On Mon, Apr 16, 2018 at 4:19 PM, Luse, Paul E wrote: > Hi Ming, > > Any chance of seeing a patch series before then? That would be a valuable contribution to the community for sure! Hi Paul, We are on the process to get internal approve and will send the patches out then. Regards, Ming > > Thx > Paul > > -----Original Message----- > From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of Ming Lin > Sent: Monday, April 16, 2018 4:15 PM > To: Storage Performance Development Kit > Subject: Re: [SPDK] vhost target failover? > > On Mon, Apr 16, 2018 at 12:37 PM, Harris, James R wrote: >> I agree with Pawel regarding vhost crashes. If the SPDK vhost target >> crashed, I would recommend treating it similarly to the host kernel >> crashing. There’s no way to know exactly what may have been >> inadvertently modified due to the crash. >> >> >> >> But the idea of “managed failover” could be useful in terms of >> upgrading the vhost target. I’m not aware of anyone actively working >> on this at the moment however. > > Hi Jim, > > We(Alibaba) have done some work to handle vhost target crash. > We'll share it(and other modification&improvement) in the coming US SPDK summit. > > Regards, > Ming > >> >> >> >> Regards, >> >> >> >> -Jim >> >> >> >> >> >> From: "Wodkowski, PawelX" >> Date: Monday, April 16, 2018 at 1:47 AM >> To: Storage Performance Development Kit , James >> Harris >> Subject: RE: Re: [SPDK] vhost target failover? >> >> >> >> We can implement any kind of failover mechanism. Starting some kind of >> proxy process to pass vhost user messages to child process would not >> be so hard to implement. In theory. >> >> But the question is how to handle crash in the middle of request? In >> virtio-net situation is much simpler – if TCP network packet is lost >> it will be retransmitted. If packet is retransmitted after vhost-net >> target restart >> - it will be filtered by TCP layer. What to do if in the middle of eg >> 2MB write vhost crashes and restarts? One solution could be to promote >> the vhost target restart/recover to the SCSI reset event. It's doable. >> >> >> >> Another issue is that if vhost crashes it mean there was some serious >> issue including possibility of trashing guest memory. Personally, I >> recommend (and I think DPDK recommend this also) to save what you can >> and restart everything. >> >> >> >> Adding Jim as he could write something more here. >> >> >> >> Pawel >> >> >> >> From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of Huang Frank >> Sent: Monday, April 16, 2018 10:09 AM >> To: spdk >> Subject: Re: [SPDK] vhost target failover? >> >> >> >> hi, Pawel >> >> >> >> Thanks. >> >> Is there any suggestions for this issue? Or any plans to provide High >> Availability of vhost target in the future? >> >> >> >> ________________________________ >> >> kinzent(a)hotmail.com >> >> >> >> From: Wodkowski, PawelX >> >> Date: 2018-04-16 16:02 >> >> To: Storage Performance Development Kit >> >> Subject: Re: [SPDK] vhost target failover? >> >> There is none currently. Device will be seen as dead. All requests >> will stuck. Anything else related to guest should be unaffected. >> >> >> >> Pawel >> >> >> >> From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of Huang Frank >> Sent: Monday, April 16, 2018 9:42 AM >> To: spdk >> Subject: [SPDK] vhost target failover? >> >> >> >> Hi，all >> >> >> >> What's the failover mechism of vhost target? If the vhost target goes >> to crash, how to make sure the guest can process without affectting? >> >> >> >> Thanks, >> >> Frank. >> >> >> >> ________________________________ >> >> kinzent(a)hotmail.com >> >> >> _______________________________________________ >> SPDK mailing list >> SPDK(a)lists.01.org >> https://lists.01.org/mailman/listinfo/spdk >> > _______________________________________________ > SPDK mailing list > SPDK(a)lists.01.org > https://lists.01.org/mailman/listinfo/spdk > _______________________________________________ > SPDK mailing list > SPDK(a)lists.01.org > https://lists.01.org/mailman/listinfo/spdk