--- /dev/null
+.. BSD LICENSE
+ Copyright(c) 2016-2017 Intel Corporation. All rights reserved.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+ * Neither the name of Intel Corporation nor the names of its
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Server-Node EFD Sample Application
+==================================
+
+This sample application demonstrates the use of EFD library as a flow-level
+load balancer, for more information about the EFD Library please refer to the
+DPDK programmer's guide.
+
+This sample application is a variant of the
+:ref:`client-server sample application <multi_process_app>`
+where a specific target node is specified for every and each flow
+(not in a round-robin fashion as the original load balancing sample application).
+
+Overview
+--------
+
+The architecture of the EFD flow-based load balancer sample application is
+presented in the following figure.
+
+.. _figure_efd_sample_app_overview:
+
+.. figure:: img/server_node_efd.*
+
+ Using EFD as a Flow-Level Load Balancer
+
+As shown in :numref:`figure_efd_sample_app_overview`,
+the sample application consists of a front-end node (server)
+using the EFD library to create a load-balancing table for flows,
+for each flow a target backend worker node is specified. The EFD table does not
+store the flow key (unlike a regular hash table), and hence, it can
+individually load-balance millions of flows (number of targets * maximum number
+of flows fit in a flow table per target) while still fitting in CPU cache.
+
+It should be noted that although they are referred to as nodes, the frontend
+server and worker nodes are processes running on the same platform.
+
+Front-end Server
+~~~~~~~~~~~~~~~~
+
+Upon initializing, the frontend server node (process) creates a flow
+distributor table (based on the EFD library) which is populated with flow
+information and its intended target node.
+
+The sample application assigns a specific target node_id (process) for each of
+the IP destination addresses as follows:
+
+.. code-block:: c
+
+ node_id = i % num_nodes; /* Target node id is generated */
+ ip_dst = rte_cpu_to_be_32(i); /* Specific ip destination address is
+ assigned to this target node */
+
+then the pair of <key,target> is inserted into the flow distribution table.
+
+The main loop of the server process receives a burst of packets, then for
+each packet, a flow key (IP destination address) is extracted. The flow
+distributor table is looked up and the target node id is returned. Packets are
+then enqueued to the specified target node id.
+
+It should be noted that flow distributor table is not a membership test table.
+I.e. if the key has already been inserted the target node id will be correct,
+but for new keys the flow distributor table will return a value (which can be
+valid).
+
+Backend Worker Nodes
+~~~~~~~~~~~~~~~~~~~~
+
+Upon initializing, the worker node (process) creates a flow table (a regular
+hash table that stores the key default size 1M flows) which is populated with
+only the flow information that is serviced at this node. This flow key is
+essential to point out new keys that have not been inserted before.
+
+The worker node's main loop is simply receiving packets then doing a hash table
+lookup. If a match occurs then statistics are updated for flows serviced by
+this node. If no match is found in the local hash table then this indicates
+that this is a new flow, which is dropped.
+
+
+Compiling the Application
+-------------------------
+
+The sequence of steps used to build the application is:
+
+#. Export the required environment variables:
+
+ .. code-block:: console
+
+ export RTE_SDK=/path/to/rte_sdk
+ export RTE_TARGET=x86_64-native-linuxapp-gcc
+
+#. Build the application executable file:
+
+ .. code-block:: console
+
+ cd ${RTE_SDK}/examples/server_node_efd/
+ make
+
+ For more details on how to build the DPDK libraries and sample
+ applications,
+ please refer to the *DPDK Getting Started Guide.*
+
+
+Running the Application
+-----------------------
+
+The application has two binaries to be run: the front-end server
+and the back-end node.
+
+The frontend server (server) has the following command line options::
+
+ ./server [EAL options] -- -p PORTMASK -n NUM_NODES -f NUM_FLOWS
+
+Where,
+
+* ``-p PORTMASK:`` Hexadecimal bitmask of ports to configure
+* ``-n NUM_NODES:`` Number of back-end nodes that will be used
+* ``-f NUM_FLOWS:`` Number of flows to be added in the EFD table (1 million, by default)
+
+The back-end node (node) has the following command line options::
+
+ ./node [EAL options] -- -n NODE_ID
+
+Where,
+
+* ``-n NODE_ID:`` Node ID, which cannot be equal or higher than NUM_MODES
+
+
+First, the server app must be launched, with the number of nodes that will be run.
+Once it has been started, the node instances can be run, with different NODE_ID.
+These instances have to be run as secondary processes, with ``--proc-type=secondary``
+in the EAL options, which will attach to the primary process memory, and therefore,
+they can access the queues created by the primary process to distribute packets.
+
+To successfully run the application, the command line used to start the
+application has to be in sync with the traffic flows configured on the traffic
+generator side.
+
+For examples of application command lines and traffic generator flows, please
+refer to the DPDK Test Report. For more details on how to set up and run the
+sample applications provided with DPDK package, please refer to the
+:ref:`DPDK Getting Started Guide for Linux <linux_gsg>` and
+:ref:`DPDK Getting Started Guide for FreeBSD <freebsd_gsg>`.
+
+
+Explanation
+-----------
+
+As described in previous sections, there are two processes in this example.
+
+The first process, the front-end server, creates and populates the EFD table,
+which is used to distribute packets to nodes, which the number of flows
+specified in the command line (1 million, by default).
+
+
+.. code-block:: c
+
+ static void
+ create_efd_table(void)
+ {
+ uint8_t socket_id = rte_socket_id();
+
+ /* create table */
+ efd_table = rte_efd_create("flow table", num_flows * 2, sizeof(uint32_t),
+ 1 << socket_id, socket_id);
+
+ if (efd_table == NULL)
+ rte_exit(EXIT_FAILURE, "Problem creating the flow table\n");
+ }
+
+ static void
+ populate_efd_table(void)
+ {
+ unsigned int i;
+ int32_t ret;
+ uint32_t ip_dst;
+ uint8_t socket_id = rte_socket_id();
+ uint64_t node_id;
+
+ /* Add flows in table */
+ for (i = 0; i < num_flows; i++) {
+ node_id = i % num_nodes;
+
+ ip_dst = rte_cpu_to_be_32(i);
+ ret = rte_efd_update(efd_table, socket_id,
+ (void *)&ip_dst, (efd_value_t)node_id);
+ if (ret < 0)
+ rte_exit(EXIT_FAILURE, "Unable to add entry %u in "
+ "EFD table\n", i);
+ }
+
+ printf("EFD table: Adding 0x%x keys\n", num_flows);
+ }
+
+After initialization, packets are received from the enabled ports, and the IPv4
+address from the packets is used as a key to look up in the EFD table,
+which tells the node where the packet has to be distributed.
+
+.. code-block:: c
+
+ static void
+ process_packets(uint32_t port_num __rte_unused, struct rte_mbuf *pkts[],
+ uint16_t rx_count, unsigned int socket_id)
+ {
+ uint16_t i;
+ uint8_t node;
+ efd_value_t data[EFD_BURST_MAX];
+ const void *key_ptrs[EFD_BURST_MAX];
+
+ struct ipv4_hdr *ipv4_hdr;
+ uint32_t ipv4_dst_ip[EFD_BURST_MAX];
+
+ for (i = 0; i < rx_count; i++) {
+ /* Handle IPv4 header.*/
+ ipv4_hdr = rte_pktmbuf_mtod_offset(pkts[i], struct ipv4_hdr *,
+ sizeof(struct ether_hdr));
+ ipv4_dst_ip[i] = ipv4_hdr->dst_addr;
+ key_ptrs[i] = (void *)&ipv4_dst_ip[i];
+ }
+
+ rte_efd_lookup_bulk(efd_table, socket_id, rx_count,
+ (const void **) key_ptrs, data);
+ for (i = 0; i < rx_count; i++) {
+ node = (uint8_t) ((uintptr_t)data[i]);
+
+ if (node >= num_nodes) {
+ /*
+ * Node is out of range, which means that
+ * flow has not been inserted
+ */
+ flow_dist_stats.drop++;
+ rte_pktmbuf_free(pkts[i]);
+ } else {
+ flow_dist_stats.distributed++;
+ enqueue_rx_packet(node, pkts[i]);
+ }
+ }
+
+ for (i = 0; i < num_nodes; i++)
+ flush_rx_queue(i);
+ }
+
+The burst of packets received is enqueued in temporary buffers (per node),
+and enqueued in the shared ring between the server and the node.
+After this, a new burst of packets is received and this process is
+repeated infinitely.
+
+.. code-block:: c
+
+ static void
+ flush_rx_queue(uint16_t node)
+ {
+ uint16_t j;
+ struct node *cl;
+
+ if (cl_rx_buf[node].count == 0)
+ return;
+
+ cl = &nodes[node];
+ if (rte_ring_enqueue_bulk(cl->rx_q, (void **)cl_rx_buf[node].buffer,
+ cl_rx_buf[node].count, NULL) != cl_rx_buf[node].count){
+ for (j = 0; j < cl_rx_buf[node].count; j++)
+ rte_pktmbuf_free(cl_rx_buf[node].buffer[j]);
+ cl->stats.rx_drop += cl_rx_buf[node].count;
+ } else
+ cl->stats.rx += cl_rx_buf[node].count;
+
+ cl_rx_buf[node].count = 0;
+ }
+
+The second process, the back-end node, receives the packets from the shared
+ring with the server and send them out, if they belong to the node.
+
+At initialization, it attaches to the server process memory, to have
+access to the shared ring, parameters and statistics.
+
+.. code-block:: c
+
+ rx_ring = rte_ring_lookup(get_rx_queue_name(node_id));
+ if (rx_ring == NULL)
+ rte_exit(EXIT_FAILURE, "Cannot get RX ring - "
+ "is server process running?\n");
+
+ mp = rte_mempool_lookup(PKTMBUF_POOL_NAME);
+ if (mp == NULL)
+ rte_exit(EXIT_FAILURE, "Cannot get mempool for mbufs\n");
+
+ mz = rte_memzone_lookup(MZ_SHARED_INFO);
+ if (mz == NULL)
+ rte_exit(EXIT_FAILURE, "Cannot get port info structure\n");
+ info = mz->addr;
+ tx_stats = &(info->tx_stats[node_id]);
+ filter_stats = &(info->filter_stats[node_id]);
+
+Then, the hash table that contains the flows that will be handled
+by the node is created and populated.
+
+.. code-block:: c
+
+ static struct rte_hash *
+ create_hash_table(const struct shared_info *info)
+ {
+ uint32_t num_flows_node = info->num_flows / info->num_nodes;
+ char name[RTE_HASH_NAMESIZE];
+ struct rte_hash *h;
+
+ /* create table */
+ struct rte_hash_parameters hash_params = {
+ .entries = num_flows_node * 2, /* table load = 50% */
+ .key_len = sizeof(uint32_t), /* Store IPv4 dest IP address */
+ .socket_id = rte_socket_id(),
+ .hash_func_init_val = 0,
+ };
+
+ snprintf(name, sizeof(name), "hash_table_%d", node_id);
+ hash_params.name = name;
+ h = rte_hash_create(&hash_params);
+
+ if (h == NULL)
+ rte_exit(EXIT_FAILURE,
+ "Problem creating the hash table for node %d\n",
+ node_id);
+ return h;
+ }
+
+ static void
+ populate_hash_table(const struct rte_hash *h, const struct shared_info *info)
+ {
+ unsigned int i;
+ int32_t ret;
+ uint32_t ip_dst;
+ uint32_t num_flows_node = 0;
+ uint64_t target_node;
+
+ /* Add flows in table */
+ for (i = 0; i < info->num_flows; i++) {
+ target_node = i % info->num_nodes;
+ if (target_node != node_id)
+ continue;
+
+ ip_dst = rte_cpu_to_be_32(i);
+
+ ret = rte_hash_add_key(h, (void *) &ip_dst);
+ if (ret < 0)
+ rte_exit(EXIT_FAILURE, "Unable to add entry %u "
+ "in hash table\n", i);
+ else
+ num_flows_node++;
+
+ }
+
+ printf("Hash table: Adding 0x%x keys\n", num_flows_node);
+ }
+
+After initialization, packets are dequeued from the shared ring
+(from the server) and, like in the server process,
+the IPv4 address from the packets is used as a key to look up in the hash table.
+If there is a hit, packet is stored in a buffer, to be eventually transmitted
+in one of the enabled ports. If key is not there, packet is dropped, since the
+flow is not handled by the node.
+
+.. code-block:: c
+
+ static inline void
+ handle_packets(struct rte_hash *h, struct rte_mbuf **bufs, uint16_t num_packets)
+ {
+ struct ipv4_hdr *ipv4_hdr;
+ uint32_t ipv4_dst_ip[PKT_READ_SIZE];
+ const void *key_ptrs[PKT_READ_SIZE];
+ unsigned int i;
+ int32_t positions[PKT_READ_SIZE] = {0};
+
+ for (i = 0; i < num_packets; i++) {
+ /* Handle IPv4 header.*/
+ ipv4_hdr = rte_pktmbuf_mtod_offset(bufs[i], struct ipv4_hdr *,
+ sizeof(struct ether_hdr));
+ ipv4_dst_ip[i] = ipv4_hdr->dst_addr;
+ key_ptrs[i] = &ipv4_dst_ip[i];
+ }
+ /* Check if packets belongs to any flows handled by this node */
+ rte_hash_lookup_bulk(h, key_ptrs, num_packets, positions);
+
+ for (i = 0; i < num_packets; i++) {
+ if (likely(positions[i] >= 0)) {
+ filter_stats->passed++;
+ transmit_packet(bufs[i]);
+ } else {
+ filter_stats->drop++;
+ /* Drop packet, as flow is not handled by this node */
+ rte_pktmbuf_free(bufs[i]);
+ }
+ }
+ }
+
+Finally, note that both processes updates statistics, such as transmitted, received
+and dropped packets, which are shown and refreshed by the server app.
+
+.. code-block:: c
+
+ static void
+ do_stats_display(void)
+ {
+ unsigned int i, j;
+ const char clr[] = {27, '[', '2', 'J', '\0'};
+ const char topLeft[] = {27, '[', '1', ';', '1', 'H', '\0'};
+ uint64_t port_tx[RTE_MAX_ETHPORTS], port_tx_drop[RTE_MAX_ETHPORTS];
+ uint64_t node_tx[MAX_NODES], node_tx_drop[MAX_NODES];
+
+ /* to get TX stats, we need to do some summing calculations */
+ memset(port_tx, 0, sizeof(port_tx));
+ memset(port_tx_drop, 0, sizeof(port_tx_drop));
+ memset(node_tx, 0, sizeof(node_tx));
+ memset(node_tx_drop, 0, sizeof(node_tx_drop));
+
+ for (i = 0; i < num_nodes; i++) {
+ const struct tx_stats *tx = &info->tx_stats[i];
+
+ for (j = 0; j < info->num_ports; j++) {
+ const uint64_t tx_val = tx->tx[info->id[j]];
+ const uint64_t drop_val = tx->tx_drop[info->id[j]];
+
+ port_tx[j] += tx_val;
+ port_tx_drop[j] += drop_val;
+ node_tx[i] += tx_val;
+ node_tx_drop[i] += drop_val;
+ }
+ }
+
+ /* Clear screen and move to top left */
+ printf("%s%s", clr, topLeft);
+
+ printf("PORTS\n");
+ printf("-----\n");
+ for (i = 0; i < info->num_ports; i++)
+ printf("Port %u: '%s'\t", (unsigned int)info->id[i],
+ get_printable_mac_addr(info->id[i]));
+ printf("\n\n");
+ for (i = 0; i < info->num_ports; i++) {
+ printf("Port %u - rx: %9"PRIu64"\t"
+ "tx: %9"PRIu64"\n",
+ (unsigned int)info->id[i], info->rx_stats.rx[i],
+ port_tx[i]);
+ }
+
+ printf("\nSERVER\n");
+ printf("-----\n");
+ printf("distributed: %9"PRIu64", drop: %9"PRIu64"\n",
+ flow_dist_stats.distributed, flow_dist_stats.drop);
+
+ printf("\nNODES\n");
+ printf("-------\n");
+ for (i = 0; i < num_nodes; i++) {
+ const unsigned long long rx = nodes[i].stats.rx;
+ const unsigned long long rx_drop = nodes[i].stats.rx_drop;
+ const struct filter_stats *filter = &info->filter_stats[i];
+
+ printf("Node %2u - rx: %9llu, rx_drop: %9llu\n"
+ " tx: %9"PRIu64", tx_drop: %9"PRIu64"\n"
+ " filter_passed: %9"PRIu64", "
+ "filter_drop: %9"PRIu64"\n",
+ i, rx, rx_drop, node_tx[i], node_tx_drop[i],
+ filter->passed, filter->drop);
+ }
+
+ printf("\n");
+ }
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