From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <v.shpilevoy@tarantool.org>
Received: from smtp3.mail.ru (smtp3.mail.ru [94.100.179.58])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by dev.tarantool.org (Postfix) with ESMTPS id 3CDD34696C3
 for <tarantool-patches@dev.tarantool.org>;
 Sat,  2 May 2020 23:12:12 +0300 (MSK)
References: <cover.1588292014.git.v.shpilevoy@tarantool.org>
 <8ef56505d0ff0302c09570eecc55fdbe911c3f17.1588292014.git.v.shpilevoy@tarantool.org>
 <17f95a5f-9fa5-3807-265c-e66fe176ff21@tarantool.org>
From: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>
Message-ID: <859f127f-742d-f1ca-43c4-e7badbd7d6ff@tarantool.org>
Date: Sat, 2 May 2020 22:12:10 +0200
MIME-Version: 1.0
In-Reply-To: <17f95a5f-9fa5-3807-265c-e66fe176ff21@tarantool.org>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Subject: Re: [Tarantool-patches] [PATCH vshard 7/7] router: introduce
	discovery mode 'once'
List-Id: Tarantool development patches <tarantool-patches.dev.tarantool.org>
List-Unsubscribe: <https://lists.tarantool.org/mailman/options/tarantool-patches>, 
 <mailto:tarantool-patches-request@dev.tarantool.org?subject=unsubscribe>
List-Archive: <https://lists.tarantool.org/pipermail/tarantool-patches/>
List-Post: <mailto:tarantool-patches@dev.tarantool.org>
List-Help: <mailto:tarantool-patches-request@dev.tarantool.org?subject=help>
List-Subscribe: <https://lists.tarantool.org/mailman/listinfo/tarantool-patches>, 
 <mailto:tarantool-patches-request@dev.tarantool.org?subject=subscribe>
To: Oleg Babin <olegrok@tarantool.org>, tarantool-patches@dev.tarantool.org

Thanks for the review!

>> @@ -342,6 +342,13 @@ discovery_f = function(router)
>>               unknown_bucket_count =
>>                   router.total_bucket_count - router.known_bucket_count
>>               if unknown_bucket_count == 0 then
>> +                if router.discovery_mode == 'once' then
>> +                    log.info("Discovery mode is 'once', and all is "..
>> +                             "discovered - shut down the discovery process")
>> +                    router.discovery_fiber = nil
>> +                    lfiber.self():cancel()
>> +                    return
>> +                end
> 
> I'm not sure that self.cancel is a good approach. I think simple "return" should be enough.

The discovery fiber is restarted if it returns or throws. The only
way to stop it is to cancel. See reloadable_fiber_main_loop() in
vshard/vshard/util.lua.