From: Serge Petrenko via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: v.ioffe@tarantool.org, kyukhin@tarantool.org Cc: tarantool-patches@dev.tarantool.org Subject: [Tarantool-patches] [PATCH] applier: fix upstream.lag calculations Date: Fri, 13 Aug 2021 17:25:46 +0300 [thread overview] Message-ID: <20210813142546.41696-1-sergepetrenko@tarantool.org> (raw) upstream.lag is the delta between the moment when a row was written to master's journal and the moment when it was received by the replica. It's an important metric to check whether the replica has fallen too far behind master. Not all the rows coming from master have a valid time of creation. For example, RAFT system messages don't have one, and we can't assign correct time to them: these messages do not originate from the journal, and assigning current time to them would lead to jumps in upstream.lag results. Stop updating upstream.lag for rows which don't have creation time assigned. This also fixes the flaky replication/errinj.test.lua --- https://github.com/tarantool/tarantool/tree/sp/applier-lag-fix src/box/applier.cc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/box/applier.cc b/src/box/applier.cc index 902d0bc72..9256078e1 100644 --- a/src/box/applier.cc +++ b/src/box/applier.cc @@ -664,7 +664,8 @@ applier_read_tx_row(struct applier *applier, double timeout) coio_read_xrow_timeout_xc(coio, ibuf, row, timeout); - applier->lag = ev_now(loop()) - row->tm; + if (row->tm > 0) + applier->lag = ev_now(loop()) - row->tm; applier->last_row_time = ev_monotonic_now(loop()); return tx_row; } -- 2.30.1 (Apple Git-130)
next reply other threads:[~2021-08-13 14:25 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-13 14:25 Serge Petrenko via Tarantool-patches [this message] 2021-08-14 6:42 ` Vitaliia Ioffe via Tarantool-patches 2021-08-14 8:03 ` Serge Petrenko via Tarantool-patches
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