Re: [Tarantool-patches] [PATCH 2/2] test: speed up election_qsync

[Serge Petrenko <sergepetrenko@tarantool.org>]

07.11.2020 02:46, Vladislav Shpilevoy пишет:
> The test used default election timeout - 5 seconds. That made the
> test work at least 5 seconds when test re-election. 5 seconds to
> ensure the old leader is dead + some time to perform the election.
>
> Closes #5499
> ---

Hi! Thanks for the patch!

Please see one question below.

>   test/replication/election_qsync.result   | 6 ++++++
>   test/replication/election_qsync.test.lua | 4 ++++
>   2 files changed, 10 insertions(+)
>
> diff --git a/test/replication/election_qsync.result b/test/replication/election_qsync.result
> index 086b17686..abf43201f 100644
> --- a/test/replication/election_qsync.result
> +++ b/test/replication/election_qsync.result
> @@ -9,6 +9,9 @@ box.schema.user.grant('guest', 'super')
>   old_election_mode = box.cfg.election_mode
>    | ---
>    | ...
> +old_election_timeout = box.cfg.election_timeout
> + | ---
> + | ...
>   old_replication_synchro_timeout = box.cfg.replication_synchro_timeout
>    | ---
>    | ...
> @@ -62,6 +65,7 @@ fiber = require('fiber')
>   -- Replication timeout is small to speed up a first election start.

I checked, and the test speeds up a lot with this patch. But I don't 
understand
why. We have only two instances, only one of them is candidate.
Thanks to the small replication_timeout, the election starts shortly 
after the
old leader dies. election_timeout isn't involved here, AFAICS.
Am I missing something?
Even when the test is restarted, there shouldn't be any 're-elections'.

>   box.cfg{                                                                        \
>       election_mode = 'candidate',                                                \
> +    election_timeout = 0.1,                                                     \
>       replication_synchro_quorum = 3,                                             \
>       replication_synchro_timeout = 1000000,                                      \
>       replication_timeout = 0.1,                                                  \
> @@ -116,6 +120,7 @@ box.cfg{replication_synchro_timeout = 1000000}
>   -- up notice of the old leader death.
>   box.cfg{                                                                        \
>       election_mode = 'candidate',                                                \
> +    election_timeout = 0.1,                                                     \
>       replication_timeout = 0.01,                                                 \
>   }
>    | ---
> @@ -143,6 +148,7 @@ test_run:cmd('delete server replica')
>    | ...
>   box.cfg{                                                                        \
>       election_mode = old_election_mode,                                          \
> +    election_timeout = old_election_timeout,                                    \
>       replication_timeout = old_replication_timeout,                              \
>       replication = old_replication,                                              \
>       replication_synchro_timeout = old_replication_synchro_timeout,              \
> diff --git a/test/replication/election_qsync.test.lua b/test/replication/election_qsync.test.lua
> index 6a80f4859..f668a9d78 100644
> --- a/test/replication/election_qsync.test.lua
> +++ b/test/replication/election_qsync.test.lua
> @@ -2,6 +2,7 @@ test_run = require('test_run').new()
>   box.schema.user.grant('guest', 'super')
>   
>   old_election_mode = box.cfg.election_mode
> +old_election_timeout = box.cfg.election_timeout
>   old_replication_synchro_timeout = box.cfg.replication_synchro_timeout
>   old_replication_timeout = box.cfg.replication_timeout
>   old_replication = box.cfg.replication
> @@ -30,6 +31,7 @@ fiber = require('fiber')
>   -- Replication timeout is small to speed up a first election start.
>   box.cfg{                                                                        \
>       election_mode = 'candidate',                                                \
> +    election_timeout = 0.1,                                                     \
>       replication_synchro_quorum = 3,                                             \
>       replication_synchro_timeout = 1000000,                                      \
>       replication_timeout = 0.1,                                                  \
> @@ -59,6 +61,7 @@ box.cfg{replication_synchro_timeout = 1000000}
>   -- up notice of the old leader death.
>   box.cfg{                                                                        \
>       election_mode = 'candidate',                                                \
> +    election_timeout = 0.1,                                                     \
>       replication_timeout = 0.01,                                                 \
>   }
>   
> @@ -70,6 +73,7 @@ box.space.test:drop()
>   test_run:cmd('delete server replica')
>   box.cfg{                                                                        \
>       election_mode = old_election_mode,                                          \
> +    election_timeout = old_election_timeout,                                    \
>       replication_timeout = old_replication_timeout,                              \
>       replication = old_replication,                                              \
>       replication_synchro_timeout = old_replication_synchro_timeout,              \

-- 
Serge Petrenko