- Adds a check for strong consistency configuration -- warning when

  strong consistency is enabled and AAE is disabled
  (defect basho/riak_kv#959)

src/weatherreport/src/riaknostic_check_strong_consistency.erl

@@ -0,0 +1,58 @@
+%% -------------------------------------------------------------------
+%%
+%% riaknostic - automated diagnostic tools for Riak
+%%
+%% Copyright (c) 2011 Basho Technologies, Inc.  All Rights Reserved.
+%%
+%% This file is provided to you under the Apache License,
+%% Version 2.0 (the "License"); you may not use this file
+%% except in compliance with the License.  You may obtain
+%% a copy of the License at
+%%
+%%   http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing,
+%% software distributed under the License is distributed on an
+%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%% KIND, either express or implied.  See the License for the
+%% specific language governing permissions and limitations
+%% under the License.
+%%
+%% -------------------------------------------------------------------
+
+%% @doc Diagnostic that checks Riak's current memory usage. If memory
+%% usage is high, a warning message will be sent, otherwise only
+%% informational messages.
+-module(riaknostic_check_strong_consistency).
+-behaviour(riaknostic_check).
+
+-export([description/0,
+         valid/0,
+         check/0,
+         format/1]).
+
+-spec description() -> string().
+description() ->
+    "Strong consistency configuration valid".
+
+-spec valid() -> boolean().
+valid() ->
+    riaknostic_node:can_connect().
+
+-spec check() -> [{lager:log_level(), term()}].
+check() ->
+    StrongConsistencyOption = riaknostic_config:get_app_env([riak_core, enable_consensus]),
+    { AAEOption, _ } = riaknostic_config:get_app_env([riak_kv, anti_entropy]),
+    maybe_strong_consistency_aae_misconfigured(StrongConsistencyOption, AAEOption).
+
+-spec maybe_strong_consistency_aae_misconfigured(boolean, on | off | any()) -> [ { term(), term() } ] | [].
+maybe_strong_consistency_aae_misconfigured(true, off) ->
+    [ { critical, { strong_consistency_aae_misconfigured } } ];
+maybe_strong_consistency_aae_misconfigured(false, _) ->
+    [];
+maybe_strong_consistency_aae_misconfigured(true, on) ->
+    [].
+
+-spec format(term()) -> {io:format(), [term()]}.
+format({ strong_consistency_aae_misconfigured }) ->
+    { "Strong consistency has been enabled without AAE -- all consistent operations will timeout until AAE is enabled.", [] }.