Hello,
On Tue, 30 Dec 2014, Marcelo Ricardo Leitner wrote:
> What if we make the backup server purge the old entry, just like the active server does, and ignore old updates if needed? Please note the new hunk on ip_vs_sync.c. This is the patch I'm using so far, and I'm seeing good results with even with master/backup. Backup server successfully purges the old and creates a new entry when it detects such update:
>
> [ 344.971673] IPVS: Bind-dest TCP c:192.168.122.1:22222 v:192.168.122.200:80 d:192.168.122.67:80 fwd:R s:0 conn->flags:A3 conn->refcnt:1 dest->refcnt:2
> [ 344.972071] IPVS: Unbind-dest TCP c:192.168.122.1:22222 v:192.168.122.200:80 d:192.168.122.95:80 fwd:R s:4 conn->flags:1A3 conn->refcnt:0 dest->refcnt:2
Good idea
> -- 8< --
>
> /* IPVS core functions
> diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
> index 990decba1fe418e36e59a1f081fcf0e47188da29..da2760496314d49a5b4f6f588de7cb565a28e223 100644
> --- a/net/netfilter/ipvs/ip_vs_core.c
> +++ b/net/netfilter/ipvs/ip_vs_core.c
> @@ -1036,6 +1036,20 @@ static inline bool is_new_conn(const struct sk_buff *skb,
> }
> }
>
> +static inline bool is_new_conn_expected(const struct ip_vs_conn *cp,
> + int conn_reuse_mode)
> +{
> + if ((cp->protocol != IPPROTO_TCP) && (cp->protocol != IPPROTO_SCTP))
> + return false;
If we want SCTP support may be we have to check
cp->state for IP_VS_SCTP_S_CLOSED, it is analog to
our IP_VS_TCP_S_TIME_WAIT state. But cp->state checks
should be per protocol, eg:
/* Controlled (FTP DATA or persistence)? */
if (cp->control)
return false;
switch (cp->protocol)
{
case IPPROTO_TCP:
return ...
case IPPROTO_SCTP:
return cp->state == IP_VS_SCTP_S_CLOSED;
default:
return false;
}
> + /* Controlled (FTP DATA or persistence)? */
> + if (cp->control)
> + return false;
> + return (cp->state == IP_VS_TCP_S_TIME_WAIT) ||
> + ((conn_reuse_mode & 2) &&
> + (cp->state == IP_VS_TCP_S_FIN_WAIT) &&
> + (cp->flags & IP_VS_CONN_F_NOOUTPUT));
> +}
> +
> /* Handle response packets: rewrite addresses and send away...
> */
> static unsigned int
> @@ -1574,6 +1588,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
> struct ip_vs_conn *cp;
> int ret, pkts;
> struct netns_ipvs *ipvs;
> + int conn_reuse_mode;
>
> /* Already marked as IPVS request or reply? */
> if (skb->ipvs_property)
> @@ -1642,9 +1657,13 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
> */
> cp = pp->conn_in_get(af, skb, &iph, 0);
>
> - if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp && cp->dest &&
> - unlikely(!atomic_read(&cp->dest->weight)) && !iph.fragoffs &&
> - is_new_conn(skb, &iph)) {
> + conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
> + if (conn_reuse_mode && !iph.fragoffs &&
> + is_new_conn(skb, &iph) && cp &&
> + !atomic_read(&cp->n_control) &&
Above n_control check will prevent FTP:21 connections
to be replaced when expire_nodest_conn=1. May be the n_control
check should be moved below to avoid ip_vs_conn_expire_now?
Like this:
if (!atomic_read(&cp->n_control))
ip_vs_conn_expire_now(cp);
__ip_vs_conn_put(cp);
cp = NULL;
I.e. old connection will not be tried for expiration
but we still create new connection. The old will not be visible
to packets.
> + ((unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest &&
> + unlikely(!atomic_read(&cp->dest->weight))) ||
> + unlikely(is_new_conn_expected(cp, conn_reuse_mode)))) {
> ip_vs_conn_expire_now(cp);
> __ip_vs_conn_put(cp);
> cp = NULL;
> diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
> index c47ffd7a0a709cb73834c84652f251960f25db79..7ed4484c2c93e0aed89be55c773c94f3c80cc09e 100644
> --- a/net/netfilter/ipvs/ip_vs_sync.c
> +++ b/net/netfilter/ipvs/ip_vs_sync.c
> @@ -850,6 +850,21 @@ static void ip_vs_proc_conn(struct net *net, struct ip_vs_conn_param *param,
> else
> cp = ip_vs_ct_in_get(param);
>
> + if (cp && ((cp->dport != dport) ||
> + !ip_vs_addr_equal(cp->af, &cp->daddr, daddr))) {
Better to use here the new cp->daf field
instead of cp->af.
> + if (!(flags & IP_VS_CONN_F_INACTIVE)) {
I guess, we here try to avoid old sync message to
expire new connection. The problem is that UDP conns and
templates are always IP_VS_CONN_F_INACTIVE, may be a TCP+SCTP
protocol check is needed.
> + ip_vs_conn_expire_now(cp);
> + __ip_vs_conn_put(cp);
> + cp = NULL;
> + } else {
> + /* This is the expiration message for the
> + * connection that was already replaced, so we
> + * just ignore it.
> + */
> + goto out;
> + }
> + }
> +
> if (cp) {
> /* Free pe_data */
> kfree(param->pe_data);
> @@ -925,6 +940,8 @@ static void ip_vs_proc_conn(struct net *net, struct ip_vs_conn_param *param,
> else
> cp->timeout = (3*60*HZ);
> }
> +
> +out:
> ip_vs_conn_put(cp);
> }
>
Regards
--
Julian Anastasov <ja@xxxxxx>
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