[CRIU] [Users] socket will take at least 0.5 seconds to recovery after docker restore done

Pavel Emelyanov xemul at parallels.com
Tue Jul 14 06:59:25 PDT 2015


On 07/14/2015 04:43 PM, Yanbao Cui wrote:
> Server is working always and waiting. It seems the client, which is in the container, cannot send data out after restored.
> 
> For TCP, yeah, the client try to reconnect manually.

You mean that after restore new connect()-s hang for a while? Why do these connect()-s happen?
Or _existing_ migrated connections hang?

> The delay is happened after restore successful, although the network is recovered
> 
> 
> Pavel Emelyanov <xemul at parallels.com <mailto:xemul at parallels.com>>于2015年7月14日 周二 21:31写道:
> 
>     On 07/14/2015 04:15 PM, Yanbao Cui wrote:
>     > Sorry for mistake.
>     > For UDP, I mean the sever can receive the packet from client again.
> 
>     So where's the 0.5 seconds delay? Server sleeps and doesn't wake up, packets
>     do not reach the server or something else?
> 
>     > Actually, I have analysis the tcpdump output, in my case, the client try to reconnect
>     > to the server again, but can not receive SYN+ACK, so it re-transmission after 1 second
>     > according to the client rule, and then try again.
> 
>     During migration we don't reconnect TCP (with regular SYN, SYNACK, ACK sequence),
>     do you reconnect them manually?
> 
>     -- Pavel
> 



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