diff --git a/contrib/spoa_example/spoa.c b/contrib/spoa_example/spoa.c
index ce59c04..5c3a453 100644
--- a/contrib/spoa_example/spoa.c
+++ b/contrib/spoa_example/spoa.c
@@ -14,39 +14,45 @@
  * 2 of the License, or (at your option) any later version.
  *
  */
-#include <stdio.h>
+#include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
-#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
 #include <signal.h>
-#include <pthread.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <sys/socket.h>
 #include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <err.h>
+#include <ctype.h>
+
+#include <pthread.h>
+
+#include <event2/util.h>
+#include <event2/event.h>
+#include <event2/event_struct.h>
+#include <event2/thread.h>
 
-#define DEFAULT_PORT      12345
-#define NUM_WORKERS       5
-#define MAX_FRAME_SIZE    16384
-#define SPOP_VERSION      "1.0"
-#define SPOA_CAPABILITIES ""
+#include <common/mini-clist.h>
+
+#define DEFAULT_PORT       12345
+#define CONNECTION_BACKLOG 10
+#define NUM_WORKERS        10
+#define MAX_FRAME_SIZE     16384
+#define SPOP_VERSION       "1.0"
 
 #define SLEN(str) (sizeof(str)-1)
 
-#define LOG(fmt, args...)                                           \
-	do {							    \
-		struct timeval now;				    \
-		int wid = *((int*)pthread_getspecific(worker_id));  \
-								    \
-		gettimeofday(&now, NULL);			    \
-		fprintf(stderr, "%ld.%06ld [%02d] " fmt "\n",	    \
-			now.tv_sec, now.tv_usec, wid, ##args);	    \
+#define LOG(worker, fmt, args...)                                       \
+	do {								\
+		struct timeval  now;					\
+                                                                        \
+		gettimeofday(&now, NULL);				\
+		fprintf(stderr, "%ld.%06ld [%02d] " fmt "\n",		\
+			now.tv_sec, now.tv_usec, (worker)->id, ##args);	\
 	} while (0)
 
-#define DEBUG(x...)                             \
+#define DEBUG(x...)				\
 	do {					\
 		if (debug)			\
 			LOG(x);			\
@@ -113,6 +119,17 @@
 	SPOE_SCOPE_RES,      /* <=> SCOPE_RES  */
 };
 
+enum spoa_state {
+	SPOA_ST_CONNECTING = 0,
+	SPOA_ST_PROCESSING,
+	SPOA_ST_DISCONNECTING,
+};
+
+enum spoa_frame_type {
+	SPOA_FRM_T_UNKNOWN = 0,
+	SPOA_FRM_T_HAPROXY,
+	SPOA_FRM_T_AGENT,
+};
 
 /* Masks to get data type or flags value */
 #define SPOE_DATA_T_MASK  0x0F
@@ -121,35 +138,82 @@
 /* Flags to set Boolean values */
 #define SPOE_DATA_FL_FALSE 0x00
 #define SPOE_DATA_FL_TRUE  0x10
-static const char *spoe_frm_err_reasons[SPOE_FRM_ERRS] = {
-	[SPOE_FRM_ERR_NONE]           = "normal",
-	[SPOE_FRM_ERR_IO]             = "I/O error",
-	[SPOE_FRM_ERR_TOUT]           = "a timeout occurred",
-	[SPOE_FRM_ERR_TOO_BIG]        = "frame is too big",
-	[SPOE_FRM_ERR_INVALID]        = "invalid frame received",
-	[SPOE_FRM_ERR_NO_VSN]         = "version value not found",
-	[SPOE_FRM_ERR_NO_FRAME_SIZE]  = "max-frame-size value not found",
-	[SPOE_FRM_ERR_NO_CAP]         = "capabilities value not found",
-	[SPOE_FRM_ERR_BAD_VSN]        = "unsupported version",
-	[SPOE_FRM_ERR_BAD_FRAME_SIZE] = "max-frame-size too big or too small",
-	[SPOE_FRM_ERR_UNKNOWN]        = "an unknown error occurred",
+
+struct spoe_engine {
+	char       *id;
+
+	struct list processing_frames;
+	struct list outgoing_frames;
+
+	struct list clients;
+	struct list list;
+};
+
+struct spoe_frame {
+	enum spoa_frame_type type;
+	char                *buf;
+	unsigned int         offset;
+	unsigned int         len;
+
+	unsigned int         stream_id;
+	unsigned int         frame_id;
+	bool                 hcheck;    /* true is the CONNECT frame is a healthcheck */
+	int                  ip_score;  /* -1 if unset, else between 0 and 100 */
+
+	struct event         process_frame_event;
+	struct worker       *worker;
+	struct spoe_engine  *engine;
+	struct client       *client;
+	struct list          list;
+
+	char                 data[0];
+};
+
+struct client {
+	int                 fd;
+	unsigned long       id;
+	enum spoa_state     state;
+
+	struct event        read_frame_event;
+	struct event        write_frame_event;
+
+	struct spoe_frame  *incoming_frame;
+	struct spoe_frame  *outgoing_frame;
+
+	struct list         processing_frames;
+	struct list         outgoing_frames;
+
+	unsigned int        max_frame_size;
+	int                 status_code;
+
+	char               *engine_id;
+	struct spoe_engine *engine;
+	bool                pipelining;
+	bool                async;
+
+	struct worker      *worker;
+	struct list         by_worker;
+	struct list         by_engine;
 };
 
 struct worker {
-	unsigned int id;
-	char         buf[MAX_FRAME_SIZE];
-	unsigned int len;
-	unsigned int size;
-	int          status_code;
-	unsigned int stream_id;
-	unsigned int frame_id;
-	bool         healthcheck;
-	int          ip_score; /* -1 if unset, else between 0 and 100 */
+	pthread_t           thread;
+	int                 id;
+	struct event_base  *base;
+	struct event       *monitor_event;
+
+	struct list         engines;
+
+	unsigned int        nbclients;
+	struct list         clients;
+
+	struct list         frames;
 };
 
+
 struct chunk {
-	char *str;	/* beginning of the string itself. Might not be 0-terminated */
-	int len;	/* current size of the string from first to last char */
+	char *str;  /* beginning of the string itself. Might not be 0-terminated */
+	int len;    /* current size of the string from first to last char */
 };
 
 union spoe_value {
@@ -169,139 +233,73 @@
 	union spoe_value    u;     /* spoe data value */
 };
 
+/* Globals */
+static struct worker *workers          = NULL;
+static struct worker  null_worker      = { .id = 0 };
+static unsigned long  clicount         = 0;
+static int            server_port      = DEFAULT_PORT;
+static int            num_workers      = NUM_WORKERS;
+static unsigned int   max_frame_size   = MAX_FRAME_SIZE;
+struct timeval        processing_delay = {0, 0};
+static bool           debug            = false;
+static bool           pipelining       = false;
+static bool           async            = false;
+
+
+static const char *spoe_frm_err_reasons[SPOE_FRM_ERRS] = {
+	[SPOE_FRM_ERR_NONE]           = "normal",
+	[SPOE_FRM_ERR_IO]             = "I/O error",
+	[SPOE_FRM_ERR_TOUT]           = "a timeout occurred",
+	[SPOE_FRM_ERR_TOO_BIG]        = "frame is too big",
+	[SPOE_FRM_ERR_INVALID]        = "invalid frame received",
+	[SPOE_FRM_ERR_NO_VSN]         = "version value not found",
+	[SPOE_FRM_ERR_NO_FRAME_SIZE]  = "max-frame-size value not found",
+	[SPOE_FRM_ERR_NO_CAP]         = "capabilities value not found",
+	[SPOE_FRM_ERR_BAD_VSN]        = "unsupported version",
+	[SPOE_FRM_ERR_BAD_FRAME_SIZE] = "max-frame-size too big or too small",
+	[SPOE_FRM_ERR_UNKNOWN]        = "an unknown error occurred",
+};
+
-static bool debug = false;
-static pthread_key_t worker_id;
+static void signal_cb(evutil_socket_t, short, void *);
+static void accept_cb(evutil_socket_t, short, void *);
+static void worker_monitor_cb(evutil_socket_t, short, void *);
+static void process_frame_cb(evutil_socket_t, short, void *);
+static void read_frame_cb(evutil_socket_t, short, void *);
+static void write_frame_cb(evutil_socket_t, short, void *);
+
+static void use_spoe_engine(struct client *);
+static void unuse_spoe_engine(struct client *);
+static void release_frame(struct spoe_frame *);
+static void release_client(struct client *);
 
 static void
-check_ipv4_reputation(struct worker *w, struct in_addr *ipv4)
+check_ipv4_reputation(struct spoe_frame *frame, struct in_addr *ipv4)
 {
 	char str[INET_ADDRSTRLEN];
 
 	if (inet_ntop(AF_INET, ipv4, str, INET_ADDRSTRLEN) == NULL)
 		return;
 
-	w->ip_score = random() % 100;
+	frame->ip_score = random() % 100;
 
-	DEBUG("  IP score for %.*s is: %d", INET_ADDRSTRLEN, str, w->ip_score);
+	DEBUG(frame->worker, "IP score for %.*s is %d",
+	      INET_ADDRSTRLEN, str, frame->ip_score);
 }
 
 static void
-check_ipv6_reputation(struct worker *w, struct in6_addr *ipv6)
+check_ipv6_reputation(struct spoe_frame *frame, struct in6_addr *ipv6)
 {
 	char str[INET6_ADDRSTRLEN];
 
 	if (inet_ntop(AF_INET6, ipv6, str, INET6_ADDRSTRLEN) == NULL)
 		return;
 
-	w->ip_score = random() % 100;
-
-	DEBUG("  IP score for %.*s is: %d", INET6_ADDRSTRLEN, str, w->ip_score);
-}
-
-static int
-do_read(int sock, void *buf, int read_len)
-{
-	fd_set readfds;
-	int    n = 0, total = 0, bytesleft = read_len;
-
-	FD_ZERO(&readfds);
-	FD_SET(sock, &readfds);
-
-	while (total < read_len) {
-		if (select(FD_SETSIZE, &readfds, NULL, NULL, NULL) == -1)
-			return -1;
-		if (!FD_ISSET(sock, &readfds))
-			return -1;
-
-		n = read(sock, buf + total, bytesleft);
-		if (n <= 0)
-			break;
-
-		total += n;
-		bytesleft -= n;
-	}
-
-	return (n == -1) ? -1 : total;
-}
-
-static int
-do_write(int sock, void *buf, int write_len)
-{
-	fd_set writefds;
-	int    n = 0, total = 0, bytesleft = write_len;
-
-	FD_ZERO(&writefds);
-	FD_SET(sock, &writefds);
-
-	while (total < write_len) {
-		if (select(FD_SETSIZE, NULL, &writefds, NULL, NULL) == -1)
-			return -1;
-		if (!FD_ISSET(sock, &writefds))
-			return -1;
-
-		n = write(sock, buf + total, bytesleft);
-		if (n <= 0)
-			break;
-
-		total += n;
-		bytesleft -= n;
-	}
-
-	return (n == -1) ? -1 : total;
-}
-
-/* Receive a frame sent by HAProxy. It returns -1 if an error occurred,
- * otherwise the number of read bytes.*/
-static int
-read_frame(int sock, struct worker *w)
-{
-	uint32_t     netint;
-	unsigned int framesz;
-
-	/* Read the frame size, on 4 bytes */
-	if (do_read(sock, &netint, sizeof(netint)) != 4) {
-		w->status_code = SPOE_FRM_ERR_IO;
-		return -1;
-	}
-
-	/* Check it against the max size */
-	framesz = ntohl(netint);
-	if (framesz > w->size) {
-		w->status_code = SPOE_FRM_ERR_TOO_BIG;
-		return -1;
-	}
+	frame->ip_score = random() % 100;
 
-	/* Read the frame */
-	if (do_read(sock, w->buf, framesz) != framesz) {
-		w->status_code = SPOE_FRM_ERR_IO;
-		return -1;
-	}
-
-	w->len = framesz;
-	return framesz;
+	DEBUG(frame->worker, "IP score for %.*s is %d",
+	      INET6_ADDRSTRLEN, str, frame->ip_score);
 }
 
-/* Send a frame to HAProxy. It returns -1 if an error occurred, otherwise the
- * number of written bytes. */
-static int
-write_frame(int sock, struct worker *w)
-{
-	uint32_t netint;
-
-	/* Write the frame size, on 4 bytes */
-	netint = htonl(w->len);
-	if (do_write(sock, &netint, sizeof(netint)) != 4) {
-		w->status_code = SPOE_FRM_ERR_IO;
-		return -1;
-	}
-
-	/* Write the frame */
-	if (do_write(sock, w->buf, w->len) != w->len) {
-		w->status_code = SPOE_FRM_ERR_IO;
-		return -1;
-	}
-	return w->len;
-}
 
 /* Encode a variable-length integer. This function never fails and returns the
  * number of written bytes. */
@@ -391,7 +389,7 @@
 	*str = buf+idx;
 	return (idx + *len);
 
-error:
+  error:
 	return -1;
 }
 
@@ -530,21 +528,20 @@
 /* Check the protocol version. It returns -1 if an error occurred, the number of
  * read bytes otherwise. */
 static int
-check_proto_version(struct worker *w, int idx)
+check_proto_version(struct spoe_frame *frame, int idx)
 {
-	char    *str;
-	uint64_t sz;
+	char      *str;
+	uint64_t   sz;
 
 	/* Get the list of all supported versions by HAProxy */
-	if ((w->buf[idx++] & SPOE_DATA_T_MASK) != SPOE_DATA_T_STR) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	if ((frame->buf[idx++] & SPOE_DATA_T_MASK) != SPOE_DATA_T_STR)
 		return -1;
-	}
-	idx += decode_spoe_string(w->buf+idx, w->buf+w->len, &str, &sz);
-	if (str == NULL) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	idx += decode_spoe_string(frame->buf+idx, frame->buf+frame->len, &str, &sz);
+	if (str == NULL)
 		return -1;
-	}
+
+	DEBUG(frame->worker, "<%lu> Supported versions : %.*s",
+	      frame->client->id, (int)sz, str);
 
 	/* TODO: Find the right verion in supported ones */
 
@@ -554,29 +551,28 @@
 /* Check max frame size value. It returns -1 if an error occurred, the number of
  * read bytes otherwise. */
 static int
-check_max_frame_size(struct worker *w, int idx)
+check_max_frame_size(struct spoe_frame *frame, int idx)
 {
 	uint64_t sz;
 	int      type, i;
 
 	/* Get the max-frame-size value of HAProxy */
-	type =  w->buf[idx++];
+	type =  frame->buf[idx++];
 	if ((type & SPOE_DATA_T_MASK) != SPOE_DATA_T_INT32  &&
 	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_INT64  &&
 	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_UINT32 &&
-	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_UINT64) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_UINT64)
 		return -1;
-	}
-	if ((i = decode_spoe_varint(w->buf+idx, w->buf+w->len, &sz)) == -1) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	if ((i = decode_spoe_varint(frame->buf+idx, frame->buf+frame->len, &sz)) == -1)
 		return -1;
-	}
 	idx += i;
 
 	/* Keep the lower value */
-	if (sz < w->size)
-		w->size = sz;
+	if (sz < frame->client->max_frame_size)
+		frame->client->max_frame_size = sz;
+
+	DEBUG(frame->worker, "<%lu> HAProxy maximum frame size : %u",
+	      frame->client->id, (unsigned int)sz);
 
 	return idx;
 }
@@ -584,493 +580,1268 @@
 /* Check healthcheck value. It returns -1 if an error occurred, the number of
  * read bytes otherwise. */
 static int
-check_healthcheck(struct worker *w, int idx)
+check_healthcheck(struct spoe_frame *frame, int idx)
 {
 	int type;
 
+	/* Get the "healthcheck" value */
+	type = frame->buf[idx++];
+	if ((type & SPOE_DATA_T_MASK) != SPOE_DATA_T_BOOL)
+		return -1;
+	frame->hcheck = ((type & SPOE_DATA_FL_TRUE) == SPOE_DATA_FL_TRUE);
+
+	DEBUG(frame->worker, "<%lu> HELLO healthcheck : %s",
+	      frame->client->id, (frame->hcheck ? "true" : "false"));
+	return idx;
+}
+
+/* Check capabilities value. It returns -1 if an error occurred, the number of
+ * read bytes otherwise. */
+static int
+check_capabilities(struct spoe_frame *frame, int idx)
+{
+	struct client *client = frame->client;
+	char          *str;
+	uint64_t       sz;
+	int            i;
+
-	/* Get the "healthcheck" value of HAProxy */
-	type = w->buf[idx++];
-	if ((type & SPOE_DATA_T_MASK) != SPOE_DATA_T_BOOL) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	if ((frame->buf[idx++] & SPOE_DATA_T_MASK) != SPOE_DATA_T_STR)
 		return -1;
+	idx += decode_spoe_string(frame->buf+idx, frame->buf+frame->len, &str, &sz);
+	if (str == NULL) /* this is not an error */
+		return idx;
+
+	DEBUG(frame->worker, "<%lu> HAProxy capabilities : %.*s",
+	      client->id, (int)sz, str);
+
+	i = 0;
+	while (i < sz) {
+		char *delim;
+
+		/* Skip leading spaces */
+		for (; isspace(str[i]) && i < sz; i++);
+
+		if (sz - i >= 10 && !strncmp(str + i, "pipelining", 10)) {
+			i += 10;
+			if (sz == i || isspace(str[i]) || str[i] == ',') {
+				DEBUG(frame->worker,
+				      "<%lu> HAProxy supports frame pipelining",
+				      client->id);
+				client->pipelining = true;
+			}
+
+		}
+		else if (sz - i >= 5 && !strncmp(str + i, "async", 5)) {
+			i += 5;
+			if (sz == i || isspace(str[i]) || str[i] == ',') {
+				DEBUG(frame->worker,
+				      "<%lu> HAProxy supports asynchronous frame",
+				      client->id);
+				client->async = true;
+			}
+		}
+
+		if (sz == i || (delim = memchr(str + i, ',', sz-i)) == NULL)
+			break;
+		i = (delim - str) + 1;
 	}
-	w->healthcheck = ((type & SPOE_DATA_FL_TRUE) == SPOE_DATA_FL_TRUE);
+
+	return idx;
+}
+
+/* Check engine-id value. It returns -1 if an error occurred, the number of
+ * read bytes otherwise. */
+static int
+check_engine_id(struct spoe_frame *frame, int idx)
+{
+	struct client *client = frame->client;
+	char          *str;
+	uint64_t       sz;
+
+	if ((frame->buf[idx++] & SPOE_DATA_T_MASK) != SPOE_DATA_T_STR)
+		return -1;
+
+	idx += decode_spoe_string(frame->buf+idx, frame->buf+frame->len, &str, &sz);
+	if (str == NULL) /* this is not an error */
+		return idx;
+
+	if (client->engine != NULL)
+		return idx;
+
+	DEBUG(frame->worker, "<%lu> HAProxy engine id : %.*s",
+	      client->id, (int)sz, str);
+
+	client->engine_id = strndup(str, (int)sz);
+	return idx;
+}
+
+/* Check disconnect status code. It returns -1 if an error occurred, the number
+ * of read bytes otherwise. */
+static int
+check_discon_status_code(struct spoe_frame *frame, int idx)
+{
+	uint64_t sz;
+	int      type, i;
+
+	/* Get the "status-code" value */
+	type =  frame->buf[idx++];
+	if ((type & SPOE_DATA_T_MASK) != SPOE_DATA_T_INT32 &&
+	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_INT64 &&
+	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_UINT32 &&
+	    (type & SPOE_DATA_T_MASK) != SPOE_DATA_T_UINT64)
+		return -1;
+	if ((i = decode_spoe_varint(frame->buf+idx, frame->buf+frame->len, &sz)) == -1)
+		return -1;
+	idx += i;
+
+	frame->client->status_code = (unsigned int)sz;
+
+	DEBUG(frame->worker, "<%lu> Disconnect status code : %u",
+	      frame->client->id, frame->client->status_code);
+
 	return idx;
 }
 
+/* Check the disconnect message. It returns -1 if an error occurred, the number
+ * of read bytes otherwise. */
+static int
+check_discon_message(struct spoe_frame *frame, int idx)
+{
+	char    *str;
+	uint64_t sz;
+
+	/* Get the "message" value */
+	if ((frame->buf[idx++] & SPOE_DATA_T_MASK) != SPOE_DATA_T_STR)
+		return -1;
+	idx += decode_spoe_string(frame->buf+idx, frame->buf+frame->len, &str, &sz);
+	if (str == NULL)
+		return -1;
+
+	DEBUG(frame->worker, "<%lu> Disconnect message : %.*s",
+	      frame->client->id, (int)sz, str);
+
+	return idx;
+}
 
 /* Decode a HELLO frame received from HAProxy. It returns -1 if an error
- * occurred, 0 if the frame must be skipped, otherwise the number of read
- * bytes. */
+ * occurred, otherwise the number of read bytes. HELLO frame cannot be
+ * ignored and having another frame than a HELLO frame is an error. */
 static int
-handle_hahello(struct worker *w)
+handle_hahello(struct spoe_frame *frame)
 {
-	char        *end = w->buf+w->len;
-	int          i, idx = 0;
+	struct client *client = frame->client;
+	char          *buf = frame->buf;
+	char          *end = frame->buf + frame->len;
+	int            i, idx = 0;
 
-	/* Check frame type */
-	if (w->buf[idx++] != SPOE_FRM_T_HAPROXY_HELLO)
-		goto skip;
+	/* Check frame type: we really want a HELLO frame */
+	if (buf[idx++] != SPOE_FRM_T_HAPROXY_HELLO)
+		goto error;
+
+	DEBUG(frame->worker, "<%lu> Decode HAProxy HELLO frame", client->id);
 
 	/* Skip flags */
 	idx += 4;
 
 	/* stream-id and frame-id must be cleared */
-	if (w->buf[idx] != 0 || w->buf[idx+1] != 0) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	if (buf[idx] != 0 || buf[idx+1] != 0) {
+		client->status_code = SPOE_FRM_ERR_INVALID;
 		goto error;
 	}
 	idx += 2;
 
 	/* Loop on K/V items */
-	while (idx < w->len) {
+	while (buf+idx < end) {
 		char     *str;
 		uint64_t  sz;
 
 		/* Decode the item name */
-		idx += decode_spoe_string(w->buf+idx, end, &str, &sz);
+		idx += decode_spoe_string(buf+idx, end, &str, &sz);
 		if (str == NULL) {
-			w->status_code = SPOE_FRM_ERR_INVALID;
+			client->status_code = SPOE_FRM_ERR_INVALID;
 			goto error;
 		}
 
 		/* Check "supported-versions" K/V item */
 		if (!memcmp(str, "supported-versions", sz)) {
-			if ((i = check_proto_version(w, idx)) == -1)
+			if ((i = check_proto_version(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
 				goto error;
+			}
 			idx = i;
 		}
-		/* Check "max-frame-size" K/V item "*/
+		/* Check "max-frame-size" K/V item */
 		else if (!memcmp(str, "max-frame-size", sz)) {
-			if ((i = check_max_frame_size(w, idx)) == -1)
+			if ((i = check_max_frame_size(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
 				goto error;
+			}
 			idx = i;
 		}
-		/* Check "healthcheck" K/V item "*/
+		/* Check "healthcheck" K/V item */
 		else if (!memcmp(str, "healthcheck", sz)) {
-			if ((i = check_healthcheck(w, idx)) == -1)
+			if ((i = check_healthcheck(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
+				goto error;
+			}
+			idx = i;
+		}
+		/* Check "capabilities" K/V item */
+		else if (!memcmp(str, "capabilities", sz)) {
+			if ((i = check_capabilities(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
+				goto error;
+			}
+			idx = i;
+		}
+		/* Check "engine-id" K/V item */
+		else if (!memcmp(str, "engine-id", sz)) {
+			if ((i = check_engine_id(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
 				goto error;
+			}
 			idx = i;
 		}
-		/* Skip "capabilities" K/V item for now */
 		else {
+			DEBUG(frame->worker, "<%lu> Skip K/V item : key=%.*s",
+			      client->id, (int)sz, str);
+
 			/* Silently ignore unknown item */
-			if ((i = skip_spoe_data(w->buf+idx, end)) == -1) {
-				w->status_code = SPOE_FRM_ERR_INVALID;
+			if ((i = skip_spoe_data(buf+idx, end)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
 				goto error;
 			}
 			idx += i;
 		}
 	}
 
+	if (async == false || client->engine_id == NULL)
+		client->async = false;
+	if (pipelining == false)
+		client->pipelining = false;
+
+	if (client->async == true)
+		use_spoe_engine(client);
+
 	return idx;
-skip:
-	return 0;
-error:
+
+  error:
 	return -1;
 }
 
 /* Decode a DISCONNECT frame received from HAProxy. It returns -1 if an error
- * occurred, 0 if the frame must be skipped, otherwise the number of read
- * bytes. */
+ * occurred, otherwise the number of read bytes. DISCONNECT frame cannot be
+ * ignored and having another frame than a DISCONNECT frame is an error.*/
 static int
-handle_hadiscon(struct worker *w)
+handle_hadiscon(struct spoe_frame *frame)
 {
-	char        *end = w->buf+w->len;
-	int          i, idx = 0;
+	struct client *client = frame->client;
+	char          *buf    = frame->buf;
+	char          *end    = frame->buf + frame->len;
+	int            i, idx = 0;
 
-	/* Check frame type */
-	if (w->buf[idx++] != SPOE_FRM_T_HAPROXY_DISCON)
-		goto skip;
+	/* Check frame type: we really want a DISCONNECT frame */
+	if (buf[idx++] != SPOE_FRM_T_HAPROXY_DISCON)
+		goto error;
+
+	DEBUG(frame->worker, "<%lu> Decode HAProxy DISCONNECT frame", client->id);
 
 	/* Skip flags */
 	idx += 4;
 
 	/* stream-id and frame-id must be cleared */
-	if (w->buf[idx] != 0 || w->buf[idx+1] != 0) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
+	if (buf[idx] != 0 || buf[idx+1] != 0) {
+		client->status_code = SPOE_FRM_ERR_INVALID;
 		goto error;
 	}
 	idx += 2;
 
+	client->status_code = SPOE_FRM_ERR_NONE;
+
 	/* Loop on K/V items */
-	while (idx < w->len) {
+	while (buf+idx < end) {
 		char     *str;
 		uint64_t  sz;
 
 		/* Decode item key */
-		idx += decode_spoe_string(w->buf+idx, end, &str, &sz);
+		idx += decode_spoe_string(buf+idx, end, &str, &sz);
 		if (str == NULL) {
-			w->status_code = SPOE_FRM_ERR_INVALID;
+			client->status_code = SPOE_FRM_ERR_INVALID;
 			goto error;
 		}
-		/* Silently ignore unknown item */
-		if ((i = skip_spoe_data(w->buf+idx, end)) == -1) {
-			w->status_code = SPOE_FRM_ERR_INVALID;
-			goto error;
+
+		/* Check "status-code" K/V item */
+		if (!memcmp(str, "status-code", sz)) {
+			if ((i = check_discon_status_code(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
+				goto error;
+			}
+			idx = i;
+		}
+		/* Check "message" K/V item */
+		else if (!memcmp(str, "message", sz)) {
+			if ((i = check_discon_message(frame, idx)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
+				goto error;
+			}
+			idx = i;
+		}
+		else {
+			DEBUG(frame->worker, "<%lu> Skip K/V item : key=%.*s",
+			      client->id, (int)sz, str);
+
+			/* Silently ignore unknown item */
+			if ((i = skip_spoe_data(buf+idx, end)) == -1) {
+				client->status_code = SPOE_FRM_ERR_INVALID;
+				goto error;
+			}
+			idx += i;
 		}
-		idx += i;
 	}
 
-	w->status_code = SPOE_FRM_ERR_NONE;
 	return idx;
-skip:
-	return 0;
-error:
+
+  error:
 	return -1;
 }
 
 /* Decode a NOTIFY frame received from HAProxy. It returns -1 if an error
- * occurred, 0 if the frame must be skipped, otherwise the number of read
- * bytes. */
+ * occurred or if the frame must be ignored, 0 if the frame must be ack without
+ * any processing, otherwise the number of read bytes (always > 0). */
 static int
-handle_hanotify(struct worker *w)
+handle_hanotify(struct spoe_frame *frame)
 {
-	char    *end = w->buf+w->len;
-	uint64_t stream_id, frame_id;
-	int      nbargs, i, idx = 0;
+	struct client *client = frame->client;
+	char          *buf    = frame->buf;
+	char          *end    = frame->buf + frame->len;
+	uint64_t       stream_id, frame_id;
+	int            i, idx = 0;
 
 	/* Check frame type */
-	if (w->buf[idx++] != SPOE_FRM_T_HAPROXY_NOTIFY)
-		goto skip;
+	if (buf[idx++] != SPOE_FRM_T_HAPROXY_NOTIFY)
+		goto ignore;
+
+	DEBUG(frame->worker, "<%lu> Decode HAProxy NOTIFY frame", client->id);
 
 	/* Skip flags */
 	idx += 4;
 
 	/* Read the stream-id */
-	if ((i = decode_spoe_varint(w->buf+idx, end, &stream_id)) == -1) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
-		goto error;
-	}
+	if ((i = decode_spoe_varint(buf+idx, end, &stream_id)) == -1)
+		goto ignore;
 	idx += i;
 
 	/* Read the frame-id */
-	if ((i = decode_spoe_varint(w->buf+idx, end, &frame_id)) == -1) {
-		w->status_code = SPOE_FRM_ERR_INVALID;
-		goto error;
-	}
+	if ((i = decode_spoe_varint(buf+idx, end, &frame_id)) == -1)
+		goto ignore;
 	idx += i;
 
-	w->stream_id = (unsigned int)stream_id;
-	w->frame_id  = (unsigned int)frame_id;
+	frame->stream_id = (unsigned int)stream_id;
+	frame->frame_id  = (unsigned int)frame_id;
 
-	DEBUG("Notify frame received: stream-id=%u - frame-id=%u",
-	      w->stream_id, w->frame_id);
+	DEBUG(frame->worker, "<%lu> STREAM-ID=%u - FRAME-ID=%u",
+	      client->id, frame->stream_id, frame->frame_id);
 
-	/* Loop on messages */
-	while (idx < w->len) {
-		char    *str;
-		uint64_t sz;
+	if (buf + idx == end) {
+		return 0;
+	}
 
-		/* Decode the message name */
-		idx += decode_spoe_string(w->buf+idx, end, &str, &sz);
-		if (str == NULL) {
-			w->status_code = SPOE_FRM_ERR_INVALID;
-			goto error;
-		}
-		DEBUG("  Message '%.*s' received", (int)sz, str);
+	frame->offset = idx;
+	return idx;
 
-		nbargs = w->buf[idx++];
-		if (!memcmp(str, "check-client-ip", sz)) {
-			struct spoe_data data;
+  ignore:
+	return -1;
+}
 
-			memset(&data, 0, sizeof(data));
+/* Encode a HELLO frame to send it to HAProxy. It returns the number of written
+ * bytes. */
+static int
+prepare_agenthello(struct spoe_frame *frame)
+{
+	struct client *client = frame->client;
+	char          *buf    = frame->buf;
+	int            idx    = 0;
 
-			if (nbargs != 1) {
-				w->status_code = SPOE_FRM_ERR_INVALID;
-				goto error;
-			}
-			if ((i = decode_spoe_string(w->buf+idx, end, &str, &sz)) == -1) {
-				w->status_code = SPOE_FRM_ERR_INVALID;
-				goto error;
-			}
-			idx += i;
-			if ((i = decode_spoe_data(w->buf+idx, end, &data)) == -1) {
-				w->status_code = SPOE_FRM_ERR_INVALID;
-				goto error;
-			}
-			idx += i;
-			if ((data.type & SPOE_DATA_T_MASK) == SPOE_DATA_T_IPV4)
-				check_ipv4_reputation(w, &data.u.ipv4);
-			else if ((data.type & SPOE_DATA_T_MASK) == SPOE_DATA_T_IPV6)
-				check_ipv6_reputation(w, &data.u.ipv6);
-			else {
-				w->status_code = SPOE_FRM_ERR_INVALID;
-				goto error;
-			}
-		}
-		else {
-			while (nbargs-- > 0) {
-				/* Silently ignore argument: its name and its value */
-				if ((i = decode_spoe_string(w->buf+idx, end, &str, &sz)) == -1) {
-					w->status_code = SPOE_FRM_ERR_INVALID;
-					goto error;
-				}
-				idx += i;
-				if ((i = skip_spoe_data(w->buf+idx, end)) == -1) {
-					w->status_code = SPOE_FRM_ERR_INVALID;
-					goto error;
-				}
-				idx += i;
-			}
-		}
-	}
-
-	return idx;
-skip:
-	return 0;
-error:
-	return -1;
-}
-
-/* Encode a HELLO frame to send it to HAProxy. It returns -1 if an error
- * occurred, the number of written bytes otherwise. */
-static int
-prepare_agenthello(struct worker *w)
-{
-	int idx = 0;
+	DEBUG(frame->worker, "<%lu> Encode Agent HELLO frame", client->id);
+	frame->type = SPOA_FRM_T_AGENT;
 
 	/* Frame Type */
-	w->buf[idx++] = SPOE_FRM_T_AGENT_HELLO;
+	buf[idx++] = SPOE_FRM_T_AGENT_HELLO;
 
 	/* No flags for now */
-	memset(w->buf+idx, 0, 4); /* No flags */
+	memset(buf+idx, 0, 4); /* No flags */
 	idx += 4;
 
 	/* No stream-id and frame-id for HELLO frames */
-	w->buf[idx++] = 0;
-	w->buf[idx++] = 0;
+	buf[idx++] = 0;
+	buf[idx++] = 0;
 
 	/* "version" K/V item */
-	idx += encode_spoe_string("version", 7, w->buf+idx);
-	w->buf[idx++] = SPOE_DATA_T_STR;
-	idx += encode_spoe_string(SPOP_VERSION, SLEN(SPOP_VERSION), w->buf+idx);
+	idx += encode_spoe_string("version", 7, buf+idx);
+	buf[idx++] = SPOE_DATA_T_STR;
+	idx += encode_spoe_string(SPOP_VERSION, SLEN(SPOP_VERSION), buf+idx);
+	DEBUG(frame->worker, "<%lu> Agent version : %s",
+	      client->id, SPOP_VERSION);
+
 
 	/* "max-frame-size" K/V item */
-	idx += encode_spoe_string("max-frame-size", 14, w->buf+idx);
-	w->buf[idx++] = SPOE_DATA_T_UINT32;
-	idx += encode_spoe_varint(w->size, w->buf+idx);
+	idx += encode_spoe_string("max-frame-size", 14, buf+idx);
+	buf[idx++] = SPOE_DATA_T_UINT32;
+	idx += encode_spoe_varint(client->max_frame_size, buf+idx);
+	DEBUG(frame->worker, "<%lu> Agent maximum frame size : %u",
+	      client->id, client->max_frame_size);
 
 	/* "capabilities" K/V item */
-	idx += encode_spoe_string("capabilities", 12, w->buf+idx);
-	w->buf[idx++] = SPOE_DATA_T_STR;
-	idx += encode_spoe_string(SPOA_CAPABILITIES, SLEN(SPOA_CAPABILITIES), w->buf+idx);
+	idx += encode_spoe_string("capabilities", 12, buf+idx);
+	buf[idx++] = SPOE_DATA_T_STR;
+	if (client->pipelining == true && client->async == true)
+		idx += encode_spoe_string("pipelining,async", 16, buf+idx);
+	else if (client->pipelining == true)
+		idx += encode_spoe_string("pipelining", 10, buf+idx);
+	else if (client->async == true)
+		idx += encode_spoe_string("async", 5, buf+idx);
+	else
+		idx += encode_spoe_string(NULL, 0, buf+idx);
 
-	w->len = idx;
+	DEBUG(frame->worker, "<%lu> Agent capabilities : %s %s",
+	      client->id, (client->pipelining?"pipelining":""),
+	      (client->async?"async":""));
+
+	frame->len = idx;
 	return idx;
 }
 
-/* Encode a ACK frame to send it to HAProxy. It returns -1 if an error occurred,
- * the number of written bytes otherwise. */
+/* Encode a DISCONNECT frame to send it to HAProxy. It returns the number of
+ * written bytes. */
 static int
-prepare_agentack(struct worker *w)
+prepare_agentdicon(struct spoe_frame *frame)
 {
-	int idx = 0;
+	struct client *client = frame->client;
+	char           *buf   = frame->buf;
+	const char     *reason;
+	int             rlen, idx = 0;
+
+	DEBUG(frame->worker, "<%lu> Encode Agent DISCONNECT frame", client->id);
+	frame->type = SPOA_FRM_T_AGENT;
+
+	if (client->status_code >= SPOE_FRM_ERRS)
+		client->status_code = SPOE_FRM_ERR_UNKNOWN;
+	reason = spoe_frm_err_reasons[client->status_code];
+	rlen   = strlen(reason);
 
 	/* Frame type */
-	w->buf[idx++] = SPOE_FRM_T_AGENT_ACK;
+	buf[idx++] = SPOE_FRM_T_AGENT_DISCON;
 
 	/* No flags for now */
-	memset(w->buf+idx, 0, 4); /* No flags */
+	memset(buf+idx, 0, 4);
 	idx += 4;
 
-	/* Set stream-id and frame-id for ACK frames */
-	idx += encode_spoe_varint(w->stream_id, w->buf+idx);
-	idx += encode_spoe_varint(w->frame_id, w->buf+idx);
+	/* No stream-id and frame-id for DISCONNECT frames */
+	buf[idx++] = 0;
+	buf[idx++] = 0;
+
+	/* There are 2 mandatory items: "status-code" and "message" */
+
+	/* "status-code" K/V item */
+	idx += encode_spoe_string("status-code", 11, buf+idx);
+	buf[idx++] = SPOE_DATA_T_UINT32;
+	idx += encode_spoe_varint(client->status_code, buf+idx);
+	DEBUG(frame->worker, "<%lu> Disconnect status code : %u",
+	      client->id, client->status_code);
 
-	/* Data */
-	if (w->ip_score == -1)
-		goto out;
+	/* "message" K/V item */
+	idx += encode_spoe_string("message", 7, buf+idx);
+	buf[idx++] = SPOE_DATA_T_STR;
+	idx += encode_spoe_string(reason, rlen, buf+idx);
+	DEBUG(frame->worker, "<%lu> Disconnect message : %s",
+	      client->id, reason);
 
-	w->buf[idx++] = SPOE_ACT_T_SET_VAR;                   /* Action type */
-	w->buf[idx++] = 3;                                    /* Number of args */
-	w->buf[idx++] = SPOE_SCOPE_SESS;                      /* Arg 1: the scope */
-	idx += encode_spoe_string("ip_score", 8, w->buf+idx); /* Arg 2: variable name */
-	w->buf[idx++] = SPOE_DATA_T_UINT32;
-	idx += encode_spoe_varint(w->ip_score, w->buf+idx);   /* Arg 3: variable value */
-out:
-	w->len = idx;
+	frame->len = idx;
 	return idx;
 }
 
-/* Encode a DISCONNECT frame to send it to HAProxy. It returns -1 if an error
- * occurred, the number of written bytes otherwise. */
+/* Encode a ACK frame to send it to HAProxy. It returns the number of written
+ * bytes. */
 static int
-prepare_agentdicon(struct worker *w)
+prepare_agentack(struct spoe_frame *frame)
 {
-	const char *reason;
-	int         rlen, idx = 0;
+	char *buf = frame->buf;
+	int   idx = 0;
 
-	if (w->status_code >= SPOE_FRM_ERRS)
-		w->status_code = SPOE_FRM_ERR_UNKNOWN;
-	reason = spoe_frm_err_reasons[w->status_code];
-	rlen   = strlen(reason);
+	/* Be careful here, in async mode, frame->client can be NULL */
+
+	DEBUG(frame->worker, "Encode Agent ACK frame");
+	frame->type = SPOA_FRM_T_AGENT;
 
 	/* Frame type */
-	w->buf[idx++] = SPOE_FRM_T_AGENT_DISCON;
+	buf[idx++] = SPOE_FRM_T_AGENT_ACK;
 
 	/* No flags for now */
-	memset(w->buf+idx, 0, 4);
+	memset(buf+idx, 0, 4); /* No flags */
 	idx += 4;
 
-	/* No stream-id and frame-id for DISCONNECT frames */
-	w->buf[idx++] = 0;
-	w->buf[idx++] = 0;
-
-	/* There are 2 mandatory items: "status-code" and "message" */
+	/* Set stream-id and frame-id for ACK frames */
+	idx += encode_spoe_varint(frame->stream_id, buf+idx);
+	idx += encode_spoe_varint(frame->frame_id, buf+idx);
 
-	/* "status-code" K/V item */
-	idx += encode_spoe_string("status-code", 11, w->buf+idx);
-	w->buf[idx++] = SPOE_DATA_T_UINT32;
-	idx += encode_spoe_varint(w->status_code, w->buf+idx);
+	DEBUG(frame->worker, "STREAM-ID=%u - FRAME-ID=%u",
+	      frame->stream_id, frame->frame_id);
 
-	/* "message" K/V item */
-	idx += encode_spoe_string("message", 7, w->buf+idx);
-	w->buf[idx++] = SPOE_DATA_T_STR;
-	idx += encode_spoe_string(reason, rlen, w->buf+idx);
-
-	w->len = idx;
+	frame->len = idx;
 	return idx;
 }
 
 static int
-hello_handshake(int sock, struct worker *w)
+create_server_socket(void)
 {
-	if (read_frame(sock, w) < 0) {
-		LOG("Failed to read Haproxy HELLO frame");
-		goto error;
+	struct sockaddr_in listen_addr;
+	int                fd, yes = 1;
+
+	fd = socket(AF_INET, SOCK_STREAM, 0);
+	if (fd < 0) {
+		LOG(&null_worker, "Failed to create service socket : %m");
+		return -1;
 	}
-	if (handle_hahello(w) < 0) {
-		LOG("Failed to handle Haproxy HELLO frame");
-		goto error;
+
+	memset(&listen_addr, 0, sizeof(listen_addr));
+	listen_addr.sin_family = AF_INET;
+	listen_addr.sin_addr.s_addr = INADDR_ANY;
+	listen_addr.sin_port = htons(server_port);
+
+	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0 ||
+	    setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes)) < 0) {
+		LOG(&null_worker, "Failed to set option on server socket : %m");
+		return -1;
 	}
-	if (prepare_agenthello(w) < 0) {
-		LOG("Failed to prepare Agent HELLO frame");
-		goto error;
+
+	if (bind(fd, (struct sockaddr *) &listen_addr, sizeof(listen_addr)) < 0) {
+		LOG(&null_worker, "Failed to bind server socket : %m");
+		return -1;
 	}
-	if (write_frame(sock, w) < 0) {
-		LOG("Failed to write Agent frame");
-		goto error;
+
+	if (listen(fd, CONNECTION_BACKLOG) < 0) {
+		LOG(&null_worker, "Failed to listen on server socket : %m");
+		return -1;
 	}
-	DEBUG("Hello handshake done: version=%s - max-frame-size=%u - healthcheck=%s",
-	      SPOP_VERSION, w->size, (w->healthcheck ? "true" : "false"));
-	return 0;
-error:
-	return -1;
+
+	return fd;
 }
 
-static int
-notify_ack_roundtip(int sock, struct worker *w)
+static void
+release_frame(struct spoe_frame *frame)
+{
+	struct worker *worker;
+
+	if (frame == NULL)
+		return;
+
+	if (event_pending(&frame->process_frame_event, EV_TIMEOUT, NULL))
+		event_del(&frame->process_frame_event);
+
+	worker = frame->worker;
+	LIST_DEL(&frame->list);
+	memset(frame, 0, sizeof(*frame)+max_frame_size+4);
+	LIST_ADDQ(&worker->frames, &frame->list);
+}
+
+static void
+release_client(struct client *c)
 {
-	if (read_frame(sock, w) < 0) {
-		LOG("Failed to read Haproxy NOTIFY frame");
-		goto error_or_quit;
+	struct spoe_frame *frame, *back;
+
+	if (c == NULL)
+		return;
+
+	DEBUG(c->worker, "<%lu> Release client", c->id);
+
+	LIST_DEL(&c->by_worker);
+	c->worker->nbclients--;
+
+	unuse_spoe_engine(c);
+	free(c->engine_id);
+
+	if (event_pending(&c->read_frame_event, EV_READ, NULL))
+		event_del(&c->read_frame_event);
+	if (event_pending(&c->write_frame_event, EV_WRITE, NULL))
+		event_del(&c->write_frame_event);
+
+	release_frame(c->incoming_frame);
+	release_frame(c->outgoing_frame);
+	list_for_each_entry_safe(frame, back, &c->processing_frames, list) {
+		release_frame(frame);
 	}
-	if (handle_hadiscon(w) != 0) {
-		if (w->status_code != SPOE_FRM_ERR_NONE)
-			LOG("Failed to handle Haproxy DISCONNECT frame");
-		DEBUG("Disconnect frame received: reason=%s",
-		      spoe_frm_err_reasons[w->status_code]);
-		goto error_or_quit;
+	list_for_each_entry_safe(frame, back, &c->outgoing_frames, list) {
+		release_frame(frame);
 	}
-	if (handle_hanotify(w) < 0) {
-		LOG("Failed to handle Haproxy NOTIFY frame");
-		goto error_or_quit;
+
+	if (c->fd >= 0)
+		close(c->fd);
+
+	free(c);
+}
+
+static void
+reset_frame(struct spoe_frame *frame)
+{
+	if (frame == NULL)
+		return;
+
+	frame->type      = SPOA_FRM_T_UNKNOWN;
+	frame->buf       = (char *)(frame->data);
+	frame->offset    = 0;
+	frame->len       = 0;
+	frame->stream_id = 0;
+	frame->frame_id  = 0;
+	frame->hcheck    = false;
+	frame->ip_score  = -1;
+	LIST_INIT(&frame->list);
+}
+
+static void
+use_spoe_engine(struct client *client)
+{
+	struct spoe_engine *eng;
+
+	if (client->engine_id == NULL)
+		return;
+
+	list_for_each_entry(eng, &client->worker->engines, list) {
+		if (!strcmp(eng->id, client->engine_id))
+			goto end;
+	}
+
+	if ((eng = malloc(sizeof(*eng))) == NULL) {
+		client->async = false;
+		return;
+	}
+
+	eng->id = strdup(client->engine_id);
+	LIST_INIT(&eng->clients);
+	LIST_INIT(&eng->processing_frames);
+	LIST_INIT(&eng->outgoing_frames);
+	LIST_ADDQ(&client->worker->engines, &eng->list);
+	LOG(client->worker, "Add new SPOE engine '%s'", eng->id);
+
+  end:
+	client->engine = eng;
+	LIST_ADDQ(&eng->clients, &client->by_engine);
+}
+
+static void
+unuse_spoe_engine(struct client *client)
+{
+	struct spoe_engine *eng;
+	struct spoe_frame  *frame, *back;
+
+	if (client == NULL || client->engine == NULL)
+		return;
+
+	eng = client->engine;
+	client->engine = NULL;
+	LIST_DEL(&client->by_engine);
+	if (!LIST_ISEMPTY(&eng->clients))
+		return;
+
+	LOG(client->worker, "Remove SPOE engine '%s'", eng->id);
+	LIST_DEL(&eng->list);
+
+	list_for_each_entry_safe(frame, back, &eng->processing_frames, list) {
+		release_frame(frame);
+	}
+	list_for_each_entry_safe(frame, back, &eng->outgoing_frames, list) {
+		release_frame(frame);
+	}
+	free(eng->id);
+	free(eng);
+}
+
+
+static struct spoe_frame *
+acquire_incoming_frame(struct client *client)
+{
+	struct spoe_frame *frame;
+
+	frame = client->incoming_frame;
+	if (frame != NULL)
+		return frame;
+
+	if (LIST_ISEMPTY(&client->worker->frames)) {
+		if ((frame = calloc(1, sizeof(*frame)+max_frame_size+4)) == NULL) {
+			LOG(client->worker, "Failed to allocate new frame : %m");
+			return NULL;
+		}
 	}
-	if (prepare_agentack(w) < 0) {
-		LOG("Failed to prepare Agent ACK frame");
-		goto error_or_quit;
+	else {
+		frame = LIST_NEXT(&client->worker->frames, typeof(frame), list);
+		LIST_DEL(&frame->list);
 	}
-	if (write_frame(sock, w) < 0) {
-		LOG("Failed to write Agent ACK frame");
-		goto error_or_quit;
+
+	reset_frame(frame);
+	frame->worker = client->worker;
+	frame->engine = client->engine;
+	frame->client = client;
+
+	if (event_assign(&frame->process_frame_event, client->worker->base, -1,
+			 EV_TIMEOUT|EV_PERSIST, process_frame_cb, frame) < 0) {
+		LOG(client->worker, "Failed to create frame event");
+		return NULL;
 	}
-	DEBUG("Ack frame sent: stream-id=%u - frame-id=%u",
-	      w->stream_id, w->frame_id);
-	return 0;
-error_or_quit:
-	return -1;
+
+	client->incoming_frame = frame;
+	return frame;
 }
 
-static void *
-worker(void *data)
+static struct spoe_frame *
+acquire_outgoing_frame(struct client *client)
 {
-	struct worker w;
-	struct sockaddr_in client;
-	int *info = (int *)data;
-	int csock, lsock = info[0];
+	struct spoe_engine *engine = client->engine;
+	struct spoe_frame  *frame = NULL;
 
-	signal(SIGPIPE, SIG_IGN);
-	pthread_setspecific(worker_id, &info[1]);
+	if (client->outgoing_frame != NULL)
+		frame = client->outgoing_frame;
+	else if (!LIST_ISEMPTY(&client->outgoing_frames)) {
+		frame = LIST_NEXT(&client->outgoing_frames, typeof(frame), list);
+		LIST_DEL(&frame->list);
+		client->outgoing_frame = frame;
+	}
+	else if (engine!= NULL && !LIST_ISEMPTY(&engine->outgoing_frames)) {
+		frame = LIST_NEXT(&engine->outgoing_frames, typeof(frame), list);
+		LIST_DEL(&frame->list);
+		client->outgoing_frame = frame;
+	}
+	return frame;
+}
+
+static void
+write_frame(struct client *client, struct spoe_frame *frame)
+{
+	uint32_t netint;
+
+	LIST_DEL(&frame->list);
+
+	frame->buf    = (char *)(frame->data);
+	frame->offset = 0;
+	netint        = htonl(frame->len);
+	memcpy(frame->buf, &netint, 4);
 
-	while (1) {
-		socklen_t sz = sizeof(client);
+	if (client != NULL) { /* HELLO or DISCONNECT frames */
+		event_add(&client->write_frame_event, NULL);
 
-		if ((csock = accept(lsock, (struct sockaddr *)&client, &sz)) < 0) {
-			LOG("Failed to accept client connection: %m");
-			goto out;
+		/* Try to process the frame as soon as possible, and always
+		 * attach it to the client */
+		if (client->async || client->pipelining) {
+			if (client->outgoing_frame == NULL)
+				client->outgoing_frame = frame;
+			else
+				LIST_ADD(&client->outgoing_frames, &frame->list);
+		}
+		else {
+			client->outgoing_frame = frame;
+			event_del(&client->read_frame_event);
 		}
-		memset(&w, 0, sizeof(w));
-		w.id       = info[1];
-		w.size     = MAX_FRAME_SIZE;
+	}
+	else { /* for all other frames */
+		if (frame->client == NULL) { /* async mode ! */
+			LIST_ADDQ(&frame->engine->outgoing_frames, &frame->list);
+			list_for_each_entry(client, &frame->engine->clients, by_engine)
+				event_add(&client->write_frame_event, NULL);
+		}
+		else if (frame->client->pipelining) {
+			LIST_ADDQ(&frame->client->outgoing_frames, &frame->list);
+			event_add(&frame->client->write_frame_event, NULL);
+		}
+		else {
+			frame->client->outgoing_frame = frame;
+			event_add(&frame->client->write_frame_event, NULL);
+			event_del(&frame->client->read_frame_event);
+		}
+	}
+}
 
-		DEBUG("New connection from HAProxy accepted");
+static void
+process_incoming_frame(struct spoe_frame *frame)
+{
+	struct client *client = frame->client;
 
-		if (hello_handshake(csock, &w) < 0)
-			goto disconnect;
-		if (w.healthcheck == true)
+	if (event_add(&frame->process_frame_event, &processing_delay) < 0) {
+		LOG(client->worker, "Failed to process incoming frame");
+		release_frame(frame);
+		return;
+	}
+
+	if (client->async) {
+		frame->client = NULL;
+		LIST_ADDQ(&frame->engine->processing_frames, &frame->list);
+	}
+	else if (client->pipelining)
+		LIST_ADDQ(&client->processing_frames, &frame->list);
+	else
+		event_del(&client->read_frame_event);
+}
+
+static void
+signal_cb(evutil_socket_t sig, short events, void *user_data)
+{
+	struct event_base *base = user_data;
+	int                i;
+
+	DEBUG(&null_worker, "Stopping the server");
+
+	event_base_loopbreak(base);
+	DEBUG(&null_worker, "Main event loop stopped");
+
+	for (i = 0; i < num_workers; i++) {
+		event_base_loopbreak(workers[i].base);
+		DEBUG(&null_worker, "Event loop stopped for worker %02d",
+		      workers[i].id);
+	}
+}
+
+static void
+worker_monitor_cb(evutil_socket_t fd, short events, void *arg)
+{
+	struct worker *worker = arg;
+
+	LOG(worker, "%u clients connected", worker->nbclients);
+}
+
+static void
+process_frame_cb(evutil_socket_t fd, short events, void *arg)
+{
+	struct spoe_frame *frame  = arg;
+	char              *buf    = frame->buf;
+	char              *end    = frame->buf + frame->len;
+	int                idx    = frame->offset;
+
+	DEBUG(frame->worker,
+	      "Process frame messages : STREAM-ID=%u - FRAME-ID=%u",
+	      frame->stream_id, frame->frame_id);
+
+	/* Loop on messages */
+	while (buf+idx < end) {
+		char    *str;
+		uint64_t sz;
+		int      nbargs, i;
+
+		/* Decode the message name */
+		idx += decode_spoe_string(buf+idx, end, &str, &sz);
+		if (str == NULL)
+			goto stop_processing;
+
+		DEBUG(frame->worker, "Process SPOE Message '%.*s'", (int)sz, str);
+
+		nbargs = buf[idx++]; /* Get the number of arguments */
+		frame->offset = idx;    /* Save index to handle errors and skip args */
+		if (!memcmp(str, "check-client-ip", sz)) {
+			struct spoe_data data;
+
+			memset(&data, 0, sizeof(data));
+
+			if (nbargs != 1)
+				goto skip_message;
+
+			if ((i = decode_spoe_string(buf+idx, end, &str, &sz)) == -1)
+				goto stop_processing;
+			idx += i;
+
+			if ((i = decode_spoe_data(buf+idx, end, &data)) == -1)
+				goto skip_message;
+			idx += i;
+
+			if ((data.type & SPOE_DATA_T_MASK) == SPOE_DATA_T_IPV4)
+				check_ipv4_reputation(frame, &data.u.ipv4);
+			else if ((data.type & SPOE_DATA_T_MASK) == SPOE_DATA_T_IPV6)
+				check_ipv6_reputation(frame, &data.u.ipv6);
+		}
+		else {
+		  skip_message:
+			idx = frame->offset; /* Restore index */
+
+			while (nbargs-- > 0) {
+				/* Silently ignore argument: its name and its value */
+				if ((i = decode_spoe_string(buf+idx, end, &str, &sz)) == -1)
+					goto stop_processing;
+				idx += i;
+				if ((i = skip_spoe_data(buf+idx, end)) == -1)
+					goto stop_processing;
+				idx += i;
+			}
+		}
+	}
+
+  stop_processing:
+	/* Prepare agent ACK frame */
+	frame->offset = 0;
+	idx = prepare_agentack(frame);
+
+	if (frame->ip_score != -1) {
+		DEBUG(frame->worker, "Add action : set variable ip_scode=%u",
+		      frame->ip_score);
+
+		buf[idx++] = SPOE_ACT_T_SET_VAR;                      /* Action type */
+		buf[idx++] = 3;                                       /* Number of args */
+		buf[idx++] = SPOE_SCOPE_SESS;                         /* Arg 1: the scope */
+		idx += encode_spoe_string("ip_score", 8, buf+idx);    /* Arg 2: variable name */
+		buf[idx++] = SPOE_DATA_T_UINT32;
+		idx += encode_spoe_varint(frame->ip_score, buf+idx); /* Arg 3: variable value */
+		frame->len = idx;
+	}
+	write_frame(NULL, frame);
+}
+
+static void
+read_frame_cb(evutil_socket_t fd, short events, void *arg)
+{
+	struct client     *client = arg;
+	struct spoe_frame *frame;
+	uint32_t           netint;
+	int                n;
+
+	DEBUG(client->worker, "<%lu> %s", client->id, __FUNCTION__);
+	if ((frame = acquire_incoming_frame(client)) == NULL)
+		goto close;
+
+	frame->type = SPOA_FRM_T_HAPROXY;
+	if (frame->buf == (char *)(frame->data)) {
+		/* Read the frame length: frame->buf points on length part (frame->data) */
+		n = read(client->fd, frame->buf+frame->offset, 4-frame->offset);
+		if (n <= 0) {
+			if (n < 0)
+				LOG(client->worker, "Failed to read frame length : %m");
 			goto close;
-		while (1) {
-			w.ip_score = -1;
-			if (notify_ack_roundtip(csock, &w) < 0)
-				break;
 		}
+		frame->offset += n;
+		if (frame->offset != 4)
+			return;
+		memcpy(&netint, frame->buf, 4);
+		frame->buf   += 4;
+		frame->offset = 0;
+		frame->len    = ntohl(netint);
+	}
 
-	disconnect:
-		if (w.status_code == SPOE_FRM_ERR_IO) {
-			LOG("Close the client socket because of I/O errors");
+	/* Read the frame: frame->buf points on frame part (frame->data+4)*/
+	n = read(client->fd, frame->buf + frame->offset,
+		 frame->len - frame->offset);
+	if (n <= 0) {
+		if (n < 0) {
+			LOG(client->worker, "Frame to read frame : %m");
 			goto close;
 		}
-		if (prepare_agentdicon(&w) < 0) {
-			LOG("Failed to prepare Agent DISCONNECT frame");
+		return;
+	}
+	frame->offset += n;
+	if (frame->offset != frame->len)
+		return;
+	frame->offset = 0;
+
+	DEBUG(client->worker, "<%lu> New Frame of %u bytes received",
+	      client->id, frame->len);
+
+	switch (client->state) {
+		case SPOA_ST_CONNECTING:
+			if (handle_hahello(frame) < 0) {
+				LOG(client->worker, "Failed to decode HELLO frame");
+				goto disconnect;
+			}
+			prepare_agenthello(frame);
+			goto write_frame;
+
+		case SPOA_ST_PROCESSING:
+			n = handle_hanotify(frame);
+			if (n < 0 && frame->buf[0] == SPOE_FRM_T_HAPROXY_DISCON) {
+				client->state = SPOA_ST_DISCONNECTING;
+				goto disconnecting;
+			}
+			if (n < 0) {
+				LOG(client->worker, "Ignore invalid or unknown frame");
+				goto ignore_frame;
+			}
+			if (n == 0) {
+				DEBUG(client->worker, "<%lu> No message found, ack it now",
+				      client->id);
+				prepare_agentack(frame);
+				goto write_frame;
+			}
+			else
+				goto process_frame;
+
+		case SPOA_ST_DISCONNECTING:
+		  disconnecting:
+			if (handle_hadiscon(frame) < 0) {
+				LOG(client->worker, "Failed to decode DISCONNECT frame");
+				goto disconnect;
+			}
+			if (client->status_code != SPOE_FRM_ERR_NONE)
+				LOG(client->worker, "<%lu> Peer closed connection: %s",
+				    client->id, spoe_frm_err_reasons[client->status_code]);
+			client->status_code = SPOE_FRM_ERR_NONE;
+			goto disconnect;
+	}
+
+  ignore_frame:
+	reset_frame(frame);
+	return;
+
+  process_frame:
+	process_incoming_frame(frame);
+	client->incoming_frame = NULL;
+	return;
+
+  write_frame:
+	write_frame(client, frame);
+	client->incoming_frame = NULL;
+	return;
+
+  disconnect:
+	client->state = SPOA_ST_DISCONNECTING;
+	if (prepare_agentdicon(frame) < 0) {
+		LOG(client->worker, "Failed to encode DISCONNECT frame");
+		goto close;
+	}
+	goto write_frame;
+
+  close:
+	release_client(client);
+}
+
+static void
+write_frame_cb(evutil_socket_t fd, short events, void *arg)
+{
+	struct client     *client = arg;
+	struct spoe_frame *frame;
+	int                n;
+
+	DEBUG(client->worker, "<%lu> %s", client->id, __FUNCTION__);
+	if ((frame = acquire_outgoing_frame(client)) == NULL) {
+		event_del(&client->write_frame_event);
+		return;
+	}
+
+	if (frame->buf == (char *)(frame->data)) {
+		/* Write the frame length: frame->buf points on length part (frame->data) */
+		n = write(client->fd, frame->buf+frame->offset, 4-frame->offset);
+		if (n <= 0) {
+			if (n < 0)
+				LOG(client->worker, "Failed to write frame length : %m");
 			goto close;
 		}
-		if (write_frame(csock, &w) < 0) {
-			LOG("Failed to write Agent DISCONNECT frame");
+		frame->offset += n;
+		if (frame->offset != 4)
+			return;
+		frame->buf   += 4;
+		frame->offset = 0;
+	}
+
+	/* Write the frame: frame->buf points on frame part (frame->data+4)*/
+	n = write(client->fd, frame->buf + frame->offset,
+		  frame->len - frame->offset);
+	if (n <= 0) {
+		if (n < 0) {
+			LOG(client->worker, "Failed to write frame : %m");
 			goto close;
 		}
-		DEBUG("Disconnect frame sent: reason=%s",
-		      spoe_frm_err_reasons[w.status_code]);
+		return;
+	}
+	frame->offset += n;
+	if (frame->offset != frame->len)
+		return;
+
+	DEBUG(client->worker, "<%lu> Frame of %u bytes send",
+	      client->id, frame->len);
+
+	switch (client->state) {
+		case SPOA_ST_CONNECTING:
+			if (frame->hcheck == true) {
+				DEBUG(client->worker,
+				      "<%lu> Close client after healthcheck",
+				      client->id);
+				goto close;
+			}
+			client->state = SPOA_ST_PROCESSING;
+			break;
+
+		case SPOA_ST_PROCESSING:
+			break;
+
+		case SPOA_ST_DISCONNECTING:
+			goto close;
+	}
+
+	release_frame(frame);
+	client->outgoing_frame = NULL;
+	if (!client->async && !client->pipelining) {
+		event_del(&client->write_frame_event);
+		event_add(&client->read_frame_event, NULL);
+	}
+	return;
+
+  close:
+	release_client(client);
+}
+
+static void
+accept_cb(int listener, short event, void *arg)
+{
+	struct worker     *worker;
+	struct client     *client;
+	int                fd;
+
+	worker = &workers[clicount++ % num_workers];
+
+	if ((fd = accept(listener, NULL, NULL)) < 0) {
+		if (errno != EAGAIN && errno != EWOULDBLOCK)
+			LOG(worker, "Failed to accept client connection : %m");
+		return;
+	}
+
+	DEBUG(&null_worker,
+	      "<%lu> New Client connection accepted and assigned to worker %02d",
+	      clicount, worker->id);
+
+	if (evutil_make_socket_nonblocking(fd) < 0) {
+		LOG(&null_worker, "Failed to set client socket to non-blocking : %m");
+		close(fd);
+		return;
+	}
+
+	if ((client = calloc(1, sizeof(*client))) == NULL) {
+		LOG(&null_worker, "Failed to allocate memory for client state : %m");
+		close(fd);
+		return;
+	}
+
+	client->id             = clicount;
+	client->fd             = fd;
+	client->worker         = worker;
+	client->state          = SPOA_ST_CONNECTING;
+	client->status_code    = SPOE_FRM_ERR_NONE;
+	client->max_frame_size = max_frame_size;
+	client->engine         = NULL;
+	client->pipelining     = false;
+	client->async          = false;
+	client->incoming_frame = NULL;
+	client->outgoing_frame = NULL;
+	LIST_INIT(&client->processing_frames);
+	LIST_INIT(&client->outgoing_frames);
+
+	LIST_ADDQ(&worker->clients, &client->by_worker);
+
+	worker->nbclients++;
+
+	if (event_assign(&client->read_frame_event, worker->base, fd,
+			 EV_READ|EV_PERSIST, read_frame_cb, client) < 0     ||
+	    event_assign(&client->write_frame_event, worker->base, fd,
+			 EV_WRITE|EV_PERSIST, write_frame_cb, client) < 0) {
+		LOG(&null_worker, "Failed to create client events");
+		release_client(client);
+		return;
+	}
+	event_add(&client->read_frame_event,  NULL);
+}
+
+static void *
+worker_function(void *data)
+{
+	struct client     *client, *cback;
+	struct spoe_frame *frame, *fback;
+	struct worker     *worker = data;
+
+	DEBUG(worker, "Worker ready to process client messages");
+	event_base_dispatch(worker->base);
 
-	close:
-		close(csock);
+	list_for_each_entry_safe(client, cback, &worker->clients, by_worker) {
+		release_client(client);
 	}
 
+	list_for_each_entry_safe(frame, fback, &worker->frames, list) {
+		LIST_DEL(&frame->list);
+		free(frame);
+	}
+
+	event_free(worker->monitor_event);
+	event_base_free(worker->base);
+	DEBUG(worker, "Worker is stopped");
+	pthread_exit(&null_worker);
+}
+
+
-out:
-	free(info);
-	pthread_exit(NULL);
+static int
+parse_processing_delay(const char *str)
+{
+        unsigned long value;
+
+        value = 0;
+        while (1) {
+                unsigned int j;
+
+                j = *str - '0';
+                if (j > 9)
+                        break;
+                str++;
+                value *= 10;
+                value += j;
+        }
+
+        switch (*str) {
+		case '\0': /* no unit = millisecond */
+			value *= 1000;
+			break;
+		case 's': /* second */
+			value *= 1000000;
+			str++;
+			break;
+		case 'm': /* millisecond : "ms" */
+			if (str[1] != 's')
+				return -1;
+			value *= 1000;
+			str += 2;
+			break;
+		case 'u': /* microsecond : "us" */
+			if (str[1] != 's')
+				return -1;
+			str += 2;
+			break;
+		default:
+			return -1;
+        }
+	if (*str)
+		return -1;
+
+	processing_delay.tv_sec = (time_t)(value / 1000000);
+	processing_delay.tv_usec = (suseconds_t)(value % 1000000);
+        return 0;
 }
 
+
 static void
 usage(char *prog)
 {
-	fprintf(stderr, "Usage: %s [-h] [-d] [-p <port>] [-n <num-workers>]\n", prog);
-	fprintf(stderr, "    -h                  Print this message\n");
-	fprintf(stderr, "    -d                  Enable the debug mode\n");
-	fprintf(stderr, "    -p <port>           Specify the port to listen on (default: 12345)\n");
-	fprintf(stderr, "    -n <num-workers>    Specify the number of workers (default: 5)\n");
+	fprintf(stderr,
+		"Usage : %s [OPTION]...\n"
+		"    -h                   Print this message\n"
+		"    -d                   Enable the debug mode\n"
+		"    -m <max-frame-size>  Specify the maximum frame size (default : %u)\n"
+		"    -p <port>            Specify the port to listen on (default : %d)\n"
+		"    -n <num-workers>     Specify the number of workers (default : %d)\n"
+		"    -c <capability>      Enable the support of the specified capability\n"
+		"    -t <time>            Set a delay to process a message (default: 0)\n"
+		"                           The value is specified in milliseconds by default,\n"
+		"                           but can be in any other unit if the number is suffixed\n"
+		"                           by a unit (us, ms, s)\n"
+		"\n"
+		"    Supported capabilities: pipelining, async\n",
+		prog, MAX_FRAME_SIZE, DEFAULT_PORT, NUM_WORKERS);
 }
 
 int
 main(int argc, char **argv)
 {
-	pthread_t *ts = NULL;
-	struct sockaddr_in server;
-	int i, sock, opt, nbworkers, port;
+	struct event_base *base = NULL;
+	struct event      *signal_event = NULL, *accept_event = NULL;
+	int                opt, i, fd = -1;
 
-	nbworkers = NUM_WORKERS;
-	port      = DEFAULT_PORT;
-	while ((opt = getopt(argc, argv, "hdn:p:")) != -1) {
+	// TODO: add '-t <processing-time>' option
+	while ((opt = getopt(argc, argv, "hdm:n:p:c:t:")) != -1) {
 		switch (opt) {
 			case 'h':
 				usage(argv[0]);
@@ -1078,75 +1849,150 @@
 			case 'd':
 				debug = true;
 				break;
+			case 'm':
+				max_frame_size = atoi(optarg);
+				break;
 			case 'n':
-				nbworkers = atoi(optarg);
+				num_workers = atoi(optarg);
 				break;
 			case 'p':
-				port = atoi(optarg);
+				server_port = atoi(optarg);
 				break;
+			case 'c':
+				if (!strcmp(optarg, "pipelining"))
+					pipelining = true;
+				else if (!strcmp(optarg, "async"))
+					async = true;
+				else
+					fprintf(stderr, "WARNING: unsupported capability '%s'\n", optarg);
+				break;
+			case 't':
+				if (!parse_processing_delay(optarg))
+					break;
+				fprintf(stderr, "%s: failed to parse time '%s'.\n", argv[0], optarg);
+				fprintf(stderr, "Try '%s -h' for more information.\n", argv[0]);
+				return EXIT_FAILURE;
 			default:
 				usage(argv[0]);
 				return EXIT_FAILURE;
 		}
 	}
 
-	if (nbworkers <= 0) {
-		fprintf(stderr, "%s: Invalid number of workers '%d'\n",
-			argv[0], nbworkers);
+	if (num_workers <= 0) {
+		LOG(&null_worker, "%s : Invalid number of workers '%d'\n",
+		    argv[0], num_workers);
 		goto error;
 	}
-	if (port <= 0) {
-		fprintf(stderr, "%s: Invalid port '%d'\n", argv[0], port);
+
+	if (server_port <= 0) {
+		LOG(&null_worker, "%s : Invalid port '%d'\n",
+		    argv[0], server_port);
 		goto error;
 	}
 
-	if((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
-		fprintf(stderr, "Failed creating socket: %m\n");
+
+	if (evthread_use_pthreads() < 0) {
+		LOG(&null_worker, "No pthreads support for libevent");
 		goto error;
 	}
 
-	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (int []){1}, sizeof(int));
-	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (int []){1}, sizeof(int));
+	if ((base = event_base_new()) == NULL) {
+		LOG(&null_worker, "Failed to initialize libevent : %m");
+		goto error;
+	}
 
-	memset(&server, 0, sizeof(server));
-	server.sin_family      = AF_INET;
-	server.sin_addr.s_addr = INADDR_ANY;
-	server.sin_port        = htons(port);
+	signal(SIGPIPE, SIG_IGN);
 
-	if (bind(sock, (struct sockaddr *)&server, sizeof(server)) < 0) {
-		fprintf(stderr, "Failed to bind the socket: %m\n");
+	if ((fd = create_server_socket()) < 0) {
+		LOG(&null_worker, "Failed to create server socket");
+		goto error;
+	}
+	if (evutil_make_socket_nonblocking(fd) < 0) {
+		LOG(&null_worker, "Failed to set server socket to non-blocking");
 		goto error;
 	}
 
-	if (listen(sock , 10) < 0) {
-		fprintf(stderr, "Failed to listen on the socket: %m\n");
+	if ((workers = calloc(num_workers, sizeof(*workers))) == NULL) {
+		LOG(&null_worker, "Failed to set allocate memory for workers");
 		goto error;
 	}
-	fprintf(stderr, "SPOA is listening on port %d\n", port);
+
+	for (i = 0; i < num_workers; ++i) {
+		struct worker *w = &workers[i];
 
-	ts = calloc(nbworkers, sizeof(*ts));
-	pthread_key_create(&worker_id, NULL);
-	for (i = 0; i < nbworkers; i++) {
-		int *info = calloc(2, sizeof(*info));
+		w->id        = i+1;
+		w->nbclients = 0;
+		LIST_INIT(&w->engines);
+		LIST_INIT(&w->clients);
+		LIST_INIT(&w->frames);
+
+		if ((w->base = event_base_new()) == NULL) {
+			LOG(&null_worker,
+			    "Failed to initialize libevent for worker %02d : %m",
+			    w->id);
+			goto error;
+		}
 
-		info[0] = sock;
-		info[1] = i+1;
-		if (pthread_create(&ts[i], NULL,  worker, info) < 0) {
-			fprintf(stderr, "Failed to create thread %d: %m\n", i+1);
+		w->monitor_event = event_new(w->base, fd, EV_PERSIST,
+					     worker_monitor_cb, (void *)w);
+		if (w->monitor_event == NULL ||
+		    event_add(w->monitor_event, (struct timeval[]){{5,0}}) < 0) {
+			LOG(&null_worker,
+			    "Failed to create monitor event for worker %02d",
+			    w->id);
 			goto error;
 		}
-		fprintf(stderr, "SPOA worker %02d started\n", i+1);
+
+		if (pthread_create(&w->thread, NULL, worker_function, (void *)w)) {
+			LOG(&null_worker,
+			    "Failed to start thread for worker %02d : %m",
+			    w->id);
+		}
+		DEBUG(&null_worker, "Worker %02d initialized", w->id);
+	}
+
+	accept_event = event_new(base, fd, EV_READ|EV_PERSIST, accept_cb,
+				 (void *)base);
+	if (accept_event == NULL || event_add(accept_event, NULL) < 0) {
+		LOG(&null_worker, "Failed to create accept event : %m");
+	}
+
+	signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base);
+	if (signal_event == NULL || event_add(signal_event, NULL) < 0) {
+		LOG(&null_worker, "Failed to create signal event : %m");
 	}
 
+	DEBUG(&null_worker,
+	      "Server is ready"
+	      " [pipelining=%s - async=%s - debug=%s - max-frame-size=%u]",
+	      (pipelining?"true":"false"), (async?"true":"false"),
+	      (debug?"true":"false"), max_frame_size);
+	event_base_dispatch(base);
+
-	for (i = 0; i < nbworkers; i++) {
-		pthread_join(ts[i], NULL);
-		fprintf(stderr, "SPOA worker %02d stopped\n", i+1);
+	for (i = 0; i < num_workers; i++) {
+		struct worker *w = &workers[i];
+
+		pthread_join(w->thread, NULL);
+		DEBUG(&null_worker, "Worker %02d terminated", w->id);
 	}
-	pthread_key_delete(worker_id);
-	free(ts);
-	close(sock);
+
+	free(workers);
+	event_free(signal_event);
+	event_free(accept_event);
+	event_base_free(base);
+	close(fd);
 	return EXIT_SUCCESS;
-error:
-	free(ts);
+
+  error:
+	if (workers != NULL)
+		free(workers);
+	if (signal_event != NULL)
+		event_free(signal_event);
+	if (accept_event != NULL)
+		event_free(accept_event);
+	if (base != NULL)
+		event_base_free(base);
+	if (fd != -1)
+		close(fd);
 	return EXIT_FAILURE;
 }