[Gzz-commits] storm/doc/pegboard/available_overlays--hemppah ...

[Hermanni Hyytiälä]

CVSROOT:        /cvsroot/storm
Module name:    storm
Branch:         
Changes by:     Hermanni Hyytiälä <address@hidden>      03/07/28 07:58:29

Modified files:
        doc/pegboard/available_overlays--hemppah: peg.rst 

Log message:
        more

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/storm/storm/doc/pegboard/available_overlays--hemppah/peg.rst.diff?tr1=1.29&tr2=1.30&r1=text&r2=text

Patches:
Index: storm/doc/pegboard/available_overlays--hemppah/peg.rst
diff -u storm/doc/pegboard/available_overlays--hemppah/peg.rst:1.29 
storm/doc/pegboard/available_overlays--hemppah/peg.rst:1.30
--- storm/doc/pegboard/available_overlays--hemppah/peg.rst:1.29 Mon Jul 28 
05:10:55 2003
+++ storm/doc/pegboard/available_overlays--hemppah/peg.rst      Mon Jul 28 
07:58:28 2003
@@ -4,8 +4,8 @@
 
 :Authors:  Hermanni Hyytiälä
 :Date-Created: 2003-06-18
-:Last-Modified: $Date: 2003/07/28 09:10:55 $
-:Revision: $Revision: 1.29 $
+:Last-Modified: $Date: 2003/07/28 11:58:28 $
+:Revision: $Revision: 1.30 $
 :Status:   Incomplete
 
 .. :Stakeholders:
@@ -15,17 +15,15 @@
 .. Affect-PEGs:
 
 The purpose of this PEG document is to give a short overview of existing 
-overlays which have an implementation and try to choose an implementation
-that suits best to our needs.
+overlays which have an open source implementation. 
 
-The reason for creating this PEG document is that, quite recently, we have 
-noticed that the current implementation of GISP [5]_  seems to 
-have (too) many obvious security exploits. This indiciates that GISP is in 
early 
-phase of development. Therefore, we need to examine other 
-available overlays which have an implementation in hope for finding a more 
-mature tightly structured P2P platform. 
+The reason for creating this PEG document is that the current implementation 
+of GISP [5]_ seems to have (too) many obvious security exploits. For us this 
+indiciates that GISP is in early phase of development. Therefore we need to 
+examine other available overlays which have an implementation in hope for 
+finding a more mature tightly structured P2P platform. 
 
-The list of implemented overlays is of as of June 2003.
+The list of implemented overlays is as of July 2003.
 
 Issues
 ======
@@ -87,7 +85,8 @@
     Who is developing a software.
 
 Language
-    What programming language is used to program a software.
+    What programming language is used to program a software + additional
+    software packages which are required.
 
 License
     Under what license a software is distributed.
@@ -98,7 +97,10 @@
 Implemented overlays
 ====================
 
-.. a "reST" table is created when text editing finished for this section
+In this section we list the structured P2P overlays which have been 
implemented.
+Please notice that features described for each implementation are deliberately
+kept short. For more depth information about the *design* of the overlay see 
+the original publications.
 
 Chord [1]_
 ----------
@@ -115,8 +117,12 @@
 Activity of development
     Quite high.
 
-    Currently, no official release for Chord [1]_ is available. However,
-    nightly snapshots are available.
+    According to the Chord [1]_ website:
+
+        At this point no official release for 
+        Chord is available, but you are welcome to check out the latest 
version 
+        from the CVS repository. This version is experimental, under active 
+        development, and may frequently be broken.
 
 Developer
     MIT (research community)
@@ -136,13 +142,7 @@
     No support for network locality- do not take network latencies into 
account.
 
     Includes a Chord [1]_ simulator.
-
-    According to the Chord [1]_ website:
-
-        At this point no official release for 
-        Chord is available, but you are welcome to check out the latest 
version 
-        from the CVS repository. This version is experimental, under active 
-        development, and may frequently be broken.
+    
 
 Tapestry [2]_
 --------------
@@ -175,24 +175,19 @@
         protocols to route messages around failures, providing successful 
         delivery with high probability if a path between the endpoints exists.
 
-        Replication, backup links
-
+    
 Fault tolerance against hostile nodes
     * PKI is used while creating node identifiers
     * MACs are used to maintain integrity of overlay traffic
     * Monitoring system for maintaining neighbor links
 
 Activity of development
-    Very active.
+    Active.
 
     Tapestry  1.0 (April 2002)
 
     According to the Tapestry [2]_ website::
 
-        Tapestry 2.0 is coming soon, with support 
-        for massively parallel insertions, voluntary deletions, 
-        and a distributed test framework.
-    
         Tapestry Version 1.0 contains the following functionality:
 
         * Basic Tapestry Java code running on the SEDA stage-driven event model
@@ -244,22 +239,16 @@
     release).
 
 Additional requirements
-    * The Cryptix JCE library (included with the 1.0 release)
+    * The Cryptix JCE library (included with the 2.0 release)
     * UNIX make program
     * The Java interface libraries for the BerkeleyDB database 
-      (included with the 1.0 release)
-  
+      (included with the 2.0 release) 
+    
 License
     BSD-like
 
 Other notes
-    Support for network locality.
-
-    According to the Tapestry [2]_ website:
-
-       "Tapestry is the networking substrate of 
-        OceanStore_, a storage system aiming to provide global-scale 
persistent and 
-        secure storage."
+    Support for network locality when building neighbor links.
 
     Why Oceanstore_ uses Tapestry [2]_? 
     See http://www.oceanstore.org/info/whytapestry.html 
@@ -271,9 +260,25 @@
     DHT_
 
 Redundancy
-    No simulations or test performed.
-    In theory, however, the "free-choice" feature
-    gives peers freedom to adapt different conditions.
+    No simulation or test results published (not even in the original 
publication)
+    In *theory*, however, the "free-choice" feature
+    gives peers freedom to adapt different conditions. However, the
+    author of SharkyPy says:
+    
+        Kademlia has (in my taste, that's why I decided to drop it) a bad
+       hole which makes it's use in remote querying for packets pretty useless:
+       When you have key->value mappings, which have an equal key, in even in
+       semi-large networks it gets very unprobable that you get all mappings,
+       the more hosts there are, the less probable it is, and the more mappings
+       there are, the less probable it is too. I've tried to remedy this in a
+       later implementation, at the cost of lookup speed, but have never
+       managed to get all entries when the network had over 100 nodes. (the
+       later implementation is based on my own server-framework and uses no
+       threads, btw.) This made it unusable for me, as basically I basically
+       had to change the lookup-algorithm to query all nodes (back to gnutella,
+       then...), to get all answers. And that's what is important in the
+       network I designed it for.
+
 
 Fault tolerance against hostile nodes
     Nothing said, expect the "free-choice" feature. 
@@ -292,22 +297,26 @@
     GPL (Java), "Free for non-commercial use" (C++)
 
 Other notes
-    (none)    
+    The implementation of the Java version is discontinued. 
 
 Pastry [4]_
 -----------
 
 Abstraction
-    DHT_/DOLR_
+    DHT_
 
 Redundancy
    Backup links.
 
 Fault tolerance against hostile nodes
-   (undefined)
+   Accordin to the release notes of 1.2, "Security support does not exist in 
+    this release. Therefore, the  software should only be run in trusted 
+    environments. Future releases will include security."
 
 Activity of development
-    Current release is 1.2 (January 28, 2003)
+    Active
+    
+    Current release is 1.3 (July 23, 2003)
 
     According to the Pastry [4]_ website:
 
@@ -330,11 +339,7 @@
     Support for network locality - Pastry [4]_ actively replicates the objects 
and 
     places them at random locations in the network. Result: When locating
     nearby object it might require the client to route to a distant replica of 
-    the object.
-
-    Accordin to the release notes of 1.2, "Security support does not exist in 
-    this release. Therefore, the  software should only be run in trusted 
-    environments. Future releases will include security."
+    the object. 
 
 GISP [5]_
 ---------
@@ -376,7 +381,10 @@
     Not-known
 
 Fault tolerance against hostile nodes
-    Not-known
+    According to Info-Anarchy Wiki:
+
+        Problems are: The DHT implementation is 
+        vulnerable to denial of service attacks.
 
 Activity of development
     Active, the current version is 0.35 (30 May 2003)
@@ -391,12 +399,8 @@
     GPL
 
 Other notes
-    Uses MD5 hashes.
-
-    According to Info-Anarchy Wiki:
-
-        Problems are: The DHT implementation is 
-        vulnerable to denial of service attacks.
+    Uses MD5 hashes for generating IDs.
+    
 
 Khashmir [7]_
 -------------
@@ -574,19 +578,26 @@
     LGPL
 
 Other notes
-    (none)
+    According to the author of SharkyPy:
+    
+        This implementation is heavily based on threads, which makes it
+       pretty resource-intensive on the computer it is running on. I never
+       intended it to serve more than 30-40 clients, so this didn't matter to
+       me. When you use it as a P2P network backend, things will certainly look
+       different.
 
 Changes
 =======
 
-Based on this PEG document we recommend using Tapestry [2]_ with Storm. The
-reasons are:
+Based on this PEG document we recommend using Tapestry's implementation with 
+Storm. The reasons are:
 
-- maturity of the implementation (the most important aspect)
-- activity of development
+- the maturity of the implementation
 - the license
+- the activity of development
 
-
+For detailed changes and information about using Tapestry with Storm, please
+see `storm_with_tapestry--hemppah` PEG document.
  
 
 .. [1] http://www.pdos.lcs.mit.edu/chord/