From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp44.i.mail.ru (smtp44.i.mail.ru [94.100.177.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id EA9B3469710 for ; Fri, 20 Nov 2020 15:41:13 +0300 (MSK) References: <20201119194100.840495-1-gorcunov@gmail.com> <20201119194100.840495-5-gorcunov@gmail.com> <1e448048-ac86-2c58-ed0a-2cc2f6a5df11@tarantool.org> <20201120120103.GD875895@grain> From: Serge Petrenko Message-ID: <63c1afba-1001-289d-57bc-9dc35679ffc7@tarantool.org> Date: Fri, 20 Nov 2020 15:41:12 +0300 MIME-Version: 1.0 In-Reply-To: <20201120120103.GD875895@grain> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Content-Language: en-GB Subject: Re: [Tarantool-patches] [RFC 4/4] qsync: allow to specify replication_synchro_quorum as a formula List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cyrill Gorcunov Cc: tml , Vladislav Shpilevoy 20.11.2020 15:01, Cyrill Gorcunov пишет: > On Fri, Nov 20, 2020 at 01:50:50PM +0300, Serge Petrenko wrote: >>> @@ -4216,6 +4217,7 @@ unregister_replica(struct trigger *trigger, void * /* event */) >>> struct replica *replica = replica_by_uuid(&old_uuid); >>> assert(replica != NULL); >>> replica_clear_id(replica); >>> + replication_on_cluster_update(); >>> return 0; >>> } >> We usually perform all the work related to replica register/unregister >> directly in replica_set_id >> and replica_clear_id. >> >> Besides, these are the places where replicaset.registered_count is updated, >> so it'd be nice to call replication_on_cluster_update from there. > Sure. > >>> --- a/src/box/box.cc >>> +++ b/src/box/box.cc >>> @@ -634,14 +634,6 @@ box_check_replication_synchro_quorum(void) >>> */ >>> int value = replication_synchro_quorum; >>> quorum = eval_replication_synchro_quorum(value); >>> Pass replicaset.registered_count instead of replication_synchro_quorum here. > Wait, this is bootstrap, replicaset.registered_count is 0 at this moment, no? Hm, I didn't think of this. Yes, this is  either bootstrap or reconfiguration. Well, if we have a max(1, value)  guard nothing bad should happen even if we pass 0 on bootstrap. The formula will be reevaluated each time a replica is registered anyway. Even when the node registers itself. Anyway, passing replication_synchro_quorum as parameter to evaluate quorum is even more random. > >>> } >>> +/** >>> + * Evaluate the new synchro quorum number when replica >>> + * get registered/unregistered and the quorum depends on >>> + * their amount via formula in config. >>> + */ >>> +void >>> +replication_on_cluster_update(void) >>> +{ >>> + if (!replication_synchro_quorum_eval) >>> + return; >>> + >>> + /* >>> + * Account only registered replicas when evaluating >>> + * quorum number from a fromula present in config. >>> + */ >>> + int value = replicaset.registered_count - replicaset.anon_count; >> >> registered_count stands for 'normal' replica count, so no need to subtract >> anon_count from it. > Yeah, thanks! > >>> + >>> + say_info("replication: evaluated quorum is %d", quorum); >> >> quorum -> replication_synchro_quorum > ok -- Serge Petrenko