| % Licensed 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. |
| |
| -module(custodian_db_checker). |
| -behaviour(gen_server). |
| -vsn(1). |
| |
| -export([start_link/0]). |
| |
| -export([ |
| init/1, |
| terminate/2, |
| handle_call/3, |
| handle_cast/2, |
| handle_info/2, |
| code_change/3 |
| ]). |
| |
| -export([ |
| check_dbs/0 |
| ]). |
| |
| -record(st, { |
| checker |
| }). |
| |
| start_link() -> |
| gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). |
| |
| init(_) -> |
| process_flag(trap_exit, true), |
| net_kernel:monitor_nodes(true), |
| {ok, restart_checker(#st{})}. |
| |
| terminate(_Reason, St) -> |
| couch_util:shutdown_sync(St#st.checker), |
| ok. |
| |
| handle_call(Msg, _From, St) -> |
| {stop, {invalid_call, Msg}, {invalid_call, Msg}, St}. |
| |
| handle_cast(refresh, St) -> |
| {noreply, restart_checker(St)}; |
| handle_cast(Msg, St) -> |
| {stop, {invalid_cast, Msg}, St}. |
| |
| handle_info({nodeup, _}, St) -> |
| {noreply, restart_checker(St)}; |
| handle_info({nodedown, _}, St) -> |
| {noreply, restart_checker(St)}; |
| handle_info({'EXIT', Pid, normal}, #st{checker = Pid} = St) -> |
| {noreply, St#st{checker = undefined}}; |
| handle_info({'EXIT', Pid, Reason}, #st{checker = Pid} = St) -> |
| couch_log:notice("custodian db checker died ~p", [Reason]), |
| {noreply, restart_checker(St#st{checker = undefined})}; |
| handle_info(Msg, St) -> |
| {stop, {invalid_info, Msg}, St}. |
| |
| code_change(_OldVsn, St, _Extra) -> |
| {ok, St}. |
| |
| restart_checker(#st{checker = undefined} = St) -> |
| Pid = spawn_link(fun ?MODULE:check_dbs/0), |
| St#st{checker = Pid}; |
| restart_checker(#st{checker = Pid} = St) when is_pid(Pid) -> |
| St. |
| |
| check_dbs() -> |
| {ok, DbsDb} = custodian_util:ensure_dbs_exists(), |
| try |
| Missing = lists:foldl( |
| fun(DbName, Count) -> |
| case check_db(DbsDb, DbName) of |
| ok -> Count; |
| missing -> Count + 1 |
| end |
| end, |
| 0, |
| get_dbs() |
| ), |
| case Missing == 0 of |
| true -> clear_missing_dbs_alert(); |
| false -> ok |
| end |
| after |
| couch_db:close(DbsDb) |
| end. |
| |
| check_db(DbsDb, DbName) when is_binary(DbName) -> |
| try |
| case couch_db:open_doc(DbsDb, DbName, []) of |
| {ok, _} -> |
| ok; |
| _ -> |
| send_missing_db_alert(DbName), |
| missing |
| end |
| catch |
| _:_ -> |
| send_missing_db_alert(DbName), |
| missing |
| end. |
| |
| get_dbs() -> |
| lists:flatten([ |
| get_users_db(), |
| get_stats_db() |
| ]). |
| |
| get_users_db() -> |
| UsersDb = chttpd_auth_cache:dbname(), |
| [list_to_binary(UsersDb)]. |
| |
| get_stats_db() -> |
| case application:get_env(ioq, stats_db) of |
| {ok, DbName} when is_binary(DbName) -> |
| [DbName]; |
| {ok, DbName} when is_list(DbName) -> |
| [iolist_to_binary(DbName)]; |
| _ -> |
| [] |
| end. |
| |
| send_missing_db_alert(DbName) -> |
| couch_log:notice("Missing system database ~s", [DbName]), |
| ?CUSTODIAN_MONITOR:send_missing_db_alert(DbName). |
| |
| clear_missing_dbs_alert() -> |
| couch_log:notice("All system databases exist.", []), |
| ?CUSTODIAN_MONITOR:clear_missing_dbs_alert(). |