It really depends on the hypervisor. A lot of the "in-sequence" flags were
set back when CloudStack supported open-source Xen and the toolstack on
OSS Xen was really flaky in the context of concurrent requests.
On 7/26/13 3:29 PM, "Gavin Lee" <gavin....@gmail.com> wrote:
>The command transported to agent can be kept in sequence or not.
>
>If the command needs to be sent in sequence, it will make other
>non-sequencepending in the same host.
>
>For example, the migration command is labeled as keep-in-sequence, if we
>do
>following on the same host:
>1. migrate vm-1 from host A to host B
>2. start/deploy vm-2 on host A (command not keep-in-sequence)
>3. stop vm-3, vm-4, vm-5 on host A (command not keep-in-sequence)
>
>step 2 and step 3 are in pending state until vm-1 is migrated
>successfully.
>
>
>Some related log(After migration commands sent):
>2013-07-22 10:32:26,960 DEBUG [agent.transport.Request]
>(Job-Executor-27:job-588)
>Seq 32-1213290688: Waiting for Seq 1213290686 Scheduling: { Cmd , MgmtId:
>258319164151440, via: 32, Ver: v1, Flags: 100111,
>[{"routing.DhcpEntryCommand":{"vmMac":"06:c2:48:00:00:19","vmIpAddress":"1
>0.9.9.55","vmName":"test8","defaultRouter":"10.9.9.1","defaultDns":"10.9.9
>.53","accessDetails":{"router.guest.ip":"10.9.9.53","zone.network.type":"B
>asic","
>router.name":"r-398-VM","router.ip":"169.254.0.40"},"wait":0}}] }
>2013-07-22 10:52:40,613 DEBUG [agent.transport.Request]
>(Job-Executor-29:job-590)
>Seq 32-1213290757: Waiting for Seq 1213290749 Scheduling: { Cmd , MgmtId:
>258319164151440, via: 32, Ver: v1, Flags: 100111,
>[{"StopCommand":{"isProxy"
>:false,"vmName":"i-2-627-VM","wait":0}}] }
>
>My question is if it's really necessary to control resource in host level?
>I think the granularity is a little big, it should be limited to VM not
>the
>host, it won't cause problem but I think it's not reasonable.
>
>
>Another question is how to determine the command should be set in
>keep-in-sequence
>when sending to agent/host?
>
>Appreciate if anyone can give an explanation.
>
>--
>Gavin
