diff --git a/gdb.sh b/gdb.sh
index 89b864f7..acc2e12f 100755
--- a/gdb.sh
+++ b/gdb.sh
@@ -6,6 +6,7 @@ mkdir -p /run/${instance}
 chown readsb /run/${instance}
 source /etc/default/${instance}
 
-runuser -u readsb -- gdb -batch -ex 'set confirm off' -ex 'handle SIGTERM nostop print pass' -ex 'handle SIGINT nostop print pass' -ex run -ex 'bt full' --args /usr/bin/readsb --quiet $RECEIVER_OPTIONS $DECODER_OPTIONS $NET_OPTIONS $JSON_OPTIONS --write-json /run/${instance} $@
+runuser -u readsb -- gdb -batch -ex 'set confirm off' -ex 'handle SIGTERM nostop print pass' -ex 'handle SIGINT nostop print pass' -ex run -ex 'bt full' \
+    --args /usr/bin/readsb --quiet $RECEIVER_OPTIONS $DECODER_OPTIONS $NET_OPTIONS $JSON_OPTIONS --write-json /run/${instance} $@
 #/usr/bin/sudo -u readsb /usr/bin/readsb --quiet $RECEIVER_OPTIONS $DECODER_OPTIONS $NET_OPTIONS $JSON_OPTIONS --write-json /run/${instance} $@
 
diff --git a/net_io.c b/net_io.c
index 37b98f7c..427a51b0 100644
--- a/net_io.c
+++ b/net_io.c
@@ -275,6 +275,54 @@ static void setBuffers(int fd, int sndsize, int rcvsize) {
     }
 }
 
+static struct client *getClientById(int32_t id) {
+    return Modes.clientsById[id];
+}
+
+static int32_t getClientId(struct client *c) {
+    //fprintf(stderr, "getClientId called, clientCount: %d clientsByIdAlloc: %d\n", (int) Modes.modesClientCount, (int) Modes.clientsByIdAlloc);
+
+    if (Modes.modesClientCount * 2 > Modes.clientsByIdAlloc) {
+        if (0) {
+            getClientById(0);
+            for (int i = 0; i < Modes.clientsByIdAlloc; i++) {
+                fprintf(stderr, "%p\n", Modes.clientsById[i]);
+            }
+        }
+        int oldBytes = Modes.clientsByIdAlloc * sizeof(*Modes.clientsById);
+        int newSize = Modes.clientsByIdAlloc * 2;
+        int newBytes = newSize * sizeof(*Modes.clientsById);
+        int addedBytes = newBytes - oldBytes;
+        Modes.clientsById = realloc(Modes.clientsById, newBytes);
+        if (Modes.clientsById == NULL) {
+            fprintf(stderr, "FATAL: realloc clientsById: out of memory\n");
+            exit(1);
+        }
+
+        memset((char *)Modes.clientsById + oldBytes, 0, addedBytes);
+        Modes.clientsByIdAlloc = newSize;
+
+    }
+
+    int32_t stride = 16;
+    for (int k = 0; k < Modes.clientsByIdAlloc / stride; k++) {
+        int32_t startValue = ((random() % Modes.clientsByIdAlloc) / stride) * stride;
+        int32_t endValue = startValue + stride;
+        if (endValue > Modes.clientsByIdAlloc) {
+            endValue = Modes.clientsByIdAlloc;
+        }
+        for (int32_t i = startValue; i < endValue; i++) {
+            if (Modes.clientsById[i] == NULL) {
+                Modes.clientsById[i] = c;
+                return i;
+            }
+        }
+    }
+
+    fprintf(stderr, "warning: getClientId no available slots found, this should be rare!\n");
+    return -1;
+}
+
 // Create a client attached to the given service using the provided socket FD ... not a socket in some exceptions
 static struct client *createSocketClient(struct net_service *service, int fd) {
     struct client *c;
@@ -290,6 +338,11 @@ static struct client *createSocketClient(struct net_service *service, int fd) {
     }
     memset(c, 0, sizeof (struct client));
 
+    c->id = getClientId(c);
+    if (c->id < 0) {
+        sfree(c);
+        return NULL;
+    }
     c->service = service;
     c->fd = fd;
     c->last_flush = now;
@@ -889,6 +942,11 @@ void modesInitNet(void) {
 
     if (!Modes.net)
         return;
+
+    Modes.clientsByIdAlloc = 32; // initial
+    Modes.clientsById = cmalloc(Modes.clientsByIdAlloc * sizeof(*Modes.clientsById));
+    memset(Modes.clientsById, 0, Modes.clientsByIdAlloc * sizeof(*Modes.clientsById));
+
     struct net_service *beast_out;
     struct net_service *beast_reduce_out;
     struct net_service *garbage_out;
@@ -1135,19 +1193,30 @@ static void modesAcceptClients(struct client *c, int64_t now) {
 
         if (Modes.modesClientCount > Modes.max_fds_net) {
             // drop new modes clients if the count gets near resource limits
-            anetCloseSocket(c->fd);
+            anetCloseSocket(fd);
             static int64_t antiSpam;
             if (now > antiSpam) {
                 antiSpam = now + 30 * SECONDS;
                 fprintf(stderr, "<3> Can't accept new connection, limited to %d clients, consider increasing ulimit!\n", Modes.max_fds_net);
             }
+            continue;
         }
 
         c = createSocketClient(s, fd);
-        if (s->unixSocket && c) {
+        if (!c) {
+            anetCloseSocket(fd);
+            static int64_t antiSpam;
+            if (now > antiSpam) {
+                antiSpam = now + 30 * SECONDS;
+                fprintf(stderr, "%s: Error accepting new connection (createSocketClient failed)\n", s->descr);
+            }
+            continue;
+        }
+
+        if (s->unixSocket) {
             strcpy(c->host, s->unixSocket);
             fprintf(stderr, "%s: new c at %s\n", c->service->descr, s->unixSocket);
-        } else if (c) {
+        } else {
             // We created the client, save the sockaddr info and 'hostport'
             getnameinfo(saddr, slen,
                     c->host, sizeof(c->host),
@@ -1161,9 +1230,6 @@ static void modesAcceptClients(struct client *c, int64_t now) {
             }
             if (anetTcpKeepAlive(Modes.aneterr, fd) != ANET_OK)
                 fprintf(stderr, "%s: Unable to set keepalive on connection from %s port %s (fd %d)\n", c->service->descr, c->host, c->port, fd);
-        } else {
-            fprintf(stderr, "%s: Fatal: createSocketClient shouldn't fail!\n", s->descr);
-            exit(1);
         }
 
 
@@ -1240,6 +1306,8 @@ static void modesCloseClient(struct client *c) {
     c->service = NULL;
     c->modeac_requested = 0;
 
+    Modes.clientsById[c->id] = NULL;
+
     if (Modes.mode_ac_auto)
         autoset_modeac();
 }
@@ -5742,6 +5810,8 @@ void cleanupNetwork(void) {
     sfree(Modes.net_connectors);
     sfree(Modes.net_events);
 
+    sfree(Modes.clientsById);
+
     Modes.net_connectors_count = 0;
 
 }
diff --git a/net_io.h b/net_io.h
index 7eb5e92f..2ec34e7c 100644
--- a/net_io.h
+++ b/net_io.h
@@ -95,6 +95,7 @@ struct client
     char *buf; // read buffer
     char *som;
     char *eod;
+    int32_t id;
     int buflen; // Amount of data on read buffer
     int bufmax; // size of the read buffer
     int fd; // File descriptor
diff --git a/readsb.h b/readsb.h
index ad7d739c..358d0b44 100644
--- a/readsb.h
+++ b/readsb.h
@@ -570,6 +570,9 @@ struct _Modes
     pthread_mutex_t trackLock;
     pthread_mutex_t outputLock;
 
+    struct client **clientsById;
+    int clientsByIdAlloc;
+
     int max_fds;
     int max_fds_api;
     int max_fds_net;
diff --git a/valgrind.sh b/valgrind.sh
index 551f1f3b..7911f616 100755
--- a/valgrind.sh
+++ b/valgrind.sh
@@ -14,5 +14,8 @@ MEM="--show-leak-kinds=all --leak-check=full"
 MEM="--show-leak-kinds=all --track-origins=yes --leak-check=full"
 MEM=""
 
+#runuser -u readsb -- gdb -batch -ex 'set confirm off' -ex 'handle SIGTERM nostop print pass' -ex 'handle SIGINT nostop print pass' -ex run -ex 'bt full' \
+#    --args /tmp/test123 --net --net-bo-port 1234 $@
+#valgrind $MASSIF $FIRST $MEM /tmp/test123 --net --net-bo-port 1234 $@
 valgrind $MASSIF $FIRST $MEM /tmp/test123 $RECEIVER_OPTIONS $DECODER_OPTIONS $NET_OPTIONS $JSON_OPTIONS --quiet --db-file=none $@