Re: [Qemu-devel] [PATCH 3/5] QMP: Introduce MIGRATION events

[Luiz Capitulino]

On Tue, 25 May 2010 16:21:03 +0200
Juan Quintela <address@hidden> wrote:

> They are emitted when migration starts, ends, has a failure or is canceled.
> 
> Signed-off-by: Juan Quintela <address@hidden>
> ---
>  QMP/qmp-events.txt |   50 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  monitor.c          |   12 ++++++++++++
>  monitor.h          |    4 ++++
>  3 files changed, 66 insertions(+), 0 deletions(-)
> 
> diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
> index 01ec85f..93caa4d 100644
> --- a/QMP/qmp-events.txt
> +++ b/QMP/qmp-events.txt
> @@ -26,6 +26,56 @@ Example:
>  Note: If action is "stop", a STOP event will eventually follow the
>  BLOCK_IO_ERROR event.
> 
> +MIGRATION_CANCELED
> +------------------
> +
> +Emitted when migration is canceled.  This is emitted in the source.

 Shouldn't this one be emitted in the destination?

> +Target will emit MIGRATION_FAILED (no way to differentiate a FAILED
> +and CANCELED migration for target).
> +
> +Data: None
> +
> +Example:
> +
> +{ "event": "MIGRATION_CANCELED",
> +    "timestamp": {"seconds": 1274687575, "microseconds": 592483} }
> +
> +MIGRATION_ENDED
> +---------------
> +
> +Emitted when migration ends (both in source and target)
> +
> +Data: None
> +
> +Example:
> +
> +{ "event": "MIGRATION_ENDED",
> +    "timestamp": {"seconds": 1274687575, "microseconds": 592483} }
> +
> +MIGRATION_FAILED
> +----------------
> +
> +Emitted when migration fails (both is source and target).
> +
> +Data: None
> +
> +Example:
> +
> +{ "event": "MIGRATION_FAILED",
> +    "timestamp": {"seconds": 1274687575, "microseconds": 592483} }

 What about a MIGRATION_FINISHED event, which contains a 'success'
key which is a bool?

 The only disadvantage of this is if we decide to add more information
to the event (say, stats) then it'd get ugly. Otherwise, one event is enough.

 Anyway, the counterpart of MIGRATION_FAILED is MIGRATION_SUCCEEDED.

> +
> +MIGRATION_STARTED
> +-----------------
> +
> +Emitted when migration starts (both in source and target).

 Don't you need this only on the destination?