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author | 2016-08-04 16:13:09 +0100 | |
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committer | 2016-08-11 14:05:40 +0000 | |
commit | 041eacc81656d2ed5bc01b96b15a7d03a1700f13 (patch) | |
tree | f1cded1a27f92bab90fec8e5ea9d991ee2ff7eb5 /plugins/lb-plugin/lb/lb.h | |
parent | 3590ac5881261c95a3c575360e24903d60fac392 (diff) |
VPP-130: MagLev-like Load Balancer
This plugin provides load balancing for VPP in a way that is largely inspired
from Google's MagLev: http://research.google.com/pubs/pub44824.html
More info in the README.md
Change-Id: I1223f495d5c2d5200808a398504119f2830337e9
Signed-off-by: Pierre Pfister <ppfister@cisco.com>
Diffstat (limited to 'plugins/lb-plugin/lb/lb.h')
-rw-r--r-- | plugins/lb-plugin/lb/lb.h | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/plugins/lb-plugin/lb/lb.h b/plugins/lb-plugin/lb/lb.h new file mode 100644 index 00000000..3d250319 --- /dev/null +++ b/plugins/lb-plugin/lb/lb.h @@ -0,0 +1,304 @@ +/* + * Copyright (c) 2016 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * lb-plugin implements a MagLev-like load balancer. + * http://research.google.com/pubs/pub44824.html + * + * It hasn't been tested for interoperability with the original MagLev + * but intends to provide similar functionality. + * The load-balancer receives traffic destined to VIP (Virtual IP) + * addresses from one or multiple(ECMP) routers. + * The load-balancer tunnels the traffic toward many application servers + * ensuring session stickyness (i.e. that a single sessions is tunneled + * towards a single application server). + * + */ + +#ifndef LB_PLUGIN_LB_LB_H_ +#define LB_PLUGIN_LB_LB_H_ + +#include <lb/util.h> +#include <lb/refcount.h> + +#include <vnet/vnet.h> +#include <vnet/ip/ip.h> + +#include <lb/lbhash.h> + +#define LB_DEFAULT_PER_CPU_STICKY_BUCKETS 1 << 10 +#define LB_DEFAULT_FLOW_TIMEOUT 40 + +/** + * Each VIP is configured with a set of + * application server. + */ +typedef struct { + /** + * Destination address used to tunnel traffic towards + * that application server. + * The address is also used as ID and pseudo-random + * seed for the load-balancing process. + */ + ip46_address_t address; + + /** + * ASs are indexed by address and VIP Index. + * Which means there will be duplicated if the same server + * address is used for multiple VIPs. + */ + u32 vip_index; + + /** + * Some per-AS flags. + * For now only LB_AS_FLAGS_USED is defined. + */ + u8 flags; + +#define LB_AS_FLAGS_USED 0x1 + + /** + * Rotating timestamp of when LB_AS_FLAGS_USED flag was last set. + * + * AS removal is based on garbage collection and reference counting. + * When an AS is removed, there is a race between configuration core + * and worker cores which may still add a reference while it should not + * be used. This timestamp is used to not remove the AS while a race condition + * may happen. + */ + u32 last_used; +} lb_as_t; + +format_function_t format_lb_as; + +typedef struct { + u32 as_index; +} lb_new_flow_entry_t; + +#define lb_foreach_vip_counter \ + _(TRACKED_SESSION, "tracked session", 0) \ + _(UNTRACKED_PACKET, "untracked packet", 1) + +typedef enum { +#define _(a,b,c) LB_VIP_COUNTER_##a = c, + lb_foreach_vip_counter +#undef _ + LB_N_VIP_COUNTERS +} lb_vip_counter_t; + +/** + * The load balancer supports IPv4 and IPv6 traffic + * and GRE4 and GRE6 encap. + */ +typedef enum { + LB_VIP_TYPE_IP6_GRE6, + LB_VIP_TYPE_IP6_GRE4, + LB_VIP_TYPE_IP4_GRE6, + LB_VIP_TYPE_IP4_GRE4, + LB_VIP_N_TYPES, +} lb_vip_type_t; + +format_function_t format_lb_vip_type; +unformat_function_t unformat_lb_vip_type; + +/** + * Load balancing service is provided per VIP. + * In this data model, a VIP can be a whole prefix. + * But load balancing only + * occurs on a per-source-address/port basis. Meaning that if a given source + * reuses the same port for multiple destinations within the same VIP, + * they will be considered as a single flow. + */ +typedef struct { + + //Runtime + + /** + * Vector mapping (flow-hash & new_connect_table_mask) to AS index. + * This is used for new flows. + */ + lb_new_flow_entry_t *new_flow_table; + + /** + * New flows table length - 1 + * (length MUST be a power of 2) + */ + u32 new_flow_table_mask; + + /** + * Last time garbage collection was run to free the ASs. + */ + u32 last_garbage_collection; + + //Not runtime + + /** + * A Virtual IP represents a given service delivered + * by a set of application servers. It can be a single + * address or a prefix. + * IPv4 prefixes are encoded using IPv4-in-IPv6 embedded address + * (i.e. ::/96 prefix). + */ + ip46_address_t prefix; + + /** + * The VIP prefix length. + * In case of IPv4, plen = 96 + ip4_plen. + */ + u8 plen; + + /** + * The type of traffic for this. + * LB_TYPE_UNDEFINED if unknown. + */ + lb_vip_type_t type; + + /** + * Flags related to this VIP. + * LB_VIP_FLAGS_USED means the VIP is active. + * When it is not set, the VIP in the process of being removed. + * We cannot immediately remove a VIP because the VIP index still may be stored + * in the adjacency index. + */ + u8 flags; + + /** + * Pool of AS indexes used for this VIP. + * This also includes ASs that have been removed (but are still referenced). + */ + u32 *as_indexes; + +#define LB_VIP_FLAGS_USED 0x1 + +} lb_vip_t; + +#define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 || (vip)->type == LB_VIP_TYPE_IP4_GRE4) +#define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 || (vip)->type == LB_VIP_TYPE_IP4_GRE4) +format_function_t format_lb_vip; +format_function_t format_lb_vip_detailed; + +typedef struct { + /** + * Each CPU has its own sticky flow hash table. + * One single table is used for all VIPs. + */ + lb_hash_t *sticky_ht; +} lb_per_cpu_t; + +typedef struct { + /** + * Pool of all Virtual IPs + */ + lb_vip_t *vips; + + /** + * Pool of ASs. + * ASs are referenced by address and vip index. + * The first element (index 0) is special and used only to fill + * new_flow_tables when no AS has been configured. + */ + lb_as_t *ass; + + /** + * Each AS has an associated reference counter. + * As ass[0] has a special meaning, its associated counter + * starts at 0 and is decremented instead. i.e. do not use it. + */ + vlib_refcount_t as_refcount; + + /** + * Some global data is per-cpu + */ + lb_per_cpu_t *per_cpu; + + /** + * Node next index for IP adjacencies, for each of the traffic types. + */ + u32 ip_lookup_next_index[LB_VIP_N_TYPES]; + + /** + * Source address used in IPv6 encapsulated traffic + */ + ip6_address_t ip6_src_address; + + /** + * Source address used for IPv4 encapsulated traffic + */ + ip4_address_t ip4_src_address; + + /** + * Number of buckets in the per-cpu sticky hash table. + */ + u32 per_cpu_sticky_buckets; + + /** + * Flow timeout in seconds. + */ + u32 flow_timeout; + + /** + * Per VIP counter + */ + vlib_simple_counter_main_t vip_counters[LB_N_VIP_COUNTERS]; + + /** + * API dynamically registered base ID. + */ + u16 msg_id_base; + + volatile u32 *writer_lock; +} lb_main_t; + +/** + * struct stored in adj->opaque data. + */ +typedef struct { + /** + * Index of the VIP associated with that IP adjacency. + */ + u32 vip_index; +} lb_adj_data_t; + +extern lb_main_t lb_main; +extern vlib_node_registration_t lb6_node; +extern vlib_node_registration_t lb4_node; + +/** + * Fix global load-balancer parameters. + * @param ip4_address IPv4 source address used for encapsulated traffic + * @param ip6_address IPv6 source address used for encapsulated traffic + * @return 0 on success. VNET_LB_ERR_XXX on error + */ +int lb_conf(ip4_address_t *ip4_address, ip6_address_t *ip6_address, + u32 sticky_buckets, u32 flow_timeout); + +int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type, + u32 new_length, u32 *vip_index); +int lb_vip_del(u32 vip_index); + +int lb_vip_find_index(ip46_address_t *prefix, u8 plen, u32 *vip_index); + +#define lb_vip_get_by_index(index) (pool_is_free_index(lb_main.vips, index)?NULL:pool_elt_at_index(lb_main.vips, index)) + +int lb_vip_add_ass(u32 vip_index, ip46_address_t *addresses, u32 n); +int lb_vip_del_ass(u32 vip_index, ip46_address_t *addresses, u32 n); + +u32 lb_hash_time_now(vlib_main_t * vm); + +void lb_garbage_collection(); + +format_function_t format_lb_main; + +#endif /* LB_PLUGIN_LB_LB_H_ */ |