Consistent hashing for balancer

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "subprojects/json"]
 	path = subprojects/json
 	url = https://github.com/nlohmann/json.git
+[submodule "subprojects/chash"]
+	path = subprojects/chash
+	url = https://github.com/yanet-platform/chash.git

autotest/units/001_one_port/055_balancer_wlc/autotest.yaml

@@ -14,11 +14,12 @@ steps:
     YANET_FORMAT_COLUMNS=module,virtual_ip,proto,virtual_port,scheduler,real_ip,real_port,enabled,weight,connections,packets,bytes balancer real any
     module     virtual_ip  proto  virtual_port  scheduler  real_ip  real_port  enabled  weight  connections  packets  bytes
     ---------  ----------  -----  ------------  ---------  -------  ---------  -------  ------  -----------  -------  -----
-    balancer0  10.1.0.55   tcp    443           wlc        2443::1  443        true     2       16           16       1568
-    balancer0  10.1.0.55   tcp    443           wlc        2443::2  443        true     1       8            8        784
-    balancer0  10.1.0.55   tcp    443           wlc        2443::3  443        true     1       8            8        784
+    balancer0  10.1.0.55   tcp    443           wlc        2443::1  443        true     2       34           34       3332
+    balancer0  10.1.0.55   tcp    443           wlc        2443::2  443        true     1       19           19       1862
+    balancer0  10.1.0.55   tcp    443           wlc        2443::3  443        true     1       11           11       1078
     balancer0  10.1.0.55   tcp    443           wlc        2443::4  443        false    4       0            0        0
 
+
 - cli:
     - balancer real enable balancer0 10.1.0.55 tcp 443 2443::4 443
     - balancer real flush
@@ -30,10 +31,10 @@ steps:
     YANET_FORMAT_COLUMNS=module,virtual_ip,proto,virtual_port,scheduler,real_ip,real_port,enabled,weight,connections,packets,bytes balancer real any
     module     virtual_ip  proto  virtual_port  scheduler  real_ip  real_port  enabled  weight  connections  packets  bytes
     ---------  ----------  -----  ------------  ---------  -------  ---------  -------  ------  -----------  -------  -----
-    balancer0  10.1.0.55   tcp    443           wlc        2443::1  443        true     2       17           17       1666
-    balancer0  10.1.0.55   tcp    443           wlc        2443::2  443        true     1       10           10       980
-    balancer0  10.1.0.55   tcp    443           wlc        2443::3  443        true     1       9            9        882
-    balancer0  10.1.0.55   tcp    443           wlc        2443::4  443        true     4       28           28       2744
+    balancer0  10.1.0.55   tcp    443           wlc        2443::1  443        true     2       35           35       3430
+    balancer0  10.1.0.55   tcp    443           wlc        2443::2  443        true     1       23           23       2254
+    balancer0  10.1.0.55   tcp    443           wlc        2443::3  443        true     1       11           11       1078
+    balancer0  10.1.0.55   tcp    443           wlc        2443::4  443        true     4       59           59       5782
 
 - sleep: 2
 - sendPackets:
@@ -44,7 +45,8 @@ steps:
     YANET_FORMAT_COLUMNS=module,virtual_ip,proto,virtual_port,scheduler,real_ip,real_port,enabled,weight,connections,packets,bytes balancer real any
     module     virtual_ip  proto  virtual_port  scheduler  real_ip  real_port  enabled  weight  connections  packets  bytes
     ---------  ----------  -----  ------------  ---------  -------  ---------  -------  ------  -----------  -------  -----
-    balancer0  10.1.0.55   tcp    443           wlc        2443::1  443        true     2       24           24       2352
-    balancer0  10.1.0.55   tcp    443           wlc        2443::2  443        true     1       11           11       1078
-    balancer0  10.1.0.55   tcp    443           wlc        2443::3  443        true     1       12           12       1176
-    balancer0  10.1.0.55   tcp    443           wlc        2443::4  443        true     4       49           49       4802
+    balancer0  10.1.0.55   tcp    443           wlc        2443::1  443        true     2       40           40       3920
+    balancer0  10.1.0.55   tcp    443           wlc        2443::2  443        true     1       27           27       2646
+    balancer0  10.1.0.55   tcp    443           wlc        2443::3  443        true     1       20           20       1960
+    balancer0  10.1.0.55   tcp    443           wlc        2443::4  443        true     4       73           73       7154
+

autotest/units/001_one_port/055_balancer_wlc/check.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import sys
+from scapy.all import *
+
+def dist(packets):
+    d = {}
+    for packet in packets:
+        dst = packet.getlayer(IPv6).dst
+        if dst not in d:
+            d[dst] = 0
+        d[dst] += 1
+    return d
+
+def dist_cmd():
+    if len(sys.argv) < 3:
+        print("Provide file name.")
+        exit(1)
+    packets = rdpcap(sys.argv[2])
+    print(dist(packets))
+    exit(0)
+
+def main():
+    if len(sys.argv) < 2:
+        print("Provide command.")
+        exit(1)
+    if sys.argv[1] == "dist":
+        dist_cmd()
+    print("Command not found.")
+    exit(1)
+
+if __name__ == "__main__":
+    main()
+

autotest/units/001_one_port/055_balancer_wlc/gen.py

@@ -22,9 +22,9 @@ def write_pcap(filename, *packetsList):
 
 
 packages1 = [Ether(dst="00:11:22:33:44:55", src="00:00:00:00:00:02") / Dot1Q(vlan=200) / IP(dst="10.1.0.55", src=f"1.{a_h}.{a_m}.{a_l}", ttl=64) / TCP(dport=443, sport=sport)
-             for sport in (12443, 12444) for a_h in range(2) for a_m in range(2) for a_l in range(4)]
+             for sport in (12443, 12444) for a_h in range(4) for a_m in range(2) for a_l in range(4)]
 packages2 = [Ether(dst="00:11:22:33:44:55", src="00:00:00:00:00:02") / Dot1Q(vlan=200) / IP(dst="10.1.0.55", src=f"1.{a_h}.{a_m}.{a_l}", ttl=64) / TCP(dport=443, sport=sport)
-             for sport in (11443, 11444) for a_h in range(2) for a_m in range(0, 2) for a_l in range(4)]
+             for sport in (11443, 11444) for a_h in range(4) for a_m in range(0, 2) for a_l in range(4)]
 packages3 = [Ether(dst="00:11:22:33:44:55", src="00:00:00:00:00:02") / Dot1Q(vlan=200) / IP(dst="10.1.0.55", src=f"1.{a_h}.{a_m}.{a_l}", ttl=64) / TCP(dport=443, sport=sport)
              for sport in (11443, 11444) for a_h in range(2) for a_m in range(2, 4) for a_l in range(4)]
 

common/controlplaneconfig.h

@@ -207,7 +207,7 @@ using service_t = std::tuple<balancer_service_id_t,
                              std::optional<uint16_t>, ///< vport
                              std::optional<std::string>, ///< version
                              ::balancer::scheduler,
-                             ::balancer::scheduler_params,
+                             uint32_t, ///< wlc power
                              ::balancer::forwarding_method,
                              uint8_t, ///< flags: mss_fix|ops
                              std::optional<common::ipv4_prefix_t>, ///< ipv4_outer_source_network

common/deferer.h

@@ -0,0 +1,23 @@
+namespace utils
+{
+
+template<typename F>
+class Deferer
+{
+	F action_;
+
+public:
+	Deferer(F&& action) :
+	        action_{std::move(action)}
+	{}
+	Deferer(const Deferer& other) = delete;
+	Deferer(Deferer&& other) = delete;
+	Deferer& operator=(const Deferer& other) = delete;
+	Deferer& operator=(Deferer&& other) = delete;
+	~Deferer()
+	{
+		action_();
+	}
+};
+
+} // namespace utils

common/define.h

@@ -98,6 +98,8 @@ extern LogPriority logPriority;
 #define YANET_BALANCER_DEFAULT_MSS_SIZE 536
 #define YANET_BALANCER_FIX_MSS_SIZE 1220
 #define YANET_BALANCER_FIX_MSS_FLAG ((uint8_t)(1u << 0))
+static constexpr size_t YANET_DEFAULT_BALANCER_REAL_MAPPINGS_LIMIT = 100;
+static constexpr size_t YANET_DEFAULT_BALANCER_CELLS_PER_WEIGHT_UNIT = 20;
 
 #define YANET_BALANCER_OPS_FLAG ((uint8_t)(1u << 1))
 #define YANET_BALANCER_PURE_L3 ((uint8_t)(1u << 2))

common/idp.h

@@ -286,7 +286,6 @@ using service = std::tuple<balancer_service_id_t, /// service id
                            tCounterId, ///< size 4
                            balancer::scheduler,
                            balancer::forwarding_method, // tunneling method (default ipip)
-                           uint32_t, /// default_wlc_power
                            uint32_t, ///< real_start
                            uint32_t, ///< real_size
                            std::optional<common::ipv4_prefix_t>, ///< ipv4_outer_source_network

common/scheduler.h

@@ -9,34 +9,24 @@ enum class scheduler : uint8_t
 	rr,
 	wrr,
 	wlc,
-};
-
-class scheduler_params
-{
-public:
-	scheduler_params() = default;
-	uint32_t wlc_power;
+	chash
 };
 
 [[maybe_unused]] constexpr const char* to_string(const scheduler& scheduler)
 {
 	switch (scheduler)
 	{
 		case scheduler::rr:
-		{
 			return "rr";
-		}
 		case scheduler::wrr:
-		{
 			return "wrr";
-		}
 		case scheduler::wlc:
-		{
 			return "wlc";
-		}
+		case scheduler::chash:
+			return "chash";
+		default:
+			return "unknown";
 	}
-
-	return "unknown";
 }
 
 }

controlplane/balancer.cpp

@@ -757,14 +757,14 @@ void balancer_t::compile(common::idp::updateGlobalBase::request& globalbase,
 		                  virtual_port,
 		                  version,
 		                  scheduler,
-		                  scheduler_params,
+		                  wlc_power,
 		                  forwarding_method,
 		                  flags,
 		                  ipv4_outer_source_network,
 		                  ipv6_outer_source_network,
 		                  reals] : balancer.services)
 		{
-			GCC_BUG_UNUSED(scheduler_params);
+			GCC_BUG_UNUSED(wlc_power);
 			GCC_BUG_UNUSED(version);
 
 			if (service_id >= YANET_CONFIG_BALANCER_SERVICES_SIZE)
@@ -808,7 +808,6 @@ void balancer_t::compile(common::idp::updateGlobalBase::request& globalbase,
 			        counter_id,
 			        scheduler,
 			        forwarding_method,
-			        balancer.default_wlc_power, // todo use scheduler_params.wlc_power when other services will be able to set it
 			        (uint32_t)real_start,
 			        (uint32_t)(req_reals.size() - real_start),
 			        ipv4_outer_source_network,
@@ -955,7 +954,7 @@ bool balancer_t::reconfigure_wlc()
 		                  virtual_port,
 		                  version,
 		                  scheduler,
-		                  scheduler_params,
+		                  requested_wlc_power,
 		                  forwarding_method,
 		                  flags,
 		                  ipv4_outer_source_network,
@@ -979,6 +978,7 @@ bool balancer_t::reconfigure_wlc()
 			}
 
 			std::vector<std::tuple<balancer::real_key_global_t, uint32_t, uint32_t>> service_reals_usage_info;
+			service_reals_usage_info.reserve(reals.size());
 			uint32_t connection_sum = 0;
 			uint32_t weight_sum = 0;
 
@@ -1026,7 +1026,7 @@ bool balancer_t::reconfigure_wlc()
 			           effective_weight,
 			           connections] : service_reals_usage_info)
 			{
-				uint32_t wlc_power = scheduler_params.wlc_power;
+				uint32_t wlc_power = requested_wlc_power;
 				if (wlc_power < 1 || wlc_power > 100)
 				{
 					wlc_power = YANET_CONFIG_BALANCER_WLC_DEFAULT_POWER;

controlplane/configparser.cpp

@@ -1660,8 +1660,8 @@ void config_parser_t::loadConfig_balancer_services(controlplane::base_t& baseNex
 		std::string scheduler_string = service_json["scheduler"];
 
 		balancer::scheduler scheduler{};
-		balancer::scheduler_params scheduler_params{};
 		uint8_t flags = 0;
+		std::uint32_t wlc_power{};
 		if (scheduler_string == "rr")
 		{
 			scheduler = balancer::scheduler::rr;
@@ -1675,9 +1675,13 @@ void config_parser_t::loadConfig_balancer_services(controlplane::base_t& baseNex
 			scheduler = balancer::scheduler::wlc;
 			if (exist(service_json, "scheduler_params") && exist(service_json["scheduler_params"], "wlc_power"))
 			{
-				scheduler_params.wlc_power = std::stoll(service_json["scheduler_params"]["wlc_power"].get<std::string>(), nullptr, 10);
+				wlc_power = std::stoll(service_json["scheduler_params"]["wlc_power"].get<std::string>(), nullptr, 10);
 			}
 		}
+		else if (scheduler_string == "chash")
+		{
+			scheduler = balancer::scheduler::chash;
+		}
 		else if (scheduler_string == "purr")
 		{
 			scheduler = balancer::scheduler::wrr;
@@ -1764,7 +1768,7 @@ void config_parser_t::loadConfig_balancer_services(controlplane::base_t& baseNex
 		                               exist(service_json, "vport") ? std::make_optional(std::stoll(service_json["vport"].get<std::string>(), nullptr, 0)) : std::nullopt,
 		                               service_version,
 		                               scheduler,
-		                               scheduler_params,
+		                               wlc_power,
 		                               forwarding_method,
 		                               flags,
 		                               ipv4_outer_source_network,