Merge pull request #97 from yossigo/fix/ae-failure-handling

AE error response not properly handled.
willemt · Oct 6, 2018 · 4ddc273 · 4ddc273
2 parents 0e75563 + f8236e0
commit 4ddc273
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Showing 2 changed files with 81 additions and 2 deletions.
diff --git a/src/raft_server.c b/src/raft_server.c
@@ -311,8 +311,7 @@ int raft_recv_appendentries_response(raft_server_t* me_,
         raft_index_t next_idx = raft_node_get_next_idx(node);
         assert(0 < next_idx);
         /* Stale response -- ignore */
-        assert(match_idx <= next_idx - 1);
-        if (match_idx == next_idx - 1)
+        if (r->current_idx < match_idx)
             return 0;
         if (r->current_idx < next_idx - 1)
             raft_node_set_next_idx(node, min(r->current_idx + 1, raft_get_current_idx(me_)));

diff --git a/tests/test_snapshotting.c b/tests/test_snapshotting.c
@@ -66,6 +66,16 @@ static int __raft_send_appendentries_capture(raft_server_t* raft,
     return 0;
 }
 
+static int __raft_send_snapshot_increment(raft_server_t* raft,
+        void* udata,
+        raft_node_t* node)
+{
+    int *counter = udata;
+
+    (*counter)++;
+    return 0;
+}
+
 /* static raft_cbs_t generic_funcs = { */
 /*     .persist_term = __raft_persist_term, */
 /*     .persist_vote = __raft_persist_vote, */
@@ -735,3 +745,73 @@ void TestRaft_cancel_snapshot_restores_state(CuTest* tc)
     CuAssertIntEquals(tc, 2, raft_get_snapshot_last_idx(r));
 }
 
+void TestRaft_leader_sends_snapshot_if_log_was_compacted(CuTest* tc)
+{
+    raft_cbs_t funcs = {
+        .send_snapshot = __raft_send_snapshot_increment,
+        .send_appendentries = __raft_send_appendentries
+    };
+
+    int send_snapshot_count = 0;
+
+    void *r = raft_new();
+    raft_set_callbacks(r, &funcs, &send_snapshot_count);
+
+    raft_node_t* node;
+    raft_add_node(r, NULL, 1, 1);
+    node = raft_add_node(r, NULL, 2, 0);
+    raft_add_node(r, NULL, 3, 0);
+
+    raft_set_state(r, RAFT_STATE_LEADER);
+    raft_set_current_term(r, 1);
+
+    /* entry 1 */
+    char *str = "aaa";
+    raft_entry_t ety = {};
+    ety.term = 1;
+    ety.id = 1;
+    ety.data.buf = str;
+    ety.data.len = 3;
+    raft_append_entry(r, &ety);
+
+    /* entry 2 */
+    ety.term = 1;
+    ety.id = 2;
+    ety.data.buf = str;
+    ety.data.len = 3;
+    raft_append_entry(r, &ety);
+
+    /* entry 3 */
+    ety.term = 1;
+    ety.id = 3;
+    ety.data.buf = str;
+    ety.data.len = 3;
+    raft_append_entry(r, &ety);
+    CuAssertIntEquals(tc, 3, raft_get_current_idx(r));
+
+    /* compact entry 1 & 2 */
+    raft_set_commit_idx(r, 2);
+    CuAssertIntEquals(tc, 0, raft_begin_snapshot(r, 0));
+    CuAssertIntEquals(tc, 0, raft_end_snapshot(r));
+    CuAssertIntEquals(tc, 1, raft_get_log_count(r));
+
+    /* at this point a snapshot should have been sent; we'll continue
+     * assuming the node was not available to get it.
+     */
+    CuAssertIntEquals(tc, 2, send_snapshot_count);
+    send_snapshot_count = 0;
+
+    /* node wants an entry that was compacted */
+    raft_node_set_match_idx(node, 1);
+    raft_node_set_next_idx(node, 2);
+
+    msg_appendentries_response_t aer;
+    aer.term = 1;
+    aer.success = 0;
+    aer.current_idx = 1;
+    aer.first_idx = 4;
+
+    raft_recv_appendentries_response(r, node, &aer);
+    CuAssertIntEquals(tc, 1, send_snapshot_count);
+}
+