
   helper.furl = pb://ggti5ssoklj4y7eok5c3xkmj@helper.tahoe.example:7054/kk8lhr
-  
+
   [storage]
   enabled = True
   readonly = True
   reserved_space = 10000000000
-  
+
   [helper]
   enabled = True
 
diff --git a/src/allmydata/client.py b/src/allmydata/client.py
index b78fd7b..7200856 100644
--- a/src/allmydata/client.py
+++ b/src/allmydata/client.py
@@ -35,6 +35,8 @@ GiB=1024*MiB
 TiB=1024*GiB
 PiB=1024*TiB
 
+MULTI_INTRODUCERS_CFG = "introducers"
+
 class StubClient(Referenceable):
     implements(RIStubClient)
 
@@ -137,7 +139,7 @@ class Client(node.Node, pollmixin.PollMixin):
         self.started_timestamp = time.time()
         self.logSource="Client"
         self.DEFAULT_ENCODING_PARAMETERS = self.DEFAULT_ENCODING_PARAMETERS.copy()
-        self.init_introducer_client()
+        self.init_introducer_clients()
         self.init_stats_provider()
         self.init_secrets()
         self.init_storage()
@@ -169,13 +171,47 @@ class Client(node.Node, pollmixin.PollMixin):
         if webport:
             self.init_web(webport) # strports string
 
-    def init_introducer_client(self):
-        self.introducer_furl = self.get_config("client", "introducer.furl")
-        ic = IntroducerClient(self.tub, self.introducer_furl,
+    def init_introducer_clients(self):
+        self.introducer_furls = []
+        self.warn_flag = False
+        # Try to load ""BASEDIR/introducers" cfg file
+        cfg = os.path.join(self.basedir, MULTI_INTRODUCERS_CFG)
+        if os.path.exists(cfg):
+           f = open(cfg, 'r')
+           for introducer_furl in  f.read().split('\n'):
+                if not introducer_furl.strip():
+                    continue
+                self.introducer_furls.append(introducer_furl)
+           f.close()
+        furl_count = len(self.introducer_furls)
+        #print "@icfg: furls: %d" %furl_count
+
+        # read furl from tahoe.cfg
+        ifurl = self.get_config("client", "introducer.furl", None)
+        if ifurl and ifurl not in self.introducer_furls:
+            self.introducer_furls.append(ifurl)
+            f = open(cfg, 'a')
+            f.write(ifurl)
+            f.write('\n')
+            f.close()
+            if furl_count > 1:
+                self.warn_flag = True
+                self.log("introducers config file modified.")
+                print "Warning! introducers config file modified."
+
+        # create a pool of introducer_clients
+        self.introducer_clients = []
+        for introducer_furl in self.introducer_furls:
+            ic = IntroducerClient(self.tub, introducer_furl,
                               self.nickname,
                               str(allmydata.__full_version__),
                               str(self.OLDEST_SUPPORTED_VERSION))
-        self.introducer_client = ic
+            self.introducer_clients.append(ic)
+        # init introducer_clients as usual
+        for ic in self.introducer_clients:
+            self.init_introducer_client(ic)
+
+    def init_introducer_client(self, ic):
         # hold off on starting the IntroducerClient until our tub has been
         # started, so we'll have a useful address on our RemoteReference, so
         # that the introducer's status page will show us.
@@ -263,7 +299,9 @@ class Client(node.Node, pollmixin.PollMixin):
             furl_file = os.path.join(self.basedir, "private", "storage.furl").encode(get_filesystem_encoding())
             furl = self.tub.registerReference(ss, furlFile=furl_file)
             ri_name = RIStorageServer.__remote_name__
-            self.introducer_client.publish(furl, "storage", ri_name)
+            # Now, publish multiple introducers
+            for ic in self.introducer_clients:
+                ic.publish(furl, "storage", ri_name)
         d.addCallback(_publish)
         d.addErrback(log.err, facility="tahoe.init",
                      level=log.BAD, umid="aLGBKw")
@@ -316,7 +354,10 @@ class Client(node.Node, pollmixin.PollMixin):
         # check to see if we're supposed to use the introducer too
         if self.get_config("client-server-selection", "use_introducer",
                            default=True, boolean=True):
-            sb.use_introducer(self.introducer_client)
+
+            # Now, use our multiple introducers
+            for ic in self.introducer_clients:
+                sb.use_introducer(ic)
 
     def get_storage_broker(self):
         return self.storage_broker
@@ -329,7 +370,9 @@ class Client(node.Node, pollmixin.PollMixin):
             sc = StubClient()
             furl = self.tub.registerReference(sc)
             ri_name = RIStubClient.__remote_name__
-            self.introducer_client.publish(furl, "stub_client", ri_name)
+            # Now publish our multiple introducers
+            for ic in self.introducer_clients:
+                ic.publish(furl, "stub_client", ri_name)
         d = self.when_tub_ready()
         d.addCallback(_publish)
         d.addErrback(log.err, facility="tahoe.init",
@@ -469,10 +512,15 @@ class Client(node.Node, pollmixin.PollMixin):
     def get_encoding_parameters(self):
         return self.DEFAULT_ENCODING_PARAMETERS
 
+    # In case we configure multiple introducers
     def connected_to_introducer(self):
-        if self.introducer_client:
-            return self.introducer_client.connected_to_introducer()
-        return False
+        status = []
+        if self.introducer_clients:
+            s = False
+            for ic in self.introducer_clients:
+                s = ic.connected_to_introducer()
+                status.append(s)
+        return status
 
     def get_renewal_secret(self): # this will go away
         return self._secret_holder.get_renewal_secret()
diff --git a/src/allmydata/test/test_web.py b/src/allmydata/test/test_web.py
index 1c7dada..52656b1 100644
--- a/src/allmydata/test/test_web.py
+++ b/src/allmydata/test/test_web.py
@@ -42,7 +42,7 @@ from allmydata.introducer import IntroducerNode
 # create a fake uploader/downloader, and a couple of fake dirnodes, then
 # create a webserver that works against them
 
-timeout = 480 # Most of these take longer than 240 seconds on Francois's arm box.
+timeout = 960 # allmydata.test.test_web.Grid.test_deep_check took longer than 480 seconds on zomp
 
 unknown_rwcap = u"lafs://from_the_future_rw_\u263A".encode('utf-8')
 unknown_rocap = u"ro.lafs://readonly_from_the_future_ro_\u263A".encode('utf-8')
@@ -171,13 +171,13 @@ class FakeClient(Client):
         self.all_contents = {}
         self.nodeid = "fake_nodeid"
         self.nickname = "fake_nickname"
-        self.introducer_furl = "None"
+        self.introducer_furls = "None"
         self.stats_provider = FakeStatsProvider()
         self._secret_holder = SecretHolder("lease secret", "convergence secret")
         self.helper = None
         self.convergence = "some random string"
         self.storage_broker = StorageFarmBroker(None, permute_peers=True)
-        self.introducer_client = None
+        self.introducer_clients = None
         self.history = FakeHistory()
         self.uploader = FakeUploader()
         self.uploader.all_contents = self.all_contents
diff --git a/src/allmydata/web/root.py b/src/allmydata/web/root.py
index 3b9dd1c..956de67 100644
--- a/src/allmydata/web/root.py
+++ b/src/allmydata/web/root.py
@@ -219,12 +219,26 @@ class Root(rend.Page):
 
         return ctx.tag[ul]
 
-    def data_introducer_furl(self, ctx, data):
-        return self.client.introducer_furl
-    def data_connected_to_introducer(self, ctx, data):
-        if self.client.connected_to_introducer():
-            return "yes"
-        return "no"
+    # In case we configure multiple introducers
+    def data_introducers(self, ctx, data):
+        connection_status = []
+        connection_status = self.client.connected_to_introducer()
+        s = []
+        furls = self.client.introducer_furls
+        for furl in furls:
+            if connection_status:
+                i = furls.index(furl)
+                s.append((furl, bool(connection_status[i])))
+        s.sort()
+        return s
+
+    def render_introducers_row(self, ctx, s):
+        (furl, connected) = s
+        status = ("No", "Yes")
+        ctx.fillSlots("introducer_furl", "%s" % (furl))
+        ctx.fillSlots("connected-bool", "%s" % (connected))
+        ctx.fillSlots("connected", "%s" % (status[int(connected)]))
+        return ctx.tag
 
     def data_helper_furl(self, ctx, data):
         try:
diff --git a/src/allmydata/web/welcome.xhtml b/src/allmydata/web/welcome.xhtml
index 5fd3cdd..a3b546c 100644
--- a/src/allmydata/web/welcome.xhtml
+++ b/src/allmydata/web/welcome.xhtml
@@ -35,16 +35,31 @@
   <div n:render="download_form" />
 </div>
 
+<h2>Connected Introducer(s)</h2>
+
+<div>
+<table n:render="sequence" n:data="introducers">
+  <tr n:pattern="header">
+    <td>Introducer FURL</td>
+    <td>Connected?</td>
+  </tr>
+  <tr n:pattern="item" n:render="introducers_row">
+    <td><tt><n:slot name="introducer_furl"/></tt></td>
+    <td>
+      <n:slot name="connected"/>
+      <n:attr name="class">service-connected connected-<n:slot name="connected-bool"/></n:attr>
+    </td>
+  </tr>
+  <tr n:pattern="empty"><td>no introducers!</td></tr>
+</table>
+</div>
+
+
+
 <div class="section" id="grid">
   <h2>Status of the Storage Grid</h2>
 
   <div>
-    <n:attr name="class">connected-<n:invisible n:render="string" n:data="connected_to_introducer" /></n:attr>
-    <div>Introducer: <span class="data-chars" n:render="string" n:data="introducer_furl" /></div>
-    <div>Connected to introducer?: <span n:render="string" n:data="connected_to_introducer" /></div>
-  </div>
-
-  <div>
     <n:attr name="class">connected-<n:invisible n:render="string" n:data="connected_to_helper" /></n:attr>
     <div>Helper: <span n:render="string" n:data="helper_furl" /></div>
     <div>Connected to helper?: <span n:render="string" n:data="connected_to_helper" /></div>