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 Mon, 25 Nov 2019 18:31:44 +0300 (MSK)
Date: Mon, 25 Nov 2019 18:31:41 +0300
From: Alexander Turenko <alexander.turenko@tarantool.org>
Message-ID: <20191125153140.pgpok3phtvqqts7n@tkn_work_nb>
References: <20191123145012.16074-1-i.kosarev@tarantool.org>
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In-Reply-To: <20191123145012.16074-1-i.kosarev@tarantool.org>
Subject: Re: [Tarantool-patches] [PATCH] Stabilize tcp_connect in
	test_run:cmd()
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To: Ilya Kosarev <i.kosarev@tarantool.org>
Cc: tarantool-patches@dev.tarantool.org

On Sat, Nov 23, 2019 at 05:50:12PM +0300, Ilya Kosarev wrote:
> For some tests, for example, replication/box_set_replication_stress,
> socket.tcp_connect() in test_run:cmd() might sometimes fail when
> running under high load. Now it is fixed.
> 
> Closes #193
> ---
> https://github.com/tarantool/test-run/tree/i.kosarev/gh-193-stabilize-test-run-cmd
> https://github.com/tarantool/test-run/issues/193
> 
>  test_run.lua | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/test_run.lua b/test_run.lua
> index 63dfdef..0d450bd 100644
> --- a/test_run.lua
> +++ b/test_run.lua
> @@ -11,6 +11,9 @@ local clock = require('clock')
>  
>  local function cmd(self, msg)
>      local sock = socket.tcp_connect(self.host, self.port)
> +    while sock == nil do
> +        sock = socket.tcp_connect(self.host, self.port)
> +    end
>      local data = msg .. '\n'
>      sock:send(data)

I'm tentative about possibly infinite loop. I know, test-run will fail a
hung test, but it would be better to fail gracefully and provide some
information about an error (is socket.tcp_connect returns something
about?)

Let's consider using wait_cond or, better, set a connection timeout (if
possible).

It also interesting what is the reason of the connection error in the
first place. Whether test-run actually listens at the moment? Maybe it
unable to proceed much incoming connection requests at time?

Please, don't bury youself with that, but look around briefly.

WBR, Alexander Turenko.