diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/rabbit.erl | 2 | ||||
| -rw-r--r-- | src/rabbit_mnesia.erl | 2 | ||||
| -rw-r--r-- | src/rabbit_peer_discovery.erl | 56 |
3 files changed, 59 insertions, 1 deletions
diff --git a/src/rabbit.erl b/src/rabbit.erl index c52949af4c..5228984ad2 100644 --- a/src/rabbit.erl +++ b/src/rabbit.erl @@ -328,6 +328,8 @@ broker_start() -> start_apps(ToBeLoaded), maybe_sd_notify(), ok = log_broker_started(rabbit_plugins:strictly_plugins(rabbit_plugins:active())), + %% See rabbitmq/rabbitmq-server#1202 for details. + rabbit_peer_discovery:maybe_inject_randomized_delay(), rabbit_peer_discovery:maybe_register(), ok. diff --git a/src/rabbit_mnesia.erl b/src/rabbit_mnesia.erl index 68fe5468af..e48eb2b91f 100644 --- a/src/rabbit_mnesia.erl +++ b/src/rabbit_mnesia.erl @@ -119,6 +119,8 @@ init_from_config() -> (Name, BadNames) when is_atom(Name) -> BadNames; (Name, BadNames) -> [Name | BadNames] end, + %% See rabbitmq/rabbitmq-server#1202 for details. + rabbit_peer_discovery:maybe_inject_randomized_delay(), {DiscoveredNodes, NodeType} = case rabbit_peer_discovery:discover_cluster_nodes() of {ok, {Nodes, Type} = Config} diff --git a/src/rabbit_peer_discovery.erl b/src/rabbit_peer_discovery.erl index 98d2f9e7c5..52eac1c14e 100644 --- a/src/rabbit_peer_discovery.erl +++ b/src/rabbit_peer_discovery.erl @@ -22,7 +22,8 @@ -export([discover_cluster_nodes/0, backend/0, node_type/0, normalize/1, format_discovered_nodes/1, log_configured_backend/0, - register/0, unregister/0, maybe_register/0, maybe_unregister/0]). + register/0, unregister/0, maybe_register/0, maybe_unregister/0, + maybe_inject_randomized_delay/0]). -export([append_node_prefix/1, node_prefix/0]). -define(DEFAULT_BACKEND, rabbit_peer_discovery_classic_config). @@ -31,6 +32,9 @@ -define(DEFAULT_NODE_TYPE, disc). %% default node prefix to attach to discovered hostnames -define(DEFAULT_PREFIX, "rabbit"). +%% default randomized delay range, in seconds +-define(DEFAULT_STARTUP_RANDOMIZED_DELAY, {5, 60}). + -define(NODENAME_PART_SEPARATOR, "@"). @@ -99,6 +103,56 @@ maybe_unregister() -> end. +-spec maybe_inject_randomized_delay() -> ok. +maybe_inject_randomized_delay() -> + Backend = backend(), + case Backend:supports_registration() of + true -> + rabbit_log:info("Peer discovery backend ~s supports registration.", [Backend]), + inject_randomized_delay(); + false -> + rabbit_log:info("Peer discovery backend ~s does not support registration, skipping randomized startup delay.", [Backend]), + ok + end. + +-spec inject_randomized_delay() -> ok. + +inject_randomized_delay() -> + {Min, Max} = case randomized_delay_range() of + {A, B} -> {A, B}; + [A, B] -> {A, B} + end, + case {Min, Max} of + %% When the max value is set to 0, consider the delay to be disabled. + %% In addition, `rand:uniform/1` will fail with a "no function clause" + %% when the argument is 0. + {_, 0} -> + rabbit_log:info("Randomized delay range's upper bound is set to 0. Considering it disabled."), + ok; + {_, N} when is_number(N) -> + rand:seed(exsplus), + RandomVal = rand:uniform(round(N)), + rabbit_log:debug("Randomized startup delay: configured range is from ~p to ~p, PRNG pick: ~p...", [Min, Max, RandomVal]), + Effective = case RandomVal < Min of + true -> Min; + false -> RandomVal + end, + rabbit_log:info("Will wait for ~p seconds before proceeding with regitration...", [Effective]), + timer:sleep(Effective * 1000), + ok + end. + +-spec randomized_delay_range() -> {integer(), integer()}. + +randomized_delay_range() -> + case application:get_env(rabbit, autocluster) of + {ok, Proplist} -> + proplists:get_value(randomized_startup_delay_range, Proplist, ?DEFAULT_STARTUP_RANDOMIZED_DELAY); + undefined -> + ?DEFAULT_STARTUP_RANDOMIZED_DELAY + end. + + -spec register() -> ok. register() -> |