[Cluster-devel] [PATCH] rgmanager: Don't duplicate configuration change events

[Lon Hohberger <lhh@redhat.com>]

On 02/26/2013 11:40 AM, Ryan McCabe wrote:
> If a cluster configuration change is detected while there are events
> on the event queue that take some time to process, a large number of
> duplicate configuration update events are put onto the event queue.
> With a large number of services and a small status poll interval,
> thousands of duplicate events can be put onto the queue.
> 
> This patch causes rgmanager to queue only one config event per detected
> configuration change.

Good catch there.

Ack /

Reviewed-by: Lon Hohberger <lhh@redhat.com>

-- Lon

> 
> This applies only to the RHEL5 branch.
> 
> Signed-off-by: Ryan McCabe <rmccabe@redhat.com>
> ---
>  rgmanager/src/daemons/main.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/rgmanager/src/daemons/main.c b/rgmanager/src/daemons/main.c
> index 1c7f746..59150c3 100644
> --- a/rgmanager/src/daemons/main.c
> +++ b/rgmanager/src/daemons/main.c
> @@ -73,6 +73,7 @@ static int port = RG_PORT;
>  static char *rgmanager_lsname = "rgmanager"; /* XXX default */
>  static int status_poll_interval = DEFAULT_CHECK_INTERVAL;
>  static int stops_queued = 0;
> +static int lastqver = 0;
>  
>  int next_node_id(cluster_member_list_t *membership, int me);
>  
> @@ -750,7 +751,7 @@ dump_internal_state(int fd)
>  int
>  event_loop(msgctx_t *localctx, msgctx_t *clusterctx)
>  {
> -	int n = 0, max, ret, oldver, newver;
> +	int n = 0, max, ret, oldver = 0, newver = 0;
>  	fd_set rfds;
>  	msgctx_t *newctx;
>  	struct timeval tv;
> @@ -826,9 +827,14 @@ event_loop(msgctx_t *localctx, msgctx_t *clusterctx)
>  		return 0;
>  
>  	if (need_reconfigure || check_config_update(&oldver, &newver)) {
> +		/* Only queue configuration events once per detected config update */
> +		if (!need_reconfigure && newver <= lastqver)
> +			return 0;
> +
>  		need_reconfigure = 0;
>  		configure_rgmanager(-1, 0, NULL);
>  		config_event_q(oldver, newver);
> +		lastqver = newver;
>  		return 0;
>  	}
>  
>