[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] [PATCH] keepalive: Add ability to disable keepalive messages



On Tue, Apr 24, 2012 at 16:56:37 +0200, Peter Krempa wrote:
> The docs for virConnectSetKeepAlive() advertise that this function
> should be able to disable keepalives on negative or zero interval time.
> 
> This patch removes the check that prohibited this and adds code to
> disable keepalives on negative/zero interval.

OK, makes sense, if the client wants to change keepalive settings in runtime.
That is, it can dynamically start/stop sending keepalive requests to the
server.

> * src/libvirt.c: virConnectSetKeepAlive(): - remove check for negative
>                                              values
> * src/rpc/virnetclient.c
> * src/rpc/virnetclient.h: - add virNetClientKeepAliveStop() to disable
>                             keepalive messages
> * src/remote/remote_driver.c: remoteSetKeepAlive(): -add ability to
>                                                      disable keepalives
> ---
>  src/libvirt.c              |    6 ------
>  src/remote/remote_driver.c |    7 ++++++-
>  src/rpc/virnetclient.c     |    8 ++++++++
>  src/rpc/virnetclient.h     |    2 ++
>  4 files changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/src/libvirt.c b/src/libvirt.c
> index af42d3b..3f043e1 100644
> --- a/src/libvirt.c
> +++ b/src/libvirt.c
> @@ -18452,12 +18452,6 @@ int virConnectSetKeepAlive(virConnectPtr conn,
>          return -1;
>      }
> 
> -    if (interval <= 0) {
> -        virLibConnError(VIR_ERR_INVALID_ARG,
> -                        _("negative or zero interval make no sense"));
> -        goto error;
> -    }
> -
>      if (conn->driver->setKeepAlive) {
>          ret = conn->driver->setKeepAlive(conn, interval, count);
>          if (ret < 0)
> diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
> index af46384..7863b73 100644
> --- a/src/remote/remote_driver.c
> +++ b/src/remote/remote_driver.c
> @@ -4631,7 +4631,12 @@ remoteSetKeepAlive(virConnectPtr conn, int interval, unsigned int count)
>          goto cleanup;
>      }
> 
> -    ret = virNetClientKeepAliveStart(priv->client, interval, count);
> +    if (interval > 0) {
> +        ret = virNetClientKeepAliveStart(priv->client, interval, count);
> +    } else {
> +        virNetClientKeepAliveStop(priv->client);
> +        ret = 0;
> +    }

This is not exactly what you want to do here. virKeepAliveStop (which is what
virNetClientKeepAliveStop ends up calling) was meant to be called only when a
connection is getting closed and thus it does more than we need. In addition
to disabling the timer which sends keepalive requests to the server,
virKeepAliveStop disables even the response timer, which means no keepalive
response will be sent anymore. As a result of it, the server will just
automatically close the connection sooner or later.

Jirka


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]