From: Vladislav Shpilevoy via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: Serge Petrenko <sergepetrenko@tarantool.org>, gorcunov@gmail.com Cc: tarantool-patches@dev.tarantool.org Subject: Re: [Tarantool-patches] [PATCH v3 07/12] box: introduce `box.ctl.demote` Date: Thu, 22 Jul 2021 01:28:32 +0200 [thread overview] Message-ID: <9ae5765f-ffcb-af66-469b-b0a99d71c331@tarantool.org> (raw) In-Reply-To: <3b4f7752-f68b-afce-c83a-355bcfbc28cc@tarantool.org> Thanks for the fixes! >> 2. On top of this commit and on top of the branch too I tried to >> promote a candidate and got a strange error in the logs, although >> the promotion was successful: >> >> -- >> -- Instance 1 >> -- >> >> -- Step 1 >> box.cfg{ >> listen = 3313, >> election_mode = 'candidate', >> replication_synchro_quorum = 2, >> replication = {'localhost:3314', 'localhost:3313'} >> } >> box.schema.user.grant('guest', 'super') >> >> >> -- >> -- Instance 2 >> -- >> >> -- Step 2 >> box.cfg{ >> listen = 3314, >> election_mode = 'voter', >> replication_synchro_quorum = 2, >> replication = {'localhost:3314', 'localhost:3313'}, >> read_only = true, >> } >> >> -- Step 3 >> box.cfg{read_only = false, election_mode = 'candidate'} >> >> -- Step 4 >> box.ctl.promote() >> >> main/112/raft_worker box.cc:1538 E> ER_UNSUPPORTED: box.ctl.promote does not support simultaneous invocations >> --- >> ... > > That's because once a candidate becomes the leader, it tries to issue `box.ctl.promote()`, and fails, > since we're already in `box.ctl.promote()` call. > I'm not sure how to handle that properly. This doesn't break anything though. Still, the error message looks really not good. There is an option - make box_promote() for candidate node just call raft_promote() and set box_in_promote = false. Then wait for the term outcome. Will it work? You would need to rebase your patchset on master branch then. It might be a little easier to do if you apply the diff below. (Warning: I didn't test it.) The motivation is that one of the main reasons why I wanted box_promote() simplified was because of the strange meaning of some flags. In particular, try_wait flag somewhy triggered elections before the waiting which is super not obvious why. How does 'wait' come to 'elections'? In the diff I tried to remove these flags entirely. And now you have a single place in the code of box_promote(), where ELECTION_MODE_CANDIDATE stuff is handled. Here you could try the proposal I gave above. ==================== diff --git a/src/box/box.cc b/src/box/box.cc index f68fffcab..e7765b657 100644 --- a/src/box/box.cc +++ b/src/box/box.cc @@ -1698,34 +1698,6 @@ box_issue_demote(uint32_t prev_leader_id, int64_t promote_lsn) assert(txn_limbo_is_empty(&txn_limbo)); } -/** - * Check whether this instance may run a promote() and set promote parameters - * according to its election mode. - */ -static int -box_check_promote_election_mode(bool *try_wait, bool *run_elections) -{ - switch (box_election_mode) { - case ELECTION_MODE_OFF: - if (try_wait != NULL) - *try_wait = true; - break; - case ELECTION_MODE_VOTER: - assert(box_raft()->state == RAFT_STATE_FOLLOWER); - diag_set(ClientError, ER_UNSUPPORTED, "election_mode='voter'", - "manual elections"); - return -1; - case ELECTION_MODE_MANUAL: - case ELECTION_MODE_CANDIDATE: - if (run_elections != NULL) - *run_elections = box_raft()->state != RAFT_STATE_LEADER; - break; - default: - unreachable(); - } - return 0; -} - /* A guard to block multiple simultaneous promote()/demote() invocations. */ static bool box_in_promote = false; @@ -1757,27 +1729,35 @@ box_promote(void) if (is_leader) return 0; - bool run_elections = false; - bool try_wait = false; - - if (box_check_promote_election_mode(&try_wait, &run_elections) < 0) - return -1; - - int64_t wait_lsn = -1; - - if (run_elections && box_run_elections() < 0) - return -1; - if (try_wait) { - if (box_try_wait_confirm(2 * replication_synchro_timeout) < 0) + switch (box_election_mode) { + case ELECTION_MODE_OFF: + if (box_try_wait_confirm(2 * replication_synchro_timeout) != 0) + return -1; + if (box_trigger_elections() != 0) return -1; - if (box_trigger_elections() < 0) + break; + case ELECTION_MODE_VOTER: + assert(box_raft()->state == RAFT_STATE_FOLLOWER); + diag_set(ClientError, ER_UNSUPPORTED, "election_mode='voter'", + "manual elections"); + return -1; + case ELECTION_MODE_MANUAL: + case ELECTION_MODE_CANDIDATE: + if (box_raft()->state != RAFT_STATE_LEADER && + box_run_elections() != 0) return -1; + break; + default: + unreachable(); } - if ((wait_lsn = box_wait_limbo_acked()) < 0) + if (box_check_promote_election_mode(&try_wait, &run_elections) < 0) return -1; - box_issue_promote(txn_limbo.owner_id, wait_lsn); + int64_t wait_lsn = box_wait_limbo_acked(); + if (wait_lsn < 0) + return -1; + box_issue_promote(txn_limbo.owner_id, wait_lsn); return 0; } @@ -1804,29 +1784,16 @@ box_demote(void) is_leader = is_leader && box_raft()->state == RAFT_STATE_LEADER; if (!is_leader) return 0; - - bool try_wait = false; - - if (box_check_promote_election_mode(&try_wait, NULL) < 0) - return -1; - - int64_t wait_lsn = -1; - if (box_trigger_elections() < 0) return -1; - if (box_election_mode != ELECTION_MODE_OFF) return 0; - - if (try_wait && - box_try_wait_confirm(2 * replication_synchro_timeout) < 0) + if (box_try_wait_confirm(2 * replication_synchro_timeout) != 0) return -1; - - if ((wait_lsn = box_wait_limbo_acked()) < 0) + int64_t wait_lsn = box_wait_limbo_acked(); + if (wait_lsn < 0) return -1; - box_issue_demote(txn_limbo.owner_id, wait_lsn); - return 0; }
next prev parent reply other threads:[~2021-07-21 23:28 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-28 22:12 [Tarantool-patches] [PATCH v3 00/12] forbid implicit limbo ownership transition Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 01/12] replication: always send raft state to subscribers Serge Petrenko via Tarantool-patches 2021-07-04 12:12 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-09 9:43 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 02/12] txn_limbo: fix promote term filtering Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 03/12] raft: refactor raft_new_term() Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 04/12] box: make promote always bump the term Serge Petrenko via Tarantool-patches 2021-07-04 12:14 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:26 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 05/12] replication: forbid implicit limbo owner transition Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 06/12] box: allow calling promote on a candidate Serge Petrenko via Tarantool-patches 2021-07-04 12:14 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:26 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 07/12] box: introduce `box.ctl.demote` Serge Petrenko via Tarantool-patches 2021-07-04 12:27 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:28 ` Serge Petrenko via Tarantool-patches 2021-07-21 23:28 ` Vladislav Shpilevoy via Tarantool-patches [this message] 2021-07-23 7:44 ` Sergey Petrenko via Tarantool-patches 2021-07-26 23:50 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-29 20:56 ` Sergey Petrenko via Tarantool-patches 2021-08-01 16:19 ` Vladislav Shpilevoy via Tarantool-patches 2021-08-03 7:56 ` Serge Petrenko via Tarantool-patches 2021-08-03 23:25 ` Vladislav Shpilevoy via Tarantool-patches 2021-08-04 13:08 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 08/12] txn_limbo: persist the latest effective promote in snapshot Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 09/12] replication: encode version in JOIN request Serge Petrenko via Tarantool-patches 2021-07-04 12:27 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:28 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 10/12] replication: add META stage to JOIN Serge Petrenko via Tarantool-patches 2021-07-04 12:28 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:28 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 11/12] replication: send latest effective promote in initial join Serge Petrenko via Tarantool-patches 2021-07-04 12:28 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:28 ` Serge Petrenko via Tarantool-patches 2021-06-28 22:12 ` [Tarantool-patches] [PATCH v3 12/12] replication: send current Raft term in join response Serge Petrenko via Tarantool-patches 2021-07-04 12:29 ` Vladislav Shpilevoy via Tarantool-patches 2021-07-14 18:28 ` Serge Petrenko via Tarantool-patches 2021-08-04 22:41 ` [Tarantool-patches] [PATCH v3 00/12] forbid implicit limbo ownership transition Vladislav Shpilevoy via Tarantool-patches 2021-08-06 7:54 ` Vitaliia Ioffe via Tarantool-patches 2021-08-06 8:31 ` Kirill Yukhin via Tarantool-patches 2021-08-08 10:46 ` Vladislav Shpilevoy via Tarantool-patches 2021-08-09 7:14 ` Kirill Yukhin via Tarantool-patches
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=9ae5765f-ffcb-af66-469b-b0a99d71c331@tarantool.org \ --to=tarantool-patches@dev.tarantool.org \ --cc=gorcunov@gmail.com \ --cc=sergepetrenko@tarantool.org \ --cc=v.shpilevoy@tarantool.org \ --subject='Re: [Tarantool-patches] [PATCH v3 07/12] box: introduce `box.ctl.demote`' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox