]> arthur.barton.de Git - netdata.git/blobdiff - src/web_server.c
improved netdata cleanup/exit procedure
[netdata.git] / src / web_server.c
old mode 100755 (executable)
new mode 100644 (file)
index 3cfc405..39e5ef0
-// enable strcasestr()
-#define _GNU_SOURCE
-
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <errno.h>
-#include <pthread.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <netinet/tcp.h>
-#include <malloc.h>
-
 #include "common.h"
-#include "log.h"
-#include "config.h"
-#include "url.h"
-#include "web_buffer.h"
-#include "web_client.h"
-#include "web_server.h"
-#include "global_statistics.h"
-#include "rrd.h"
-#include "rrd2json.h"
 
 int listen_backlog = LISTEN_BACKLOG;
-
-int listen_fd = -1;
+size_t listen_fds_count = 0;
+int listen_fds[MAX_LISTEN_FDS] = { [0 ... 99] = -1 };
+char *listen_fds_names[MAX_LISTEN_FDS] = { [0 ... 99] = NULL };
 int listen_port = LISTEN_PORT;
+int web_server_mode = WEB_SERVER_MODE_MULTI_THREADED;
 
-#define DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS 60
-
-int web_client_timeout = DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS;
+static int shown_server_socket_error = 0;
 
+#ifdef NETDATA_INTERNAL_CHECKS
 static void log_allocations(void)
 {
-       static int mem = 0;
+#ifdef HAVE_C_MALLINFO
+    static int heap = 0, used = 0, mmap = 0;
+
+    struct mallinfo mi;
+
+    mi = mallinfo();
+    if(mi.uordblks > used) {
+        int clients = 0;
+        struct web_client *w;
+        for(w = web_clients; w ; w = w->next) clients++;
+
+        info("Allocated memory: used %d KB (+%d B), mmap %d KB (+%d B), heap %d KB (+%d B). %d web clients connected.",
+            mi.uordblks / 1024,
+            mi.uordblks - used,
+            mi.hblkhd / 1024,
+            mi.hblkhd - mmap,
+            mi.arena / 1024,
+            mi.arena - heap,
+            clients);
+
+        used = mi.uordblks;
+        heap = mi.arena;
+        mmap = mi.hblkhd;
+    }
+#else /* ! HAVE_C_MALLINFO */
+    ;
+#endif /* ! HAVE_C_MALLINFO */
+
+#ifdef has_jemalloc
+    malloc_stats_print(NULL, NULL, NULL);
+#endif
+}
+#endif /* NETDATA_INTERNAL_CHECKS */
+
+#ifndef HAVE_ACCEPT4
+int accept4(int sock, struct sockaddr *addr, socklen_t *addrlen, int flags) {
+    int fd = accept(sock, addr, addrlen);
+    int newflags = 0;
+
+    if (fd < 0) return fd;
+
+    if (flags & SOCK_NONBLOCK) {
+        newflags |= O_NONBLOCK;
+        flags &= ~SOCK_NONBLOCK;
+    }
+
+#ifdef SOCK_CLOEXEC
+#ifdef O_CLOEXEC
+    if (flags & SOCK_CLOEXEC) {
+        newflags |= O_CLOEXEC;
+        flags &= ~SOCK_CLOEXEC;
+    }
+#endif
+#endif
+
+    if (flags) {
+        errno = -EINVAL;
+        return -1;
+    }
+
+    if (fcntl(fd, F_SETFL, newflags) < 0) {
+        int saved_errno = errno;
+        close(fd);
+        errno = saved_errno;
+        return -1;
+    }
+
+    return fd;
+}
+#endif
+
+int create_listen_socket4(const char *ip, int port, int listen_backlog) {
+    int sock;
+    int sockopt = 1;
+
+    debug(D_LISTENER, "IPv4 creating new listening socket on ip '%s' port %d", ip, port);
+
+    sock = socket(AF_INET, SOCK_STREAM, 0);
+    if(sock < 0) {
+        error("IPv4 socket() on ip '%s' port %d failed.", ip, port);
+        shown_server_socket_error = 1;
+        return -1;
+    }
+
+    /* avoid "address already in use" */
+    if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*)&sockopt, sizeof(sockopt)) != 0)
+        error("Cannot set SO_REUSEADDR on ip '%s' port's %d.", ip, port);
+
+    struct sockaddr_in name;
+    memset(&name, 0, sizeof(struct sockaddr_in));
+    name.sin_family = AF_INET;
+    name.sin_port = htons (port);
+
+    int ret = inet_pton(AF_INET, ip, (void *)&name.sin_addr.s_addr);
+    if(ret != 1) {
+        error("Failed to convert IP '%s' to a valid IPv4 address.", ip);
+        shown_server_socket_error = 1;
+        close(sock);
+        return -1;
+    }
+
+    if(bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0) {
+        close(sock);
+        error("IPv4 bind() on ip '%s' port %d failed.", ip, port);
+        shown_server_socket_error = 1;
+        return -1;
+    }
+
+    if(listen(sock, listen_backlog) < 0) {
+        close(sock);
+        error("IPv4 listen() on ip '%s' port %d failed.", ip, port);
+        shown_server_socket_error = 1;
+        return -1;
+    }
+
+    debug(D_LISTENER, "Listening on IPv4 ip '%s' port %d", ip, port);
+    return sock;
+}
 
-       struct mallinfo mi;
+int create_listen_socket6(const char *ip, int port, int listen_backlog) {
+    int sock = -1;
+    int sockopt = 1;
+    int ipv6only = 1;
+
+    debug(D_LISTENER, "IPv6 creating new listening socket on ip '%s' port %d", ip, port);
+
+    sock = socket(AF_INET6, SOCK_STREAM, 0);
+    if (sock < 0) {
+        error("IPv6 socket() on ip '%s' port %d failed.", ip, port);
+        shown_server_socket_error = 1;
+        return -1;
+    }
+
+    /* avoid "address already in use" */
+    if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*)&sockopt, sizeof(sockopt)) != 0)
+        error("Cannot set SO_REUSEADDR on ip '%s' port's %d.", ip, port);
+
+    /* IPv6 only */
+    if(setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (void*)&ipv6only, sizeof(ipv6only)) != 0)
+        error("Cannot set IPV6_V6ONLY on ip '%s' port's %d.", ip, port);
+
+    struct sockaddr_in6 name;
+    memset(&name, 0, sizeof(struct sockaddr_in6));
+    name.sin6_family = AF_INET6;
+    name.sin6_port = htons ((uint16_t) port);
+
+    int ret = inet_pton(AF_INET6, ip, (void *)&name.sin6_addr.s6_addr);
+    if(ret != 1) {
+        error("Failed to convert IP '%s' to a valid IPv6 address.", ip);
+        shown_server_socket_error = 1;
+        close(sock);
+        return -1;
+    }
+
+    name.sin6_scope_id = 0;
+
+    if (bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0) {
+        close(sock);
+        error("IPv6 bind() on ip '%s' port %d failed.", ip, port);
+        shown_server_socket_error = 1;
+        return -1;
+    }
+
+    if (listen(sock, listen_backlog) < 0) {
+        close(sock);
+        error("IPv6 listen() on ip '%s' port %d failed.", ip, port);
+        shown_server_socket_error = 1;
+        return -1;
+    }
+
+    debug(D_LISTENER, "Listening on IPv6 ip '%s' port %d", ip, port);
+    return sock;
+}
 
-       mi = mallinfo();
-       if(mi.uordblks > mem) {
-               int clients = 0;
-               struct web_client *w;
-               for(w = web_clients; w ; w = w->next) clients++;
+static inline int add_listen_socket(int fd, const char *ip, int port) {
+    if(listen_fds_count >= MAX_LISTEN_FDS) {
+        error("Too many listening sockets. Failed to add listening socket at ip '%s' port %d", ip, port);
+        shown_server_socket_error = 1;
+        close(fd);
+        return -1;
+    }
 
-               info("Allocated memory increased from %d to %d (increased by %d bytes). There are %d web clients connected.", mem, mi.uordblks, mi.uordblks - mem, clients);
-               mem = mi.uordblks;
-       }
-}
+    listen_fds[listen_fds_count] = fd;
 
-int create_listen_socket4(int port, int listen_backlog)
-{
-               int sock = -1;
-               int sockopt = 1;
-               struct sockaddr_in name;
-
-               debug(D_LISTENER, "IPv4 creating new listening socket on port %d", port);
-
-               sock = socket(AF_INET, SOCK_STREAM, 0);
-               if(sock < 0) {
-                       error("IPv4 socket() failed.");
-                       return -1;
-               }
-
-               /* avoid "address already in use" */
-               setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*)&sockopt, sizeof(sockopt));
-
-               memset(&name, 0, sizeof(struct sockaddr_in));
-               name.sin_family = AF_INET;
-               name.sin_port = htons (port);
-               name.sin_addr.s_addr = htonl (INADDR_ANY);
-
-               if(bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0) {
-                       close(sock);
-                       error("IPv4 bind() failed.");
-                       return -1;
-               }
-
-               if(listen(sock, listen_backlog) < 0) {
-                       close(sock);
-                       fatal("IPv4 listen() failed.");
-                       return -1;
-               }
-
-               debug(D_LISTENER, "IPv4 listening port %d created", port);
-               return sock;
-}
+    char buffer[100 + 1];
+    snprintfz(buffer, 100, "[%s]:%d", ip, port);
+    listen_fds_names[listen_fds_count] = strdupz(buffer);
 
-int create_listen_socket6(int port, int listen_backlog)
-{
-               int sock = -1;
-               int sockopt = 1;
-               struct sockaddr_in6 name;
-
-               debug(D_LISTENER, "IPv6 creating new listening socket on port %d", port);
-
-               sock = socket(AF_INET6, SOCK_STREAM, 0);
-               if (sock < 0) {
-                       error("IPv6 socket() failed.");
-                       return -1;
-               }
-
-               /* avoid "address already in use" */
-               setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*)&sockopt, sizeof(sockopt));
-
-               memset(&name, 0, sizeof(struct sockaddr_in6));
-               name.sin6_family = AF_INET6;
-               name.sin6_port = htons (port);
-               name.sin6_addr = in6addr_any;
-               name.sin6_scope_id = 0;
-
-               if (bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0) {
-                       close(sock);
-                       error("IPv6 bind() failed.");
-                       return -1;
-               }
-
-               if (listen(sock, listen_backlog) < 0) {
-                       close(sock);
-                       fatal("IPv6 listen() failed.");
-                       return -1;
-               }
-
-               debug(D_LISTENER, "IPv6 listening port %d created", port);
-               return sock;
+    listen_fds_count++;
+    return 0;
 }
 
+int is_listen_socket(int fd) {
+    size_t i;
+    for(i = 0; i < listen_fds_count ;i++)
+        if(listen_fds[i] == fd) return 1;
 
-int mysendfile(struct web_client *w, char *filename)
-{
-       static char *web_dir = NULL;
-       if(!web_dir) web_dir = config_get("global", "web files directory", "web");
-
-       debug(D_WEB_CLIENT, "%llu: Looking for file '%s'...", w->id, filename);
-
-       // skip leading slashes
-       while (*filename == '/') filename++;
-
-       // if the filename contain known paths, skip them
-                if(strncmp(filename, WEB_PATH_DATA       "/", strlen(WEB_PATH_DATA)       + 1) == 0) filename = &filename[strlen(WEB_PATH_DATA)       + 1];
-       else if(strncmp(filename, WEB_PATH_DATASOURCE "/", strlen(WEB_PATH_DATASOURCE) + 1) == 0) filename = &filename[strlen(WEB_PATH_DATASOURCE) + 1];
-       else if(strncmp(filename, WEB_PATH_GRAPH      "/", strlen(WEB_PATH_GRAPH)      + 1) == 0) filename = &filename[strlen(WEB_PATH_GRAPH)      + 1];
-       else if(strncmp(filename, WEB_PATH_FILE       "/", strlen(WEB_PATH_FILE)       + 1) == 0) filename = &filename[strlen(WEB_PATH_FILE)       + 1];
-
-       // if the filename contains a / or a .., refuse to serve it
-       if(strchr(filename, '/') != 0 || strstr(filename, "..") != 0) {
-               debug(D_WEB_CLIENT_ACCESS, "%llu: File '%s' is not acceptable.", w->id, filename);
-               web_buffer_printf(w->data, "File '%s' cannot be served. Filenames cannot contain / or ..", filename);
-               return 400;
-       }
-
-       // access the file
-       char webfilename[FILENAME_MAX + 1];
-       snprintf(webfilename, FILENAME_MAX, "%s/%s", web_dir, filename);
-
-       // check if the file exists
-       struct stat stat;
-       if(lstat(webfilename, &stat) != 0) {
-               error("%llu: File '%s' is not found.", w->id, webfilename);
-               web_buffer_printf(w->data, "File '%s' does not exist, or is not accessible.", filename);
-               return 404;
-       }
-
-       // check if the file is owned by us
-       if(stat.st_uid != getuid() && stat.st_uid != geteuid()) {
-               error("%llu: File '%s' is owned by user %d (I run as user %d). Access Denied.", w->id, webfilename, stat.st_uid, getuid());
-               web_buffer_printf(w->data, "Access to file '%s' is not permitted.", filename);
-               return 403;
-       }
-
-       // open the file
-       w->ifd = open(webfilename, O_NONBLOCK, O_RDONLY);
-       if(w->ifd == -1) {
-               w->ifd = w->ofd;
-
-               if(errno == EBUSY || errno == EAGAIN) {
-                       error("%llu: File '%s' is busy, sending 307 Moved Temporarily to force retry.", w->id, webfilename);
-                       snprintf(w->response_header, MAX_HTTP_HEADER_SIZE, "Location: /" WEB_PATH_FILE "/%s\r\n", filename);
-                       web_buffer_printf(w->data, "The file '%s' is currently busy. Please try again later.", filename);
-                       return 307;
-               }
-               else {
-                       error("%llu: Cannot open file '%s'.", w->id, webfilename);
-                       web_buffer_printf(w->data, "Cannot open file '%s'.", filename);
-                       return 404;
-               }
-       }
-       
-       // pick a Content-Type for the file
-                if(strstr(filename, ".html") != NULL)  w->data->contenttype = CT_TEXT_HTML;
-       else if(strstr(filename, ".js")   != NULL)      w->data->contenttype = CT_APPLICATION_X_JAVASCRIPT;
-       else if(strstr(filename, ".css")  != NULL)      w->data->contenttype = CT_TEXT_CSS;
-       else if(strstr(filename, ".xml")  != NULL)      w->data->contenttype = CT_TEXT_XML;
-       else if(strstr(filename, ".xsl")  != NULL)      w->data->contenttype = CT_TEXT_XSL;
-       else if(strstr(filename, ".txt")  != NULL)  w->data->contenttype = CT_TEXT_PLAIN;
-       else if(strstr(filename, ".svg")  != NULL)  w->data->contenttype = CT_IMAGE_SVG_XML;
-       else if(strstr(filename, ".ttf")  != NULL)  w->data->contenttype = CT_APPLICATION_X_FONT_TRUETYPE;
-       else if(strstr(filename, ".otf")  != NULL)  w->data->contenttype = CT_APPLICATION_X_FONT_OPENTYPE;
-       else if(strstr(filename, ".woff") != NULL)  w->data->contenttype = CT_APPLICATION_FONT_WOFF;
-       else if(strstr(filename, ".eot")  != NULL)  w->data->contenttype = CT_APPLICATION_VND_MS_FONTOBJ;
-       else w->data->contenttype = CT_APPLICATION_OCTET_STREAM;
-
-       debug(D_WEB_CLIENT_ACCESS, "%llu: Sending file '%s' (%ld bytes, ifd %d, ofd %d).", w->id, webfilename, stat.st_size, w->ifd, w->ofd);
-
-       w->mode = WEB_CLIENT_MODE_FILECOPY;
-       w->wait_receive = 1;
-       w->wait_send = 0;
-       w->data->bytes = 0;
-       w->data->buffer[0] = '\0';
-       w->data->rbytes = stat.st_size;
-       w->data->date = stat.st_mtim.tv_sec;
-
-       return 200;
+    return 0;
 }
 
-void web_client_reset(struct web_client *w)
-{
-       struct timeval tv;
-       gettimeofday(&tv, NULL);
-
-       long sent = w->zoutput?(long)w->zstream.total_out:((w->mode == WEB_CLIENT_MODE_FILECOPY)?w->data->rbytes:w->data->bytes);
-       long size = (w->mode == WEB_CLIENT_MODE_FILECOPY)?w->data->rbytes:w->data->bytes;
-       
-       if(w->last_url[0]) log_access("%llu: (sent/all = %ld/%ld bytes %0.0f%%, prep/sent/total = %0.2f/%0.2f/%0.2f ms) %s: '%s'",
-               w->id,
-               sent, size, -((size>0)?((float)(size-sent)/(float)size * 100.0):0.0),
-               (float)usecdiff(&w->tv_ready, &w->tv_in) / 1000.0,
-               (float)usecdiff(&tv, &w->tv_ready) / 1000.0,
-               (float)usecdiff(&tv, &w->tv_in) / 1000.0,
-               (w->mode == WEB_CLIENT_MODE_FILECOPY)?"filecopy":"data",
-               w->last_url
-               );
-
-       debug(D_WEB_CLIENT, "%llu: Reseting client.", w->id);
-
-       if(w->mode == WEB_CLIENT_MODE_FILECOPY) {
-               debug(D_WEB_CLIENT, "%llu: Closing filecopy input file.", w->id);
-               close(w->ifd);
-               w->ifd = w->ofd;
-       }
-
-       w->last_url[0] = '\0';
-
-       w->data->contenttype = CT_TEXT_PLAIN;
-       w->mode = WEB_CLIENT_MODE_NORMAL;
-
-       w->data->rbytes = 0;
-       w->data->bytes = 0;
-       w->data->sent = 0;
-
-       w->response_header[0] = '\0';
-       w->data->buffer[0] = '\0';
-
-       w->wait_receive = 1;
-       w->wait_send = 0;
-
-       // if we had enabled compression, release it
-       if(w->zinitialized) {
-               debug(D_DEFLATE, "%llu: Reseting compression.", w->id);
-               deflateEnd(&w->zstream);
-               w->zoutput = 0;
-               w->zsent = 0;
-               w->zhave = 0;
-               w->zstream.avail_in = 0;
-               w->zstream.avail_out = 0;
-               w->zstream.total_in = 0;
-               w->zstream.total_out = 0;
-               w->zinitialized = 0;
-       }
-}
+static inline void close_listen_sockets(void) {
+    size_t i;
+    for(i = 0; i < listen_fds_count ;i++) {
+        close(listen_fds[i]);
+        listen_fds[i] = -1;
 
-void web_client_enable_deflate(struct web_client *w) {
-       if(w->zinitialized == 1) {
-               error("%llu: Compression has already be initialized for this client.", w->id);
-               return;
-       }
-
-       if(w->data->sent) {
-               error("%llu: Cannot enable compression in the middle of a conversation.", w->id);
-               return;
-       }
-
-       w->zstream.zalloc = Z_NULL;
-       w->zstream.zfree = Z_NULL;
-       w->zstream.opaque = Z_NULL;
-
-       w->zstream.next_in = (Bytef *)w->data->buffer;
-       w->zstream.avail_in = 0;
-       w->zstream.total_in = 0;
-
-       w->zstream.next_out = w->zbuffer;
-       w->zstream.avail_out = 0;
-       w->zstream.total_out = 0;
-
-       w->zstream.zalloc = Z_NULL;
-       w->zstream.zfree = Z_NULL;
-       w->zstream.opaque = Z_NULL;
-
-//     if(deflateInit(&w->zstream, Z_DEFAULT_COMPRESSION) != Z_OK) {
-//             error("%llu: Failed to initialize zlib. Proceeding without compression.", w->id);
-//             return;
-//     }
-
-       // Select GZIP compression: windowbits = 15 + 16 = 31
-       if(deflateInit2(&w->zstream, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
-               error("%llu: Failed to initialize zlib. Proceeding without compression.", w->id);
-               return;
-       }
-
-       w->zsent = 0;
-       w->zoutput = 1;
-       w->zinitialized = 1;
-
-       debug(D_DEFLATE, "%llu: Initialized compression.", w->id);
-}
+        freez(listen_fds_names[i]);
+        listen_fds_names[i] = NULL;
+    }
 
-int web_client_data_request(struct web_client *w, char *url, int datasource_type)
-{
-       char *args = strchr(url, '?');
-       if(args) {
-               *args='\0';
-               args = &args[1];
-       }
-
-       // get the name of the data to show
-       char *tok = mystrsep(&url, "/");
-       debug(D_WEB_CLIENT, "%llu: Searching for RRD data with name '%s'.", w->id, tok);
-
-       // do we have such a data set?
-       RRDSET *st = rrdset_find_byname(tok);
-       if(!st) st = rrdset_find(tok);
-       if(!st) {
-               // we don't have it
-               // try to send a file with that name
-               w->data->bytes = 0;
-               return(mysendfile(w, tok));
-       }
-
-       // we have it
-       debug(D_WEB_CLIENT, "%llu: Found RRD data with name '%s'.", w->id, tok);
-
-       // how many entries does the client want?
-       long lines = rrd_default_history_entries;
-       long group_count = 1;
-       time_t after = 0, before = 0;
-       int group_method = GROUP_AVERAGE;
-       int nonzero = 0;
-
-       if(url) {
-               // parse the lines required
-               tok = mystrsep(&url, "/");
-               if(tok) lines = atoi(tok);
-               if(lines < 1) lines = 1;
-       }
-       if(url) {
-               // parse the group count required
-               tok = mystrsep(&url, "/");
-               if(tok) group_count = atoi(tok);
-               if(group_count < 1) group_count = 1;
-               //if(group_count > save_history / 20) group_count = save_history / 20;
-       }
-       if(url) {
-               // parse the grouping method required
-               tok = mystrsep(&url, "/");
-               if(strcmp(tok, "max") == 0) group_method = GROUP_MAX;
-               else if(strcmp(tok, "average") == 0) group_method = GROUP_AVERAGE;
-               else if(strcmp(tok, "sum") == 0) group_method = GROUP_SUM;
-               else debug(D_WEB_CLIENT, "%llu: Unknown group method '%s'", w->id, tok);
-       }
-       if(url) {
-               // parse after time
-               tok = mystrsep(&url, "/");
-               if(tok) after = strtoul(tok, NULL, 10);
-               if(after < 0) after = 0;
-       }
-       if(url) {
-               // parse before time
-               tok = mystrsep(&url, "/");
-               if(tok) before = strtoul(tok, NULL, 10);
-               if(before < 0) before = 0;
-       }
-       if(url) {
-               // parse nonzero
-               tok = mystrsep(&url, "/");
-               if(tok && strcmp(tok, "nonzero") == 0) nonzero = 1;
-       }
-
-       w->data->contenttype = CT_APPLICATION_JSON;
-       w->data->bytes = 0;
-
-       char *google_version = "0.6";
-       char *google_reqId = "0";
-       char *google_sig = "0";
-       char *google_out = "json";
-       char *google_responseHandler = "google.visualization.Query.setResponse";
-       char *google_outFileName = NULL;
-       unsigned long last_timestamp_in_data = 0;
-       if(datasource_type == DATASOURCE_GOOGLE_JSON || datasource_type == DATASOURCE_GOOGLE_JSONP) {
-
-               w->data->contenttype = CT_APPLICATION_X_JAVASCRIPT;
-
-               while(args) {
-                       tok = mystrsep(&args, "&");
-                       if(tok) {
-                               char *name = mystrsep(&tok, "=");
-                               if(name && strcmp(name, "tqx") == 0) {
-                                       char *key = mystrsep(&tok, ":");
-                                       char *value = mystrsep(&tok, ";");
-                                       if(key && value && *key && *value) {
-                                               if(strcmp(key, "version") == 0)
-                                                       google_version = value;
-
-                                               else if(strcmp(key, "reqId") == 0)
-                                                       google_reqId = value;
-
-                                               else if(strcmp(key, "sig") == 0)
-                                                       google_sig = value;
-                                               
-                                               else if(strcmp(key, "out") == 0)
-                                                       google_out = value;
-                                               
-                                               else if(strcmp(key, "responseHandler") == 0)
-                                                       google_responseHandler = value;
-                                               
-                                               else if(strcmp(key, "outFileName") == 0)
-                                                       google_outFileName = value;
-                                       }
-                               }
-                       }
-               }
-
-               debug(D_WEB_CLIENT_ACCESS, "%llu: GOOGLE JSONP: version = '%s', reqId = '%s', sig = '%s', out = '%s', responseHandler = '%s', outFileName = '%s'",
-                       w->id, google_version, google_reqId, google_sig, google_out, google_responseHandler, google_outFileName
-                       );
-
-               if(datasource_type == DATASOURCE_GOOGLE_JSONP) {
-                       last_timestamp_in_data = strtoul(google_sig, NULL, 0);
-
-                       // check the client wants json
-                       if(strcmp(google_out, "json") != 0) {
-                               w->data->bytes = snprintf(w->data->buffer, w->data->size, 
-                                       "%s({version:'%s',reqId:'%s',status:'error',errors:[{reason:'invalid_query',message:'output format is not supported',detailed_message:'the format %s requested is not supported by netdata.'}]});",
-                                       google_responseHandler, google_version, google_reqId, google_out);
-                                       return 200;
-                       }
-               }
-       }
-
-       if(datasource_type == DATASOURCE_GOOGLE_JSONP) {
-               w->data->bytes = snprintf(w->data->buffer, w->data->size, 
-                       "%s({version:'%s',reqId:'%s',status:'ok',sig:'%lu',table:",
-                       google_responseHandler, google_version, google_reqId, st->last_updated.tv_sec);
-       }
-       
-       debug(D_WEB_CLIENT_ACCESS, "%llu: Sending RRD data '%s' (id %s, %d lines, %d group, %d group_method, %lu after, %lu before).", w->id, st->name, st->id, lines, group_count, group_method, after, before);
-       unsigned long timestamp_in_data = rrd_stats_json(datasource_type, st, w->data, lines, group_count, group_method, after, before, nonzero);
-
-       if(datasource_type == DATASOURCE_GOOGLE_JSONP) {
-               if(timestamp_in_data > last_timestamp_in_data)
-                       w->data->bytes += snprintf(&w->data->buffer[w->data->bytes], w->data->size - w->data->bytes, "});");
-
-               else {
-                       // the client already has the latest data
-                       w->data->bytes = snprintf(w->data->buffer, w->data->size, 
-                               "%s({version:'%s',reqId:'%s',status:'error',errors:[{reason:'not_modified',message:'Data not modified'}]});",
-                               google_responseHandler, google_version, google_reqId);
-               }
-       }
-
-       return 200;
+    listen_fds_count = 0;
 }
 
-void web_client_process(struct web_client *w)
-{
-       int code = 500;
-       int bytes;
-
-       w->wait_receive = 0;
-
-       // check if we have an empty line (end of HTTP header)
-       if(strstr(w->data->buffer, "\r\n\r\n")) {
-               global_statistics_lock();
-               global_statistics.web_requests++;
-               global_statistics_unlock();
-
-               gettimeofday(&w->tv_in, NULL);
-               debug(D_WEB_DATA, "%llu: Processing data buffer of %d bytes: '%s'.", w->id, w->data->bytes, w->data->buffer);
-
-               // check if the client requested keep-alive HTTP
-               if(strcasestr(w->data->buffer, "Connection: keep-alive")) w->keepalive = 1;
-               else w->keepalive = 0;
-
-               // check if the client accepts deflate
-               if(strstr(w->data->buffer, "gzip"))
-                       web_client_enable_deflate(w);
-
-               int datasource_type = DATASOURCE_GOOGLE_JSONP;
-               //if(strstr(w->data->buffer, "X-DataSource-Auth"))
-               //      datasource_type = DATASOURCE_GOOGLE_JSON;
-
-               char *buf = w->data->buffer;
-               char *tok = strsep(&buf, " \r\n");
-               char *url = NULL;
-               char *pointer_to_free = NULL; // keep url_decode() allocated buffer
-
-               if(buf && strcmp(tok, "GET") == 0) {
-                       tok = strsep(&buf, " \r\n");
-                       pointer_to_free = url = url_decode(tok);
-                       debug(D_WEB_CLIENT, "%llu: Processing HTTP GET on url '%s'.", w->id, url);
-               }
-               else if (buf && strcmp(tok, "POST") == 0) {
-                       w->keepalive = 0;
-                       tok = strsep(&buf, " \r\n");
-                       pointer_to_free = url = url_decode(tok);
-
-                       debug(D_WEB_CLIENT, "%llu: I don't know how to handle POST with form data. Assuming it is a GET on url '%s'.", w->id, url);
-               }
-
-               w->last_url[0] = '\0';
-               if(url) {
-                       strncpy(w->last_url, url, URL_MAX);
-                       w->last_url[URL_MAX] = '\0';
-
-                       tok = mystrsep(&url, "/?&");
-
-                       debug(D_WEB_CLIENT, "%llu: Processing command '%s'.", w->id, tok);
-
-                       if(strcmp(tok, WEB_PATH_DATA) == 0) { // "data"
-                               // the client is requesting rrd data
-                               datasource_type = DATASOURCE_JSON;
-                               code = web_client_data_request(w, url, datasource_type);
-                       }
-                       else if(strcmp(tok, WEB_PATH_DATASOURCE) == 0) { // "datasource"
-                               // the client is requesting google datasource
-                               code = web_client_data_request(w, url, datasource_type);
-                       }
-                       else if(strcmp(tok, WEB_PATH_GRAPH) == 0) { // "graph"
-                               // the client is requesting an rrd graph
-
-                               // get the name of the data to show
-                               tok = mystrsep(&url, "/?&");
-                               debug(D_WEB_CLIENT, "%llu: Searching for RRD data with name '%s'.", w->id, tok);
-
-                               // do we have such a data set?
-                               RRDSET *st = rrdset_find_byname(tok);
-                               if(!st) st = rrdset_find(tok);
-                               if(!st) {
-                                       // we don't have it
-                                       // try to send a file with that name
-                                       w->data->bytes = 0;
-                                       code = mysendfile(w, tok);
-                               }
-                               else {
-                                       code = 200;
-                                       debug(D_WEB_CLIENT_ACCESS, "%llu: Sending %s.json of RRD_STATS...", w->id, st->name);
-                                       w->data->contenttype = CT_APPLICATION_JSON;
-                                       w->data->bytes = 0;
-                                       rrd_stats_graph_json(st, url, w->data);
-                               }
-                       }
-                       else if(strcmp(tok, "debug") == 0) {
-                               w->data->bytes = 0;
-
-                               // get the name of the data to show
-                               tok = mystrsep(&url, "/?&");
-                               debug(D_WEB_CLIENT, "%llu: Searching for RRD data with name '%s'.", w->id, tok);
-
-                               // do we have such a data set?
-                               RRDSET *st = rrdset_find_byname(tok);
-                               if(!st) st = rrdset_find(tok);
-                               if(!st) {
-                                       code = 404;
-                                       web_buffer_printf(w->data, "Chart %s is not found.\r\n", tok);
-                                       debug(D_WEB_CLIENT_ACCESS, "%llu: %s is not found.", w->id, tok);
-                               }
-                               else {
-                                       code = 200;
-                                       debug_flags |= D_RRD_STATS;
-                                       st->debug = st->debug?0:1;
-                                       web_buffer_printf(w->data, "Chart %s has now debug %s.\r\n", tok, st->debug?"enabled":"disabled");
-                                       debug(D_WEB_CLIENT_ACCESS, "%llu: debug for %s is %s.", w->id, tok, st->debug?"enabled":"disabled");
-                               }
-                       }
-                       else if(strcmp(tok, "mirror") == 0) {
-                               code = 200;
-
-                               debug(D_WEB_CLIENT_ACCESS, "%llu: Mirroring...", w->id);
-
-                               // replace the zero bytes with spaces
-                               int i;
-                               for(i = 0; i < w->data->size; i++)
-                                       if(w->data->buffer[i] == '\0') w->data->buffer[i] = ' ';
-
-                               // just leave the buffer as is
-                               // it will be copied back to the client
-                       }
-                       else if(strcmp(tok, "list") == 0) {
-                               code = 200;
-
-                               debug(D_WEB_CLIENT_ACCESS, "%llu: Sending list of RRD_STATS...", w->id);
-
-                               w->data->bytes = 0;
-                               RRDSET *st = rrdset_root;
-
-                               for ( ; st ; st = st->next )
-                                       web_buffer_printf(w->data, "%s\n", st->name);
-                       }
-                       else if(strcmp(tok, "all.json") == 0) {
-                               code = 200;
-                               debug(D_WEB_CLIENT_ACCESS, "%llu: Sending JSON list of all monitors of RRD_STATS...", w->id);
-
-                               w->data->contenttype = CT_APPLICATION_JSON;
-                               w->data->bytes = 0;
-                               rrd_stats_all_json(w->data);
-                       }
-                       else if(strcmp(tok, "netdata.conf") == 0) {
-                               code = 200;
-                               debug(D_WEB_CLIENT_ACCESS, "%llu: Sending netdata.conf ...", w->id);
-
-                               w->data->contenttype = CT_TEXT_PLAIN;
-                               w->data->bytes = 0;
-                               generate_config(w->data, 0);
-                       }
-                       else if(strcmp(tok, WEB_PATH_FILE) == 0) { // "file"
-                               tok = mystrsep(&url, "/?&");
-                               if(tok && *tok) code = mysendfile(w, tok);
-                               else {
-                                       code = 400;
-                                       w->data->bytes = 0;
-                                       strcpy(w->data->buffer, "You have to give a filename to get.\r\n");
-                                       w->data->bytes = strlen(w->data->buffer);
-                               }
-                       }
-                       else if(!tok[0]) {
-                               w->data->bytes = 0;
-                               code = mysendfile(w, "index.html");
-                       }
-                       else {
-                               w->data->bytes = 0;
-                               code = mysendfile(w, tok);
-                       }
-
-               }
-               else {
-                       strcpy(w->last_url, "not a valid response");
-
-                       if(buf) debug(D_WEB_CLIENT_ACCESS, "%llu: Cannot understand '%s'.", w->id, buf);
-
-                       code = 500;
-                       w->data->bytes = 0;
-                       strcpy(w->data->buffer, "I don't understand you...\r\n");
-                       w->data->bytes = strlen(w->data->buffer);
-               }
-               
-               // free url_decode() buffer
-               if(pointer_to_free) free(pointer_to_free);
-       }
-       else if(w->data->bytes > 8192) {
-               strcpy(w->last_url, "too big request");
-
-               debug(D_WEB_CLIENT_ACCESS, "%llu: Received request is too big.", w->id);
-
-               code = 400;
-               w->data->bytes = 0;
-               strcpy(w->data->buffer, "Received request is too big.\r\n");
-               w->data->bytes = strlen(w->data->buffer);
-       }
-       else {
-               // wait for more data
-               w->wait_receive = 1;
-               return;
-       }
-
-       if(w->data->bytes > w->data->size) {
-               error("%llu: memory overflow encountered (size is %ld, written %ld).", w->data->size, w->data->bytes);
-       }
-
-       gettimeofday(&w->tv_ready, NULL);
-       w->data->date = time(NULL);
-       w->data->sent = 0;
-
-       // prepare the HTTP response header
-       debug(D_WEB_CLIENT, "%llu: Generating HTTP header with response %d.", w->id, code);
-
-       char *content_type_string = "";
-       switch(w->data->contenttype) {
-               case CT_TEXT_HTML:
-                       content_type_string = "text/html";
-                       break;
-
-               case CT_APPLICATION_XML:
-                       content_type_string = "application/xml";
-                       break;
-
-               case CT_APPLICATION_JSON:
-                       content_type_string = "application/json";
-                       break;
-
-               case CT_APPLICATION_X_JAVASCRIPT:
-                       content_type_string = "application/x-javascript";
-                       break;
-
-               case CT_TEXT_CSS:
-                       content_type_string = "text/css";
-                       break;
-
-               case CT_TEXT_XML:
-                       content_type_string = "text/xml";
-                       break;
-
-               case CT_TEXT_XSL:
-                       content_type_string = "text/xsl";
-                       break;
-
-               case CT_APPLICATION_OCTET_STREAM:
-                       content_type_string = "application/octet-stream";
-                       break;
-
-               case CT_IMAGE_SVG_XML:
-                       content_type_string = "image/svg+xml";
-                       break;
-
-               case CT_APPLICATION_X_FONT_TRUETYPE:
-                       content_type_string = "application/x-font-truetype";
-                       break;
-
-               case CT_APPLICATION_X_FONT_OPENTYPE:
-                       content_type_string = "application/x-font-opentype";
-                       break;
-
-               case CT_APPLICATION_FONT_WOFF:
-                       content_type_string = "application/font-woff";
-                       break;
-
-               case CT_APPLICATION_VND_MS_FONTOBJ:
-                       content_type_string = "application/vnd.ms-fontobject";
-                       break;
-
-               default:
-               case CT_TEXT_PLAIN:
-                       content_type_string = "text/plain";
-                       break;
-       }
-
-       char *code_msg = "";
-       switch(code) {
-               case 200:
-                       code_msg = "OK";
-                       break;
-
-               case 307:
-                       code_msg = "Temporary Redirect";
-                       break;
-
-               case 400:
-                       code_msg = "Bad Request";
-                       break;
-
-               case 403:
-                       code_msg = "Forbidden";
-                       break;
-
-               case 404:
-                       code_msg = "Not Found";
-                       break;
-
-               default:
-                       code_msg = "Internal Server Error";
-                       break;
-       }
-
-       char date[100];
-       struct tm tm = *gmtime(&w->data->date);
-       strftime(date, sizeof(date), "%a, %d %b %Y %H:%M:%S %Z", &tm);
-
-       char custom_header[MAX_HTTP_HEADER_SIZE + 1] = "";
-       if(w->response_header[0]) 
-               strcpy(custom_header, w->response_header);
-
-       int headerlen = 0;
-       headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
-               "HTTP/1.1 %d %s\r\n"
-               "Connection: %s\r\n"
-               "Server: NetData Embedded HTTP Server\r\n"
-               "Content-Type: %s\r\n"
-               "Access-Control-Allow-Origin: *\r\n"
-               "Date: %s\r\n"
-               , code, code_msg
-               , w->keepalive?"keep-alive":"close"
-               , content_type_string
-               , date
-               );
-
-       if(custom_header[0])
-               headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen, "%s", custom_header);
-
-       if(w->mode == WEB_CLIENT_MODE_NORMAL) {
-               headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
-                       "Expires: %s\r\n"
-                       "Cache-Control: no-cache\r\n"
-                       , date
-                       );
-       }
-       else {
-               headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
-                       "Cache-Control: public\r\n"
-                       );
-       }
-
-       // if we know the content length, put it
-       if(!w->zoutput && (w->data->bytes || w->data->rbytes))
-               headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
-                       "Content-Length: %ld\r\n"
-                       , w->data->bytes?w->data->bytes:w->data->rbytes
-                       );
-       else if(!w->zoutput)
-               w->keepalive = 0;       // content-length is required for keep-alive
-
-       if(w->zoutput) {
-               headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
-                       "Content-Encoding: gzip\r\n"
-                       "Transfer-Encoding: chunked\r\n"
-                       );
-       }
-
-       headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen, "\r\n");
-
-       // disable TCP_NODELAY, to buffer the header
-       int flag = 0;
-       if(setsockopt(w->ofd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int)) != 0) error("%llu: failed to disable TCP_NODELAY on socket.", w->id);
-
-       // sent the HTTP header
-       debug(D_WEB_DATA, "%llu: Sending response HTTP header of size %d: '%s'", w->id, headerlen, w->response_header);
-
-       bytes = send(w->ofd, w->response_header, headerlen, 0);
-       if(bytes != headerlen)
-               error("%llu: HTTP Header failed to be sent (I sent %d bytes but the system sent %d bytes).", w->id, headerlen, bytes);
-       else {
-               global_statistics_lock();
-               global_statistics.bytes_sent += bytes;
-               global_statistics_unlock();
-       }
-
-       // enable TCP_NODELAY, to send all data immediately at the next send()
-       flag = 1;
-       if(setsockopt(w->ofd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int)) != 0) error("%llu: failed to enable TCP_NODELAY on socket.", w->id);
-
-       // enable sending immediately if we have data
-       if(w->data->bytes) w->wait_send = 1;
-       else w->wait_send = 0;
-
-       // pretty logging
-       switch(w->mode) {
-               case WEB_CLIENT_MODE_NORMAL:
-                       debug(D_WEB_CLIENT, "%llu: Done preparing the response. Sending data (%d bytes) to client.", w->id, w->data->bytes);
-                       break;
-
-               case WEB_CLIENT_MODE_FILECOPY:
-                       if(w->data->rbytes) {
-                               debug(D_WEB_CLIENT, "%llu: Done preparing the response. Will be sending data file of %d bytes to client.", w->id, w->data->rbytes);
-                               w->wait_receive = 1;
-
-                               /*
-                               // utilize the kernel sendfile() for copying the file to the socket.
-                               // this block of code can be commented, without anything missing.
-                               // when it is commented, the program will copy the data using async I/O.
-                               {
-                                       long len = sendfile(w->ofd, w->ifd, NULL, w->data->rbytes);
-                                       if(len != w->data->rbytes) error("%llu: sendfile() should copy %ld bytes, but copied %ld. Falling back to manual copy.", w->id, w->data->rbytes, len);
-                                       else web_client_reset(w);
-                               }
-                               */
-                       }
-                       else
-                               debug(D_WEB_CLIENT, "%llu: Done preparing the response. Will be sending an unknown amount of bytes to client.", w->id);
-                       break;
-
-               default:
-                       fatal("%llu: Unknown client mode %d.", w->id, w->mode);
-                       break;
-       }
+static inline int bind_to_one(const char *definition, int default_port, int listen_backlog) {
+    int added = 0;
+    struct addrinfo hints;
+    struct addrinfo *result = NULL, *rp = NULL;
+
+    char buffer[strlen(definition) + 1];
+    strcpy(buffer, definition);
+
+    char buffer2[10 + 1];
+    snprintfz(buffer2, 10, "%d", default_port);
+
+    char *ip = buffer, *port = buffer2;
+
+    char *e = ip;
+    if(*e == '[') {
+        e = ++ip;
+        while(*e && *e != ']') e++;
+        if(*e == ']') {
+            *e = '\0';
+            e++;
+        }
+    }
+    else {
+        while(*e && *e != ':') e++;
+    }
+
+    if(*e == ':') {
+        port = e + 1;
+        *e = '\0';
+    }
+
+    if(!*ip || *ip == '*' || !strcmp(ip, "any") || !strcmp(ip, "all"))
+        ip = NULL;
+    if(!*port)
+        port = buffer2;
+
+    memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
+    hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
+    hints.ai_flags = AI_PASSIVE;    /* For wildcard IP address */
+    hints.ai_protocol = 0;          /* Any protocol */
+    hints.ai_canonname = NULL;
+    hints.ai_addr = NULL;
+    hints.ai_next = NULL;
+
+    int r = getaddrinfo(ip, port, &hints, &result);
+    if (r != 0) {
+        error("getaddrinfo('%s', '%s'): %s\n", ip, port, gai_strerror(r));
+        return -1;
+    }
+
+    for (rp = result; rp != NULL; rp = rp->ai_next) {
+        int fd = -1;
+
+        char rip[INET_ADDRSTRLEN + INET6_ADDRSTRLEN] = "INVALID";
+        int rport = default_port;
+
+        switch (rp->ai_addr->sa_family) {
+            case AF_INET: {
+                struct sockaddr_in *sin = (struct sockaddr_in *) rp->ai_addr;
+                inet_ntop(AF_INET, &sin->sin_addr, rip, INET_ADDRSTRLEN);
+                rport = ntohs(sin->sin_port);
+                fd = create_listen_socket4(rip, rport, listen_backlog);
+                break;
+            }
+
+            case AF_INET6: {
+                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) rp->ai_addr;
+                inet_ntop(AF_INET6, &sin6->sin6_addr, rip, INET6_ADDRSTRLEN);
+                rport = ntohs(sin6->sin6_port);
+                fd = create_listen_socket6(rip, rport, listen_backlog);
+                break;
+            }
+        }
+
+        if (fd == -1)
+            error("Cannot bind to ip '%s', port %d", rip, rport);
+        else {
+            add_listen_socket(fd, rip, rport);
+            added++;
+        }
+    }
+
+    freeaddrinfo(result);
+
+    return added;
 }
 
-long web_client_send_chunk_header(struct web_client *w, int len)
-{
-       debug(D_DEFLATE, "%llu: OPEN CHUNK of %d bytes (hex: %x).", w->id, len, len);
-       char buf[1024]; 
-       sprintf(buf, "%X\r\n", len);
-       int bytes = send(w->ofd, buf, strlen(buf), MSG_DONTWAIT);
+int create_listen_sockets(void) {
+    shown_server_socket_error = 0;
 
-       if(bytes > 0) debug(D_DEFLATE, "%llu: Sent chunk header %d bytes.", w->id, bytes);
-       else if(bytes == 0) debug(D_DEFLATE, "%llu: Did not send chunk header to the client.", w->id);
-       else debug(D_DEFLATE, "%llu: Failed to send chunk header to client. Reason: %s", w->id, strerror(errno));
+    listen_backlog = (int) config_get_number("global", "http port listen backlog", LISTEN_BACKLOG);
 
-       return bytes;
-}
+    if(config_exists("global", "bind socket to IP") && !config_exists("global", "bind to"))
+        config_rename("global", "bind socket to IP", "bind to");
 
-long web_client_send_chunk_close(struct web_client *w)
-{
-       //debug(D_DEFLATE, "%llu: CLOSE CHUNK.", w->id);
+    if(config_exists("global", "port") && !config_exists("global", "default port"))
+        config_rename("global", "port", "default port");
 
-       int bytes = send(w->ofd, "\r\n", 2, MSG_DONTWAIT);
+    listen_port = (int) config_get_number("global", "default port", LISTEN_PORT);
+    if(listen_port < 1 || listen_port > 65535) {
+        error("Invalid listen port %d given. Defaulting to %d.", listen_port, LISTEN_PORT);
+        listen_port = (int) config_set_number("global", "default port", LISTEN_PORT);
+    }
+    debug(D_OPTIONS, "Default listen port set to %d.", listen_port);
 
-       if(bytes > 0) debug(D_DEFLATE, "%llu: Sent chunk suffix %d bytes.", w->id, bytes);
-       else if(bytes == 0) debug(D_DEFLATE, "%llu: Did not send chunk suffix to the client.", w->id);
-       else debug(D_DEFLATE, "%llu: Failed to send chunk suffix to client. Reason: %s", w->id, strerror(errno));
+    char *s = config_get("global", "bind to", "*");
+    while(*s) {
+        char *e = s;
 
-       return bytes;
-}
+        // skip separators, moving both s(tart) and e(nd)
+        while(isspace(*e) || *e == ',') s = ++e;
 
-long web_client_send_chunk_finalize(struct web_client *w)
-{
-       //debug(D_DEFLATE, "%llu: FINALIZE CHUNK.", w->id);
+        // move e(nd) to the first separator
+        while(*e && !isspace(*e) && *e != ',') e++;
 
-       int bytes = send(w->ofd, "\r\n0\r\n\r\n", 7, MSG_DONTWAIT);
+        // is there anything?
+        if(!*s || s == e) break;
 
-       if(bytes > 0) debug(D_DEFLATE, "%llu: Sent chunk suffix %d bytes.", w->id, bytes);
-       else if(bytes == 0) debug(D_DEFLATE, "%llu: Did not send chunk suffix to the client.", w->id);
-       else debug(D_DEFLATE, "%llu: Failed to send chunk suffix to client. Reason: %s", w->id, strerror(errno));
+        char buf[e - s + 1];
+        strncpyz(buf, s, e - s);
+        bind_to_one(buf, listen_port, listen_backlog);
 
-       return bytes;
-}
+        s = e;
+    }
 
-long web_client_send_deflate(struct web_client *w)
-{
-       long bytes = 0, t = 0;
-
-       // when using compression,
-       // w->data->sent is the amount of bytes passed through compression
-
-       // debug(D_DEFLATE, "%llu: TEST w->data->bytes = %d, w->data->sent = %d, w->zhave = %d, w->zsent = %d, w->zstream.avail_in = %d, w->zstream.avail_out = %d, w->zstream.total_in = %d, w->zstream.total_out = %d.", w->id, w->data->bytes, w->data->sent, w->zhave, w->zsent, w->zstream.avail_in, w->zstream.avail_out, w->zstream.total_in, w->zstream.total_out);
-
-       if(w->data->bytes - w->data->sent == 0 && w->zstream.avail_in == 0 && w->zhave == w->zsent && w->zstream.avail_out != 0) {
-               // there is nothing to send
-
-               debug(D_WEB_CLIENT, "%llu: Out of output data.", w->id);
-
-               // finalize the chunk
-               if(w->data->sent != 0)
-                       t += web_client_send_chunk_finalize(w);
-
-               // there can be two cases for this
-               // A. we have done everything
-               // B. we temporarily have nothing to send, waiting for the buffer to be filled by ifd
-
-               if(w->mode == WEB_CLIENT_MODE_FILECOPY && w->wait_receive && w->ifd != w->ofd && w->data->rbytes && w->data->rbytes > w->data->bytes) {
-                       // we have to wait, more data will come
-                       debug(D_WEB_CLIENT, "%llu: Waiting for more data to become available.", w->id);
-                       w->wait_send = 0;
-                       return(0);
-               }
-
-               if(w->keepalive == 0) {
-                       debug(D_WEB_CLIENT, "%llu: Closing (keep-alive is not enabled). %ld bytes sent.", w->id, w->data->sent);
-                       errno = 0;
-                       return(-1);
-               }
-
-               // reset the client
-               web_client_reset(w);
-               debug(D_WEB_CLIENT, "%llu: Done sending all data on socket. Waiting for next request on the same socket.", w->id);
-               return(0);
-       }
-
-       if(w->zstream.avail_out == 0 && w->zhave == w->zsent) {
-               // compress more input data
-
-               // close the previous open chunk
-               if(w->data->sent != 0) t += web_client_send_chunk_close(w);
-
-               debug(D_DEFLATE, "%llu: Compressing %d bytes starting from %d.", w->id, (w->data->bytes - w->data->sent), w->data->sent);
-
-               // give the compressor all the data not passed through the compressor yet
-               if(w->data->bytes > w->data->sent) {
-                       w->zstream.next_in = (Bytef *)&w->data->buffer[w->data->sent];
-                       w->zstream.avail_in = (w->data->bytes - w->data->sent);
-               }
-
-               // reset the compressor output buffer
-               w->zstream.next_out = w->zbuffer;
-               w->zstream.avail_out = ZLIB_CHUNK;
-
-               // ask for FINISH if we have all the input
-               int flush = Z_SYNC_FLUSH;
-               if(w->mode == WEB_CLIENT_MODE_NORMAL
-                       || (w->mode == WEB_CLIENT_MODE_FILECOPY && w->data->bytes == w->data->rbytes)) {
-                       flush = Z_FINISH;
-                       debug(D_DEFLATE, "%llu: Requesting Z_FINISH.", w->id);
-               }
-               else {
-                       debug(D_DEFLATE, "%llu: Requesting Z_SYNC_FLUSH.", w->id);
-               }
-
-               // compress
-               if(deflate(&w->zstream, flush) == Z_STREAM_ERROR) {
-                       error("%llu: Compression failed. Closing down client.", w->id);
-                       web_client_reset(w);
-                       return(-1);
-               }
-
-               w->zhave = ZLIB_CHUNK - w->zstream.avail_out;
-               w->zsent = 0;
-
-               // keep track of the bytes passed through the compressor
-               w->data->sent = w->data->bytes;
-
-               debug(D_DEFLATE, "%llu: Compression produced %d bytes.", w->id, w->zhave);
-
-               // open a new chunk
-               t += web_client_send_chunk_header(w, w->zhave);
-       }
-
-       bytes = send(w->ofd, &w->zbuffer[w->zsent], w->zhave - w->zsent, MSG_DONTWAIT);
-       if(bytes > 0) {
-               w->zsent += bytes;
-               if(t > 0) bytes += t;
-               debug(D_WEB_CLIENT, "%llu: Sent %d bytes.", w->id, bytes);
-       }
-       else if(bytes == 0) debug(D_WEB_CLIENT, "%llu: Did not send any bytes to the client.", w->id);
-       else debug(D_WEB_CLIENT, "%llu: Failed to send data to client. Reason: %s", w->id, strerror(errno));
-
-       return(bytes);
+    if(!listen_fds_count)
+        fatal("Cannot listen on any socket. Exiting...");
+    else if(shown_server_socket_error) {
+        size_t i;
+        for(i = 0; i < listen_fds_count ;i++)
+            info("Listen socket %s opened.", listen_fds_names[i]);
+    }
+
+    return (int)listen_fds_count;
 }
 
-long web_client_send(struct web_client *w)
-{
-       if(w->zoutput) return web_client_send_deflate(w);
+// --------------------------------------------------------------------------------------
+// the main socket listener
 
-       long bytes;
+static inline void cleanup_web_clients(void) {
+    struct web_client *w;
+
+    for (w = web_clients; w;) {
+        if (w->obsolete) {
+            debug(D_WEB_CLIENT, "%llu: Removing client.", w->id);
+            // pthread_cancel(w->thread);
+            // pthread_join(w->thread, NULL);
+            w = web_client_free(w);
+#ifdef NETDATA_INTERNAL_CHECKS
+            log_allocations();
+#endif
+        }
+        else w = w->next;
+    }
+}
 
-       if(w->data->bytes - w->data->sent == 0) {
-               // there is nothing to send
+// 1. it accepts new incoming requests on our port
+// 2. creates a new web_client for each connection received
+// 3. spawns a new pthread to serve the client (this is optimal for keep-alive clients)
+// 4. cleans up old web_clients that their pthreads have been exited
 
-               debug(D_WEB_CLIENT, "%llu: Out of output data.", w->id);
+#define CLEANUP_EVERY_EVENTS 100
+
+void *socket_listen_main_multi_threaded(void *ptr) {
+    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;
+
+    web_server_mode = WEB_SERVER_MODE_MULTI_THREADED;
+    info("Multi-threaded WEB SERVER thread created with task id %d", gettid());
+
+    struct web_client *w;
+    int retval, counter = 0;
+
+    if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
+        error("Cannot set pthread cancel type to DEFERRED.");
+
+    if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
+        error("Cannot set pthread cancel state to ENABLE.");
+
+    if(!listen_fds_count)
+        fatal("LISTENER: No sockets to listen to.");
+
+    struct pollfd *fds = callocz(sizeof(struct pollfd), listen_fds_count);
+
+    size_t i;
+    for(i = 0; i < listen_fds_count ;i++) {
+        fds[i].fd = listen_fds[i];
+        fds[i].events = POLLIN;
+        fds[i].revents = 0;
+
+        info("Listening on '%s'", (listen_fds_names[i])?listen_fds_names[i]:"UNKNOWN");
+    }
+
+    int timeout = 10 * 1000;
+
+    for(;;) {
+        // debug(D_WEB_CLIENT, "LISTENER: Waiting...");
+        retval = poll(fds, listen_fds_count, timeout);
+
+        if(unlikely(retval == -1)) {
+            error("LISTENER: poll() failed.");
+            continue;
+        }
+        else if(unlikely(!retval)) {
+            debug(D_WEB_CLIENT, "LISTENER: select() timeout.");
+            counter = 0;
+            cleanup_web_clients();
+            continue;
+        }
+
+        for(i = 0 ; i < listen_fds_count ; i++) {
+            short int revents = fds[i].revents;
+
+            // check for new incoming connections
+            if(revents & POLLIN || revents & POLLPRI) {
+                fds[i].revents = 0;
+
+                w = web_client_create(fds[i].fd);
+                if(unlikely(!w)) {
+                    // no need for error log - web_client_create already logged the error
+                    continue;
+                }
+
+                if(pthread_create(&w->thread, NULL, web_client_main, w) != 0) {
+                    error("%llu: failed to create new thread for web client.", w->id);
+                    w->obsolete = 1;
+                }
+                else if(pthread_detach(w->thread) != 0) {
+                    error("%llu: Cannot request detach of newly created web client thread.", w->id);
+                    w->obsolete = 1;
+                }
+            }
+        }
+
+        // cleanup unused clients
+        counter++;
+        if(counter >= CLEANUP_EVERY_EVENTS) {
+            counter = 0;
+            cleanup_web_clients();
+        }
+    }
+
+    debug(D_WEB_CLIENT, "LISTENER: exit!");
+    close_listen_sockets();
+
+    static_thread->enabled = 0;
+    static_thread->thread = NULL;
+    pthread_exit(NULL);
+    return NULL;
+}
 
-               // there can be two cases for this
-               // A. we have done everything
-               // B. we temporarily have nothing to send, waiting for the buffer to be filled by ifd
+struct web_client *single_threaded_clients[FD_SETSIZE];
 
-               if(w->mode == WEB_CLIENT_MODE_FILECOPY && w->wait_receive && w->ifd != w->ofd && w->data->rbytes && w->data->rbytes > w->data->bytes) {
-                       // we have to wait, more data will come
-                       debug(D_WEB_CLIENT, "%llu: Waiting for more data to become available.", w->id);
-                       w->wait_send = 0;
-                       return(0);
-               }
+static inline int single_threaded_link_client(struct web_client *w, fd_set *ifds, fd_set *ofds, fd_set *efds, int *max) {
+    if(unlikely(w->obsolete || w->dead || (!w->wait_receive && !w->wait_send)))
+        return 1;
 
-               if(w->keepalive == 0) {
-                       debug(D_WEB_CLIENT, "%llu: Closing (keep-alive is not enabled). %ld bytes sent.", w->id, w->data->sent);
-                       errno = 0;
-                       return(-1);
-               }
+    if(unlikely(w->ifd < 0 || w->ifd >= FD_SETSIZE || w->ofd < 0 || w->ofd >= FD_SETSIZE)) {
+        error("%llu: invalid file descriptor, ifd = %d, ofd = %d (required 0 <= fd < FD_SETSIZE (%d)", w->id, w->ifd, w->ofd, FD_SETSIZE);
+        return 1;
+    }
 
-               web_client_reset(w);
-               debug(D_WEB_CLIENT, "%llu: Done sending all data on socket. Waiting for next request on the same socket.", w->id);
-               return(0);
-       }
+    FD_SET(w->ifd, efds);
+    if(unlikely(*max < w->ifd)) *max = w->ifd;
 
-       bytes = send(w->ofd, &w->data->buffer[w->data->sent], w->data->bytes - w->data->sent, MSG_DONTWAIT);
-       if(bytes > 0) {
-               w->data->sent += bytes;
-               debug(D_WEB_CLIENT, "%llu: Sent %d bytes.", w->id, bytes);
-       }
-       else if(bytes == 0) debug(D_WEB_CLIENT, "%llu: Did not send any bytes to the client.", w->id);
-       else debug(D_WEB_CLIENT, "%llu: Failed to send data to client. Reason: %s", w->id, strerror(errno));
+    if(unlikely(w->ifd != w->ofd)) {
+        if(*max < w->ofd) *max = w->ofd;
+        FD_SET(w->ofd, efds);
+    }
 
+    if(w->wait_receive) FD_SET(w->ifd, ifds);
+    if(w->wait_send)    FD_SET(w->ofd, ofds);
 
-       return(bytes);
-}
+    single_threaded_clients[w->ifd] = w;
+    single_threaded_clients[w->ofd] = w;
 
-long web_client_receive(struct web_client *w)
-{
-       // do we have any space for more data?
-       web_buffer_increase(w->data, WEB_DATA_LENGTH_INCREASE_STEP);
-
-       long left = w->data->size - w->data->bytes;
-       long bytes;
-
-       if(w->mode == WEB_CLIENT_MODE_FILECOPY)
-               bytes = read(w->ifd, &w->data->buffer[w->data->bytes], (left-1));
-       else
-               bytes = recv(w->ifd, &w->data->buffer[w->data->bytes], left-1, MSG_DONTWAIT);
-
-       if(bytes > 0) {
-               int old = w->data->bytes;
-               w->data->bytes += bytes;
-               w->data->buffer[w->data->bytes] = '\0';
-
-               debug(D_WEB_CLIENT, "%llu: Received %d bytes.", w->id, bytes);
-               debug(D_WEB_DATA, "%llu: Received data: '%s'.", w->id, &w->data->buffer[old]);
-
-               if(w->mode == WEB_CLIENT_MODE_FILECOPY) {
-                       w->wait_send = 1;
-                       if(w->data->rbytes && w->data->bytes >= w->data->rbytes) w->wait_receive = 0;
-               }
-       }
-       else if(bytes == 0) {
-               debug(D_WEB_CLIENT, "%llu: Out of input data.", w->id);
-
-               // if we cannot read, it means we have an error on input.
-               // if however, we are copying a file from ifd to ofd, we should not return an error.
-               // in this case, the error should be generated when the file has been sent to the client.
-
-               if(w->mode == WEB_CLIENT_MODE_FILECOPY) {
-                       // we are copying data fron ifd to ofd
-                       // let it finish copying...
-                       w->wait_receive = 0;
-                       debug(D_WEB_CLIENT, "%llu: Disabling input.", w->id);
-               }
-               else {
-                       bytes = -1;
-                       errno = 0;
-               }
-       }
-
-       return(bytes);
+    return 0;
 }
 
+static inline int single_threaded_unlink_client(struct web_client *w, fd_set *ifds, fd_set *ofds, fd_set *efds) {
+    FD_CLR(w->ifd, efds);
+    if(unlikely(w->ifd != w->ofd)) FD_CLR(w->ofd, efds);
 
-// --------------------------------------------------------------------------------------
-// the thread of a single client
-
-// 1. waits for input and output, using async I/O
-// 2. it processes HTTP requests
-// 3. it generates HTTP responses
-// 4. it copies data from input to output if mode is FILECOPY
-
-void *new_client(void *ptr)
-{
-       if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
-               error("Cannot set pthread cancel type to DEFERRED.");
-
-       if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
-               error("Cannot set pthread cancel state to ENABLE.");
-
-       struct timeval tv;
-       struct web_client *w = ptr;
-       int retval;
-       fd_set ifds, ofds, efds;
-       int fdmax = 0;
-
-       for(;;) {
-               FD_ZERO (&ifds);
-               FD_ZERO (&ofds);
-               FD_ZERO (&efds);
-
-               FD_SET(w->ifd, &efds);
-
-               if(w->ifd != w->ofd)
-                       FD_SET(w->ofd, &efds);
-
-               if (w->wait_receive) {
-                       FD_SET(w->ifd, &ifds);
-                       if(w->ifd > fdmax) fdmax = w->ifd;
-               }
-
-               if (w->wait_send) {
-                       FD_SET(w->ofd, &ofds);
-                       if(w->ofd > fdmax) fdmax = w->ofd;
-               }
-
-               tv.tv_sec = web_client_timeout;
-               tv.tv_usec = 0;
-
-               debug(D_WEB_CLIENT, "%llu: Waiting socket async I/O for %s %s", w->id, w->wait_receive?"INPUT":"", w->wait_send?"OUTPUT":"");
-               retval = select(fdmax+1, &ifds, &ofds, &efds, &tv);
-
-               if(retval == -1) {
-                       debug(D_WEB_CLIENT_ACCESS, "%llu: LISTENER: select() failed.", w->id);
-                       continue;
-               }
-               else if(!retval) {
-                       // timeout
-                       web_client_reset(w);
-                       w->obsolete = 1;
-                       return NULL;
-               }
-
-               if(FD_ISSET(w->ifd, &efds)) {
-                       debug(D_WEB_CLIENT_ACCESS, "%llu: Received error on input socket (%s).", w->id, strerror(errno));
-                       web_client_reset(w);
-                       w->obsolete = 1;
-                       return NULL;
-               }
-
-               if(FD_ISSET(w->ofd, &efds)) {
-                       debug(D_WEB_CLIENT_ACCESS, "%llu: Received error on output socket (%s).", w->id, strerror(errno));
-                       web_client_reset(w);
-                       w->obsolete = 1;
-                       return NULL;
-               }
-
-               if(w->wait_send && FD_ISSET(w->ofd, &ofds)) {
-                       long bytes;
-                       if((bytes = web_client_send(w)) < 0) {
-                               debug(D_WEB_CLIENT, "%llu: Closing client (input: %s).", w->id, strerror(errno));
-                               web_client_reset(w);
-                               w->obsolete = 1;
-                               errno = 0;
-                               return NULL;
-                       }
-                       else {
-                               global_statistics_lock();
-                               global_statistics.bytes_sent += bytes;
-                               global_statistics_unlock();
-                       }
-               }
-
-               if(w->wait_receive && FD_ISSET(w->ifd, &ifds)) {
-                       long bytes;
-                       if((bytes = web_client_receive(w)) < 0) {
-                               debug(D_WEB_CLIENT, "%llu: Closing client (output: %s).", w->id, strerror(errno));
-                               web_client_reset(w);
-                               w->obsolete = 1;
-                               errno = 0;
-                               return NULL;
-                       }
-                       else {
-                               if(w->mode != WEB_CLIENT_MODE_FILECOPY) {
-                                       global_statistics_lock();
-                                       global_statistics.bytes_received += bytes;
-                                       global_statistics_unlock();
-                               }
-                       }
-
-                       if(w->mode == WEB_CLIENT_MODE_NORMAL) web_client_process(w);
-               }
-       }
-       debug(D_WEB_CLIENT, "%llu: done...", w->id);
-
-       return NULL;
-}
+    if(w->wait_receive) FD_CLR(w->ifd, ifds);
+    if(w->wait_send)    FD_CLR(w->ofd, ofds);
 
-// --------------------------------------------------------------------------------------
-// the main socket listener
+    single_threaded_clients[w->ifd] = NULL;
+    single_threaded_clients[w->ofd] = NULL;
 
-// 1. it accepts new incoming requests on our port
-// 2. creates a new web_client for each connection received
-// 3. spawns a new pthread to serve the client (this is optimal for keep-alive clients)
-// 4. cleans up old web_clients that their pthreads have been exited
+    if(unlikely(w->obsolete || w->dead || (!w->wait_receive && !w->wait_send)))
+        return 1;
 
-void *socket_listen_main(void *ptr)
-{
-       if(ptr) { ; }
-       struct web_client *w;
-       struct timeval tv;
-       int retval;
-
-       if(ptr) { ; }
-
-       if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
-               error("Cannot set pthread cancel type to DEFERRED.");
-
-       if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
-               error("Cannot set pthread cancel state to ENABLE.");
-
-       web_client_timeout = config_get_number("global", "disconnect idle web clients after seconds", DEFAULT_DISCONNECT_IDLE_WEB_CLIENTS_AFTER_SECONDS);
-
-       if(listen_fd < 0) fatal("LISTENER: Listen socket is not ready.");
-
-       fd_set ifds, ofds, efds;
-       int fdmax = listen_fd;
-
-       FD_ZERO (&ifds);
-       FD_ZERO (&ofds);
-       FD_ZERO (&efds);
-
-       for(;;) {
-               tv.tv_sec = 0;
-               tv.tv_usec = 200000;
-
-               if(listen_fd >= 0) {
-                       FD_SET(listen_fd, &ifds);
-                       FD_SET(listen_fd, &efds);
-               }
-
-               // debug(D_WEB_CLIENT, "LISTENER: Waiting...");
-               retval = select(fdmax+1, &ifds, &ofds, &efds, &tv);
-
-               if(retval == -1) {
-                       error("LISTENER: select() failed.");
-                       continue;
-               }
-               else if(retval) {
-                       // check for new incoming connections
-                       if(FD_ISSET(listen_fd, &ifds)) {
-                               w = web_client_create(listen_fd);
-
-                               if(pthread_create(&w->thread, NULL, new_client, w) != 0) {
-                                       error("%llu: failed to create new thread for web client.");
-                                       w->obsolete = 1;
-                               }
-                               else if(pthread_detach(w->thread) != 0) {
-                                       error("%llu: Cannot request detach of newly created web client thread.", w->id);
-                                       w->obsolete = 1;
-                               }
-
-                               log_access("%llu: %s port %s connected", w->id, w->client_ip, w->client_port);
-                       }
-                       else debug(D_WEB_CLIENT, "LISTENER: select() didn't do anything.");
-
-               }
-               //else {
-               //      debug(D_WEB_CLIENT, "LISTENER: select() timeout.");
-               //}
-
-               // cleanup unused clients
-               for(w = web_clients; w ; w = w?w->next:NULL) {
-                       if(w->obsolete) {
-                               log_access("%llu: %s port %s disconnected", w->id, w->client_ip, w->client_port);
-                               debug(D_WEB_CLIENT, "%llu: Removing client.", w->id);
-                               // pthread_join(w->thread,  NULL);
-                               w = web_client_free(w);
-                               log_allocations();
-                       }
-               }
-       }
-
-       error("LISTENER: exit!");
-
-       if(listen_fd >= 0) close(listen_fd);
-       exit(2);
-
-       return NULL;
+    return 0;
 }
 
+void *socket_listen_main_single_threaded(void *ptr) {
+    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;
+
+    web_server_mode = WEB_SERVER_MODE_SINGLE_THREADED;
+
+    info("Single-threaded WEB SERVER thread created with task id %d", gettid());
+
+    struct web_client *w;
+    int retval;
+
+    if(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL) != 0)
+        error("Cannot set pthread cancel type to DEFERRED.");
+
+    if(pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) != 0)
+        error("Cannot set pthread cancel state to ENABLE.");
+
+    if(!listen_fds_count)
+        fatal("LISTENER: no listen sockets available.");
+
+    size_t i;
+    for(i = 0; i < FD_SETSIZE ; i++)
+        single_threaded_clients[i] = NULL;
+
+    fd_set ifds, ofds, efds, rifds, rofds, refds;
+    FD_ZERO (&ifds);
+    FD_ZERO (&ofds);
+    FD_ZERO (&efds);
+    int fdmax = 0;
+
+    for(i = 0; i < listen_fds_count ; i++) {
+        if (listen_fds[i] < 0 || listen_fds[i] >= FD_SETSIZE)
+            fatal("LISTENER: Listen socket %d is not ready, or invalid.", listen_fds[i]);
+
+        info("Listening on '%s'", (listen_fds_names[i])?listen_fds_names[i]:"UNKNOWN");
+
+        FD_SET(listen_fds[i], &ifds);
+        FD_SET(listen_fds[i], &efds);
+        if(fdmax < listen_fds[i])
+            fdmax = listen_fds[i];
+    }
+
+    for(;;) {
+        debug(D_WEB_CLIENT_ACCESS, "LISTENER: single threaded web server waiting (fdmax = %d)...", fdmax);
+
+        struct timeval tv = { .tv_sec = 1, .tv_usec = 0 };
+        rifds = ifds;
+        rofds = ofds;
+        refds = efds;
+        retval = select(fdmax+1, &rifds, &rofds, &refds, &tv);
+
+        if(unlikely(retval == -1)) {
+            error("LISTENER: select() failed.");
+            continue;
+        }
+        else if(likely(retval)) {
+            debug(D_WEB_CLIENT_ACCESS, "LISTENER: got something.");
+
+            for(i = 0; i < listen_fds_count ; i++) {
+                if (FD_ISSET(listen_fds[i], &rifds)) {
+                    debug(D_WEB_CLIENT_ACCESS, "LISTENER: new connection.");
+                    w = web_client_create(listen_fds[i]);
+                    if (single_threaded_link_client(w, &ifds, &ofds, &ifds, &fdmax) != 0) {
+                        web_client_free(w);
+                    }
+                }
+            }
+
+            for(i = 0 ; i <= (size_t)fdmax ; i++) {
+                if(likely(!FD_ISSET(i, &rifds) && !FD_ISSET(i, &rofds) && !FD_ISSET(i, &refds)))
+                    continue;
+
+                w = single_threaded_clients[i];
+                if(unlikely(!w))
+                    continue;
+
+                if(unlikely(single_threaded_unlink_client(w, &ifds, &ofds, &efds) != 0)) {
+                    web_client_free(w);
+                    continue;
+                }
+
+                if (unlikely(FD_ISSET(w->ifd, &refds) || FD_ISSET(w->ofd, &refds))) {
+                    web_client_free(w);
+                    continue;
+                }
+
+                if (unlikely(w->wait_receive && FD_ISSET(w->ifd, &rifds))) {
+                    if (unlikely(web_client_receive(w) < 0)) {
+                        web_client_free(w);
+                        continue;
+                    }
+
+                    if (w->mode != WEB_CLIENT_MODE_FILECOPY) {
+                        debug(D_WEB_CLIENT, "%llu: Processing received data.", w->id);
+                        web_client_process(w);
+                    }
+                }
+
+                if (unlikely(w->wait_send && FD_ISSET(w->ofd, &rofds))) {
+                    if (unlikely(web_client_send(w) < 0)) {
+                        debug(D_WEB_CLIENT, "%llu: Cannot send data to client. Closing client.", w->id);
+                        web_client_free(w);
+                        continue;
+                    }
+                }
+
+                if(unlikely(single_threaded_link_client(w, &ifds, &ofds, &efds, &fdmax) != 0)) {
+                    web_client_free(w);
+                }
+            }
+        }
+        else {
+            debug(D_WEB_CLIENT_ACCESS, "LISTENER: single threaded web server timeout.");
+#ifdef NETDATA_INTERNAL_CHECKS
+            log_allocations();
+#endif
+        }
+    }
+
+    debug(D_WEB_CLIENT, "LISTENER: exit!");
+    close_listen_sockets();
+
+    static_thread->enabled = 0;
+    static_thread->thread = NULL;
+    pthread_exit(NULL);
+    return NULL;
+}