From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 30 Oct 2018 19:13:56 +0300 From: Vladimir Davydov Subject: Re: [tarantool-patches] [PATCH v2] box: fixed comparison of old and new config options Message-ID: <20181030161356.ko3twf5vbvxmhl2j@esperanza> References: <20181030120423.69490-1-arkholga@tarantool.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181030120423.69490-1-arkholga@tarantool.org> To: Olga Arkhangelskaia Cc: tarantool-patches@freelists.org List-ID: On Tue, Oct 30, 2018 at 03:04:23PM +0300, Olga Arkhangelskaia wrote: > Due to incorrect configuration comparison, some options, especially > replication, were reseted and restarted, despite that configurations > were equivalent. Bad description. Please describe why exactly we're doing this, i.e. what happens if we don't check whether box.cfg.replication actually changed. > > Closes #3711 > --- > Issue: > https://github.com/tarantool/tarantool/issues/3711 > Branch: > https://github.com/tarantool/tarantool/tree/OKriw/gh-3711-do-not-restart-replication-if-config-did-not-change-2.1 > > v1: > https://www.freelists.org/post/tarantool-patches/PATCH-box-fixed-comparison-of-old-and-new-config-options > > Changes in v2: > - changed test > - conversion from num to string now in modify_cfg > - no sort table in comparison > - got rid of table.getn > > src/box/lua/load_cfg.lua | 33 +++++++++++++++++++-- > test/replication/misc.result | 65 ++++++++++++++++++++++++++++++++++++++++++ > test/replication/misc.test.lua | 24 ++++++++++++++++ > 3 files changed, 119 insertions(+), 3 deletions(-) > > diff --git a/src/box/lua/load_cfg.lua b/src/box/lua/load_cfg.lua > index df0c3c6ae..6d3c7f62c 100644 > --- a/src/box/lua/load_cfg.lua > +++ b/src/box/lua/load_cfg.lua > @@ -145,7 +145,11 @@ local template_cfg = { > } > > local function normalize_uri(port) > - if port == nil or type(port) == 'table' then > + if port == nil then return port end Nit: we never write 'then' and 'return' at the same line, please fix here and everywhere. > + if type (port) == 'table' then ^^^ Nit: extra space > + for i in pairs(port) do > + port[i] = tostring(port[i]) > + end > return port > end > return tostring(port); This function is also used for normalizing box.cfg.listen, which can't be a table. IMHO we'd better introduce normalize_uri_list instead of patching it. > @@ -365,6 +369,29 @@ local function apply_default_cfg(cfg, default_cfg) > end > end > > +-- check whether two configurations are equivalent, returns true, if yes, > +-- false otherwise. Nit: we start comments with a capital letter and try to limit the text width to ~65 symbols. Anyway, let's rewrite this comment to be as simple as: -- Return true if the two configurations are equivalent. > +local function equivalent (t1, t2) Please name this function compare_cfg() as you used to - this would be consistent with load_cfg() and modify_cfg(). I wanted you to just fix the comment. > + if type(t1) ~= 'table' and type(t2) ~= 'table' then return t1 == t2 end > + if type(t1) == "table" and type(t2) ~= "table" then Nit: please use the same quote style ("" or '') everywhere. > + if #t1 == 1 then return t1[1] == t2 end As I said, you should do all config interpretation in modify_cfg(), in particular turning a scalar into a table if necessary. > + return false > + end > + if type(t2) == "table" and type(t1) ~= "table" then > + if #t2 == 1 then return t2[1] == t1 end ^^ Nit: extra space (it's very annoying, please self-review your code before sending it for review). > + return false > + end > + if type(t1) == 'table' and type(t2) == 'table' then > + if #t1 ~= #t2 then return false end > + for i in pairs(t2) do > + if equivalent(t1[i], t2[i]) == false then We don't use nested tables in configuration yet. Since this function isn't generic anyway (it doesn't support Lua maps), I think we should simplify it: for k, v in ipairs(t1) do if t2[k] ~= v then return false end end > + return false > + end > + end > + return true > + end > +end > + > local function reload_cfg(oldcfg, cfg) > cfg = upgrade_cfg(cfg, translate_cfg) > local newcfg = prepare_cfg(cfg, default_cfg, template_cfg, modify_cfg) > @@ -377,7 +404,7 @@ local function reload_cfg(oldcfg, cfg) > for key in pairs(cfg) do > local val = newcfg[key] > local oldval = oldcfg[key] > - if oldval ~= val then > + if not equivalent(val, oldval) then > rawset(oldcfg, key, val) > if not pcall(dynamic_cfg[key]) then > rawset(oldcfg, key, oldval) -- revert the old value > @@ -452,7 +479,7 @@ local function load_cfg(cfg) > local val = cfg[key] > if val ~= nil and not dynamic_cfg_skip_at_load[key] then > fun() > - if val ~= default_cfg[key] then > + if not equivalent(val, default_cfg[key]) then > log.info("set '%s' configuration option to %s", key, json.encode(val)) > end > end > diff --git a/test/replication/misc.test.lua b/test/replication/misc.test.lua > index 46726b7f4..7a3020f6e 100644 > --- a/test/replication/misc.test.lua > +++ b/test/replication/misc.test.lua > @@ -191,3 +191,27 @@ test_run:cmd("stop server replica") > test_run:cmd("cleanup server replica") > test_run:cmd("delete server replica") > box.schema.user.revoke('guest', 'replication') > + > + > +-- > +-- gh-3711 Do not restart replication on box.cfg if the configuration didn't change > +-- > +box.schema.user.grant('guest', 'replication') > + > +test_run:cmd("create server replica with rpl_master=default, script='replication/replica.lua'") > +test_run:cmd("start server replica") > +test_run:cmd("switch replica") > +replication = box.cfg.replication > +test_run:cmd("switch default") > +box.schema.user.revoke('guest', 'replication') It would be nice if you described why you revoke replication privileges here. > +test_run:cmd("switch replica") > +box.cfg{replication_sync_timeout = 0.5} Why? > +box.cfg{replication = {replication}} > +box.info.status == 'running' > +box.cfg{replication = replication} > +box.info.status == 'running' I want you to also check the case when box.cfg.replication is a table of more than one element. You can use self as the second replication source. > + > +test_run:cmd("switch default") > +test_run:cmd("stop server replica") > +test_run:cmd("cleanup server replica") > +test_run:cmd("delete server replica")