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authorSage Weil <sage@inktank.com>2012-05-31 16:42:38 -0700
committerSage Weil <sage@inktank.com>2012-05-31 16:42:38 -0700
commita4c90b725024c155b79d511822ce541aa83f5d65 (patch)
tree61292bfa1f567c5429055a69263e56183862d114 /doc
parentfb7ce59b9a18ac26882836de366629a4593855a6 (diff)
parent504c6ce95799fe3f559cdfee4e758a6ea5608ab9 (diff)
downloadceph-a4c90b725024c155b79d511822ce541aa83f5d65.tar.gz
Merge remote-tracking branch 'gh/wip-mon-doc'
Diffstat (limited to 'doc')
-rw-r--r--doc/mon/README.txt27
-rw-r--r--doc/mon/paxos-call-chain.dot82
2 files changed, 109 insertions, 0 deletions
diff --git a/doc/mon/README.txt b/doc/mon/README.txt
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+paxos-call-chain.dot describes to some detail the call chain involved in the
+Paxos algorithm, paying special consideration to the messages involved.
+
+This information is not easily obtainable by Doxygen, as it does not follow
+the call chain when messages are involved, since it becomes an async workflow.
+
+To obtain the graph one should run
+
+ dot -T<format> paxos-call-chain.dot -o paxos-call-chain.<format>
+
+e.g.,
+
+ dot -Tps paxos-call-chain.dot -o paxos-call-chain.ps
+
+or
+
+ dot -Tpng paxos-call-chain.dot -o paxos-call-chain.png
+
+It should do the trick.
+
+Also, for future reference, we consider that:
+ - boxed nodes refer to the Leader;
+ - elliptical nodes refer to the Peon;
+ - diamond shaped nodes refer to state changes;
+ - dotted lines illustrate a message being sent from the Leader to the Peon,
+ or vice-versa.
+
diff --git a/doc/mon/paxos-call-chain.dot b/doc/mon/paxos-call-chain.dot
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+digraph Paxos {
+ concentrate=true
+// subgraph cluster0 {
+ collect -> state_recovering;
+ collect -> send_mmp_collect -> handle_collect [style=dotted];
+ handle_collect -> send_mmp_last;
+ send_mmp_last -> handle_last [style=dotted];
+ handle_last -> collect [label="collect(last_pn)"];
+ handle_last -> send_mmp_commit;
+ handle_last -> state_active;
+ handle_last -> begin;
+ handle_last -> extend_lease;
+
+// color=grey;
+// style=filled;
+// label="Post-Election call chain";
+// }
+
+ election_finished -> leader_init;
+ leader_init -> collect [label="collect(0)"];
+ send_mmp_commit -> handle_commit [style=dotted];
+
+ begin -> state_updating;
+ begin -> send_mmp_begin;
+ begin -> commit;
+
+ send_mmp_begin -> handle_begin [style=dotted];
+ handle_begin -> state_updating;
+ handle_begin -> send_mmp_accept;
+ send_mmp_accept -> handle_accept [style=dotted];
+
+ handle_accept -> extend_lease;
+ handle_accept -> state_active;
+ handle_accept -> commit;
+
+ extend_lease -> send_mmp_lease;
+ send_mmp_lease -> handle_lease [style=dotted];
+ handle_lease -> state_active;
+ handle_lease -> send_mmp_lease_ack;
+ send_mmp_lease_ack -> handle_lease_ack [style=dotted];
+
+ commit -> send_mmp_commit;
+ commit -> "last_committed++" [shape=box];
+ send_mmp_commit -> handle_commit [style=dotted];
+
+ handle_commit -> store_state;
+
+ propose_pending -> propose_new_value;
+ propose_new_value -> begin;
+
+ election_finished [label="Election Finished", shape=box, bgcolor=grey, style=filled];
+ collect [label="collect()", shape=box];
+ commit [label="commit()", shape=box];
+ begin [label="begin()", shape=box];
+ extend_lease [label="extend_lease()", shape=box];
+ store_state [label="store_state()"]; // peon
+
+ propose_pending [label="PaxosService::propose_pending()"];
+ propose_new_value [label="propose_new_value"];
+
+ send_mmp_collect [label="send(OP_COLLECT)", shape=box];
+ send_mmp_last [label="send(OP_LAST)"];
+ send_mmp_commit [label="send(OP_COMMIT)", shape=box];
+ send_mmp_begin [label="send(OP_BEGIN)", shape=box];
+ send_mmp_accept [label="send(OP_ACCEPT)"];
+ send_mmp_lease [label="send(OP_LEASE)", shape=box];
+ send_mmp_lease_ack [label="send(OP_LEASE_ACK)"];
+
+ handle_collect [label="handle_collect()"];
+ handle_last [label="handle_last()", shape=box];
+ handle_begin [label="handle_begin()"];
+ handle_accept [label="handle_accept()", shape=box];
+ handle_lease [label="handle_lease()"];
+ handle_lease_ack [label="handle_lease_ack()", shape=box];
+ handle_commit [label="handle_commit()"];
+
+ leader_init [label="Paxos::leader_init()", shape=box];
+
+ state_recovering [label="RECOVERING", shape=diamond];
+ state_active [label="ACTIVE", shape=diamond];
+ state_updating [label="UPDATING", shape=diamond];
+}