From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 21 Aug 2019 14:35:11 +0300 From: Vladimir Davydov Subject: Re: [tarantool-patches] [PATCH 3/7] Replication: Relay does not rely on xlog boundaries Message-ID: <20190821113511.GA13834@esperanza> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: To: Georgy Kirichenko Cc: tarantool-patches@freelists.org List-ID: On Tue, Aug 13, 2019 at 09:27:41AM +0300, Georgy Kirichenko wrote: > When relay got an ACK then it matches received vclock against xlog file > boundaries detected using on_close_log trigger and send a consumer > advance message. However, for each ACK relay send a status update > message to the tx cord which could be used for gc purposes. > This patch removes any knowledge about xlog boundaries from relay > because there would not any xlog files in case of in-memory replication. > As gc now tracks all xlog files then it is able to handle garbage files > using relay status updates. > > Note: after parallel applier there is no more one ACK per transaction > so it should not be too expensive to advance a consumer on each status > update. However I think it could be improved, for instance with tracking > the next wal file vclock. I don't see a way to preserve the old behavior after switching to replication from memory so I guess this patch is okay.