From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp16.mail.ru (smtp16.mail.ru [94.100.176.153]) (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 E698D4696C3 for ; Thu, 16 Apr 2020 15:07:11 +0300 (MSK) From: Serge Petrenko Date: Thu, 16 Apr 2020 15:06:58 +0300 Message-Id: <20200416120658.33777-1-sergepetrenko@tarantool.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Tarantool-patches] [PATCH] relay: move relay_schedule_pending_gc before status update List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: gorcunov@gmail.com, v.shpilevoy@tarantool.org Cc: tarantool-patches@dev.tarantool.org relay_schedule_pending_gc() is executed after relay status update, which made perfect sense before we've introduced local spaces rework, making local space operations use a special instance id: 0. Relay status update is performed only when the remote instance has reported a bigger vclock, than its previous one. However, we may have an entire WAL file filled with local space changes, in which case the changes won't be transmitted to replica, and it will report the same vclock as before, postponing the scheduled gc until a non-local row is created on master. Fix this by reordering relay_schedule_pending_gc() and relay status update. In case nothing new is added to pending_gc queue and replica clock is not updated, relay_schedule_pending_gc() will exit on the first loop iteration, so it doesn't add an overhead. Also make relay_schedule_pending_gc() use vclock_compare_ignore0() instead of plain vclock_compare(). Follow-up #4114 --- This code was present in v5 of the patchset regarding local space replication rework, but I accidentally threw it away during the review. Sorry. The letter was "[PATCH v5 2/4] replication: hide 0-th vclock components in replication responses" Branch: https://github.com/tarantool/tarantool/tree/sp/relay-gc-fix src/box/relay.cc | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/src/box/relay.cc b/src/box/relay.cc index dd6c3a580..2ad02cb8a 100644 --- a/src/box/relay.cc +++ b/src/box/relay.cc @@ -464,7 +464,7 @@ relay_schedule_pending_gc(struct relay *relay, const struct vclock *vclock) * the greater signatures is due to changes pulled * from other members of the cluster. */ - if (vclock_compare(&curr->vclock, vclock) > 0) + if (vclock_compare_ignore0(&curr->vclock, vclock) > 0) break; stailq_shift(&relay->pending_gc); free(gc_msg); @@ -638,6 +638,10 @@ relay_subscribe_f(va_list ap) send_vclock = &r->vclock; else send_vclock = &relay->recv_vclock; + + /* Collect xlog files received by the replica. */ + relay_schedule_pending_gc(relay, send_vclock); + if (vclock_sum(&relay->status_msg.vclock) == vclock_sum(send_vclock)) continue; @@ -648,8 +652,6 @@ relay_subscribe_f(va_list ap) vclock_copy(&relay->status_msg.vclock, send_vclock); relay->status_msg.relay = relay; cpipe_push(&relay->tx_pipe, &relay->status_msg.msg); - /* Collect xlog files received by the replica. */ - relay_schedule_pending_gc(relay, send_vclock); } /* -- 2.21.1 (Apple Git-122.3)