ipvs: SH fallback and L4 hashing
By default the SH scheduler rejects connections that are hashed onto a realserver of weight 0. This patch adds a flag to make SH choose a different realserver in this case, instead of rejecting the connection. The patch also adds a flag to make SH include the source port (TCP, UDP, SCTP) in the hash as well as the source address. This basically allows for deterministic round-robin load balancing (i.e., where any director in a cluster of directors with identical config will send the same packet the same way). The flags are service flags (IP_VS_SVC_F_SCHED*) so that these options can be set per service. They are set using a new option to ipvsadm. Signed-off-by: Alexander Frolkin <avf@eldamar.org.uk> Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
This commit is contained in:
parent
acaac5d8bb
commit
eba3b5a787
|
@ -20,6 +20,12 @@
|
||||||
#define IP_VS_SVC_F_PERSISTENT 0x0001 /* persistent port */
|
#define IP_VS_SVC_F_PERSISTENT 0x0001 /* persistent port */
|
||||||
#define IP_VS_SVC_F_HASHED 0x0002 /* hashed entry */
|
#define IP_VS_SVC_F_HASHED 0x0002 /* hashed entry */
|
||||||
#define IP_VS_SVC_F_ONEPACKET 0x0004 /* one-packet scheduling */
|
#define IP_VS_SVC_F_ONEPACKET 0x0004 /* one-packet scheduling */
|
||||||
|
#define IP_VS_SVC_F_SCHED1 0x0008 /* scheduler flag 1 */
|
||||||
|
#define IP_VS_SVC_F_SCHED2 0x0010 /* scheduler flag 2 */
|
||||||
|
#define IP_VS_SVC_F_SCHED3 0x0020 /* scheduler flag 3 */
|
||||||
|
|
||||||
|
#define IP_VS_SVC_F_SCHED_SH_FALLBACK IP_VS_SVC_F_SCHED1 /* SH fallback */
|
||||||
|
#define IP_VS_SVC_F_SCHED_SH_PORT IP_VS_SVC_F_SCHED2 /* SH use port */
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Destination Server Flags
|
* Destination Server Flags
|
||||||
|
|
|
@ -48,6 +48,10 @@
|
||||||
|
|
||||||
#include <net/ip_vs.h>
|
#include <net/ip_vs.h>
|
||||||
|
|
||||||
|
#include <net/tcp.h>
|
||||||
|
#include <linux/udp.h>
|
||||||
|
#include <linux/sctp.h>
|
||||||
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* IPVS SH bucket
|
* IPVS SH bucket
|
||||||
|
@ -71,10 +75,19 @@ struct ip_vs_sh_state {
|
||||||
struct ip_vs_sh_bucket buckets[IP_VS_SH_TAB_SIZE];
|
struct ip_vs_sh_bucket buckets[IP_VS_SH_TAB_SIZE];
|
||||||
};
|
};
|
||||||
|
|
||||||
|
/* Helper function to determine if server is unavailable */
|
||||||
|
static inline bool is_unavailable(struct ip_vs_dest *dest)
|
||||||
|
{
|
||||||
|
return atomic_read(&dest->weight) <= 0 ||
|
||||||
|
dest->flags & IP_VS_DEST_F_OVERLOAD;
|
||||||
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Returns hash value for IPVS SH entry
|
* Returns hash value for IPVS SH entry
|
||||||
*/
|
*/
|
||||||
static inline unsigned int ip_vs_sh_hashkey(int af, const union nf_inet_addr *addr)
|
static inline unsigned int
|
||||||
|
ip_vs_sh_hashkey(int af, const union nf_inet_addr *addr,
|
||||||
|
__be16 port, unsigned int offset)
|
||||||
{
|
{
|
||||||
__be32 addr_fold = addr->ip;
|
__be32 addr_fold = addr->ip;
|
||||||
|
|
||||||
|
@ -83,7 +96,8 @@ static inline unsigned int ip_vs_sh_hashkey(int af, const union nf_inet_addr *ad
|
||||||
addr_fold = addr->ip6[0]^addr->ip6[1]^
|
addr_fold = addr->ip6[0]^addr->ip6[1]^
|
||||||
addr->ip6[2]^addr->ip6[3];
|
addr->ip6[2]^addr->ip6[3];
|
||||||
#endif
|
#endif
|
||||||
return (ntohl(addr_fold)*2654435761UL) & IP_VS_SH_TAB_MASK;
|
return (offset + (ntohs(port) + ntohl(addr_fold))*2654435761UL) &
|
||||||
|
IP_VS_SH_TAB_MASK;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
@ -91,12 +105,42 @@ static inline unsigned int ip_vs_sh_hashkey(int af, const union nf_inet_addr *ad
|
||||||
* Get ip_vs_dest associated with supplied parameters.
|
* Get ip_vs_dest associated with supplied parameters.
|
||||||
*/
|
*/
|
||||||
static inline struct ip_vs_dest *
|
static inline struct ip_vs_dest *
|
||||||
ip_vs_sh_get(int af, struct ip_vs_sh_state *s, const union nf_inet_addr *addr)
|
ip_vs_sh_get(struct ip_vs_service *svc, struct ip_vs_sh_state *s,
|
||||||
|
const union nf_inet_addr *addr, __be16 port)
|
||||||
{
|
{
|
||||||
return rcu_dereference(s->buckets[ip_vs_sh_hashkey(af, addr)].dest);
|
unsigned int hash = ip_vs_sh_hashkey(svc->af, addr, port, 0);
|
||||||
|
struct ip_vs_dest *dest = rcu_dereference(s->buckets[hash].dest);
|
||||||
|
|
||||||
|
return (!dest || is_unavailable(dest)) ? NULL : dest;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
/* As ip_vs_sh_get, but with fallback if selected server is unavailable */
|
||||||
|
static inline struct ip_vs_dest *
|
||||||
|
ip_vs_sh_get_fallback(struct ip_vs_service *svc, struct ip_vs_sh_state *s,
|
||||||
|
const union nf_inet_addr *addr, __be16 port)
|
||||||
|
{
|
||||||
|
unsigned int offset;
|
||||||
|
unsigned int hash;
|
||||||
|
struct ip_vs_dest *dest;
|
||||||
|
|
||||||
|
for (offset = 0; offset < IP_VS_SH_TAB_SIZE; offset++) {
|
||||||
|
hash = ip_vs_sh_hashkey(svc->af, addr, port, offset);
|
||||||
|
dest = rcu_dereference(s->buckets[hash].dest);
|
||||||
|
if (!dest)
|
||||||
|
break;
|
||||||
|
if (is_unavailable(dest))
|
||||||
|
IP_VS_DBG_BUF(6, "SH: selected unavailable server "
|
||||||
|
"%s:%d (offset %d)",
|
||||||
|
IP_VS_DBG_ADDR(svc->af, &dest->addr),
|
||||||
|
ntohs(dest->port), offset);
|
||||||
|
else
|
||||||
|
return dest;
|
||||||
|
}
|
||||||
|
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Assign all the hash buckets of the specified table with the service.
|
* Assign all the hash buckets of the specified table with the service.
|
||||||
*/
|
*/
|
||||||
|
@ -213,13 +257,33 @@ static int ip_vs_sh_dest_changed(struct ip_vs_service *svc,
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
/*
|
/* Helper function to get port number */
|
||||||
* If the dest flags is set with IP_VS_DEST_F_OVERLOAD,
|
static inline __be16
|
||||||
* consider that the server is overloaded here.
|
ip_vs_sh_get_port(const struct sk_buff *skb, struct ip_vs_iphdr *iph)
|
||||||
*/
|
|
||||||
static inline int is_overloaded(struct ip_vs_dest *dest)
|
|
||||||
{
|
{
|
||||||
return dest->flags & IP_VS_DEST_F_OVERLOAD;
|
__be16 port;
|
||||||
|
struct tcphdr _tcph, *th;
|
||||||
|
struct udphdr _udph, *uh;
|
||||||
|
sctp_sctphdr_t _sctph, *sh;
|
||||||
|
|
||||||
|
switch (iph->protocol) {
|
||||||
|
case IPPROTO_TCP:
|
||||||
|
th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph);
|
||||||
|
port = th->source;
|
||||||
|
break;
|
||||||
|
case IPPROTO_UDP:
|
||||||
|
uh = skb_header_pointer(skb, iph->len, sizeof(_udph), &_udph);
|
||||||
|
port = uh->source;
|
||||||
|
break;
|
||||||
|
case IPPROTO_SCTP:
|
||||||
|
sh = skb_header_pointer(skb, iph->len, sizeof(_sctph), &_sctph);
|
||||||
|
port = sh->source;
|
||||||
|
break;
|
||||||
|
default:
|
||||||
|
port = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
return port;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
@ -232,15 +296,21 @@ ip_vs_sh_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
|
||||||
{
|
{
|
||||||
struct ip_vs_dest *dest;
|
struct ip_vs_dest *dest;
|
||||||
struct ip_vs_sh_state *s;
|
struct ip_vs_sh_state *s;
|
||||||
|
__be16 port = 0;
|
||||||
|
|
||||||
IP_VS_DBG(6, "ip_vs_sh_schedule(): Scheduling...\n");
|
IP_VS_DBG(6, "ip_vs_sh_schedule(): Scheduling...\n");
|
||||||
|
|
||||||
|
if (svc->flags & IP_VS_SVC_F_SCHED_SH_PORT)
|
||||||
|
port = ip_vs_sh_get_port(skb, iph);
|
||||||
|
|
||||||
s = (struct ip_vs_sh_state *) svc->sched_data;
|
s = (struct ip_vs_sh_state *) svc->sched_data;
|
||||||
dest = ip_vs_sh_get(svc->af, s, &iph->saddr);
|
|
||||||
if (!dest
|
if (svc->flags & IP_VS_SVC_F_SCHED_SH_FALLBACK)
|
||||||
|| !(dest->flags & IP_VS_DEST_F_AVAILABLE)
|
dest = ip_vs_sh_get_fallback(svc, s, &iph->saddr, port);
|
||||||
|| atomic_read(&dest->weight) <= 0
|
else
|
||||||
|| is_overloaded(dest)) {
|
dest = ip_vs_sh_get(svc, s, &iph->saddr, port);
|
||||||
|
|
||||||
|
if (!dest) {
|
||||||
ip_vs_scheduler_err(svc, "no destination available");
|
ip_vs_scheduler_err(svc, "no destination available");
|
||||||
return NULL;
|
return NULL;
|
||||||
}
|
}
|
||||||
|
|
Loading…
Reference in New Issue