[CRIU] Do anyone knows how to migrate a container with web app
Weicheng SUN
sunweicheng0001 at gmail.com
Tue May 3 09:18:30 PDT 2016
Thankfully, You understand what I mean. I know that I should request a same
IP address and the CRIU I use is the release you give in cr-combined(I
guess this is the modified CRIU you mentioned).
The problem is I do not know how to request a container with specific IP
address via docker command or RESTful API. I know there is docker run --ip
for later than docker v1.10, but the latest release of cr-combined doesn't
support this flag.
I tried to modified the source code of docker v1.10, but it always hangs on
without any response while running, :(.
Do you know how to request such a container with the release version you
give?
Regards,
David Sun 孙炜程
School of Software Engineering, Shanghai Jiaotong University
Mobile: 15921638078
E-mail: SunWeicheng0001 at gmail.com
2016-05-04 0:09 GMT+08:00 Ross Boucher <rboucher at gmail.com>:
> What we've done is modified the CRIU source to simply drop these
> unrestorable connections, rather than error out. Perhaps that could be
> turned into an option.
>
> On Tue, May 3, 2016 at 12:08 PM Ross Boucher <rboucher at gmail.com> wrote:
>
>> You should be able to request the same IP when creating the new docker
>> container. Similarly, you could do the same for any linked containers.
>>
>> On Tue, May 3, 2016 at 12:07 PM Weicheng SUN <sunweicheng0001 at gmail.com>
>> wrote:
>>
>>> I know what you mean. But I just want to migrate some containers to
>>> another host, all of those application can deal tcp reconnection.
>>> You say if there are some packets cannot deliver into new container's
>>> location, the restore will broken.
>>> So, If there is* a method to skip this progress, just to bind the old
>>> ip address to the container on the new host.*
>>> Everytime I checkpoint a container with tcp connection, scp to another
>>> host, then restore, the restore log always say that
>>>
>>> (00.294516) 1: Found id pipe:[6392267] (fd 1) in inherit fd list
>>> (00.294520) 1: File pipe:[6392267] will be restored from fd 3
>>> dumped from inherit fd 1
>>> (00.294535) 1: Found fd 1 (id pipe:[6392267]) in inherit fd list
>>> (caller inherit_fd_resolve_clash)
>>> (00.294538) 1: Inherit fd 1 moved to 3 to resolve clash
>>> (00.294541) 1: Create fd for 1
>>> (00.294544) 1: Restoring fd 2 (state -> create)
>>> (00.294545) 1: Creating pipe pipe_id=0x6189cc id=0x3
>>> (00.294547) 1: Found id pipe:[6392268] (fd 2) in inherit fd list
>>> (00.294548) 1: File pipe:[6392268] will be restored from fd 4
>>> dumped from inherit fd 2
>>> (00.294554) 1: Found fd 2 (id pipe:[6392268]) in inherit fd list
>>> (caller inherit_fd_resolve_clash)
>>> (00.294555) 1: Inherit fd 2 moved to 4 to resolve clash
>>> (00.294558) 1: Create fd for 2
>>> (00.294560) 1: Restoring fd 4 (state -> create)
>>> (00.294569) 1: Restore: family 10 type 1 proto 6 port 6379
>>> state 10 src_addr ::
>>> (00.294592) 1: 5 restore sndbuf 16384 rcv buf 87380
>>> (00.294595) 1: restore priority 0 for socket
>>> (00.294596) 1: restore rcvlowat 1 for socket
>>> (00.294598) 1: restore mark 0 for socket
>>> (00.294611) 1: Found fd 4 (id pipe:[6392268]) in inherit fd list
>>> (caller inherit_fd_resolve_clash)
>>> (00.294616) 1: Inherit fd 4 moved to 6 to resolve clash
>>> (00.294619) 1: Create fd for 4
>>> (00.294622) 1: Restoring fd 5 (state -> create)
>>> (00.294625) 1: Restore: family 2 type 1 proto 6 port 6379 state
>>> 10 src_addr 0.0.0.0
>>> (00.294633) 1: 5 restore sndbuf 16384 rcv buf 87380
>>> (00.294635) 1: restore priority 0 for socket
>>> (00.294636) 1: restore rcvlowat 1 for socket
>>> (00.294638) 1: restore mark 0 for socket
>>> (00.294640) 1: Create fd for 5
>>> (00.294642) 1: Restoring fd 6 (state -> create)
>>> (00.294644) 1: Restore: family 2 type 1 proto 6 port 6379 state
>>> 1 src_addr 172.17.128.2
>>> (00.294646) 1: Restoring TCP connection
>>> (00.294649) 1: Restoring TCP connection id 7 ino 619526
>>> (00.294657) 1: Setting 1 queue seq to 2786935679
>>> (00.294659) 1: Setting 2 queue seq to 919486667
>>> (00.294679) 1: Error (sk-inet.c:721): Can't bind inet socket (id
>>> 7): Cannot assign requested address
>>>
>>> You see, 172.17.128.2 is the old ip, criu tried to bind this ip to new
>>> container, but failed.
>>>
>>> Regards,
>>>
>>> David Sun 孙炜程
>>> School of Software Engineering, Shanghai Jiaotong University
>>>
>>> Mobile: 15921638078
>>>
>>> E-mail: SunWeicheng0001 at gmail.com
>>>
>>> 2016-04-28 18:33 GMT+08:00 Pavel Emelyanov <xemul at virtuozzo.com>:
>>>
>>>> On 04/28/2016 08:01 AM, Weicheng SUN wrote:
>>>> > Hi Everyone,
>>>> >
>>>> > The latest release of cr-combined said that it supports network. Then
>>>> I do some experiments. I use
>>>> > 1. docker run -d -v demo:/data --name=redis redis:latest
>>>> > 2. docker run -d -e USE_REDIS_HOST=redis --link redis:redis -p 80:80
>>>> --name=app binocarlos/moby-counter:latest
>>>> > which is a demo of simple website and redis is its storage. I first
>>>> run them on host A
>>>> >
>>>> > I try to checkpoint them and copy to another host(host B). I create
>>>> two containers with same configuration
>>>> > of them and applied the change of file system to the new created
>>>> container. Then I tried to restore them,
>>>> > which sometimes came out a wrong result.
>>>> > I notice that when redis and app have same ip address on host A and
>>>> B, then the restore will success. But,
>>>> > when they have different IP on two hosts, the restore progress will
>>>> certainly broken.
>>>> >
>>>> > The reason I guess is that the state of tcp connection in checkpoint
>>>> image didn't match the new environment
>>>> > in host B. For example, redis in host A is 17.172.20.1 and app in
>>>> host A is 17.172.20.2, then for app there
>>>> > is a connection whose remote host is 17.172.20.1. Then come to host
>>>> B, if redis in host B is 17.172.20.3 and
>>>> > when I try to restore app, criu will confuse where is
>>>> 17.172.20.1(redis)?
>>>>
>>>> After migration all the sockets get restored with the IP addresses they
>>>> had on source node,
>>>> so if for some reason packets to former container IP cannot be
>>>> delivered into container's
>>>> new location, the container would get broken. This is unavoidable
>>>> limitation of TCP protocol
>>>> itself. There can be workarounds to this (DNAT-like for example), but
>>>> this is out of CRIU's
>>>> scope and should be done on Docker level.
>>>>
>>>> > Generally, is there always a problem to checkpoint and restore a
>>>> container, who has a link with other
>>>> > containers, on the another host?
>>>> >
>>>> > And who knows that how to use a specific IP address while start a new
>>>> container? For the latest release of
>>>> > cr-combined doesn't support docker run --ip. Even --ip is supported,
>>>> it requires a user defined network,
>>>> > default network is not supported.
>>>> >
>>>> > Hopes for your kindly response & wish all of you a great day!
>>>> >
>>>> > Regards,
>>>> >
>>>> > David Sun
>>>> >
>>>> >
>>>> >
>>>> > _______________________________________________
>>>> > CRIU mailing list
>>>> > CRIU at openvz.org
>>>> > https://lists.openvz.org/mailman/listinfo/criu
>>>> >
>>>>
>>>>
>>>
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